فيزياء « WordPress.com Tag Feed

الفيزياو ،، عجاوب (4) + منوعات صورية ،!

عبد المجيد — Sat, 30 Aug 2008 14:59:10 +0000

الواو مقصودة في العنوان ،، كنوع من التغيير ،،

طيب نعود مجدداً لفيديوهات الفيزيكس المريرة دراسياً اللذيذة حياتياً وتطبيقياً ،،

وبصراحة اشتهيت أحطها لعيون عمنا عابر سبيل لأنه سبق وأن أعجبته السلسلة ،، ( شوفو الناس الي تقدر ،، موب ربعنا ما عندهم إلا التحطيم ،، زي واحد من الشباب يتطنز على المدونة ،، يقول ليه تحط مرئيات وفيزياويات كلهم سواء ،، قلت له افتح مدونة وحط فيها الي تبي طال عمرك ،، ولا يابو عامر ؟؟ وتراي ما أقصدك ،، ويبدو أني طولتها بهالاستطراد ،، خل أسكر القوس أصرف ) ،،

بصراحة ما عندي أي معلومة عن هالمقطع باستثناء أن هذا عمل الموجات الصوتية ،، أي أنها هي التي تشكل البودرة ،، أو بالأصح ،، البودرة تجعل الموجات الصوتية مرئية تقريباً ،،

10110101001101011000101101001010101010110

مجموعة أخرى من الصور بمساعدة تولبار صديقي العزيز StumpleUpon ،، ينفع للي ما عنده شغلة ولا مشغلة ومب عارف يخلص رواياته ،،

10110101001101011000101101001010101010110

صورة لذيذة جداً ،، حسستني بالبرودة من مشاهدتها فقط ،، آخ أبي أيسكريم ،،

10110101001101011000101101001010101010110

خشو هنا ولن تندموا ،، صورة سمائية لناطحة السحاب "برج دبي" ،، بصراحة بعد التدقيق شكيت أن الصورة بالكمبيوتر ،،

10110101001101011000101101001010101010110

بالله هذا وجه ولا مشغل نسائي ؟؟ لكن الألوان رهيبة ،،

10110101001101011000101101001010101010110

يالله فتكوا بعافية على قولة العم مراد الله يحفظه مع أني كنت أقولها قبله لكن الشكوى لله ،،

8) ،،

Final Round ،!

عبد المجيد — Tue, 17 Jun 2008 11:37:14 +0000

،،

TOP OF THE WORLD

بكر التميمي — Sun, 04 May 2008 07:06:42 +0000

قمّة برج دبي

أعلى نقطة بناها الإنسان على كوكب الأرض

ربما يجب إعادة كتابة كتب الجامعات في مساقات الهندسة الكهربائية والفيزياء، بسبب إختراع المتفطّنات

بكر التميمي — Thu, 01 May 2008 09:38:43 +0000

المتفطّنات هي النوع الأساسي الرابع من انواع الدارات الكهرابائية الأساسية، ويأتي ترتيب المتفطّنات بعد المقاومات، والمكثّفات، والموصلات. والمتفطّنات كانت موجودة نظرياً على الأقل ، ومشار إليها في أبحاث علمية منذ سنة 1970، غير أن أحداً لم يتمكن من صنعها و إخراجها إلى حيز التطبيق حتى اليوم، حيث تمكن فريق عمل في شركة HP من إنتاجها

ولقد تمكّن الفريق من إنتاجها بواسطة تمرير تيار كهربي في شريحة رقيقة جداّ مغطّاة بطبقة من ثاني اكسيد التيتانيوم في المستوى الثاني ، حيث تتغير شدة مقاومة الشريحة بعد أن يمر فيها التيار، حسب شدة التيار، مما يعني أن الفيزياء و الهندسة الكهربائية مدعوتين اليوم إلى إعادة صياغة كافة الكتب والمراجع حيث تفرض هذه المتفطّنات نفسها على كل شيء

وسوف ينتج عن إكتشاف وإختراع المتفطّنات منتجات ودوائر كهربائية وأجهزة و معدّات جديدة لم يسبق حتى اليوم لأحد أن تخيّلها، وسوف ينتج عنها قوانين جديدية لم يسبق لأحد أن طبّقها

وسوف نرى !

PORTLAND, Ore. — The long-sought after memristor--the "missing link" in electronic circuit theory--has been invented by Hewlett Packard Senior Fellow R. Stanley Williams at HP Labs (Palo Alto, Calif.) Memristors--the fourth passive component type after resistors, capacitors and inductors--were postulated in a seminal 1971 paper in the IEEE Transactions on Circuit Theory by professor Leon Chua at the University of California (Berkeley), but their first realization was just announced today by HP. According to Williams and Chua, now virtually every electronics textbook will have to be revised to include the memristor and the new paradigm it represents for electronic circuit theory.

