Samitha's Tech Blog

Analog and Other Stuff - Ebooks

2008-07-10T13:00:00.002+06:00

This is a really cool place which I found trough a referral, It contains a good collection of e books on analog electronics and microcontrollres. Hope you enjoy it.

http://analogstuff.net/2007/06/ebooks-on-microcontroller-arm-etc.html

Ignition Coil PWM Driver

2008-06-22T19:47:00.001+06:00

High Voltage Sparks from a CRT Monitor

2008-06-22T19:45:00.001+06:00

Research Papers about Kirlian Photography

2008-06-20T21:39:00.003+06:00

Instant Kirlian diagnostic system (IKiDs). A unique form of diagnosis
Soultanov, V.; Charalambous, J.; White, E.; Sapunar, D.
Bio-electromagnetism, 1998. Proceedings of the 2nd International Conference on

Volume , Issue , 15-18 Feb 1998 Page(s):147 - 148
Digital Object Identifier 10.1109/ICBEM.1998.666438
Summary: Medicine has long been challenged to detect disease before it can do irreversible damage, usually by means of invasive tests after the presentation of symptoms. This paper introduces a unique diagnostic tool, the Instant Kirlian Diagnostic System (IKiDS) which derives from the work of the Kirlians of Russia in 1939. It delineates both the disease process and its energetic precursors in the human energy field, allowing for treatment and lifestyle changes before real damage occurs. IKiDS utilizes a sensor, high voltage electronics and computer software to “capture” an energy discharge from the fingertips which contains valuable diagnostic information. The research summary is based on analysis of over 1000 sets of prints. Whilst some diagnostic puzzles remain, it is clear that IKiDS has impressive diagnostic and evaluative capabilities. Furthermore, it is accurate, user friendly and offers a complete picture of the physical, mental and emotional condition in “real time”. Future research directions are indicated.

URL : http://ieeexplore.ieee.org/Xplore/login.jsp?url=/iel4/5414/14635/00666438.pdf?arnumber=666438

Quick Diagnostics of Human Blood Condition by Means of Gas-Discharge Visualization Method
R. A. Kolomiyetz
Microwave and Telecommunication Technology, 2006. CriMiCO apos;06. 16th International Crimean Conference
Volume 2, Issue , Sept. 2006 Page(s):905 - 906
Digital Object Identifier 10.1109/CRMICO.2006.256251
Summary: In this paper, method of quick diagnostics of human blood condition by means of gas-discharge visualization (GDV) is proposed. This method is based on Kirlian's effect. The possible variant of the generator building for GDV and basis of making of GDV-images with use computer system were also discussed.

URL: http://ieeexplore.ieee.org/Xplore/defdeny.jsp?url=/iel5/4023328/4023329/04023533.pdf&tp=&arnumber=4023533&isnumber=4023329&code=2

Kirlian Image Reel - Email From the Creator

2008-06-19T22:55:00.004+06:00

I asked about some facts regarding the kirlian video, which I have posted here. I will put the details here for readers reference.

Related Posts

http://www.hitechno.info/2008/06/kirlian-image-reel.html

Author of the video : John Campbell

Thank you very much John..

------------------------------------------------------------------
email...................................

Hi-

Thanks for your interest in my Kirlian video.

The equipment used is a CV6000 tesla coil and a transparent electrode. I bought these for about $1000 from www.kirlianlab.com. If you are a do-it-yourself person and comfortable building your own electrical equipment, you can get detailed plans in the book "Kirlian Photography- a hands-on guide" by John Iovine. I found that book using Google and bought it online. If you build it yourself- BE CAREFUL! You're dealing with high voltage!

If you buy the pre-made equipment from kirlianlab.com the builder/owner of the business is very helpful with giving advice for the best results and helping with any problems you might have.

To get good results with this equipment you'll need a video camera that has the ability to record under low light and can focus close to the surface of the transparent electrode (or can be fitted with a macro lens). The camera I use is a Canon ZR-45. It's just a consumer model that I bought at an electonics store like Best Buys.

In low-light mode the camera records images that are sort of slow and jerky because of the slow frame rate compensating for the long exposures of each frame. So I used an editing program (Final Cut Pro) to speed the shots up to look more natural.

As far as what you're seeing in the video, small thin objects that conduct electricity because they are metallic or contain moisture work the best. In order of appearance in my video they are:

1. Cross section of Starfruit
2. Starfish (he was dead but I soaked him in water to moisten him up a bit)
3. Cross section of Kumquat fruit
4. Cross section of Chinese squash
5. Catnip leaf (2 shots)
6. Crane's Bill Leaf (3 shots)
7. Misc group shots arranged in a circular pattern
8. A dead Moth (most people think it looks like a fish)
9. Small Poinsettia leaf
10. Vajra made from aluminum foil

Most of the objects you see in my video are no larger than about 1 or 2 inches. You could get a shot of a hand, but larger objects use up more energy and produce a dimmer image. The transparent electrode is only about 10 inches across so an adult hand is almost too large to frame up in the shot. The energized transparent electrode will also make your subject's hands tingle so you'll need a willing participant who isn't squeamish. For safety's sake you and your subject should wear rubber soled shoes and make sure all the equipment is properly grounded.

If you like my video, I hope you will consider buying my DVD which contains a newer version of the Kirlian video seen on YouTube as well as other interesting films that employ unusual techniques. It's available on Filmbaby for $15.99. To go directly to my DVD page go to: http://www.filmbaby.com/films/2961

Good luck- let me know how it goes!

John

Kirlian photography - Another Viewpoint

2008-06-19T12:34:00.001+06:00

Kirlian photography

In 1939, Semyon Kirlian discovered by accident that if an object photographic plate is subjected to a high-voltage electric field, an image is created on the plate. The image looks like a colored halo or coronal discharge. This image is said to be a physical manifestation of the spiritual aura or "life force" which allegedly surrounds each living thing.

Allegedly, this special method of "photographing" objects is a gateway to the paranormal world of auras. Actually, what is recorded is due to quite natural phenomena such as pressure, electrical grounding, humidity and temperature. Changes in moisture (which may reflect changes in emotions), barometric pressure, and voltage, among other things, will produce different 'auras'. Living things...are moist. When the electricity enters the living object, it produces an area of gas ionization around the photographed object, assuming moisture is present on the object. This moisture is transferred from the subject to the emulsion surface of the photographic film and causes an alternation of the electric charge pattern on the film. If a photograph is taken in a vacuum, where no ionized gas is present, no Kirlian image appears. If the Kirlian image were due to some paranormal fundamental living energy field, it should not disappear in a simple vacuum (Hines 2003).

There have even been claims of Kirlian photography being able to capture "phantom limbs," e.g., when a leaf is placed on the plate and then torn in half and "photographed," the whole leaf shows up in the picture. This is not due to paranormal forces, however, but to fraud or to residues left from the initial impression of the whole leaf.

Kirlian Image Reel

2008-06-19T12:22:00.000+06:00

Aura -Kirlian photography

2008-06-19T12:16:00.001+06:00

Aura -Kirlian photography

Definition

Kirlian photography creates a photographic image by placing the object or body part to be photographed on film or photographic paper and exposing it to an electro-magnetic field.

Process

The process of photographing an object, by exposing film in a dark room to the light that results from electronic and ionic interactions caused by placing the object in an intense electric field. The photograph shows a light, glowing band surrounding the outline of the object.

Benefits

The most common therapeutic use of Kirlian photography is as a diagnostic tool. Variations in the shapes, colors, and intensity of the images produced are said to provide clues to the patient's overall health and energy level and to indicate the presence or absence of disease, specific emotional states, and other physiological or psychological conditions. But the consistency of this method is not yet verified. The photograph may affected not only by the physical and mental conditions of the person being photographed, but also the environmental conditions such as air pressure, humidity and temperature.

Background facts

Although some have speculated that Kirlian photography actually records the aura long said by some mystics and psychic healers to exist around human beings, this is not a generally accepted viewpoint. A scientific explanation of these dramatic images is that they result from interactions between charged particles created by the electromagnetic field used to form the images.
A 1976 Science article concluded that moisture is a principal determinant of the form and color of human Kirlian photographs.
It has also been noted that variations in a variety of factors, including the amount of pressure on the plate, the voltage and frequency, and the exposure time, moisture, and temperature, can all influence the images produced.
For these reasons, as well as claims of unreliability and a lack of research data supporting its use, Kirlian photography is not recognized as a legitimate diagnostic tool by the mainstream medical community.
Nevertheless, individual practitioners and researchers continue to experiment with Kirlian photography for diagnosis, especially in Russia and Eastern Europe. It has also been used for such nonmedical purposes as detecting flaws in metal and determining the viability of seeds.

Back to Blogging

2008-06-19T12:12:00.002+06:00

Hi people, I'm here with my blog after a long time. The reason behind my absence is the heavily loaded academic stuff (specially my final year project). I hope to publish an article of it as soon as possible.

Regards,
Samitha

Piumal Gunawardana has Passed Away

2007-07-31T19:00:00.000+06:00

Our Beloved friend Piumal Gunawardana has passed away today morning (31^st August 2007). He was affected by a serious cancer in his throat. He is a final year student of faculty of engineering, University of Moratuwa, Department of Mechanical Eng. He had a great academic profile, in his Advanced Levels, and University.

The author of this post is a friend of him, within last eight years.

May He Attain Nibbana !!!!!!!!!!!!

Hybrid Stepper Motor basics

2007-07-23T12:01:00.000+06:00

The hybrid stepper motor consists of two pieces of soft iron, as well as an axially magnetized, round rotor. The term hybrid is derived from the fact that the motor is operated under the combined principles of the permanent magnet and variable-reluctance stepper motors.

The stator core structure of a hybrid motor is essentially the same as its VR counterpart. The main difference is that in the VR motor, only one of the two coils of one phase is wound on one pole, while a typical hybrid motor will have coils of two different phases wound on the same pole. The two coils at a pole are wound in a configuration known as a bifilar connection.

The teeth on the rotor provide an even better path which helps guide the magnetic flux to preferred locations in the air gap.

This type provides better performance with respect to step resolution, torque and speed. The hybrid stepper motor combines the best features of both the PM and VR type stepper motors. These facts further increase the detent, holding and dynamic torque characteristics of the motor when compared with both the VR and PM types.

Permanent Magnet Type Stepper Motor

2007-07-23T11:59:00.000+06:00

The rotor is magnetized with alternating north and south poles situated in a straight line parallel to the rotor shaft. These magnetized rotor poles provide an increased magnetic flux intensity and because of this the PM motor exhibits improved torque characteristics when compared with the VR type.

Variable Reluctance Type (VR type) Stepper Motor

2007-07-23T11:46:00.000+06:00

This type of motor consists of a soft iron multi-toothed rotor and a wound stator. When the stator windings are energized with DC current the poles become magnetized. Rotation occurs when the rotor teeth are attracted to the energized stator poles. This motor has poor torque load characteristics, rather than the motor types discussed below, hence have a low scope of applications compared to Permanent magnet and Hybrid types

Basics of Stepper Motor

2007-07-23T11:45:00.000+06:00

A stepper motor is a brush less, synchronous electric motor that can divide a full rotation into a large number of steps, for example, 200 steps. Thus the motor can be turned to a precise angle. There are three major types of stepper motors available in practice.

1. Variable Reluctance Stepper Motors
2. Permanent Magnet Stepper Motors

3. Hybrid Stepper Motors

The stepper motor required a special driving circuit. This is basically done by using an array of power transistors, or switches.

