Syntax and Semantic

Open Science - SFD 2011

2011-08-28T13:56:00.000+02:00

For the third year I was invited to give a talk at Software Freedom Day @ Alexandria University 2011 and I wanted to talk about something that links what I am doing now (I am a research assistant at E-JUST) and open source so I started researching Open Source Science.

Starting from the fact that I use a lot of open source modules and packages in my work developed by others and put on the internet for everyone to use. I began to understand the wider concept of open science which aims at enabling everyone who is willing to participate in any scientific endeavor to have a part in it.

Facilitated by the internet, ideas, tasks, documents, code, scientific data and even videos of experiments are shared by the project's coordinator for anyone to participate in anyway and every way possible. And the results are amazing !!

My main goal from the presentation and this post is to show how openness can boost research either by using the collective intelligence of all participants (as in the PolyMath project or InnoCentive) or reducing the time or the resources need as in science for citizens organization.

Other aspects of open science include making all the products of scientific projects available to the public for everyone to learn from and build on, saving money and time for other projects.

One of the best introduction you can have to open science is the presentation made by Michael Nielsen at TEDxWaterloo.

Also below is the presentation I gave at Software Freedom Day @ Alexandria University 2011.

Contributing to Open Source - SFD 2010

2010-08-25T16:55:00.000+02:00

Today I presented "Contributing to Open Source" as a part of Software Freedom Day @ Alexandria University 2010 held at Bibliotheca Alexandrina. The audience was great and helped in making the presentation better than I anticipated.

This is the presentation I hope it would be useful to those that missed the event.

Contributing to Open Source

View more presentations from Ahmed Saeed.

It was cool to be presenting at the BA for the first time.

Research Opportunities in Egypt

2010-08-02T13:32:00.000+03:00

Lately I have been exploring the research communities and opportunities in Egypt, specially Computer Science oriented research groups. I was amazed by the number of opportunities that are available now specially for a fresh graduate like myself.

I'll try to list some of the opportunities I have came across and that I consider tempting.

1. Cairo Microsoft Innovation Center (CMIC) :
One of the best research centers and it collaborates with a lot of the institutions that follows. There you'll get the chance to work with cutting edge technologies developing projects that will directly help the Arabic community.

2. Government Funded Research Projects:
Development funds like ITIDA, NTRA and STDF are providing support for research projects and IT projects on all level. It's quite interesting to be working on an independent research project that totally matches your interests with absolutely no restrictions and get payed.

3. E-JUST & Nile University:
Working on a research project at either of these universities will offer you the chance of working in an environment like no other. It tries to match the graduate studies experience in the US. Although there are some restrictions that you don't find in independent research project, you get to finish your master's degree at one of these institutions and get payed a better salary.

4. R&D Startups:
Recently R&D startups started to appear in Egypt. They offer a pretty intense experience offering the challenges and excitement that you'll find at any research project while focusing on specific targets, deadlines and specifications. Of course the salary is better than universities and independent research projects, but publications are not guaranteed.

5. Mubarak City for Science and Technology:
This one is pretty new to me. I have just learned about the options there. Some of them seems promising but the environment is awfully similar to those of public universities. Although the salary is a little bit higher than a typical Teaching Assistant position at any public university you'll end up getting you master's degree from a public university. There are specific tracks which doesn't provide a lot of flexibility but some of them are quite interesting.

6. Bibliotheca Alexandrina:
The BA has A LOT going on with different teams working on many interesting projects. They have a super computer (the only I know of in Egypt). Also their books digitization system is recognized as one of the best systems in the world. The salary is quite good but it's not easy either to get in or get out.

7. Masters Degree in Public Universities:
This is the last sanctuary to fresh graduates seeking research opportunities. The problem with this option is that any work requires commitment and this track doesn't include a payroll so you end up working at software house either part or full time. This degrades your efficiency greatly regarding time available to do the needed work or even studying the master's courses.

All the above statements are totally subjective and based on my own opinion and the opinions of anonymous people that had experience at each of those institutions.