"My situation was similar to that of the Russian chemist Dmitri Mendeleev who invented the periodic table in 1869," said Chua. "Mendeleev postulated that there were elements missing from the table, and now all those elements have been found. Likewise, Stanley Williams at HP Labs has now found the first example of the missing memristor circuit element."

When Chua wrote his seminal paper, he used mathematics to deduce the existence of a fourth circuit element type after resistors, capacitors and inductors, which he called a memristor, because it "remembers" changes in the current passing through it by changing its resistance. Now HP claims to have discovered the first instance of a memristor, which it created with a bi-level titanium dioxide thin-film that changes its resistance when current passes through it.

"This new circuit element solves many problems with circuitry today--since it improves in performance as you scale it down to smaller and smaller sizes," said Chua. "Memristors will enable very small nanoscale devices to be made without generating all the excess heat that scaling down transistors is causing today."

HP has already tested the material in its ultra-high-density crossbar switches, which use nanowires to pack a record 100 Gbits onto a single die--compared with 16 Gbits for the highest density flash memory chips extant.

"We have been looking for years for the best material to use in our ultra-dense nanowire crossbar switches, which can fit 100 billion crossbars into a square centimeter. What we have finally realized is that the ideal material is a memristor," said Williams, primary inventor of the memristor's titanium-dioxide-based material and founding director of HP's 12-year-old Information and Quantum Systems Lab, where his team perfected its formulation.

The hold-up over the last 37 years, according to professor Chua, has been a misconception that has pervaded electronic circuit theory. That misconception is that the fundamental relationship in passive circuitry is between voltage and charge. What the researchers contend is that the fundamental relationship is actually between changes-in-voltage, or flux, and charge. Such is the insight that enabled HP to invent the memristor, according to Chua and Williams.

"Electronic theorists have been using the wrong pair of variables all these years--voltage and charge. The missing part of electronic theory was that the fundamental pair of variables is flux and charge," said Chua. "The situation is analogous to what is called "Aristotle's Law of Motion, which was wrong, because he said that force must be proportional to velocity. That misled people for 2000 years until Newton came along and pointed out that Aristotle was using the wrong variables. Newton said that force is proportional to acceleration--the change in velocity. This is exactly the situation with electronic circuit theory today. All electronic textbooks have been teaching using the wrong variables--voltage and charge--explaining away inaccuracies as anomalies. What they should have been teaching is the relationship between changes in voltage, or flux, and charge."

HP invited Chua to speak about his theory a few years ago, but at that time the lab did not tell Chua that they were actively seeking the memristor. Only two weeks ago did Williams tell Chua that he had used the proper variables--flux and charge--to invent the world's first working memristor.

A memristor works by virtue of hysteresis, whereby its rate of change accelerates as it moves from one state to the other--"on" to "off," or vice versa. Hysteresis has been explained away by current circuit theory as an anomaly, according to Chua and Williams, whereas its existence is, in fact, a fundamental property of passive circuitry.

"Hysteresis is a tell-tale manifestation of the fourth circuit element--the memristor," said Chua. "And Stan Williams is very smart to have realized that if you cannot explain something properly, then there must be a better explanation."

For instance, electrical engineers have known that titanium dioxide changes its resistance in the presence of oxygen--this is the principle behind titanium dioxide oxygen sensors--but they could not explain why.

"They traced its curve, and knew it contained hysteresis, but because they could not explain it, they could only design the simplest of devices using it--sensors," said Chua. "But now that it has been explained, they will be able to design all types of new circuitry using it. This is a wonderful development."

Chua predicts that electrical engineers will soon begin discovering all types of new materials that manifest the hysteresis relationship between flux and charge. He predicts that this new era of electronics will be able to solve the problems with scaling--such as using too much power and generating too much heat--that are currently plaguing progress in circuit design.

"The memristor is our salvation, because it works better and better as you make it smaller and smaller," said Chua. "The era of nanoscale electronics will be enabled by the memristor. This is not just an invention, it is a basic scientific discovery. It has always been there--we just had to face these nanoscale problems to realize its importance."

The memristor behaves like a non-linear resistor with memory--a small, compact and highly energy-efficient means of creating a memory device. But Chua and Williams claim it is also a new type of circuit element that should enable the creation of new devices never before imagined.

The world's first memristor invented at HP Labs by Williams and his research team is based on a two-layer sandwich of titanium dioxide films. As a memory element, it works by changing the atomic structure of the films--by coupling the motion of atoms in the material with the movement of electrons through the material. The bottom layer of HP's material uses a symmetrical lattice of titanium atoms and oxygen atoms, which makes it a good insulator. But the top layer has had oxygen vacancies introduced as a dopant, which makes it into a good conductor--the more vacancies, the more conductive. HP's secret sauce for creating these oxygen vacancies in titanium dioxide involves using sputter deposition that begins with an excess of oxygen, then cuts back on the oxygen flow to create the layer with vacancies.