The theory behind stepper motor operation is the magnetic attraction. The stepper rotor will be non coiled rotor. The stator consists with a set of coils and those coils are connected as a set manner. When one set of coils energized the rotor pole will be subject to attract to particular pole and because of that the rotor axis will subject to rotate.

Fault Analysis in a Power System

2007-07-10T18:54:00.000+06:00

A fault in a power system is defined as a condition which adds a disturbance to the proper operation and the stability of the system. In simple words, a fault is referred to any abnormal condition, which has occurred in a power system, has properly operated prior to the abnormal condition.

A fault may occur due to various reasons such as environmental conditions, such as lighting, storms, etc., improper maintenance of the power system; insulation failures etc. They can cause the system instability. Therefore it is very important to study the faults and get necessary actions to overcome such situations.

It is essential to ensure the protection of the power system because a fault may cause severe damages to the expensive equipments that connected to the system, even life hazards. When in design phase of a power system, the designer should pay his attention to the protection scheme of the system, should implement the system as a system which has high degree of protection. The method of fault analyze by the aid of sequence components, is a great tool to the designer, to calculate the fault level at any point of the system prior to the implementation as well as after. The results of the fault study will be helping the designer to select the correct ratings for the protective devices such as breakers and relays.

The faults in power systems can mainly be classified as Series faults and Parallel faults. This classification is done in a broader sense. Series faults are referred as the faults that occur along the transmission line serially such as conductor aging, breaking etc. Here we consider only the Parallel faults. Parallel faults may subdivide in to two categories as Symmetrical faults and Asymmetrical faults, by the appearance of them to the system.

Assumptions made in the experiment

In order to reduce the complexity and for a trouble-free implementation in the DC network analyzer the following assumptions were made.

The pre-fault bus voltage is 1 p.u.

Fault currents are very much higher than the load currents and therefore the load currents were neglected

Line resistance is smaller compared to the reactance therefore it can be neglected.

The bus voltages kept in nominal values, therefore it is considered as the pre fault bus voltage is 1 in per unit basis. It is a valid assumption to neglect load currents compared with fault currents because fault currents are normally hundreds of times than the load currents. Normally the lines are made of good conductor materials to minimize the losses and voltage drops. So there resistance compared with reactance is very much smaller. Hence the third assumption is also a valid one and it also eases the analysis.

Generally, the majority of faults in power systems are asymmetrical in nature. Single Line to Ground, Line to Line, Double lines to Ground are the possible combinations of faults that can occur within the system. When this type of fault occurs, it gives rise to unsymmetrical currents. Unsymmetrical currents have different magnitudes in the three lines with unequal phase displacement.

The asymmetrical faults can be analyzed using symmetrical component method. This method resolves the unbalanced three phase system in to three systems, which have same phase sequence as the power system, opposite sequence to the power system, and independent in sequence to the power system, which known as positive sequence, negative sequence and zero sequence respectively. (Actually this is a theorem which can apply for any n number of unbalanced vector systems, which states that they can resolve in to n-1 number of balanced systems and an independent system to the source).

By using this theorem, we can derive the sequence networks to the unbalanced system. Then we can change the interconnections between the sequence networks to represent any type of fault that occur within the system.

The DC network analyser can be used for the simulation purpose by using proportional resistances to represent sequence impedances of generators, transformers and transmission lines. DC power supply represents the generators in this case. For a unsymmetrical fault, three sequence networks can be connected according to the fault the measurements can be taken. For a symmetrical fault equivalent single phase network can be easily implemented using suitable resistances.

Facts, which should consider when deriving, sequence networks

Transmission lines

The positive and negative sequence impedances of a line are the same and it is the normal impedance of the line. However the zero sequence impedance is much grater than the positive or negative sequence impedance.

Generators

The positive sequence impedance of a synchronous generator is equal to the synchronous impedance of the machine. The negative sequence impedance is much less than the positive sequence impedance. The zero sequence impedance is a variable.

Transformers

The positive and negative sequence impedances of a transformer are equal and it is the impedance of the transformer. But the zero sequence impedance depends on the earth connection.

Free PDF creator for you

2007-07-05T20:14:00.000+06:00

These are the links of most common free pdf creators that available for free, with their Source code.

Copy and paste this links on your browser.

PDF Creator
An excellent pdf printer driver for windows.

http://nchc.dl.sourceforge.net/sourceforge/pdfcreator/PDFCreator-0_9_3_GPLGhostscript.exe

qvPDF
qvPDF is a PDF creator for Windows. It's implemented as printer driver and uses plugins to execute different actions after creating the PDF.

http://nchc.dl.sourceforge.net/sourceforge/qvpdf/qvPDF_v300.45_setup.exe

New Trends in RFID

2007-06-29T17:41:00.001+06:00

Some active RFID tags include sensors such as temperature logging to monitor the temperature of perishable goods. Other sensors that have been married with active RFID include humidity, shock/vibration, light, radiation, temperature, and atmospherics like ethylene.

Non-silicon tags made from polymer semiconductors are currently being developed by several companies (PolyIC Germany, Philips Semiconductors Netherlands). If successfully commercialized, polymer tags will be roll-printable, like a magazine, and much less expensive than silicon-based tags.

http://www.hitechno.info/2007/06/operation-of-rfid-tag-example.html

http://www.hitechno.info/2007/06/applications-of-rfid-tags.html

http://www.hitechno.info/2007/06/problems-of-rfid-tags.html

http://www.hitechno.info/2007/06/new-trends-in-rfid.html

Problems of RFID tags

2007-06-29T17:40:00.001+06:00

No standard universal protocol defined yet, for the responding frequencies of RFID tags. (Frequencies in USA are currently incompatible with those in Europe or Japan).
Security Problems – The tags which are world readable may pose a risk to privacy, military security etc.
Since RFID systems make use of the electromagnetic spectrum they are relatively easy to jam using energy at the right frequency.
Collisions may occur between readers and/or between tags.
Implanted tag, to a person, can be read without his permission.

http://www.hitechno.info/2007/06/operation-of-rfid-tag-example.html

http://www.hitechno.info/2007/06/applications-of-rfid-tags.html

http://www.hitechno.info/2007/06/problems-of-rfid-tags.html

http://www.hitechno.info/2007/06/new-trends-in-rfid.html

Applications of RFID tags

2007-06-29T17:36:00.001+06:00

Most common applications of RFID tags can be summarized as follows.

Product tracking and identification – as a replacement for barcodes and barcode readers, library management systems, identification badges (American Express Blue™ credit card), container management systems in ports
Passports – can keep records of the travel history (time, date, and place) of entries and exits from the country (e-passport Malaysia)
Animal tracking – Implanted RFID tag can track the position of an animal
Automotive – Long range access controlling of vehicles, embedded in keys to avoid duplicates(Honda CBR RR, Toyota Camry 2007, Toyota Avalon 2006, Lexus GS), Anti theft ignition system (Honda Civic, Ford Mustang)
Automatic Logging, Security Systems – Implanted RFID tag can be used to log in to a PC or a Server with required hardware, and can be used for security systems (Banks)

http://www.hitechno.info/2007/06/operation-of-rfid-tag-example.html

http://www.hitechno.info/2007/06/applications-of-rfid-tags.html

http://www.hitechno.info/2007/06/problems-of-rfid-tags.html

http://www.hitechno.info/2007/06/new-trends-in-rfid.html

Operation of RFID tag - an example

2007-06-29T17:34:00.001+06:00

Suppose a man with implanted RFID tag in his body, approaches to a door with a security lock based on RFID. Then following events will occur, between the lock and the tag.

An RFID reader emits radio waves, which power the implanted tag. The reader sends an encryption password.
The tag, which consists of a microchip and an antenna, checks the password. If it recognizes the password, the tag’s memory unlocks.
The tag transmits a code stored in its memory back to the reader.
The reader compares the tag’s code to a key code stored in the reader. If they match, the lock opens.
The reader generates a new key and stores it, then sends the new key to the tag.
The tag writes the new key into its memory.

http://www.hitechno.info/2007/06/operation-of-rfid-tag-example.html

http://www.hitechno.info/2007/06/applications-of-rfid-tags.html

http://www.hitechno.info/2007/06/problems-of-rfid-tags.html

http://www.hitechno.info/2007/06/new-trends-in-rfid.html

RFID - Radio frequency Identification

2007-06-29T17:25:00.001+06:00

As the name implies, Radio frequency Identification (RFID) means the process that identifying objects by means of radio waves. A special device is used to identify the object uniquely, and is called as RFID tag or Radio tag. More precisely this is the process of relying on storing and remotely retrieving data using RFID tags. Nowadays this tag become very small and can be implanted to a product, an animal or even to a person for the purpose of identification by means of radio waves.

Commonly available RFID tag has two major parts. One is an integrated circuit for storing and processing information, modulating and demodulating a radio frequency (RF) signal and perhaps other specialized functions. The second is an antenna for receiving and transmitting the signal. RFID increases the speed and accuracy with which inventory can be tracked and managed thereby saving money for the business.

RFID tags come in three general varieties named as passive, semi-passive (also known as battery-assisted), or active.

Passive RFID tags

These types of RFID tags have no internal power supply to energize its internal circuitry. In the instance that a RFID reader emits its radio waves, the induced electrical current in the antenna of the tag produces the required power for the CMOS IC in the tag. From this, the tag transmits its response to reader. This means that the antenna has to be designed to both collect powers from the incoming signal and also to transmit the outbound backscatter signal. The response of a passive RFID tag is not necessarily just an ID number or a code similar to bar code; the tag chip can contain non-volatile EEPROM for storing data.

The practical read distance of a passive tag has the range of 10 cm to few meters, and it depends on the operating radio frequency, the type of antenna, the size of it and the design of RFID. The lack of an onboard power supply means that the device can be quite small: commercially available products exist that can be embedded in a sticker, or under the skin in the case of low frequency RFID tags.

In February 2007 Hitachi Cooperation announced a RFID device measuring 0.05×0.05 mm, and thins enough to be embedded in a sheet of paper. This is named as µ-Chip. Silicon on insulator (SOI) was used to achieve this integration level of the chip. The new chips can store as much data as the older tags, and the data contained on them can be extracted from as far away as a few hundred meters. This chips can wirelessly transmit a 128 bit unique ID and data (encrypted or not), which is embedded to it in manufacturing process.

Active RFID tags

Active type RFID tags have their own internal power source to energize their integrated circuit module and transmit the signals to the tag reader. Active tags have the ability to conduct a session with the reader by using a handshaking technique. Also these types of tags have the ability of transmitting higher signal power levels to the reader because of its onboard power supply. This feature leads to more effective operation rather than passive tags in environments like water, metal (shipping containers, vehicles), or at longer distances. Many active tags have practical ranges of hundreds of meters, and a battery life of 5 to 10 years. Active tags typically have much longer range (approximately 100 m/300 feet) and larger memories than passive tags, as well as the ability to store additional information sent by the transceiver.

Semi Passive RFID tags

Semi-passive tags are similar to active tags as they have their own power source, but the battery is used just to power the microchip and not broadcast a signal. The RF energy is reflected back to the reader like a passive tag.

http://www.hitechno.info/2007/06/operation-of-rfid-tag-example.html

http://www.hitechno.info/2007/06/applications-of-rfid-tags.html

http://www.hitechno.info/2007/06/problems-of-rfid-tags.html

http://www.hitechno.info/2007/06/new-trends-in-rfid.html

HITECHNO.INFO

2007-06-26T12:16:00.000+06:00

I Received a domain name, www.hitechno.info. I hope to start a tech forum from this domain. I will Inform you the contents and the policies about this. If you are willing to know more information and hope to became an administrator of a forum section, please let me know.