A Research Graduation Project Accepted in PACT 2010

2010-07-22T13:10:00.001+03:00

I have been working throughout the past year on my graduation project. The main target of the project was accelerating a Numerical Weather Prediction model (the Weather Research and Forecasting model) using GPUs. We implemented the latest version of one of the modules and our implementation was published as part of the latest release of a system supported by the United States Air Force and the National Oceanic and Atmospheric Agency (NOAA).
After our thesis defense we decided to go on with this work and submit it as a research poster to a high ranking conference and we chose PACT. International Conference on Parallel Architectures and Compilation Techniques (PACT) is a top tier, rank 1 conference. We submitted our work as a research poster for the ACM Student Research Competition in the Undergraduate Category (I have already particpated at an ACM SRC at MobiCom'09 last summer).
I was informed on 22nd of July 2010 that our work "Quantifying the Impact of GPU Specific Optimizations: An Experimental Study on a Weather Forecasting Application" was accepted and the judges' comments were great. This is yet another proof that Egyptian Public Universities, with no fund whatsoever, can produce high quality research on the undergraduate level.

Waiting for your comments :).

CUDA compilation on Linux (Makefiles)

2010-05-09T15:04:00.002+03:00

I have been struggling with compiling complex CUDA code, with complex I mean a lot of .cu .F .cpp and .c files. I have created a makefile that can help you compile that kind of code. I'll try to give a quick view of it here explaining some parts:

First you'll need to specify the CUDA path and the compilers and linkers. Here I am using gcc and g++ for .c and .cpp files and nvcc for .cu files:


CUDA_INSTALL_PATH ?= /usr/local/cuda

CXX        := g++
CC         := gcc
LINK       := g++ -fPIC
NVCC  := nvcc -ccbin /usr/bin

Then you need to specify where to locate the CUDA header files :


# Includes
INCLUDES  = -I. -I$(CUDA_INSTALL_PATH)/include

# Common flags
COMMONFLAGS += $(INCLUDES)
NVCCFLAGS += $(COMMONFLAGS)
CXXFLAGS  += $(COMMONFLAGS)
CFLAGS    += $(COMMONFLAGS)

Then you specify where to locate the CUDA binaries for linking :


LIB_CUDA       := -L$(CUDA_INSTALL_PATH)/lib -lcudart

Then you specify the object files that the executable depends on and the name of the executable flle:


OBJS =  sample_cuda_objectfile.cu.o sample_cpp_objectfile.cpp.o
TARGET = exec
LINKLINE  = $(LINK) -o $(TARGET) $(OBJS) $(LIB_CUDA)

Finally you specify the compilation rules. The following are generic rules so all you need to do is change the OBJS and TARGET variables for compilation:


.SUFFIXES: .c .cpp .cu .o

%.c.o: %.c
 $(CC) $(CFLAGS) -c $<  -o $@

 %.cu.o: %.cu
 $(NVCC) $(NVCCFLAGS) -c $<  -o $@

%.cpp.o: %.cpp
 $(CXX) $(CXXFLAGS) -c $< -o $@

$(TARGET): $(OBJS) Makefile
 $(LINKLINE)

Contributing to Open Source (Why? and How?)

2010-05-04T12:52:00.000+03:00

Open Source products are everywhere now, probably now you're using some of them. And I am sure that a lot of people are appreciating the role of open source. This post is about giving back to the community, helping others and moving forward one of the applications/tools you're using as a part of your everyday life.

Why Contribute to Open Source??

Sun Microsystems had a slogan "Change (Y)our world". And that summarizes what contributing to open source is all about. It's about making You better and making The World better. Let's make it clearer.

When you contribute to open source it helps you in some many ways, it gets you to code and practice and enhance your programming skills. Then gets your code reviewed, reviewed and then reviewed once more before it becomes a part of an official release. And finally it gets you to document your code.
Of course how much a project adds to your skills depends on the scale of the project and the importance of the feature you're implementing.

On the other hand, when you contribute to open source you're giving back to the community, helping improve the project you're contributing to and hence making someone's life easier by introducing a feature or fixing a bug and your code is out there for people to learn for it.

How to Contribute to Open Source??

First, you'll have to choose a project.