By placing the crossbar of nanowires above and below the sandwiched layers, charge can be passed through the material. "The way I discovered the material for our memristor was by studying how titanium dioxide oxygen sensors work--that got me thinking about moving oxygen vacancies around in the material to create a memristor," said Williams. "By running current through the device, we can push oxygen vacancies from the layer that has them into the layer that does not, thereby changing its resistance by a factor of 1000 or even more, thus switching the memristor 'on,' then by reversing the current we can move the vacancies back into the first layer, thereby switching the memristor 'off'."

As Chua predicted, Williams is already thinking about creating new types of devices with HP's crossbar architecture beyond a simple memory device. "If we push current through it hard and fast, it acts like a digital device, but if we run current through it gently and slowly it acts as an analog device," said Williams. "We are already designing new types of circuits in both the digital and analog domains using our crossbar architecture. In the analog domain, we want to build memristor-based devices that operate in a manner similar to how the synapse works in the brain--neuron-like analog computational elements that could perform control functions where decisions must be made involving comparisons as to whether something is larger or smaller than something else. We are not building a neural network yet, but we think that using the memristor in its analog mode with our crossbar is a pretty good representation of a neural net."

Later in 2008, HP promises to begin releasing details of how its memristor material works with its already perfected nanoscale crossbar switch architecture in these various types of circuits.

"The memristor is not just a replacement technology for existing memory devices, but will be used to make a whole range of new types of devices that no one has ever thought of before," said Williams.

فيزياء (تقويم - 4)

aDMiN — Sat, 26 Apr 2008 08:15:16 +0000

بعد غياب نعود بأول تدوينة في مادة الفيزياء ، بتمرين واحد في الكيمياء حول التركيز المولي ...

يشكل نقص المغنزيوم عند كثير من الناس مرضا خطيرا يؤدي إلى ضعف كبير، و لمعالجة ذلك نحقن المرضى بمحلول كلور المغنزيوم (Mg²⁺2Cl) حيث نأخذ محلولا إبتدائيا تركيزه المولي 10mol/l و نريد تحضير حقنة سعتها 100mL للمحلول السابق تركيزه 0.1mol/l

ماذا نسمي هذه العملية؟
أحسب معامل التمديد.
أحسب حجم المحلول الإبتدائي الواجب إستعماله.
إشرح باختصار الطريقة المتبعة لتحضير المحلول.
إستنتج كتلة (MgCl₂) الصلب المذابة في هذه الكمية (100mL).

يعطى

Cl = 35.5g/mol
Mg = 24g/mol

تحميل نسخة WORD

فيزياء (تقويم - 3)

aDMiN — Thu, 28 Feb 2008 21:07:43 +0000

تابع قراءة التدوينة لتطالع ثالث تقويم لمدونتنا في مادة العلوم الفيزيائية ، كالعادة تمرينين في الفيزياء و آخر في في الكيمياء ...

الفيزياء

التمرين الأول
نقذف من نقطة 0 شاقوليا كرة نحو الأعلى بسرعة إبتدائية . يمثل البيان التالي مخطط سرعتها خلال حركتها:

أنسب كل بيان إلى مرحلته مع التعليل
في أية لحظة تنعدم سرعة الكرية و في أية لحظة تصطدم بالأرض
ما هي سرعتها لحظة اصطدامها بالأرض ؟ ماذا تلاحظ
أحسب المسافة المقطوعة أثناء الحركة

إعتمادا على البيان أكمل الجدول التالي:

	M0	M1	M2	M3	M4	M5	M6	M7	M8
T(s)	0	2	4	6	8	10	12	14	16
ΔV(m/s)
V(m/s)

أرسم في المجال الزمني مخطط تغير السرعة ΔV = f(t).

التمرين الثاني
تسلك سيارة مسارا ABC بسرعة ثابتة كما هو موضح في الشكل التالي:

مثل على كل جزء القوى المؤثرة عليها ؟ هل مبدأ العطالة محقق على كل جزء ؟

الكيمياء

تعطى العناصر: 19K ، 17Cl ، I ، Br.

(مع مراعاة أن الرقم على اليسار يمثل العدد الذري للعنصر الكيميائي)

أعط البنية الإلكترونية لكل من Cl و K ثم استنتج موقع كل منهما في الجدول الدوري مع تحديد العائلة الكيميائية لكل واحد
يقع العنصران I و Br في نفس العمود الذي يقع فيه عنصر الكلور، لماذا ؟ ماذا نسمي هذه العائلة و ما هو سلوكها الكيميائي أثناء التحولات الكيميائية ؟
ما هي الشوارد المتحصل عليها من الذرات السابقة ؟
يتكون البروم الطبيعي من النظيرين Br79 بنسبة 50.6% و Br81 بنسبة 49.4% ، هل النظيران يقعان في نفس الموقع من الجدول الدوري ؟
يمكن لمجموعة الهالوجينات السابقة أن تتفاعل مع البوتاسيوم، ما هي الصيغة الشاردية لكل مركب من المركبات الناتجة عن هذا التفاعل