Free SMS, to Any Mobile In The World

2007-06-22T18:27:00.000+06:00

Do you want to send free SMS messages? Then become a member of SMS CITY

Advantages of SMS CITY
* Free SMS every day;
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Register Here

PSCAD, Power System Computer Aided Design

2007-06-21T14:00:00.001+06:00

The analyzing of a real world power system may be a very complex task for an engineer or for the person who moderate the power system, especially in the case of unexpected faulty conditions that may occur by various means including unpredictable natural disasters. This analyzing process should do by the equivalent mathematical models of the equipments that were connected to power system. It is a great ease, if the engineer can model the system with the aid of a software platform to analyze and simulate the behavior of power system at various scenarios and even when building new one or integrate new one to the existing power system.

PSCAD^® is a general-purpose time domain simulation tool for studying transient behavior of electrical networks. First developed in 1976, the EMTDC simulation program has been constantly evolving in its scope and capabilities. Users can now harness the power of EMTDC through the user-friendly PSCAD interface on personal computers. This seamlessly integrated visual environment supports all aspects of conducting a simulation including circuit assembly, run-time control, analysis, and reporting. Simply put, PSCAD is the professional's tool for electromagnetic transient simulation.

MATLAB™, framework also contain a library to simulate power systems, but it cannot model, all the scenarios that can happen to the power system, specially the fault conditions. Therefore PSCAD™ evolved as the only professional tool to simulate and design the power systems, nowadays. This Platform has very efficient simulate engine, with a core written by FORTRAN language. EMTDC can simulate not only complex electric networks but also has the capability of modeling complex power electronics, controls and the non-linear network. When run under the PSCAD graphical user interface, the PSCAD/EMTDC combination becomes a powerful means of visualizing the enormous complexity of portions of the electric power system.

Applications of PSCAD

· Distributed generation studies

· Control system design & optimization.

· Protection system validation

· Lightning and impulse studies

· Power transmission design and testing

· Industrial plant planning

· Power electronic circuits design analyzing and simulation

· Analyzing Asymmetrical faults of Large power systems

· Protection relay coordination

· Arc furnace flicker

· Rotating machines

· Transmission system design & performance

· Power quality studies

· Power electronic design

· Electric machine performance

Piyumal Gunawardana , Current Situation

2007-06-19T09:47:00.000+06:00

You may remember the email you received regarding the cancer affected engineering undergraduate student Piyumal Gunawardana of University of Moratuwa, Sri Lanka. This email is to inform his current situation to you.

Piyumal underwent his surgery at the Gleneagles hospital, Singapore. It was done by a group of doctors lead by Dr. Andrew H. Sea. This surgery took nearly 14 hours to complete. Major intention of this surgery was to remove the cancer tumor from Piyumal. As a result of the surgery his tongue, voice box, jaws(lower pair) and other areas of his mouth which were affected by the cancer were removed. Then muscles were taken from his chest and right thigh, and were planted to compensate the removed areas in his face. Feeding tube was attached for feeding purposes and another tube for breathing (this was attached to his throat). Piyumal was in the intensive care unit for 3 days and then transferred to a normal ward. After about three weeks he was discharged and was taken back to Sri Lanka.

This surgery cost us about 6 million LKR and earlier we had to spend another 3 million on his chemos which were given prior to the surgery. We also had to spend another 1.8 million LKR at an emergency situation where the doctors had to do a sudden surgery on Piyumal. We received a great support from people in Sri Lanka and abroad. Lot of people had responded our email and they contributed in various ways to help Piyumal and his family. We would like to mention all of those who helped us when we needed a lot of support with our heartiest gratitude.

After spending two weeks at Sri Lanka, he was consulted by a doctor and he recommended to give some more chemos (set of injections) to avoid any spreading of the cancer (if it exist any more). He has now given two cycles of chemos at the Oasis hospital, Colombo. Then a CT scan will be done and Piyumal will have to go back to Singapore for consulting the doctor. We have been able to find the money which was needed up to now with your greatest help. After six months Piyumal will undergo another surgery to make up his face to a normal position (That has not been done in the surgery). At the moment he is fed by the tube. He cannot speak because his tongue and the voice box are removed. Doctors will try to fix them at a later time. At the moment our major intention is to save him from the cancer completely.

We would like to thank all of you who helped us in all possible ways. You showed great human qualities by helping us when we were helpless. We owe all of you. We pray the Load Buddha, Jesus, Allah and all the gods to protect you from any trouble.

Please forward this to all whom you think you should.

Contact details of Piyumal’s family

Telephone : +94412228595
+94602405265

Email : piyumal123@yahoo. com

Thanking you,

Piyumal's family.

This message has been sent to me, by Amila Mahaarachchi

Dr. Amith Munindradasa -- An Article about Him

2007-06-18T13:08:00.000+06:00

I have an article about Late Dr. Amith munindradasa, including his works, his vision and mission. It was published as .pdf, in sinhala language. Those who are willing to receive this article, please send me your e mails, to samitharansara@gmail.com or post your e mail address as a comment to this post. I'll send you the article, as soon as possible.

Thyristor, Construction and Operation

2007-06-17T11:07:00.000+06:00

The Thyristor is a solid state electronic device which had four doped semiconductor layers. The layers were arranged in alternate manner to form a stack shaped structure. Three terminals were taken out from the thyristor, and named as Anode, Cathode and Gate.

Fig 1: Layered Structure of Thyristor and equivalent transistor model

The operation of a thyristor can be described easily, by using the two transistor model, if a current pulse applied to the gate terminal, it triggers the bottom transistor, and because of that, the top one automatically starts to conduct. This caused to keep the gate current until the supply stops or reversed (Anode cathode current). Operation of the thyristor is same as this. It won’t conduct till the gate received a current pulse, after that it will conduct till the removal or reversal of the external source.

Thyristor have three states:

1. Reverse blocking mode - Voltage is applied in the direction that would be blocked by a diode

2. Forward blocking mode - Voltage is applied in the direction that would cause a diode to conduct, but the thyristor has not yet been triggered into conduction

3. Forward conducting mode - The thyristor has been triggered into conduction and will remain conducting until the forward current drops below a threshold value known as the "holding current"

Fig 2: VI Characteristics of the thyristor

In a conventional thyristor, once it has been switched on by the gate terminal, the device remains latched in the on-state (i.e. do not need a continuous supply of gate current to conduct), providing the anode current has exceeded the latching current (I_L). As long as the anode remains positively biased, it cannot be switched off until the anode current falls below the holding current (I_H). The thyristor can be switched off if the external circuit causes the anode to become negatively biased. In some applications this is done by switching a second thyristor to discharge a capacitor into the cathode of the first thyristor. This method is called forced commutation.

The Smallest Linux Embedded Board Computer

2007-06-15T20:17:00.000+06:00

The picotux 100 is the world's smallest Linux computer, only slightly larger (35mm×19mm×19mm) than an RJ45 connector. Inside, there is an ARM7 CPU at 55 MHz running uClinux kernel 2.4.27 and Busybox 1.0. Two communication interfaces are provided, 10/100 Mbit half/full duplex Ethernet and a serial port with up to 230.400 baud. Five additional lines can be used for either general input/output or serial handshaking.

Technical Data	picotux 100 module

Processor:	32-bit ARM 7 Netsilicon NS7520
Processor Clock:	55 MHz
Flash Memory:	2 MB
RAM:	8 MB SDRAM
Ethernet:	10/100 Mbit, HD and FD, auto sensing
Serial (TTL):	Up to 230.400 bps
General Input/Output Pins(TTL)	5, can be used as Handshake
LED for Ethernet	2; green (programmable) and yellow (Carrier)

Supply Voltage:	3,3 Volt +- 5%
Supply Current:	250 mA

Operating System:	uClinux 2.4.27 Big Endian (native)
Shell:	Busybox 1.0 and others
File Systems:	CRAMFS, JFFS2, NFS
Applications:	Webserver, Telnet
Size of the Linux Systems in Flash:	720 KB and more
Protected Bootloader for Update over Network:	64 KB Code

Development System:	GNU Tool chain
Compiler	GCC 3.4.4 for C/C++ and Fortran
Binutils	2.15
Library:	uClibc 0.9.26

Dimensions:
Height:	19 mm
Width:	19 mm
Deep:	36 mm
Package:	Shielded by metal
Weight:	ca.18 g
Ambient Temperature:	-40°C to 85°C

Dr. Amith Munidradasa..... (Directions to his home)

2007-06-15T20:12:00.000+06:00

This is the path that you should follow if you wish to participate to Dr. Amith Munindradasa's Funeral.

In Galle road,When you pass Pinwatta Cemetery (Panadura) on sea side, there is a large billboard by Blue Waters Hotel on land side. Passing that, after about 4 by-roads there is left turn (land side) to Pinwatta Pirivena Rd.(some flags are at the road top) Go along that about 1km and you will find a y-junction. Take the right side way and go about 500m further. You will not miss his house, as there is a banner and white flags.

Dr.D.Amith Munindradasa passed away

2007-06-15T18:34:00.000+06:00

Dr. D Amith Munindradasa, had passed away suddenly in Israel on 12th of June. He was an expert in Power Electronics, Nano Technology, Mechatronics, Quantum Mechanics and also in non technical things such as photography and wildlife.

He was born in Walana, Panadura, Sri lanka in 1966. He has expertise talents in machine mechanics, from his early childhood.

He graduated from University of Moratuwa in 1993 as an Electronic and Telecommunication Engineer, and got his PhD from Liverpool university, in Semiconductor Electronics.

He developed Multi Phase Axial Flux Permanent Magnetic Motor and validate it conceptually via a mathematical model.

As the author of this post, I myself feel very sad, about this coincidence. He was my Electronic Lecturer in University.

May He Attain Nibbana !!

Obituary of Dr. Amith Munindradasa (WUS) (EESoc)

2007-06-15T13:22:00.000+06:00

Dear friends,

Dr. Amith Munindradasa has passed away on 11^th June 2007 when he was in Israel representing Sri Lanka for a conference. It is reported that he died of pneumonia but it is yet to be confirmed. He was senior lecturer at University of Moratuwa and the former Head of the Department of Electronics and Telecommunication Engineering.

He was graduated in 1993 from University of Moratuwa and was awarded the Doctorate from University of Liverpool. He had an in depth knowledge and taught analogue electronics, quantum electronics, mechatronics and photography for undergraduates and provided proper guidance for students to groom.

Dr. Amith Munindradasa was the president of World University Service (WUS) of University of Moratuwa which provided many services to students at the university. He was a great wildlife admirer and enthusiastic photographer. His knowledge was not limited to academic but widely spread through religious, astrology, astronomy, optics and thermodynamics. His ability to give knowledge to others (teach) was no second to any other; it was clear, precise and more practical. He was a leading researcher in the field of solid state electronics and has contributed an invaluable service for the field of Wildlife in Sri Lanka.

More than he was a great person to get to know who had a true spirit of friendship. He was helpful in every possible way and did his work according to the rule and in a fair manner.

He was considered a great teacher among student and great colleague among staff members and a brilliant advisor among WUS members and a great friend among his nature loving friends and most of all a great contributor for the whole nation of Sri Lanka.

It is our deepest condolences to announce his sudden death; otherwise he could have immensely contributed to the nation in the years to come.

May Dr. Amith Munindradasa attend nibbana!