Start small, choose small project with a small code base that you can get familiar with easily and you can get the people who wrote the code easily too.
Choose a project you use, so you can be able to know what it needs and have clear vision of what's used for, what type of users you're targeting and what's missing that you once needed.
Choose a project you like, and that way you'll be able to give it the time and get to have a reason to commit some time for developing, testing and documenting.

You can start by scanning active projects on sourceforge or github where you can find active small scale projects.

Second, start communicating with the development community.

Join the project's development mailing lists and start scanning the e-mails to sense the trends and topics of interest to the community currently.
Join the project's IRC channel and start asking the questions you have (search for answers on the mailing lists, wiki and blog posts before going to IRC so you get an answer).
Chekout the code and compile it.
Check the project's bug tracker and try fixing a bug or two before working on a feature.

Finally if you find that you can work on the project CHECK FEATURES LIST START CODING.

KNN Algorithm and KD-Trees

2010-03-31T00:19:00.001+02:00

I am taking a Pattern Recognition course this semester, it's not really one of my favourite topics but I am doing OK. We had an assignment last week to test and compare different classification algorithms. One of the algorithms we were asked to implement was KNN (K Nearest Neighbours). We were asked to find a way that makes searching for the K Nearest Neighbours faster; that's what this post about.

The problem briefly is that: Given two sets of K dimensional points find the N nearest points (using Euclidean distance or any other measurement) to a K dimensional point X.

The Naive Solution:
Go through the list, find the distance between X and all the points in the two sets, get the smallest N elements in the distances list... Simple enough.
As part of our assignment we were given a dataset of 100,000 points which proved this algorithm to be very slow.

My Naive WRONG Solution:
I thought that it was easy to index the points in a way that makes it efficient to find the nearest points to a given point. Multiple Dimensional Sorting... It was totally wrong because two points might have the same values of m dimensions but the values of the other (K-m) dimensions put them far away from each other.

Possible Indexing Solutions:
There are different ways to index K Dimensional Points based on how near they are to each other. I will mention here KD-Trees.

KD-Trees:
K dimensional trees is a binary tree that is based on space partitioning. It's used to index multi-dimensional data.

The idea behind it is using the tree to navigate through space partitions while decreasing the size of each partition as you go through the tree.
The figure represents a simple 3d-tree. The dimensions are X,Y and Z. Constructing such a tree is much similar to a conventional binary search tree but differs in only that splitting mechanism uses a different dimension at each level and keeps iterating on them in the same order.
The root point in the figure splits the space into two partitions X>5 and X<5. On the second level of the tree the X>5 partition is split into two partitions Y>3 and Y<3 and so on.

So as you can see by navigating through the tree you get a good approximation of the nearest points to the point you're searching for. But because the point you're searching for might be on the edge of one of the partitions a normal binary search will not always yield the correct the real nearest neighbour so re-checking is needed.

To do that re-checking the algorithm saves the point obtained by a normal binary search as the current best. Then it iterates on the nodes already visisted in the tree to check for two things:

If any of those nodes' distance is smaller than the current best.
If there exists a partition (branch) that might contain points with smaller distances. That's done by comparing the distance between the point we're searching for and the splitting point on the adjacent partition (the sibling of the node currently being examined) and the current best distance.

I have made a simple implementation of KD-Trees and a nearest neighbour search algorithm in matlab. You can find it here.

Weather Research and Forecasting Model Explained (Part 3) - System Architecture and Parallelism

2010-02-17T13:34:00.001+02:00

WRF ,as mentioned in part 1 and part2, is a system designed for both operational and research purposes, and to run on systems from conventional laptops to super computers. The design of such a versatile system is a real challenge.
In this post we will explore some of the WRF's Software Framework design and explain the functionality of the different layers of the system. Also we'll discuss how the system handles parallelism in different hardware environments.
Software Framework Architecture[1][2]:
(The following functionalities doesn't include parallelism handling)

Figure1: Hierarchical WRF Software Design

As it appears in Figure 1, the system design has 3 layers:

The Driver Layer:
It defines and allocates domains and associates them in a nest hierarchy. It also manages the flow of a system run as it's responsible for stepping the time for the loop mentioned in part1. And it's responsible for I/O operations.