تحميل نسخة WORD

فيزياء (تقويم - 2)

aDMiN — Wed, 27 Feb 2008 21:30:00 +0000

تابع قراءة التدوينة لتطالع إختبار الفصل الثاني في مادة العلوم الفيزيائية لثانوية كاتب ياسين ( تم إعادة كتابته إلكترونيا ) ، الإختبار يشمل الكيمياء بتمرين واحد ، أما الفيزياء بتمرينين

الكيمياء

1. من بين العناصر الكيميائية التالية: 18Ar ، 17Cl ، 16S ، 12Mg ، 5B ، 3Li

(مع مراعاة أن الرقم على اليسار يمثل العدد الذري للعنصر الكيميائي)

أي منها ينتمي إلى السطر 3 و العمود 2 ؟ ماذل تعني كلمة رقم السطر و رقم العمود في الجدول الدوري للعناصر
ما هي الشاردة التي يمكن أن تعطيها ذرة هذا العنصر الكيميائي ؟
2. تتفاعل ذرة هذا العنصر الكيميائي مع ذرة أحد العناصر الكيميائية السابقة الذي ينتمي إلى عائلة الهالوجينات لإعطاء مركب شاردي

جد الصيغة الكيميائية لهذا المركب
أعط تمثيل لويس لهذا المركب
ما عدد الثنائيات الإلكترونية الترابطية و غير الترابطية ؟

الفيزياء

التمرين الأول
ينطلق « محمد » و سيارته من السكون، يتجاوزه « علي » الذي يقود سيارة أخرى.
ما هو المرجع الذي يختاره محمد حتى يؤكد العبارات التالية:

إني ساكن
إني أتقدم ( أتحرك نحو الأمام )
إني أتراجع نحو الخلف

التمرين الثاني
يقفز مظلي من مروحية و هي في حالة إستقرار أو ثبات على إرتفاع كبير من سطح الأرض.
نعتبر أن تأثير الرياح مهمل و مسار حركة المظلي شاقولي في معلم أرضي
المنحنى البياني المرفق يمثل تغيرات سرعة المظلي بدلالة الزمن V = f(t)
نعتبر أن مبدأ الأزمنة t = 0 هو اللحظة التي يقفز فيها المظلي من المروحية

حدد عدد أطوار الحركة و مجالاتها الزمنية
إستنتج اللحظة التي يفتح فيها المظلي مظلته
إستنتج المدة الزمنية التي يستغرقها المظلي حتى تثبت سرعته
ما قيمة السرعة ؟
مثل القوى التي يخضع لها المظلي و مظلته في كل طور من أطوار الحركة تمثيلا كيفيا

تحميل نسخة WORD

فيزياء (تقويم - 1)

aDMiN — Wed, 30 Jan 2008 15:53:29 +0000

في هذه التدوينة تقويم لمادة العلوم الفيزيائية خاص بالفصل الثاني ، يمكنك إكمال قراءة التدوينة للإطلاع على التقويم و تحميل الملف الموجود بآخرها.

يحتوي التقويم على تمرينين ، الأول في الكيمياء و يتعلق بما تم دراسته خلال الفصلين الأول و الثاني ، أما التمرين الثاني فهو في الفيزياء و يعتبر تمرينا شاملا في دراسة الحركة.

التمرين الأول

الشحنة الإجمالية لنواة ذرة هي q=11.2×10^ -19 C :

ما هو عددها الشحني ، و ما توزيعها الإلكتروني ، مع تعيين موقعها في الجدول الدوري.
ما هي الشاردة التي تعطيها هذه الذرة ، أعط توزيعها الإلكتروني ، ما هي هذه الشاردة.

تربط الذرة السابقة بعدد n من ذرات الهيدروجين لتشكيل XHn :

عرف الرابطة التكافئية ، ما هو العدد n للحصول على جزيء مستقر ، أعط صيغته المفصلة ، ما هو الشكل الهندسي لهذا الجزيء بإمكان الجزيء أن يثبت بروتونا (H+) هل تتغير البنية الفراغية للجزيء ، يعطى .e-=1.6×10^ -19 C

التمرين الثاني

يتكون مسار من ثلاثة أجزاء ، جزءان مستقيمات و جزء دائري ، يمثل الشكلان التاليان مخططي القوة المؤثرة على المتحرك خلال حركته ، و بيان تغير سرعته أثناء الحركة.

أوجد نوع كل جزء و طبيعة الحركة على كل جزء مع التعليل
أرسم المسار باختيار سلم رسم معين R=50m
أرسم شعاع تغير السرعة في موضعين مختارين على كل جزء كيفيا
أرسم شعاع تغير السرعة في منتصف المجال كيفيا
أرسم شعاع تغير القوة على كل مسار

تحميل نسخة WORD

Professor Asad Abidi Develops A Universal Chip for Cell Phones

arabi — Mon, 01 May 2006 10:13:20 +0000

A Universal Chip for Cell Phones

News : A universal radio antenna receives all kinds of signals traveling through the air some strong, some weak and all at different frequencies.