WUS Committee members

MSI AGAIN !!!!! MSI P35 Platinum

2007-06-15T13:09:00.000+06:00

Features

Support for LGA775 Intel Core 2 Quad and Core 2 Duo, including 1333/1066/800FSB and 45nm processors;
Intel P35 Northbridge;
Intel ICH9R Southbridge;
Supports up to 8GB of dual channel DDR2 800MHz FSB, using four 240-pin, 1.8V DDR2 DIMMs;
Two PCI Express x16 slots (White = x16, Yellow = x4);
Two PCI Express x1 slots;
Two 32-bit v2.3 Master PCI bus slots (support 3.3v/5v PCI bus interface);
One IDE port;
Five SATA 3Gbps ports supporting RAID 0, 1, 0+1, 5 or JBOD;
Realtek ALC888 High-Definition audio codec supporting 7.1 channel surround sound up to 32-bit/192KHz;
One Gigabit Ethernet, one PCI-Express provided by the Realtek RTL8111B controller;
VIA VT6308P IEEE1394a Firewire controller providing two ports, one of the rear I/O and one via pin-out;
Marvell 88SE6111-NAA1 controller providing one PATA port and one 3Gbps SATA port

The Size Of Our World

2007-06-09T15:50:00.001+06:00

OpenOffice worm hits Mac, Linux and Windows

2007-06-09T15:48:00.001+06:00

According to the Symantec Security Response Web site, the worm is capable of infecting multiple operating system platforms and is spreading.

The advisory said: "A new worm is being distributed within malicious OpenOffice documents. The worm can infect Windows, Linux, and Mac OS X systems. Be cautious when handling OpenOffice files from unknown sources".

In an interview with ZDNet Australia on Thursday, Dr Jan Hruska, who co-founded rival antivirus firm Sophos and was one of the first ever PC antivirus experts, said that Apple Mac's are not a virus-free platform.

"Viruses on the Mac are here and now. They are available and they are moving around -- it is not as though the Mac is in some miraculous way a virus free environment.

"In terms of numbers, the number of viruses coming out for non-Mac platforms is higher. It gives a false impression that somehow Apple Macs are all virus free," said Hruska.

The worm was first spotted late last month but at the time, it was not thought to be "in the wild".

Once opened the OpenOffice file (badbunny.odg) launches a macro that behaves in several different ways depending on the user’s operating system.

On Windows systems, it drops a file called drop.bad which is moved to the system.ini in the user’s mIRC folder, while executing the Javascript virus badbunny.js that replicates to other files in the folder.

On Apple Mac systems, the worm drops one of two Ruby script viruses in files called badbunny.rb and badbunnya.rb.

On Linux systems, the worm drops both badbunny.py as an XChat script and badbunny.pl as a Perl virus.

Symantec rates the worm "Medium Risk".

MathWorks Plugs into Microchip MPLAB IDE

2007-06-05T11:56:00.000+06:00

Microchip Technology Inc., a leading provider of microcontroller and analog semiconductors, announced that, through its close collaboration with The MathWorks, Inc., a leading developer of technical computing and Model-Based Design software, Microchip's popular MPLAB(R) Integrated Development Environment (IDE) now features a free plug-in for The MathWorks MATLAB(R), Simulink(R) and Real-Time Workshop(R) Embedded Coder modeling and code-generation programs.

MATLAB is a high-level technical computing language and interactive environment for algorithm development, data visualization, data analysis, and numeric computation. Simulink is a platform for multi-domain simulation and Model-Based Design of dynamic systems. With Simulink, designers can quickly create, model and maintain a detailed block diagram of the system, using a comprehensive set of predefined blocks. MATLAB and Simulink are used by engineers and scientists in industry, government and education.

The MPLAB IDE is a free, feature-rich, integrated toolset for the development of embedded applications employing Microchip's PIC(R) microcontrollers and dsPIC(R) digital signal controllers. The MPLAB IDE runs as a 32-bit application on the Microsoft Windows(R) operation system, is easy to use, and includes a host of free software components for fast application development and super-charged debugging. The MPLAB IDE also serves as a single, unified graphical user interface for additional Microchip and third party software and hardware development tools. MATLAB and Simulink plug-ins debut in the current version of the MPLAB IDE, version 7.51, and enable designers to select Simulink software models, automatically generate source code, and include the files in MPLAB IDE projects for compilation and build, all within the familiar, easy-to-use MPLAB IDE graphical user interface.

"The integration between MATLAB, Simulink and the MPLAB IDE will dramatically increase the productivity of production organizations using Model-Based Design with Microchip's hardware," said Tom Erkkinen, Embedded Applications manager of The MathWorks, Inc. "With push-button automation, engineers can now generate code from their executable specification models, compile it, and download the code to their embedded processor for on-target rapid prototyping or production deployment."

"Wielding the power of MATLAB and Simulink from the MPLAB IDE desktop further empowers the designer of embedded designs using Microchip devices." said Derek Carlson, vice president of Microchip Development Tools. "This collaboration is a significant addition to our tool suite for Microchip's 16-bit microcontrollers, and sets the stage for future cooperative efforts."

Gigabyte - enters to the game !!!!!

2007-06-04T10:48:00.000+06:00

Gigabyte GA-965P-DQ6 Overview:

Support for all Intel LGA775 processors including Pentium 4, Pentium D, Pentium Extreme Edition, Core 2 Duo and Core 2 Extreme;
Intel P965 chipset and ICH8R southbridge with RAID 0, 1, 0+1 and 5 support;
Support for up to 8GB of DDR2-533, DDR2-667 or DDR2-800MHz memory;
One PCI-Express x16 slot and one PCI-Express x4 slot (x16 physical interconnect) with ATI Crossfire support using Catalyst 6.9 (or newer) drivers;
Three PCI-Express x1 slots (either use the three x1 slots, or use the PCI-Express x4 slot with no PCI-Express x1 slots) and two PCI slots;
Realtek ALC888D High Definition audio codec with 8 channel sound support, Dolby Digital and S/PDIF;
Marvell 8053 PCI-Express Gigabit Ethernet;
Six native SATA 3Gbps ports;
Two Gigabyte SATA 3Gbps ports and a single IDE channel;
Firewire T.I. TSB43AB23 with three ports;
Ten USB 2.0 ports, six internal and four on the rear I/O.

Box Contents:

User Manual, CD and RAID/eSATA floppy disks;
One blue IDE cable;
One blue floppy cable;
Four orange serial ATA cables;
Two serial SATA molex power adapter;
Two eSATA cables;
Two PCI brackets providing support for four eSATA devises;
A metal I/O shield.

Wow...Gigabyte has come so far, but left out a few essentials from the bundle. The provision of eSATA is just unheard of elsewhere, and is definitely a good thing for external storage. Having said that, though, if you don't have a case to put your hard disks in, you leave them prone to static attack or being dropped in daily life. This is a pretty big worry.

The board's layout is good, and the varying colours highlight all the necessary items distinctly without looking like it belongs in a primary school classroom. Gigabyte has used 100% solid state capacitors on the DQ6 model, which is similar to the Abit AW9D-MAX. These cost more, but performance and overclocking capabilities are improved slightly. Whilst this cost is passed onto the consumer, paying that bit more will also mean that the board lasts longer and will probably be a more consistent overclocker than anything the competition can offer.

Gigabyte has various boards that use the P965 chipset - the DQ6 version highlights the use of quad everything: support for Intel's Core 2 Quad processors when released, "Quad cooling" from the four heatsinks and heatpipe arrangement, "Quad BIOS" in the form of a dual-dual BIOS for the ultimate in screw-up proof BIOS updating support, Quad eSATA2 (in the form of four lots of two) and Quad triple-phase power regulation. That's a loose "Quad" ethos by any stretch of the "multiples of four" imagination, but don't think that we're complaining here.

The board does support CrossFire, although you are restricted to using one full speed PCI-Express x16 slot and the other at x4 speed...and that's only if you aren't using any PCI-Express x1 slots. Yes, if you plug something into any of the PCI-Express x1 slots, the orange x16 slot is reduced to a lowly x1 bandwidth - which seriously cripples any extra performance a second graphics card will give you.

The SATA ports are the clip-lock type to prevent you from accidentally pulling out the plug or bending and breaking it. Quite a few people will attest to breaking SATA plugs by simply applying a little lateral pressure. The front I/O pin header is colour-coded for ease of use, and the internal pin outs for six USB 2.0 (in orange) and two Firewire (in grey) are neatly placed and easy to get to. The power plugs are also easy to use, positioned nicely near the top edges of the board.

Extracted from Bit-tech.net

MSI P6N SLI Platinum

2007-06-02T09:36:00.000+06:00

The Platinum range is feature filled, but MSI's most high-end product. Today, we have the P6N SLI Platinum, which is based on Nvidia's nForce 650i SLI chipset. Though the P6N SLI Platinum isn't the top dog in the line-up, it's far from being a no-frills SLI motherboard - MSI has opted to kit this out with a large complement of goodies.

The nForce 650i Ultra boards were expected in February and are still due soon, but considering the low price of the nForce 650i SLI and the recent release of the nForce 680i LT SLI, there’s a question of how little these will cost. This still means the nForce 650i SLI is the bottom end SLI chipset you can buy, but does this mean it skimps on performance as well?

MSI P6N SLI Platinum Overview

Supports LGA775 Intel Core 2 Quad, Core 2 Duo, Pentium 4, Pentium 4 D, and Pentium XE, including 1333/1066/800/533MHz FSB processors;
Nvidia nForce 650i SLI SPP (C55) northbridge;
Nvidia nForce 430i (MCP51) southbridge;
Supports up to 8GB of dual channel DDR2 533/667/800, using four 240-pin/1.8V DDR2 DIMMs;
Two PCI Express x16 slots (in an x16 and x1 or x8 and x8 configuration);
One PCI Express x1 slot;
Three 32-bit v2.3 Master PCI bus slots (support 3.3v/5v PCI bus interface)
Two IDE ports;
Four SATA 3Gbps ports supporting RAID 0, 1, 0+1, 5 or JBOD;
One eSATA port by Sil3531;
Realtek ALC888 High-Definition audio codec supporting 7.1 channel surround sound;
One Gigabit Ethernet port by Realtek RTL8211BL;
VIA VT 6308P IEEE1394a Firewire chipset;

Box Contents

Three red SATA ports;
Two molex to SATA adapters;
One Red rounded IDE cable;
One Red rounded floppy cable;
One SLI bridge and retention bracket;
Additional fan for northbridge;
Single 6-pin Firewire port PCI bracket;
Two USB 2.0 ports and MSI D-LED PCI bracket;
Metal rear I/O shield;
Manual, Quick Guide and Driver CD.

The motherboard features very typical MSI Platinum styling with a black PCB, lime green and orange DIMM sockets, copper heatsinks and white PCI slots. Why change a formula that works?

There isn’t a particular theme for the board, but everything is coloured in a way that isn’t at all garish and still lets you know that every port and plug is different. The IDE ports are yellow, the SATA is purple, the Firewire pin-out is green and as I just mentioned, the memory slots are orange and lime green.

The whole board is decked out in solid aluminium capacitors apart from those that surround the sound codec, but that isn’t particularly important to the overall performance. Solid aluminium capacitors feature an “organic semi-conductive electrolyte” that increases the life and power delivery of board in general since the capacitors are often the first things to die.

The memory slots are coloured according to channel rather than according to where you should put the memory. This is a traditional MSI trait, that is different to virtually every other board on the market. Instead of putting the two sticks of memory in the same coloured slots like you would elsewhere, you now put one stick in green and one in orange, keeping the alternation.