The Mediation Layer:
It interfaces between the two other layers. For example the driver layer uses Fortran 90's derived data-types while the model layer deals with scalar arrays only. The mediation layer is responsible for dereferencing the scalar arrays from the derived data types.

The Model Layer:

It performs the actual weather prediction computations like physics calculations and time integration.

Parallelism (Two Level decomposition):

Due to the versatileness of the system mentioned before, parallel systems including shared memory and distributed memory architectures. Two level decomposition addresses that problem by decomposing domains in patches and decomposing patches into tiles. With patches being "a section of a model domain allocated to a single memory address space" and tiles being "the amount of a patch that is allocated to a one thread of execution and every cell of a patch that requires computation must fall into some tile"[2].
The driver layer is responsible for distributed and shared memory allocation. Also it handles the decomposition of domains into patches and patches into tiles. While the model layer handles only tiles. This part reflects one of the best design features of the WRF Software Framework; Model layer is meant to be programmed by meteorological scientists not computer scientists, so handling parallelism issues (i.e. synchronization, memory allocation, communication, etc) was made part of the driver layer leaving the model layer to have only "meteorological calculators"-tiles callable subroutines.

[1] John G. Michalakes, Michael McAtee and Jerry Wegiel, SOFTWARE INFRASTRUCTURE FOR THE WEATHER RESEARCH AND FORECAST MODEL
[2] Weather Research and Forecast Model 1.2: Software Design and Implementation

Weather Research and Forecasting Model Explained (Part 2) - Nesting and System Components

2010-02-12T20:37:00.007+02:00

In the part 1 we introduced WRF and discussed the meteorological basics of Advanced Research WRF. In this part we discuss the concept of nesting and explain different system parts of WRF. But first we'll define two basic terms.
Grid: Raw atmospheric data layed out as a discrete grid for an area of the map.

Figure 1 [1] Grid examples

Domian: A model created by processing grid information and making it ready for processing by WRF Model.
Nesting:
Nesting is a way of getting high resolution data from low resolution data.That's achieved by introducing more grid or grids to the initial state. Those finer grain grids force the need for more high resolution data. That data is obtained by interpolating data from coarse grain grids or could be user input.

Figure 2 [1] Nested grid

WRF System Components:

Figure3 [1] WRF system components

As it appears in figure 1, the system has 3 main components: Preprocessor (WPS), the WRF Model and Post Processor.

The WPS is responsible for preparing the input (initial conditions and lateral boundary conditions) to ARW for real-data simulations by [2]

Defining simulation domain and nested domains.
Computing latitude, longitude, map scale factors for every grid point
Interpolates time-invariant terrestrial data to simulation grids (e.g., terrain height and soil type)
Interpolates meteorological fields from another model onto simulation domains

The WRF Software Framework is the core engine of the system, it has the Dynamics solver, physics package and WRF-Chem and the interfacing between them. That core has all the equations mentioned in part 1.

The Post Processor, it processes the output of the WRF WRF Software Framework and converts it to GRIB format. For more information check [3] and [4].

[1] A Description of the Advanced Research WRF Version 3, http://www.mmm.ucar.edu/wrf/users/docs/arw_v3.pdf
[2] WPS Basics, http://www.mmm.ucar.edu/people/duda/files/wps_files/WPS-basics.pdf
[3] NCEP WRF Post Processor User Guide, http://www.emc.ncep.noaa.gov/mmb/papers/chuang/2/wrfpost.txt
[4] User's Guide for the NMM Core of the Weather Research and Forecast (WRF) Modeling System Version 3, Chapter 7: Post Processing Utilities.