In order to convert every analog signal to digital signals, a chip would require an analog to digital converter that burns “several hundred watts” of power, says Prof. Abidi far too much for a portable device.

Therefore, his team used a modified version of SDR that exploits the fact that not all incoming signals need to be converted at once. People are usually interested in only one channel at a time, he says, such as using Wi Fi or talking via a specific frequency on a cellular network.

So Abidi research group incorporated a type of device - previously used only in obscure applications into their circuit that’s able to examine the vast range of radio frequencies, pick out the band of interest, and emphasize it, while de emphasizing the others. In essence, this device - what engineers call a “wideband anti aliasing device” - is able to access the spectrum and focus on a single band, so that only small amounts of analog information need to be converted to a digital signal. By building band choosing into the circuit, the analog to digital conversion takes only tens of milliwatts of power, Professor Abidi says.

Their advance, he notes, starts from discovering the potential for this previously under used wideband anti aliasing device and integrating it with other wide band circuit components to build a complete receiver. “The concept had been around for a while,” he explains, “but no one saw how powerful it would be for software defined radio applications.”

“A chip that sorts out the incoming signal such as Prof. Abidi’s is the type of technology that could help SDR become a reality in cell phones”, says Bruce Fette, chief scientist of communication networks at General Dynamics C4 Systems, a company that builds large software defined radio equipment for military use. And the idea of SDR is becoming more attractive to the mobile device industry, he says, because it provides so much more flexibility in the functions of a single device, ranging from using the same cell phone all over the world, to having a PDA unlock your car door.

Prof. Abidi says there’s still more research to be done before the chip is ready for commercial applications. For one thing, his team has only solved the problem of converting incoming analog to digital signals over such a wide range of frequencies.

Wireless devices must also transmit an outgoing analog signal. A truly universal chip will need to convert outgoing signals from digital to analog form over a similarly wide range of frequencies. Still, his team has solved the most difficult part of the problem by addressing the receiver, Prof. Abidi says. Incoming signals are much more complicated because, with a receiver, “you’re listening to the whole world,” he says, whereas “with transmitters, you’re not contending with unwanted signals.”

Prof. Abidi and his team hope to smooth out the remaining technical issues with their universal chip by late summer. From there, the work of other researchers who design the digital processor and software for SDR will come into play, he says. Professor Abidi estimates that all these pieces will come together for a prototype sometime next year. And, he says, a universal chip could be in handheld wireless gadgets within three to five years.

Source : http://www.technologyreview.com/read_article.aspx?id=16756&ch=infotech
Information: (AA) research group comes with a single chip advanced mobile phone
Note : (AA) UCLA research group = Asad Abidi research group at UCLA More
Information: http://www.icsl.ucla.edu/aagroup/

Professor Asad Abidi

Asad A. Abidi received the B.Sc. (with Honors) degree from Imperial College, London, U.K. in 1976, and the M.S. and Ph.D. degrees in electrical engineering from the University of California, Berkeley, in 1978 and 1981, respectively.

He was at Bell Laboratories, Murray Hill, NJ, from 1981 to 1984 as a Member of Technical Staff in the Advanced LSI Development Laboratory. Since 1985, he has been with the Electrical Engineering Department of the University of California, Los Angeles, where he is Professor.

He was a Visiting Faculty Researcher at Hewlett Packard Laboratories in 1989. His research interests are in CMOS RF design, data high speed analog integrated circuit design, conversion, and other techniques of analog signal processing.

Dr. Abidi was the Program Secretary for the International Solid State Circuits Conference from 1984 to 1990, and General Chairman of the Symposium on VLSI Circuits in 1992. He was Secretary of the IEEE Solid state Circuits Council from 1990 to 1991. From 1992 to 1995, he was Editor of the IEEE Journal of Solid State Circuits.

Dr. Abidi received an IEEE Millennium Medal. He has received the 1988 TRW Award for Innovative Teaching and the 1997 IEEE Donald G. Fink Award. He was a corecipient of the Best Paper Award at the 1995 European Solid state Circuits Conference, the Jack Kilby Best Student Paper Award at the 1996 International Solid state Circuits Conference (ISSCC), the Jack Raper Award for Outstanding Technology Directions Paper at the 1997 ISSCC, and the Design Contest Award at the 1998 Design Automation Conference, and received an Honorable Mention at the 2000 Design Automation Conference.