A copper heatpipe travels from southbridge to northbridge then another joins it on its journey to the power regulation components. They are angled out of the way of the PCI/PCI-Express cards, but the 8-pin 12V power connector is placed right in the corner of the 90-degree turn making it really quite awkward to get the plug in and out. In addition, the placement means that the cable has to be contorted to a route across the motherboard, between the CPU heatsink and heatpipe array.

Included is a 40mm fan for the northbridge for additional cooling. It comes with a couple of tiny thumbscrews and sits neatly over the top of the heatsink, out of the way. The downside is that this little monster runs at an incredible 8500RPM, so if you absolutely have to use it then at least attach it to a fan controller and tone down its speed and noise. Thankfully, you don't need it providing your case has some airflow, or your CPU cooler forces some air over it.

Other ports and sockets around the board are very well placed, however. The ATX power socket, both IDE ports, all four SATA ports and the pin-outs for USB and Firewire are all placed around the edges of motherboard for easy access.

There are only four SATA ports from the southbridge since this is the older nForce 430i MCP and MSI hasn’t included an extra controller for additional internal ports. There are however, two IDE sockets to provide legacy support for those who still use IDE hard drives or need to use a ton of optical drives. Both sets of IDE and SATA ports are covered by Nvidia’s MediaShield technology.

MSI does include a single eSATA port on the back of the rear I/O powered by a Silicon Image Sil3531 chipset for extra connectivity, which is a nice touch for this price range. Despite that fact this board can be had for a bit under £100, it still has plenty of different connectivity options.

Only one Gigabit Ethernet is provided by Realtek's RTLB211BL. This is a physical layer (PHY) attachment to the southbridge. It supports FirstPacket technology, but there is no Teaming support since there isn’t a complementary port.

Sound comes via Realtek’s ALC888 codec, which offers ten DACs for 8-channel 192KHz/24bit High-Definition audio and two separate stereo channels for the front panel outputs. The two stereo inputs feature acoustic echo cancellation, beam forming and noise suppression technologies. It’s capable of up to 97dB playback and 90dB recording SNR and has an onboard front panel and S/PDIF pin-out is provided, as well as rear I/O connectors.

Three PCI slots are included, of which two are still usable when SLI is enabled with dual-slot graphics cards. A single PCI-Express x1 port has also been placed above the upper most PCI-Express x16 slot so that it's always usable. The PCI-Express x16 slots have a big enough gap between them to allow for enough airflow, without having the bottom slot so close to the base of your case that your graphics card acts as a vacuum cleaner.

MSI still uses a classic mini-PCB flip method to select between SLI and non-SLI modes. This is certainly the cheaper option, but it requires you remove one or both of your graphics cards and have some nails in order to get the mini-PCB in and out.

The four USB ports pin-outs are colour coded so you know what pin plugs in where, which undoubtedly is extremely useful. However, MSI also gave the front panel pin out a very similar colour scheme and, to confuse matters further, has placed them all in the same area of the PCB. The VIA VT6308P IEEE1394a Firewire pin-out is different in that has a keyed green plastic shroud. This means you can don't need the pins colour labelled as you can only plug the supplied PCI bracket in one way.

Seagate's Barracuda ES hard drive

2007-06-02T09:22:00.000+06:00

SCSI HAS LONG RULED the enterprise world, but Serial ATA is slowly creeping into corporate server rooms. Serial ATA simply can't be beaten when it comes to storage density, and when you're paying for not only the drives, but also the rack they sit in, density can be an even more important metric than performance.

Today, the highest capacity SCSI drives top out at 300GB—just 60% of the capacity of today's enterprise-class Serial ATA drives, which are available up to 500GB. Seagate has just raised the bar even higher, introducing a new Barracuda ES hard drive with a whopping 750GB of storage. To put that into perspective, consider the storage capacity of a four-drive 1U rack server running RAID 5. With 300GB SCSI drives, you won't even break one terabyte. 500GB Serial ATA drives could give you 1.5TB of redundant capacity, while an array of 750GB Barracuda ES drives would offer a cool 2.25TB, all in the same physical space.

The Barracuda ES owes its freakish capacity to the perpendicular recording technology it shares with Seagate's desktop-oriented Barracuda 7200.10. Physically, the drives are nearly identical. However, the Barracuda ES packs firmware optimizations that promise better performance under more demanding loads, an attribute whose appeal extends beyond the enterprise world and into the enthusiast's realm.

How does the Barracuda ES compare with other enterprise-class Serial ATA hard drives? Is it really any faster than the Barracuda 7200.10? Read on to find out.

What makes an ES?
The Barracuda ES is based on the same drive platters and mechanics as the 7200.10, but it's built to withstand cramped rackmount enclosures where drives can be packed tighter than steerage class on a budget airline. All hard drives vibrate during normal spinning and seek operations, and those vibrations can disrupt the operation of a drive in close proximity by shaking the drive head off its intended path. The disrupted drive must then wait for its head to move back into position before resuming normal operation, resulting in a performance penalty.

To combat vibration-induced performance degradation, the Barracuda ES is outfitted with sensors that detect rotational vibration and adjust the drive head accordingly. These sensors allow the ES to tolerate a rotational vibration of 12.5 rad/second² with a rotational profile of 20-800Hz. The Barracuda 7200.10, on the other hand, can only tolerate 5.5 rad/second² between 10 and 300Hz.Apart from the ES's rotational vibration sensors, the drive is physically identical to the Barracuda 7200.10. It uses the same 188GB platters with perpendicular recording and is available with up to 16MB of cache. That cache is programmed a little differently on the ES, of course, but it's the same chip.

In addition to different cache segmentation, the ES's firmware offers a handful of RAID-specific features that you won't find in the Barracuda 7200.10. Among them is Error Recovery Control, which limits the drive's error recovery time to 12 seconds. This prevents prolonged error recovery attempts from causing drives to be prematurely dropped from RAID arrays. Similar functionality is available on Western Digital's enterprise-class Serial ATA drives, although WD recommends disabling the feature for single-drive operation. Error Recovery Control apparently doesn't hinder the Barracuda ES in single-drive systems.

Error recovery is nice, but avoiding errors is even better. To help reduce the number of errors the ES encounters in thermally challenging enterprise environments, the Barracuda ES monitors temperatures and shuffles I/O requests in a manner that allows the drive to cool if it gets too hot. The ES also includes features to simplify multi-drive firmware updates and speed RAID initialization.

Although both the Barracuda ES and 7200.10 are available with a 300MB/s Serial ATA interface, the ES also comes in fibre channel flavors. Those flavors are limited to 400 and 500GB capacities with only 8MB of cache, though.

Hard drive manufacturers seem loath to publish performance specifications for their desktop hard drives, so it's hard to compare the ES's seek times and sustained transfer rate specs to those of the 7200.10. We'll see how real world seek times and transfer rates shake out when we move to our performance benchmarks.

Enterprise-class Serial ATA drives typically offer longer warranties than their desktop counterparts—often five years for enterprise models versus just three years for desktop. Seagate's a little different, though. It offers a five-year warranty for all its internal hard drive products, including desktop and enterprise drives, so the ES doesn't have an advantage over the 7200.10 in this category. Five-year hard drive warranties are pretty standard in the enterprise world, so Seagate certainly isn't skimping. The company's enthusiasm for longer desktop drive warranties has just blunted what could have been another selling point for the ES.

Google moves further into Microsoft's territory with offline software

2007-06-02T09:19:00.000+06:00

Google fired another warning shot across the bows of Microsoft yesterday with the launch of software that allows people to use its services even when they are not connected to the internet.

Google Gears will help people to take information from web-based programs and use it offline, enabling them to use services that usually requires a web connection on a computer's hard disk instead.

The system is also being opened up to allow independent developers to create their own products based on the concept.

The announcement will be watched closely by Microsoft, which recently launched its own system, Silverlight, for bridging the gap between the online and offline worlds. The arrival of Gears could be particularly threatening because it is likely to help Google Docs, the company's suite of office software, make a concerted challenge to Microsoft's core office software business.

Docs — which incorporates word processing, spreadsheet and presentation programs — only works with an active internet connection. Allowing it to operate on a computer's hard drive would bring it into competition with the dominant Microsoft Office brand and mark the latest step in Google's slow but inexorable invasion of the Seattle-based software company's territory.

Eric Schmidt, Google's chief executive, said that giving external programmers the ability to develop the system would strengthen its position.

"With Google Gears, we're tackling a key limitation of the browser in order to make it a stronger platform for deploying all types of applications," he said. "We believe strongly in the power of the community to stretch this new technology to the limits of what's possible and ultimately emerge with an open standard that benefits everyone."

The announcement came as Google launched its first international Developer Day, an open house event being held in 10 locations worldwide with more than 5,000 attendees. The concept behind it is to talk to third parties who build software and services based on Google's business, and explain some of the inner workings of its products to them.

By opening up the often-secretive world of Google and encouraging more corporate partners, it believes it can increase its penetration of the web even further. With many web start-ups created on the back of so-called "mash-ups" — hybrids that mix different online services together to create a new concept — larger technology organisations have found that third parties are even more reliant on them.

"This is a complete shift from the portal strategy of the 1990s," said Jeff Huber, Google's vice president of engineering. "Back then everyone was in it for themselves, there was no integrating with rivals and you were only working for yourself. Now we are thinking about our products as building blocks. It's a virtuous cycle."

Google is just one of a number of companies investing heavily in these concepts, with rivals such as Yahoo!, Microsoft and Amazon also following suit. Many are particularly keen to contribute to the open-source community, which develops software and tools that can be used freely by anybody at no cost. Alexandra Palace in London will play host to a "Hackday" event this month being held jointly by Yahoo! and the BBC intended to foster relations with the technical community.

"I think that all these events are part of a conversation that has to happen between companies like the BBC and everyone else," said Matthew Cashmore, development producer at the BBC. He stressed that it was important for many people to be able to talk to each other face to face and get a feeling for the internet industry outside of Silicon Valley. "It has to be very social; you can't exist solely on the web, you have to be out there rubbing shoulders with each other. It's important in this industry that it's not all just about west coast America."

The joy of mini-ITX

2007-05-31T11:54:00.000+06:00

VIA EPIA 'Mini ITX' compact SBC (Single Board Computer)

Commell LV-675 -- [Dec. 14, 2005] -- Claimed to be the first mini-ITX board to support Pentium M and Celeron M processors with a 533 MHz front side bus (FSB), the LV-675 comes with drivers for embedded Linux.

Kontron 886LCD-M/mITX(BGA) -- [Nov. 2, 2005] -- A passively cooled, Linux-ready mini-ITX motherboard with a soldered-down BGA (ball-grid array) Intel processor and long-term availability, the 886LCD-M/mITX(BGA) has a 600MHz mobile Celeron processor, and targets cost-sensitive, low-power applications, such as POS (point-of-sales/service), gaming, banking, measurement, medical, and industrial computing.

Kontron 786LCD/mITX -- [Sep. 28, 2005] -- A mini-ITX board targeting cost-constrained, high-volume applications such as gaming, POS (point-of-sales/service), data communications, and medical equipment, the 786LCD/mITX is based on a mature Intel chipset yet supports USB 2.0, SATA, FireWire, and LVDS, Kontron says.

Arbor Technology ITX-i7435 -- [Sep. 27, 2005] -- A mini-ITX motherboard graced with a PCI Express x16 slot, and targeting multimedia, gaming, and other applications requiring high-quality graphics performance, the ITX-i7435 supports several Socket 478 Pentium M/Celeron M processors.