Weather Research and Forecasting Model Explained (Part 1) - Weather Prediction Basics

2010-02-04T14:05:00.004+02:00

My goal here is to give a simple overview of the WRF for computer science students.
The Weather Resarch and Forecasting (WRF, pronounced "worf") model is an open-source numerical weather prediction (NWP) and atmospheric simulation system designed for both research and operational applications [1]. This system was developed as joint effort between National Center of Atmospheric Research, National Oceanic and Atmospheric Administration (NOAA), Air Force Weather Agency and others. In this post ,and the posts to follow, I'll try to explain the WRF from two different perspectives, the first being Meteorology and the second being Computer Science.
I am here concerned with the Advanced Research WRF (ARW) subset of WRF.
Weather Prediction Basics:
Weather Prediction means to predict the state of the atmosphere in terms of (pressure, temperature, speed of wind, etc). Our atmosphere is controlled by flow and the conditions of the air across the planet and by predicting that flow we can predict the weather conditions in the area of interest. The prediction is done by providing a system with information about the current state of the area of interest. Then the system uses that information as the parameters for its equations (usually difference equations) to produce future conditions for that area.
Euler's Equations:
Advanced Research WRF's dynamics engine integrates Euler's Equations to predict air flow.

Euler's equations are defined as a set of differential equations used in fluid dynamics to govern invscid flow (Wikipedia).

Being continuous equations, Euler's equations are discretized. Both temporal and spacial discretization are needed. So the surface of the earth is mapped as a grid ,based on the projection method used to project the spheric shape of earth, where all variable are defined on that grid.

Figure 1 Spacial discretization

(V,U,W are wind velocities, θ is the potential temperature)

For temporal discretization, the Euler's equations are integrated using a time-split integration scheme called Runge-Kutta method.

The following loop is used to integrate the equations and this loop is the main loop in the system (i.e. all other components are used to provide this loop with the information needed to compute the current time step)

Begin Time Step

Begin RK3 Loop: 

Solve the equations

End RK3 Loop

Compute non-RK3 physics 

End Time Step

Note: This is a very simple version of the loop for the complete version reference [1].

Initial and lateral boundary conditions:
For the system to be able to predict the weather for a certain area it doesn't only need its initial conditions but it also needs a way to know its boundary conditions as of course adjacent areas affect the area of interest. To solve this problem, several methods of generating lateral boundary data are used including periodic generating in which the lateral boundary conditions are repeated along the x-axis or y-axis or both.

[1] A Description of the Advanced Research WRF Version 3

Internet 4.0: Out of the Stone Age (Second Draft)

2009-11-05T18:46:00.000+02:00

(This is an enhanced version of the my earlier post with the results of your comments and my discussions with friends).
With the relatively rise of online social networks and it's uncontrolable availability to vulnerable users (children, teenager and even people with low or no technical background) exposed a huge privacy concerns for everyone. Your data that your putting on the internet are available one way or another to almost everyone. Along with web giants such as Google and Facebook keeping track of every click you make for either targeted services or anonymized purposes. And that made me ask one basic question:
Do they have the right to know all my internet behaviour ?
Lets first state some important definitions that we'll need.

My behaviour is what I the links I click on the internet to browse the web to check, read and edit free online content.
My service request is the link I click to ask some service provider to make something for me.