Office: 53 143, Eng. IV, UCLA

Homepage: http://www.icsl.ucla.edu/aagroup/aaa

Biography: http://www.icsl.ucla.edu/aagroup/cv.html

Students:
Abbas Amirichimeh (Ph.D. Student)
Abbas Amirichimeh received his B.Sc. (with Honors) in Electrical Engineering with emphasis on Microelectronics from Iran University of Science and Technology, Tehran, Iran, and ranked 4th in the class of 1988. During his bachelors program, he worked on several projects including a “Low Frequency Digitized Sweep Generator”. Abbas was with the Air Force for 5 years working on a G&C system before he joined Center for Advanced Electron Devices and Systems (CAEDS), University of Texas at Arlington in 1994 where he worked as a research assistant on 0.5 micron GaAs MESFETs and passive components at the device level and designed several monolithic wideband amplifiers. He received his Masters degree in GaAs MMIC circuits and technology with G.P.A 4.00 in 1995. Abbas was with Intel High Performance Architecture Group (IAG) in Portland, Oregon, from 1996 to 2000 working as an integral member of High-Speed Circuit Group (Fireball) in Pentium 4 development team (Willamette) where he developed and designed the Scheduler Scoreboard Unit (SSU) Fireball critical circuitries running at 2X the frequency of the rest of the chip, custom circuits and layouts running at 3GHz+ on Intel’s 0.18 micron process. Abbas joined Broadcom Networking Business Unit, Irvine, California, in 2000 and has been designing 10Gb/S SERDES chips since then. He joined UCLA Integrated Circuits and Systems Lab (ICSL) in fall 2002 where he is working toward his Ph.D. degree in the field of Analog Circuit Design. His research interests are RF, Analog and Mixed-Mode Circuits.
Abbas has been a member of IEEE since 1987 and has published a paper in “2000 Intel Design and Technology Conference (IDTC)” on “High frequency on-die interconnect modeling”, and a paper in “1996 International Conference on GaAs Manufacturing Technology,” on “Electrostatic discharge protection for GaAs devices and MMIC circuits”.

Rahim Bagheri (Ph.D. Student)

Rahim Bagheri received the B.Sc. (Ranked First) in EE and M.S. in BioElectric both from Sharif University of Technology,Tehran,Iran in 1997 and 1999 respectively. He joined UCLA in 1999, studying toward his Ph.D. and was a Graduate Student Researcher in MOSFET Research Lab (UCLA,1999-2000) working on deep submicron CMOS devices. He was at Valence Semiconductor, Irvine, as a senior design member of wireless group(2000-2001). His current research is the design of High Efficiency Linear RF Transmitters in ICSL, UCLA.
Rahim is the recipient of Gold Medal in national physics olympiad (IRAN) and Honorable Mention Diploma in the XXIV International Physics Olympiad,Virginia, USA.
Homepage: www.icsl.ucla.edu/~rahim

Rodney Chandler (M.S. Student)
Rodney Chandler received the B.E. (Electrical and Electronic) from the University of Queensland, Australia in 1998. From 2001-2003, Rodney worked for Cisco Systems Wireless Networking Business Unit (formerly Radiata) in Sydney, Australia, designing Analog to Digital Converters (ADC) and analog baseband filters. This work resulted in two patents related to design of ADCs. He joined the Integrated Circuits and Systems Lab (ICSL) at UCLA in Fall 2003, and is currently studying for the M.Sc. degree. His research interests are high speed Analog-to-Digital converters, wireless transceivers for high speed networks, and analog filters. Rodney plans to continue to the Ph.D. degree, after completing the M.Sc.

Jae-Hong Chang (Visiting Scholar)
Jae-Hong Chang was born in Republic of Korea. He received the B.Sc. degree in Electronic engineering at Kyungpook national university, Daegue, Korea, in 1998 and the M.S. degree in EECS at Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Korea in 2000, respectively. He is currently working toward the Ph.D. degree in EECS at KAIST. He was at RF CMOS TEAM in ETRI, Daejeon, as a part time engineer (2000-2002). His current research interests include the RF CMOS IC design, passive and active device modeling and RF MEMS. He received the Silver Prize in 9th 2003 Samsung Humantec Thesis Award.

Saeed Chehrazi (Ph.D. Student)

Saeed Cheharzi received his B.Sc. from Sharif University of Technology, Tehran, Iran in 2001 and his M.S. from University of California, Los Angeles in 2004. His research interests are RF, Analog and Mixed Mode Circuit Design.
Saeed was the Software Committee chair of the International Millennium Seminar on Electrical Engineering (IMSEE) held at Sharif Univ. of Tech. on March 1-3, 2000. He received the UCLA Graduate Division Fellowship for Fall 2001.

Mohammad Esmaeil Heidari (Ph.D. Student)

Mohammad Esmaeil Heidari received his B.Sc. degree in electrical engineering in 1995 and MS degree in electrical engineering in 1997 both from Sharif University of Technology, Tehran, Iran. From 1997 to 2000, he was with Emad Semiconductor Co., designing CMOS analog IC for high precision data converters, analog filters and power amplifiers. He joined Valence Co. in 2000 and was involved in the design of analog sections of Codec for telephony applications. He is currently a Ph.D. candidate at Integrated Circuits and Systems Lab (ICSL), University of California, Los Angeles. His research interests are in the area of low power CMOS RF transceivers, low phase noise Phase Locked Loops and Delta-Sigma data converters.