Kontron 886LCD/mITX -- [Aug. 28, 2005] -- A highly integrated mini-ITX motherboard with Pentium 4 and Celeron processor options up to 3 GHz, the 886LCD/mITX includes an AGP/DVO slot and targets CPU-intensive, cost-sensitive industrial applications.

Axiomtek SBC86800 board and EM603201 case -- [Jul. 7, 2005] -- A mini-ITX board supporting Intel Pentium-4 and Celeron processors, and available with a rolled steel micro-box with 180-Watt ATX power supply.

iBase MB720 -- [Apr. 29, 2005] -- A Via-based mini-ITX board that uses the same chipset used in newer Via mini-ITX boards, the MB720 is available with an LVDS module supporting 4:3 and 16:9 LCD displays. It targets industrial, gaming, medical, digital entertainment and other applications requiring stable and long lifecycle platforms.

Via ships dual-processor mini-ITX board -- [Mar. 11, 2005] -- Via is now sampling its first dual-processor mini-ITX board. The DP-310 features dual 1GHz Eden-N processors, along with gigabit Ethernet, SATA, a media-processing graphics system, and more. It targets high-density server systems, appliance servers, and compact embedded digital devices.

World's fastest Mini-ITX mobo? -- [Feb. 18, 2005] -- Powered by Pentium M processors at up to 2.3 GHz, the P620 Hawk is crammed with interfaces and expansion buses, and may also be the first Mini-ITX mobo to offer PMC expansion.

Coventive Uranus -- [Jan 4, 2005] -- A mini-ITX SBC (single-board computer) targeting Linux-based DVRs (digital video recorders), wireless TVs, network MPEG encoding boxes, and surveillance systems. The Uranus board is based on a MIP64 Toshiba SoC (system-on-chip), along with a Vweb MPEG coprocessor, and comes with a Linux SDK (software development kit).

Commell LV-667 -- [Dec. 17, 2004] -- Commell is shipping a mini-ITX board said to offer advanced graphics features, based on Via's latest northbridge. The LV-667 is available with a variety of video port options, and targets PVRs, set-top boxes, gaming machines, kiosks, POS (point-of-sales/service) devices, and more.

Toshiba mini-ITX-based PVR ref design -- [Oct. 18, 2004] -- Toshiba America Electronic Components (TAEC) has released a hardware/software reference design targeting digital multimedia appliances with sub-$100 BOMs (bills-of-material). The reference design, designated AVM49R, includes a mini-ITX board with a dedicated MPEG-1/2/4 codec chip alongside a 333MHz MIPS RISC-based SoC.

VIA dual-processor (DP) mini-ITX board -- Oct. 6, 2004 -- Via expects to ship its long-awaited "SP" mini-ITX board in November, followed in early 2005 by a "DP" model with dual nanoBGA embedded processors -- quite likely the world's first dual processor mini-ITX mobo. Both mini-ITX boards will feature a new northbridge supporting faster FSB (front-side bus), southbridge interconnect, and DDR memory speeds, and hardware MPEG-4 acceleration.

New VIA mini-ITX board targets vertically challenged apps -- June 24, 2004 -- VIA is shipping an ultra-low profile mini-ITX mainboard suitable for Linux-based flat TVs, LCD-panel computers, and other vertically challenged devices. The Epia MS uses a minimalistic I/O backplate and SODIMM memory for a slimmer form-factor, and is VIA's first mini-ITX board available with a fanless 1GHz Eden embedded processor.

Next-gen VIA mobo touts speed, security, MPEG-4 -- May 27, 2004 -- VIA will preview its next-generation mini-ITX board for the consumer electronics market at next week's Computex 2004 in Taipei. The EPIA SP features a new graphics and memory controller hub (GMCH) supporting faster front-side bus (FSB), memory, and southbridge interconnect speeds. It also features a C3 processor clocked at 1.3GHz, integrated PadLock Hardware Security Suite, and MPEG-4 acceleration.

Mini-ITX board boasts die-shrunk Pentium M -- May 25, 2004 -- Single-board computer vendor Lippert announced mini-ITX form-factor board support for Intel's new Dothan processor, a 90nm die-shrink of the Pentium M released today by Intel. The Dothan chip includes 170 million transistors, compared with 77 million on the previous Pentium M, making lots more room for on-chip memory caches, according to Lippert.

Centrino-like mini-ITX board available passively cooled -- Jan. 17, 2004 -- German single-board computer vendor Lippert is shipping a passively cooled version of its Centrino-like Thunderbird mini-ITX board based on an Intel Pentium M running at 1.3GHz. An actively cooled version running at 1.6GHz has been available since mid-December, 2003. Additionally, Lippert is readying a number of mini-PCI expansion devices and PCI riser cards for the boards.

Transmeta spins Crusoe-based mini-ITX mobo -- Jan. 07, 2004 -- Transmeta introduces two reference platforms to support device and system designs based on its Efficeon TM8600 and Crusoe TM5900 processors. Both platforms support Linux. Interestingly, the Crusoe TM5900 reference platform (pictured on the left) is implemented in the increasingly popular mini-ITX motherboard form-factor.

Mini-ITX P4M motherboard soars to 1700MHz and beyond -- Dec. 17, 2003 -- Taiwanese industrial computer board supplier Commell pushes the speed envelope for the compact mini-ITX mini motherboard form-factor, with the release of a mini-ITX board that supports Intel's mobile Pentium 4 processors at clock rates in excess of 1.7GHz.

Computing Client Development Center of Beijing launches low-end mini-ITX board for thin clients -- Dec. 11, 2003 -- The GSTB-3602 mini-ITX board and reference design kit is the very first product from Computing Client Development Center of Beijing, a joint venture between Advanced Micro Devices (AMD) and BLX IC Design Corp. Ltd.

First Pentium M based mini-ITX SBC runs Linux Sep. 03, 2003 -- Lippert GmbH introduces what is claimed to be the first mini-ITX form-factor motherboard to be based on an Intel Pentium M processor. The compact (6.7 x 6.7 in.) Thunderbird SBC features a Centrino-like architecture, with Intel northbridge and southbridge and a mini-PCI slot, and runs Linux, the company says.

2W ARM9-based mini-ITX board comes with Debian Linux -- Oct. 29, 2003 -- Simtec Electronics launches a mini-ITX based evaluation board that, in the highest specification of several available configurations, draws just 2 watts. The Simtec Samsung 2410 evaluation board is based on a Samsung S3C2410 ARM9 processor and is supplied with a Linux kernel, Debian cross-development environment, and several sample applications.

First mobile Pentium 4 mini-ITX SBC? -- Jun. 16, 2003 -- Commell announces what is claimed to be the first mini-ITX form-factor single-board computer (SBC) to be based on an Intel mobile Pentium 4 processor. Commell said its LV-670M SBC supports Linux and other embedded and desktop operating systems and targets VoD (video on demand), DVR (Digital Video Recorder), digital video broadcasting (DVB), streaming, surveillance, compression (MPEG), interactive servers, POS, Kiosk, ATM, Panel PC, transaction workstation, and terminal applications.

The joy of mini-ITX . . . -- Jun. 12, 2003 -- The Globe and Mail's "Chic Geek" Ian Johnson has discovered the mini-ITX motherboard form-factor, and he likes what he sees. In his article titled "Mini-ITX: Incredibly Tiny, eXceptionally cool," Johnson notes that "Mini-ITX motherboards are just starting to go mainstream, and they're real beauties if you want to save money and space. They're about the size of a CD jewel case and sell for between $75 and $200 (U.S.), depending on the speed of their built-in processor. All you have to do is add a case, memory and a hard disk, load an operating system and plug in a monitor, and you're off . . . "

MINI ITX

2007-05-31T11:51:00.001+06:00

Mini-ITX is an ultra-compact (6.7 x 6.7 in.) mainboard form-factor developed by Via Technologies Inc. Mini-ITX targets a new generation of quiet, small footprint, connected, information and entertainment systems and enables the creation of an exciting new generation of small, ergonomic, innovative, and affordable embedded systems through its high level of integration and vastly reduced size of less than 33% that of the FlexATX mainboard form-factor.

The mini-ITX form-factor, as originally defined by VIA

VIA launched mini-ITX as a way to showcase its inexpensive chipsets for computer hobbyists, but the form factor has since gone into many other embedded markets. Its success has brought a vast proliferation of cases, power supplies, slim-line drives, Flash-to-IDE adapters, and other handy computing components that have helped drive the form factor into applications such as living room PCs and commodity hardware-based dense computing applications.

Additionally, the charms of mini-ITX have not been lost on industrial board vendors such as Kontron and others. Of course, it's important to note that mini-ITX motherboards from industrial single-board computer (SBC) vendors typically offer thicker PCBs, more rugged designs, and better build quality, compared with mini-ITX boards aimed at the consumer market. They also have correspondingly higher prices and minimum order volumes.

Single Board Computer EBX

2007-05-31T11:45:00.001+06:00

The 5.75 x 8.0 in. Embedded Board eXpandable (EBX) specification, which was derived from Ampro's proprietary Little Board form-factor, resulted from a collaboration between Ampro and Motorola Computer Group.

As compared with PC/104 modules, these larger (but still reasonably embeddable) SBCs tend to have everything of a full PC on them, including application oriented interfaces like audio, analog, or digital I/O in many cases. Also it's much easier to fit Pentium CPUs -- whereas it's a tight squeeze (or expensive) to do so on a PC/104 SBC. Typically, EBX SBCs contain: the CPU; upgradeable RAM subassemblies (e.g. DIMM); Flash memory for solid state disk; multiple USB, serial, and parallel ports; onboard expansion via a PC/104 module stack; off-board expansion via ISA and/or PCI buses (from the PC/104 connectors); networking interface (typically Ethernet); and video (typically CRT, LCD, and TV).