My main goal is to make my behaviour totally private (owned by me) and my services request authenticatable and both "anonyimizably" trackable (we don't won't google search to fail). So lets see how this can happen.
What I am proposing is an ID that's connected to the internet 24/7 where ever it is. This ID acts as a single point of access to your whole online life from your name, date of birth and picture to your browsing habits and computer and TV preferences to social security number and credit card number.
I guess such a device can have a lot of criticism so let's answer the ones I got so far one by one,
Browsing the Internet:
The major two issues that are of concern here are Behavioural data and Web Pages Personalization that is based on tracking such behavioural data. What's happening now that data about what EXACTLY I am doing on the internet is tracked one way or another by some service and if someone can put all this data together can know exactly my behaviour and use that data the way he wants or event sell it.
This data belongs to me so what I am suggesting here is that each individual behaviour data is processed online and the extracted information should be saved into his ID. That way as an internet baby with no data about you (no character built yet) your ID will start gaining some character using the data that's processed while you are surfing the internet.
As for personalization, a web advantage that we can't afford to lose, web sites can query you ID for the characteristics it's looking for. Standardizing those characteristics should help the spreading of those IDs and make using them easier.
Shopping Online:
This activity is one basic example of a service request. Those services will need some kind of authentication so that we won't have fake IDs and impersonations with identity theft issues. Other services that will need authentication are location and country based services.
Facilitating such service will make online identity theft a more difficult job for hackers as it for thieves that that are trying to break into a secured house without the proper keys.
The need for a centralized state:
The previous point exposed a very essential issue that such a system will need to gain the trust of the users and the services providers. Having a centralized trusted centre for issuing and maintaining those IDs linking them to their true owners where you can renew and update you basic information. Also where you can track people with criminal records, bank records and other official and important records. That way service providers will be able to trust ID owners if they checked with clean records from that central point.
There are two rules that such a central point should follow, the first is having only the data needed to authenticate incoming IDs, it shouldn't contain data about their behaviour or services request. Think about it in the way the government keep track of social security numbers and driving licenses.
The second rule is having really secured links between that central point and service providers. Strict laws should be made for the violation of the terms of use of such links.
Using Multiple Devices (Extending the idea, a little):
I can imagine such a person carring such an ID and setting in front of his TV and immediately loads his TiVo programs without a click on the remote. Then, he moves toward his computer and it welcomes him while opening his front page. Then while surfing all the websites pops data and advertisement that are meant only for that person. Other websites that he never visited before use the character he already created to help him have a more personalized experience, helping him save time and money by poping only stuff that it knows he'll need.
Also that ID can start processing the data it has to extract information that a single behaviour monitor wouldn't have figured out.
Implementation:
Implementations suggested in "Privacy, Cost, and Availability Tradeoffs in Decentralized OSNs" such as having machines on the clouds or personal computers should work fine. But what I can imagine is a device as small as a flash drive that is connected to the internet through WiMax coverage and with all you data on it. That device have WiFi and Bluetooth cards to help it connect with different devices and a small processor to interact with all that environment around it.
Conclusion:
This system tries to map the world we already live in to the online world. We managed to have a very private real world and with the help of new technologies we're making it more secured and more private and yet leaving our online identities totally exposed. This system will need a lot of work to even come near being a reality but the technology needed is already here, all we need is to realize the value of our privacy and being identified as a single person online.

Getting over stone age of the internet: discovering agriculture and building homes

2009-11-01T23:41:00.001+02:00

If you look at the current internet, giving its age and the type of problems it's facing, you can see clearly that we're still in the middle of, what I'd like to call it, the stone age of the internet.
We're talking about a technology that's only 30 years old, it has yet a lot of potentials to be discovered and drawbacks and problems to be solved. The problem I want to expose here is privacy. I'd like to compare the real stone age (5000 years B.C.) to the internet stone age (1985 to 2009).
The stone age:
During the stone age humans lived in the forests and took cover in caves from the rain, they lived in tribes that shared the same interest and cared for each other's interests. Communication between those tribes was almost impossible and they probably fought over everything (territory, food, women, etc). They slept right there in the open thinking that they are well protected that way. Invented some traps and protection systems to protect them and maybe considered those who got eaten by predators just flows in the protection system they had and they probably had their engineers work on that flow. By the end of the stone age humans made some of the most important discoveries in the history and those were agricultural and building homes. Sick of being exposed to all what nature had hidden for them, they built homes to protect themselves from the predators that intentionally meant to hurt them and other occasional incidents such as rain. Building homes close together they formed cities with a great building in the middle of the city forming the city hall. That city hall is were messengers from other cities went to communicate with that city.
The internet stone age:
I think by now the analogy should be a little bit clear. We're now creating profiles leaving them exposed one some public servers with some security and privacy measures that are broken and patched all the time. Leaving the data of our teenagers exposed to all kind of e-predators and think by having that easily breakable privacy measures we're doing our best. Also we're scattering our information amongst different social networks and services that can't really agree on a way to communicate and that most of the time are fighting over the money coming from the ads business.
We're basically making one "Ahmed Saeed" appear to be 5 different persons because he has 5 accounts on different social networks and services. And by that we're wasting the precious data that can be inferred by knowing that those 5 men are basically the same (Google is working on that but it's just another patch). On the other hand, this "Ahmed Saeed" is leaving his data out there for people he don't know to use in all sorts of ways.