Aly Ismail (Ph.D. Student)

Aly Ismail received his B.Sc. and M.S.degrees both in electrical engineering from Cairo University, Giza, Egypt, in 1998 and 2000 respectively. Since September 2000, he has been with the University of California, Los Angeles as a Graduate Student Researcher. In January 2002, he joined Conexant Systems where he was working on the design of BICMOS RF circuits for cellular systems.
He is currently working toward his Ph.D. degree in integrated circuits and systems, his research is involved in the design of Ultra Wide-Band (UWB) receivers in CMOS technology.

Minjae Lee (Ph.D. Student)

Minjae Lee received his B.Sc. and M.S. degrees both in electrical engineering from Seoul National University, Seoul, Korea in 1998 and 2000 respectively.
He was a consultant with GCT semiconductor, Inc., and Silicon Image Inc., designing analog circuits for wireless communication and digital signal processing blocks for Gigabit Ethernet. He joined Silicon Image Inc., in 2001, developing Serial ATA product. Since 2003, he has been working toward the Ph.D. degree in the field of analog and mixed mode circuit design at ICSL, UCLA.

Ahmad Mirzaei (Ph.D. Student)

Ahmad Mirzaei was born in Tabriz, Iran, in 1978. He received the B.Sc. and M.S. degrees (with honors) both in Electrical Engineering from Sharif University of Technology, Tehran, Iran in 2000 and 2002 respectively. He was working in Novin Rayaneh and Emad Company in designing of high speed data-converters and RF frequency synthesizers. He is currently studying toward his PhD. in Electrical Engineering at University of California at Los Angeles. His main research interests include high speed analog integrated circuit design, high speed low-voltage ADCs, RF integrated circuit design and High-Frequency Gm-C Filters. He was the winner of Silver Medal in National Mathematical Olympiad in 1996, and was the first rank in Student Olympiad in Electronics in Iran in 2002. He was also the first rank in National University Entrance exam in Iran in 2000.

Sohrab Samadian (Ph.D. Student)

Sohrab Samadian received his B.Sc. in electrical engineeing from Sharif University of Technology, Tehran, Iran in 1998 and his M.Sc. from UCLA in 2002 where he’s pursuing his PhD degree. His research interests are RF and analog circuit design and low power frequency demodulators. He worked on a direct conversion receiver for Bluetooth and especially on a low power demodulator for his Masters. Sohrab is currently with Sequoia Communications, San Diego working on 3G transceivers. Sohrab is the recepient of the design contest award at International Symposium on Low Power Electronics and Design, 2002 and the design contest award of the 16th International conference on VLSI Design, India, 2003 for his work on low power GFSK demodulator. He also received APSIH’s award of excellence in engineering education in April 2003.
Zheming Li (Ph.D. Student)
Shervin Moloudi (Ph.D. Student)

Alumni: Hooman Darabi (Ph.D., 1999)
Hooman Darabi was born in Tehran, Iran in 1972. He received the B.Sc. and M.S. degrees in Electrical Engineering from Sharif University of Technology, Tehran, Iran in 1994 and 1996 respectively. He received the Ph.D. degree from the University of California, Los Angeles in 1999. He is currently a principle scientist in Broadcom Corporation, El Segundo, CA. His interests include analog and RF IC design for wireless communications.

Emad Hegazi (Ph.D., 2002)

Emad Hegazi received his M.S. from Ain Shams University, Cairo, Egypt, in 1998 and his Ph.D. from University of California, Los Angeles in 2002. He joined UCLA Integrated Circuits and Systems Lab. in 1998. His Ph.D. research was focused on Fractional-N Frequency Synthesizer Design. His research interests are Low Phase noise VCO design, Nonlinear Circuits, Frequency Synthesizer design and optimization methods. He is currently an Assistant Professor at Ain Shams University, Egypt.
Emad is the recipient of the IEEE Solid-State Circuits Society Pre-doctoral Fellowship award (2001-2002) and ADI Outstanding Student Designer Award from Analog Devices Inc., 2000. He has received the UCLA Graduate Division Fellowship for 1999 and the Outstanding Doctor of Philosophy in Electrical Engineering Award from UCLA.
Homepage: http://www.icsl.ucla.edu/~emad

Ali Karimi (Engineer Degree, 2001)

Ali Karimi was born in Tehran, Iran in March 1974. He received the B.Sc. and M.S. degrees (highest honors) in electrical engineering from Sharif University of Technology, Tehran, Iran, in 1995 and 1997, respectively. He received the Engineer Degree from the University of California, Los Angeles in March 2001 focusing on researches about 2.4GHz WLAN and 2.1GHz WCDMA receivers. His area of interests include analog IC’s for communication either wireless or optical applications.
Homepage: http://www.icsl.ucla.edu/~karimi

Daniel Q. Sun (Ph.D., 2004)

Daniel Qicheng Sun received B.E. in 1989 from Tsinghua University, Beijing, China, and M.Eng. in 1996 from National University of Singapore, Singapore. He is now pursuing the Ph.D. degree in eletrical engineering at University of California, Los Angeles. In 1989-1993, he was with the National Lab on Digital Microwave Communications at Tsinghua University, Beijing, China. In 1996, he joined Data Storage Insitute, Singapore, where he was engaged in the circuits design of the first MDFE read channel. Since 1997, he has been a Graduate Student Researcher at UCLA. His research interests include high-speed mixed-signal IC design, HDD read channels, signal processing and communications.