Technical Seminar on Safety in Industrial Electrical Installation

2007-05-30T14:46:00.001+06:00

THE IESL Sri Lanka

Electrical and Electronics Engineering Sectional Committee

Wednesday-May 30, 2007
Technical Seminar
on
Safety in Industrial Electrical Installation

by,
Eng Nuwan Kumarasinghe, Electronic Eng, Dept of Meteorology
(Earthing Techniques in Lightning Protection Systems)

Eng Chula De Silva ,Charted Electrical Engineer, & past president IESL, Consultant, Risk Manager Delmadge Insuarance Brokers Pvt. Ltd.
(Electrical Safety and Insurance concern)

Mr S Sivapaskeran, Former Deputy Commissioner of labour & factory inspecting Engineer
(Industrial accidents caused by improper use of electricity & case studies)

15.00-18.00 hrs

Wimalasurendra Auditorium
The Institution of Engineers Sri Lanka
120/15,Wijerama Mawata, Colombo 07

Refreshments and Course materials will be provided

World's First Quad Core Processor

2007-05-29T09:42:00.000+06:00

Intel® Core™2 Quad processor

Intel’s most advanced processor just got an upgrade to the power of four—four processing cores for the ultimate in demanding entertainment

Up to 54% better performance for intense multimedia applications, streaming movies, music, and more with powerful Intel quad-core technology¹
Up to 53% better performance when enjoying immersive 3-D gaming²
Up to 79% faster performance for highly-threaded applications when creating multimedia and 3-D content³
Up to 8MB of L2 cache and 1066 MHz Front Side Bus for an unrivaled multitasking experience

Quad-Core Intel® Xeon® processor 5300 series

Breakthrough performance from the world's first quad-core processor for mainstream servers—faster, more powerful, and more efficient

Great performance with energy efficiency
Run applications with a smaller footprint
Up to 50% better performance than Dual-Core Intel® Xeon® processor 5100 series within the same power envelope^
Delivers the multitasking performance you need to maximize your virtualization efforts—enabling your enterprise applications to be responsive, even as you consolidate server resources

Intel® Core™2 Extreme quad-core processor

The world's best desktop processor for multimedia applications and the first to quad-core∇

Up to 80% faster performance for highly-threaded appsΩ
Four processing cores to handle massive throughput
Based on leading Intel® Core™ microarchitecture, industry-first 8MB total cache

Extracted from www.intel.com

Supported Chipsets

2007-05-24T12:05:00.000+06:00

These types will achive the best with latest intel processors (LGA775)

Intel: 865PE/G/GV/G, 945P/PL/G/GZ/GC, P65P/G, 975X, P/G/Q965, Q963, 946GZ/PL; X/P/G/Q 3x
NVIDIA: nForce4 Ultra/SLI X16 for Intel, nForce 570/590 SLI for Intel and nForce 650i Ultra/650i SLI/680i SLI.
VIA: P4M800, P4M800PRO, P4M890, P4M900, PT880 Pro/Ultra, PT890.
SiS: SiS662
ATI: Radeon Xpress 200 and CrossFire Xpress 3200 for Intel

These mails are the updates of http://www.samitharansara.blogspot.com

Intel Rocks with Penryn

2007-05-24T11:33:00.000+06:00

Penryn is the code name for Intel’s Next Generation Intel® Core™ 2 Family processor micro architecture. It is also the name of the industry’s first 45 nm microprocessor. It is an improvement on the Core Micro architecture introduced last year. It delivers more performance at the same clock speed compared to our Core 2 Duo processors.

It is a dual core product with a shared 6 MB L2 cache.

Intel’s 45 nm (65 nm-60 nm in Pentium IV Family) High-K Metal Gate Silicon Technology allows Penryn to run at higher clock frequency than its predecessor. It features 47 new Intel SSE instructions designed to enhance Media, Graphic and Gaming. We have measured >20% performance improvement on existing games compared to today’s fastest dual core processors, and more than 40 percent for gaming and video encoding with Intel SSE4 optimized video encoders. But of course, as with any performance claims “Your Mileage May Vary”.

Penryn-based processors provide faster divide performance with a Fast Radix-16 Divider, roughly doubling the divider speed over previous generations for applications such as scientific computation.

Up to 6MB of L2 cache per die (50% larger) enables greater performance across workloads; and increased associativity ( 16 way to 24 way) improves the utilization of the larger cache.

All of this fits in a compact 107 mm2 die featuring 410 million transistors!

The Penryn family enables optimized products for each of the target market segments from the high end Xeon all the way to mobile.

It will enable mobile optimized processors that provide greater performance within the existing mobile form factors and support lower processor idle power with Deep Power Down Technology. It also supports increased performance on single threaded apps with Enhanced Dynamic Acceleration Technology, which uses the power headroom of an idle core to boost performance of the non-idle core.

For the Desktop, there will be two versions that will ship at greater than 3GHz. A second generation Quad-core with up to 12 MB of L2 cache that will fit into existing QC power envelopes, and an energy efficient dual-core version with up to 6MB of L2 cache that will maintain the 65 W envelope.

For the Server and Workstation segment, the Penryn family will extend the leadership that the Xeon Processor family delivers today with dual and quad core products.This expect the combination of new 1600 MHz FSB for HPC segments, >3 GHz clock speed, microarchitecture enhancements and larger caches to deliver up to 45% improvement on bandwidth intensive floating point workloads compared to today’s fastest quad core processors. Some Java workloads exhibit up to 25 percent increase.

Source: Intel Tech Blog

Membership Functions

2007-05-24T11:24:00.000+06:00

The membership function is a graphical representation of the magnitude of participation of each input. It associates a weighting with each of the inputs that are processed, define functional overlap between inputs, and ultimately determines an output response. The rules use the input membership values as weighting factors to determine their influence on the fuzzy output sets of the final output conclusion. Once the functions are inferred, scaled, and combined, they are defuzzified into a crisp output which drives the system. There are different membership functions associated with each input and output response. Some features to note are:

SHAPE - triangular is common, but bell, trapezoidal, haversine and, exponential have been used. More complex functions are possible but require greater computing overhead to implement.. HEIGHT or magnitude (usually normalized to 1) WIDTH (of the base of function), SHOULDERING (locks height at maximum if an outer function. Shouldered functions evaluate as 1.0 past their center) CENTER points (center of the member function shape) OVERLAP (N&Z, Z&P, typically about 50% of width but can be less).

Figure 5 - The features of a membership function

Figure 5 illustrates the features of the triangular membership function which is used in this example because of its mathematical simplicity. Other shapes can be used but the triangular shape lends itself to this illustration.

The degree of membership (DOM) is determined by plugging the selected input parameter (error or error-dot) into the horizontal axis and projecting vertically to the upper boundary of the membership function(s).

Figure 6 - A sample case

In Figure 6, consider an "error" of -1.0 and an "error-dot" of +2.5. These particular input conditions indicate that the feedback has exceeded the command and is still increasing.

ERROR & ERROR-DOT FUNCTION MEMBERSHIP

The degree of membership for an "error" of -1.0 projects up to the middle of the overlapping part of the "negative" and "zero" function so the result is "negative" membership = 0.5 and "zero" membership = 0.5. Only rules associated with "negative" & "zero" error will actually apply to the output response. This selects only the left and middle columns of the rule matrix.

For an "error-dot" of +2.5, a "zero" and "positive" membership of 0.5 is indicated. This selects the middle and bottom rows of the rule matrix. By overlaying the two regions of the rule matrix, it can be seen that only the rules in the 2-by-2 square in the lower left corner (rules 4,5,7,8) of the rules matrix will generate non-zero output conclusions. The others have a zero weighting due to the logical AND in the rules.

from
http://www.seattlerobotics.org

Why Use Fuzzy Logic ?

2007-05-23T11:20:00.000+06:00

Why Use Fuzzy Logic?Here is a list of general observations about fuzzy logic:

Fuzzy logic is conceptually easy to understand.
The mathematical concepts behind fuzzy reasoning are very simple.
What makes fuzzy nice is the "naturalness" of its approach and not its far-reaching complexity. Fuzzy logic is flexible.
With any given system, it's easy to massage it or layer more functionality on top of it without starting again from scratch.
Fuzzy logic is tolerant of imprecise data.
Everything is imprecise if you look closely enough, but more than that, most things are imprecise even on careful inspection.
Fuzzy reasoning builds this understanding into the process rather than tacking it onto the end. Fuzzy logic can model nonlinear functions of arbitrary complexity. You can create a fuzzy system to match any set of input-output data.
This process is made particularly easy by adaptive techniques like ANFIS (Adaptive Neuro-Fuzzy Inference Systems). Fuzzy logic can be built on top of the experience of experts. In direct contrast to neural networks, which take training data and generate opaque, impenetrable models, fuzzy logic lets you rely on the experience of people who already understand your system. Fuzzy logic can be blended with conventional control techniques.
Fuzzy systems don't necessarily replace conventional control methods. In many cases fuzzy systems augment them and simplify their implementation. Fuzzy logic is based on natural language.
The basis for fuzzy logic is the basis for human communication. This observation underpins many of the other statements about fuzzy logic. The last statement is perhaps the most important one and deserves more discussion. Natural language, that which is used by ordinary people on a daily basis, has been shaped by thousands of years of human history to be convenient and efficient.
Sentences written in ordinary language represent a triumph of efficient communication. We are generally unaware of this because ordinary language is, of course, something we use every day. Since fuzzy logic is built atop the structures of qualitative description used in everyday language, fuzzy logic is easy to use.

Extracted from a Mathworks Article.

Unmanned Surface vehicles

2007-05-23T08:47:00.000+06:00

USVs will be equipped with:

Sensor-based situation awareness
Dynamic route planning
Harbor and sea navigation, docking, evasive maneuvers
Dynamic reconfiguration and management of systems & resource

Possible USV missions include:
Persistent Intelligence Surveillance and Reconnaissance (using radar, EO/IR, SIGINT, CBN)
Port & border security
Special Ops support
Autonomous search & rescue
Communications relay (space, air, surface, special operations support; underwater)
Maritime protection: anti-submarine, sea-skim missile, small boat Improvised Explosive Devices (IED)
Track & trail
Ice patrol
Interdiction
Force Protection
Mine Detection and Neutralization
Search and Recovery
Forward Reconnaissance

Project to Refine a Prototype Unmanned, Tethered ADCP Platform for Measuring Streamflow

2007-05-21T20:54:00.000+06:00

The Indiana District office developed a prototype tethered platform for making ADCP measurements from bridges and other structures.This prototype has been used successfully by a number of USGS district offices. The Kentucky District office also had developed a remote-controlled boat for conducting bridge-scour investigations. The Texas District office and the Corps of Engineers built remote-controlled boats based on the Kentucky design. Both of these platforms have invited much interest in the USGS because of the potential they offer in reducing exposure to hazards, particularly during streamgaging activities.

At the request of the USGS Chief Hydrologist, the Office of Surface Water Hydroacoustics Workgroup prepared a proposal for refining the design of the tethered and remote boats. This proposal was submitted to the USGS Instrumentation Committee (ICOM) and was funded.

The primary objective of the project is to develop and test designs for tethered and remote-controlled boats for increasing safety during streamgaging activities. The project included the following major tasks:

develop specifications based on a survey of user needs;
investigate various models of radio modems for wireless data telemetry;
investigate commercial availability of boat hulls;
test and evaluate prototype hulls;
make designs available to USGS district offices.

Development of Specifications:

A written survey of user needs was sent to all USGS district offices and to other federal agencies known to use ADCP's. The survey asked users to specify desired features such as maximum boat length and weight.

Based on the 30 responses received, the following specifications were developed for a tethered platform:

maximum weight with payload: 40 pounds;
maximum length: 5 feet; maximum beam: 3 feet;
maximum water velocity of rivers where the platform would be used: 12 feet per second;
minimum acceptable time between battery replacement or recharge: 2 hours.

Investigation of various models of radio modems for wireless data telemetry:

To safely and efficiently acquire ADCP data from a tethered platform, data needed to be wirelessly transmitted from the ADCP to a laptop computer. It had previously been determined that a 900-MHz spread spectrum data modem could be used for this purpose. Approval from the USGS Water Resources Division radio liaison was obtained to use radios operating in the 900-MHz frequency range if the radios are license free under Part 15 of the FCC code. To use a licensed frequency in a government band will probably take 2 years (1 year for radio certification and 1 year for frequency assignment). However, the method used in initializing communication between the acquisition software and the ADCP caused limited compatibility with most wireless modems. After the problem was discussed with the manufacturer of the ADCP (RD Instruments), an alternate initialization method was implemented in the latest versions of Rio Grande firmware (10.07 and greater) and latest version of data-acquisition software (WinRiver 10.00).

A list of desired features then was developed for the radio modems. The desired features included

reliably communicate with the ADCP, using the ADCP data-acquisition software provided by the manufacturer;
have rugged, environmental housing;
operate on 12-volt DC power; and,
have 115,200-baud data-communication capability with the ADCP to maximize data throughput.

For a complete list of modems tested and for information on using radio modems with ADCP's, please see Use of Radio Modems with Acoustic Doppler Current Profilers.