I guess we're close to getting out of the internet stone age as the work suggested in "Privacy, Cost, and Availability Tradeoffs in Decentralized OSNs" published in Sigcomm's WOSN 2009 suggests what's near to discovering homes in the stone age. Probably over time we'll start building homes that are sustainable and reliable to provide us with the online cities we all dream of.

Trying to order the new Ubuntu CD and that's what I get

2009-11-01T00:47:00.000+02:00

Demand for Ubuntu CDs is very high, and we're trying to ensure that we have enough CDs for those who really need one. We've noticed that you've already received CDs of several previous Ubuntu releases. You can help us ensure the continued availability of Ubuntu CDs by

* upgrading to the new release without a CD
* downloading your own CD for free
* becoming an Ubuntu member by contributing to Ubuntu, and thereby becoming eligible for more CDs

Thanks for your support of Ubuntu!

I am sure they are trying to do there best but my point of view that people with longest history with Ubuntu are the best candidates to share the CDs with others. Maybe I am wrong but I just want a CD :(

Video Segmentation: Science fiction coming true

2009-10-25T21:16:00.001+02:00

First I'd like to define roughly what video segmentation is then talk about it in more technical details.
The term video segmentation is used with two applications in mind, the first making a long video short by extracting the key shots and images and puting them in a sequence summarizing the long video. So you can think of it as making movies trailers automatically.
The other is extracting the objects that were shot in a video and tracking them through a series of shots; in short making videos of the objects in one big video. So you can think of it as Arnold Schwarzenegger moving as the terminator identifying objects with his "eyes" and getting data about objects he's seeing.
Both problems are challenging and interesting but I'll focus more on the challenges faced when developing algorithms for the second definition.

If you used Photoshop ever then you must have done some image segmentation before. If you still don't know what I am talking about, remember the magic tool. Using that tool you can select objects in a certain image almost automatically. A lot of technquies have been developed for that problem and they are quite useful now. But lets think how complicated it can get with it turns into a moving objects.
A simple answer to the problem would be, video is just a series of images so we can just keep selecting the object in all of those frames.
Simply doing that will raise a question, how can you know that the object you're selecting now is the same object you selected in the previous frame?
Objects tend to move, backgrounds do the same thing and both tend to have at some points parts that make them look as if they were the same objects.
Also objects tend to intersect and hide behind one another making it look as if objects are disappearing.
Another important behaviour is that most objects change the way they look (think of a rubber ball).
With all of those consideration in mind, developing an algorithm that does object identification, object tracking and event detection becomes a very interesting and difficult task.
To wrap it up, I'll give a simple example which I guess must be using video or at least image segmentation. Digital Cameras, cool new digital cameras can detect faces and track them while them camera is moving. Just add some face recognition system and you got yourself a first component of terminator's system :D

ACMQ: By engineers for engineers

2009-10-21T00:28:00.000+02:00

I have joined the ACM recently and I received by first CACM magazine two days ago. I found an interesting ad while reading and it was about a magazine called ACM Queue; I have heard about ACM magazines before but not this one so I thought I should check it out and I guess you should too.
ACMQ is the ACM's magazine for practising software engineers [1]. So it has major guys talking about cuting edge technologies in a very informative way with a very wide spectrum of topics covered.
Not only ACMQ has articles but it also has some cool audio and video casts and Planet Queue. Planet Queue is is an aggregation of practitioner-oriented blogs written by the Queue author community (close to 400 and growing) [2].
The bottom line is go there and start reading :D.

[1] About ACM Queue http://queue.acm.org/whatisqueue.cfm
[2] About Planet Queue http://queue.acm.org/aboutplanetqueue.cfm

Blog Action Day: Climate Change and International Day of Climate Action

2009-10-15T19:50:00.001+02:00

Well, I just wanted to be part of that worldwide event. So I want to mention some stuff that we can do to help in saving YOUR WORLD!
Support forests for Climate
http://www.greenpeace.org/international/campaigns/forests/forest-for-climate-petition
Say no to Genetically Engineered Rice:
http://www.greenpeace.org/international/campaigns/genetic-engineering/hands-off-our-rice/hands-off-our-rice
Ask world leaders to personally attend climate conference:
http://www.greenpeace.org/international/campaigns/climate-change/take_action/leaders-go-to-copenhagen-climate-summit
DON'T UNDERESTIMATE WHAT YOU CAN DO, because you'll not be alone in this. If everyone in the world try to make a certain difference it will happen. So let's help the world be a better place for us.
If you're a blogger try blogging about climate change and how everyone can help in making the world a better, safer and greener place.