Andrea Xotta (Visiting Scholar, 2002)
Andrea Xotta received his “Laurea” degree (summa cum laude) in electrical engineering from University of Padova, Padova, Italy in 1999, where he is currently a Ph.D. Student. His Ph.D. research activity is focused on development of analog turbo decoder for Hard Disk (HD) applications. His research interests include continuous-time filters, sampled-data analog filters and analog turbo decoders.
Asad Abidi Group Members

Kashif Asad Ahmed
Farbod Behbahani (Ph.D. )
Anthony Brewster
Jing Cao
Patrick Chan
Glenn Chang
James Yung Chang
Jeffrey Chang
Paul Jinyung Chang
Michael Choi (Ph.D.)
William Colleran
Siavash Fallahi
Ramon Gomez
Koichi Hoshino
Karapet Khanoyan
Jikun Kim
Kwang-Young Kim
Haruo Kobayashi
Alexandre Rudolf Karl
Jaesup Lee
John Cumming Leete
Yoan-Tsang Liaw
Danny Daysang Loh
David John Loh
Patrick Pai
Hui Pan (Ph.D.)
Jacob Jude Rael
Ahmadreza Rofougaran (Ph.D.)
Maryam Rofougaran
Thomas Spargo
Wade Jay Stone
Shahrzad Tadjpour (Ph.D.)
Wee-Guan Tan
Chun Sei Tsai
Tyson Tuttle
Myles H. Wakayama
Yun-Ti Wang
Chun-Kai Wei
Joanne Joh-Mei Wu

Information as publishde by Prof. Asad Abidi group in 2005

Chaos Theory نظرية الفوضى

arabi — Mon, 27 Feb 2006 13:23:00 +0000

ما تقوله حقاً نظرية الفوضى، هو أن ما يبدو فوضوياً ولا يضبطه شيئ في الظاهر ، هو في الحقيقة امر منظم و منضبط تماماً و تتحكم به قوانين طبيعية في غاية الصرامة والدقّة . وان لا وجود لأحداث أو أشياء عشوائية خبط عمياء ، من وجهة نظر القوانين الطبيعيةهذا يعني أن الفيزياء مثلاً تحكم بقوانينها الدقيقة الصارمة المحكمة اموراً مثل كيفية سقوط حجر النرد على رقعة لعب طاولة زهرة، أي أن ليس هناك في العلم شيئ اسمه صدفة بحتهسوف اكتب المزيد فيما بعد عن نظرية الفوضى غير أن ما دفعني الآن للكتابة في هذا الموضوع هو هذا الشرح البسيط الرائع للنظرية

"What exactly is chaos? The name "chaos theory" comes from the fact that the systems that the theory describes are apparently disordered, but chaos theory is really about finding the underlying order in apparently random data."

Old Eur0pe Wins The 2005 UCSB International Capture The Flag

arabi — Sun, 18 Dec 2005 10:57:34 +0000

The UCSB International Capture The Flag (also known as the iCTF) is a distributed, wide-area security exercise, whose goal is to test the security skills of the participants from both the attack and defense viewpoints.The Capture The Flag contest is a multi-site, multi-team hacking contest in which a number of teams compete independently against each other.Each team is given a virtualized server installation (for example, a virtual Linux server). The server provides a number of services. The services have a number of undisclosed vulnerabilities, which have been included in the server's software by the contest organizers.The goal of each team is to maintain the set of services available and uncompromised throughout the contest phase. Each team can (and should) attempt to compromise other teams' services. Since all the teams receive an identical copy of the virtual server, the task of each team is to find vulnerabilities in their copy of the server and possibly fix the vulnerabilities without disrupting the services. At the same time, the teams have to leverage their knowledge about the vulnerabilities they found to compromise the servers run by other teams. Compromising a service will allow a team to bypass the service security mechanisms and to "capture the flag" associated with a service.During the contest a scoring system keeps track, for each team, of which services are available, and which services have been compromised.The 2005 iCTF was scheduled Friday, December 9, 2005, from 8am to 4pm, PST (note: this was changed from the initial date of December 7th).The winner of the last edition of the competition (which was held in June 2005) was the team "The Tower of Hanoi", from Politecnico di Milano, Italy.Read more at www.cs.ucsb.edu/~vigna/...