Currently, the Freewave Model DGR-115 is the only modem tested that has met all of the desired specifications. More modems may be evaluated as they are made available for testing.

Investigation and testing of hull designs:

A review of possible off-the-shelf products that could easily be modified to meet the specifications was completed. Boat-builder literature, marine-supply catalogs, and the Internet were used in the literature search for off-the-shelf products. The research resulted in the purchase of a small, plastic catamaran designed to float a single person. The catamaran was modified for use with an ADCP and tested.

Hobie Floatcat modified for use with Rio Grande ADCP.

Discharge measurements in the field were completed to test this platform. The field tests revealed some major deficiencies: the platform exceeded the design-specification weight limit; the platform was difficult to control in the water; and the platform did not readily orient itself with the flow. These operational deficiencies were primarily a result of trying to apply a product designed for slow propulsion on a lake to use in faster river velocities. Recognizing these deficiencies led to having hulls built specifically for the tethered-platform application.

Private vendors were commissioned to construct prototype hulls specifically designed for making ADCP discharge measurements. The hulls acquired from the vendors for testing included two catamaran designs, two mono-hull designs, and three trimaran designs. The hull testing included tow-tank tests preformed at the USGS Hydraulics Laboratory at Stennis Space Center and field tests in which the platforms were used to make ADCP discharge measurements over varying flow conditions.

Field tests of the platforms included testing below a U.S. Army Corps of Engineers (USACE) Reservoir. The USACE increased the release of water from the reservoir during the testing to create higher flow conditions with velocities up to 7 ft/sec. During these tests, each platform was fitted with an RD Instruments Rio Grande ADCP and wireless 900-MHz spread spectrum modems. ADCP data were acquired using RD Instruments WinRiver software.

Field testing some platforms.

For the tow-tank tests, each platform tested was fitted with an RD Instruments Rio Grande ADCP and towed the length of the tank at varying speeds. Drag was measured for each platform with a strain-gage meter, which measured the force on the towrope. The drag each platform produced while being towed was recorded. The platforms were towed through the tank at speeds varying from 1 to 12 ft/sec to simulate the desired flow rates in which the platform might be used. During some of the tow-tank tests, wireless 900-MHz spread spectrum modems were used to acquire ADCP data that included the pitch and roll of the ADCP.

Platforms ready for testing at the USGS Hydraulics Lab.

Brief description of platforms tested:

Catamaran #1 is the original prototype catamaran platform as designed by the Indiana District office. This platform is constructed of polystyrene-foam floats built from a composite of several layers of 2-inch-thick standard insulation cut into a semi-vee shape.

Catamaran #2 is a catamaran platform built by Wanamaker Pontoon and Paddle Company. This platform is constructed of molded ABS plastic and is close in size and hull shape to the original prototype platform (Catamaran #1).

Catamaran #3 is a catamaran platform built by The OceanScience Group. This platform is constructed of shaped foam covered in a thin layer of fiberglass.

The OceanScience Group built all three trimaran platforms. All of the trimarans had large center hulls with small outriggers. The same outriggers were used on all three platforms. The outriggers were constructed of molded fiberglass. The center hull for Trimaran #1 was constructed of shaped foam covered in a thin layer of fiberglass. The fore and aft of this hull were symmetrical, coming to a thin edge at the ends of the hull. The center hull for Trimaran #2 was constructed of molded fiberglass and had more of a wedge or triangle shape. Trimaran #3's center hull was constructed of molded fiberglass and was longer than the center hull of Trimaran #2.

Mono-hull #1 was a single-hull platform built by Kann Marine. The platform was constructed of aluminum and had a flat-bottom-hull design with three fins on the bottom of the hull for added directional stability.

Mono-hull #2 was a single-hull platform built by The OceanScience Group. This platform was constructed of fiberglass with a vee-shaped-hull design and two fins on the bottom of the hull for added directional stability.

Summary of test results:

The results of the testing indicate that while any of the designs could be used under certain conditions, the best all-around performance under a range of conditions resulted from the trimaran designs.

The ADCP was mounted in the hull of the mono-hull platforms. The vee-shaped mono-hull platform (Mono-hull #2) performed well in the drag test (Table 1) but stability results were less than optimal. Both mono-hull platforms had more erratic motion and were more sensitive to flow disturbances or turbulence in the water than the other platform designs.

The ADCP was mounted between the two hulls of the catamaran platforms. A higher drag resulted at higher velocities when compared to the mono-hull designs (Table 1) because of the shape of the ADCP. The catamaran platforms were more stable than the mono-hull platforms.

The ADCP was mounted in the center hull of the trimaran platforms. The trimaran platforms had lower drag while still retaining the stability of the catamaran designs (Table 1). The trimaran's advantage is realized by combining the drag efficiency gained by placing the ADCP in a hull with two outer hulls that give added stability. Placing the ADCP in a hull also has the observed advantage of lowering the flow disturbance around the head of the ADCP.

Current testing and evaluation has focused on platforms with an RD Instruments profiler because 95 percent of the profilers in use by USGS for streamgaging are RD Instruments units. Sontek also manufactures an acoustic Doppler profiler (ADP) designed to make moving-boat discharge measurements. Similar results are expected with the Sontek units when used with the tested platforms, except that the overall drag may be less for the smaller size ADP's. If funding is available, additional testing of such units may be done.

Also, it is recognized that other brands or models of river-discharge-measurement devices that can use a tethered platform may become available. Current tethered-platform designs may need slight modifications in order to be used with new devices, or new tethered-platform designs may be more desirable.

Platforms available for purchasing:

The OceanScience Group, the manufacturer of the three trimaran platforms tested, has indicated that they will begin production of a fiberglass trimaran platform by the first quarter of 2001. This platform will be based upon the trimaran prototypes tested and specifically will be designed for use as a tethered platform for use with a Rio Grande ADCP. The center hull of the trimaran will have access ports where a wireless modem and a 12-volt battery used for powering the ADCP and the modem will be housed. OceanScience Tethered Boat Pictures.

Wanamaker Pontoon and Paddle Company, the manufacturer of Catamaran #2, has indicated that they are beginning production of a molded ABS plastic catamaran platform. This platform will be based upon the design tested and specifically will be designed for use with a Rio Grande ADCP. The two hulls will have access ports where a wireless modem and a 12-volt battery used for powering the ADCP and modem will be housed. While the catamaran design has higher drag, it should prove to be a good low-cost alternative for use in conditions with velocities below 6 ft/sec.

Sontek offers a catamaran system designed for use with their Mini-ADP. This package includes an aluminum catamaran-type platform and wireless modems. The Sontek platform has not yet been tested as part of this project.

Copyright Content of
http://in.water.usgs.gov/hydroacoustics/tetheredproject.shtml

Nostradamus

2007-03-27T17:02:00.000+06:00

Nostradamus

Nostradamus - Wikipedia, the free encyclopedia

2007-03-27T17:01:00.000+06:00

Nostradamus - Wikipedia, the free encyclopedia

Dead reckoning - Wikipedia, the free encyclopedia

2007-03-27T16:57:00.000+06:00

Dead reckoning - Wikipedia, the free encyclopedia

IEEE SMC

2007-03-17T11:00:00.001+06:00

Actually, I'm preparing a research paper nowadays about collision avoidance of smart vehicles, and hope to publish it to IEEE SMC conference 2007..

Cruise control from Wiki

2007-03-17T11:00:00.000+06:00

Amazing Media Browser | Firefox Add-ons | Mozilla Corporation

2007-01-26T12:26:00.000+06:00

This is a useful firefox extension that you can download embeded media objects to your local HDD.
enjoy it..................
Amazing Media Browser | Firefox Add-ons | Mozilla Corporation

Lightning protection to BS 6651

2007-01-23T11:56:00.000+06:00

Furse Lightning Protection Schemes

Furse | Earthing & Lightning Protection | Lightning protection to BS 6651

Prisma Architectural Lighting - Download

2007-01-23T09:40:00.000+06:00

Prisma Lighting Catalogus

Prisma Architectural Lighting - Download

Harger Lightning & Grounding

2007-01-22T19:42:00.000+06:00

Harger Lightning & Grounding

Nec Regulations, Lightning Protection

2007-01-22T18:19:00.000+06:00

Fundamentals of Lightning Protection - National Lightning Safety Institute

2007-01-22T18:18:00.000+06:00

Fundamentals of Lightning Protection - National Lightning Safety Institute

Web and Mobile messenger everywhere - eBuddy former e-messenger

2007-01-22T17:34:00.000+06:00

Web and Mobile messenger everywhere - eBuddy former e-messenger

Free Touch Typing Tutor

2007-01-17T11:53:00.000+06:00

Got a free touch typing tutor, made by Macromedia flash.
The Link is
http://www.sense-lang.org/typing/Sense.exe

Blog Editor

2007-01-11T14:39:00.000+06:00

I try to find a good offline blog editor, but not yet suceeded.

Piumal's Account Info.

2006-12-28T09:58:00.001+06:00

These are the information of personal account of Piumal Gunawardana.

Name: P.A. Gunawardana
Account No: 1700833
Bank Of Ceylon Matara Super Grade Branch

Palm Jumeirah

2006-12-27T14:03:00.000+06:00

This is a project done by SNK [The trainig place of me], in saudi Arabia, all the electrical and mechanical works done by SNK. The owner is AL Nakeel investment Ltd. and the main contractor is Thai Se.

Chat Room

2006-12-27T11:49:00.000+06:00

I'm trying to find a free presonel chat room to keep in touch with my friends. If anyone know a resource please be kind enough to send it to my mail. Yahoo ID is samitharansara

Please help this budding engineer to save his life

2006-12-26T14:46:00.001+06:00

A kind Request

Dear Sir/ Madame,

Piyumal Gunawardane is a third year student at the Department of Mechanical Engineering, University of Moratuwa . Currently he is suffering from a severe throat / tongue cancer, and requires immediate surgery at Gleneagles Hospital, Singapore in order to save his life. The past few months of this young boy were spent at Karapitiya Hospital where he underwent most painful radiotherapy treatments. Then he was taken to India for a surgery at the Apollo hospital, but had to return unfortunately without undergoing the surgery.

At the moment he is undergoing chemotherapy in Singapore which will cost nearly 2 million Sri Lankan rupees. This will be followed by a surgery which is estimated to cost 4.5 Million Sri Lankan rupees, which is an amount that the boy's family can only dream to afford, his father being a retired station master and his mother being a teacher.

Piyumal was a bright student at his alma mater, Rahula College , passing out with flying colours at the G.C.E., A/L examination, 2003, when he was placed 2^nd in the Matara district in the math stream. Had fate not been thus cruel on him, he would have had a normal life that we all take so much for granted.

We would be much obliged to you if you could donate some money to save this bright young boy's life, this budding engineer's life, to help him fight the cruelty of fate with the goodness of humanity.

Please forward your donations to

Account No. 1661497 – Bank of Ceylon , Bazaar Branch, Matara.

Name: M.A. Gunawardane (Father).

You may contact Piyumal's family on 041-2228595.

In case if you need any medical records of Piyumal's ailment please do mail to help_piyumal@yahoo.com or amila_maha@yahoo.com

Yours sincerely,

Piyumal's friends at the university.

Use your Left ear....

2006-12-26T14:34:00.000+06:00

Click on the image to see in large scale...
Please use ur left ear when using a mobile.

Created ....!!!!

2006-12-26T14:05:00.000+06:00

Hi All,
Anyway, I'm start my blog. Hope to update it continously.