Also I invite you to be part of the 24th of October International Day of Climate Change. I've thought of having a celebration here in Alexandria. If you're interested comment on this post. Also comment about actions we can do to help save the climate.

Help save the climate the way it suites you but don't stand there doing nothing!

Etisalat USB Modem on Ubuntu 9.04 (Huawie E1550)

2009-10-14T11:12:00.001+02:00

I had a problem with getting my USB modem to work on Ubuntu as it didn't detect it. The answer to this is simple for Ubuntu 9.04.

First go to "System>Preferences>Network Connection".

Then click on "Mobile Broadband" tab and click on the add button.

Then choose a name for the connection and apply.
Now we're half way there. To make it work you'll have to download this package:
sudo apt-get install udev-extras
Then you'll create a file for the modem by typing:
gksu gedit /etc/udev/rules.d/15-huawei-e1550.rules
Then paste this code in the gedit window:

SUBSYSTEM=="usb",

SYSFS{idProduct}=="1446",

SYSFS{idVendor}=="12d1",

RUN+="/lib/udev/modem-modeswitch --vendor 0x12d1 --product 0x1446 --type option-zerocd"

cAll you'll need next is to plug and enjoy.
The last step was optained from here.

F5100 Flash Array: A new horizon for solid state drives

2009-10-12T17:13:00.002+02:00

Sun announced the benchmarks for its new flash array system.

Key thing is, it out performed mechanical hard drives with all the benifits that come with using solid state drives such as low power consumption, mechanical shocks tollerance and ease of deployment. You can find all the technical details explained way better than I can explain it in this video.

For further information check this here

Non-Computable Problems: Halting problem and others

2009-10-11T20:16:00.000+02:00

If you have not studied algorithm complexity analysis this might seem a little strange. There is actually problems that the computer can't solve no matter what happens. To make it a little easier to understand, we usually think that there is nothing a human can't do but can a human fly! We'll it's not possible. You can say the same thing about non-computable problems, it's just problems that the computer can't solve.
Halting Problem:
One example, that always pops to one's mind when asked about non computable problems, is the Halting Problem. This problem is fairly simple "Given a program and an input to the program, find whether the program will run indefinitely or not when processing that input" in other words find if a certain input will cause a program to enter an infinite loop. And the computer can do that!
There is a fairly complicated proof for that problem and you can find it here .
Other Problems:
What made me mention this class of problems is that we've been asked to find other problems that are not computable which seemed kind of interesting so I searched for a while and found some,
The Totality problem: this problem is just a generalization of the halting problem and it states "Given a program, find if this program will terminate on all its inputs or not". And it's fairly simple to proof non computable given that the halting problem is non computable too.
Also there is The Equivalence Problem which states "Given two programs find whether the two programs solves the same problems or not".
You can find more of those problems and there proofs here.
I hope that this post got you thinking about what the computer can really do!

Ambience analysis and discovery research

2009-09-30T19:54:00.000+02:00

Well it has been a few days after MobiCom and it's time to start blogging it technically.
I'll start with what if I heard of a little earlier would have thought science fiction. And it's ambience/ambiance analysis and discovery mentioned in a paper called "SurroundSense: Mobile Phone Localization via Ambience Fingerprinting" and a poster titled "Highlights: Event Coverage in Mobile Social Networks".
Let's start with the basics before going through them both. First, Ambience is "a feeling or mood associated with a particular place, person, or thing" Merriam Webster. So if you consider the ambience for a place it'll include the lights, sounds and colors in that place, and for a person it might include movement, facial expressions and clothes colors and styles. If you thought about it a little, every person or a place have unique ambience in some sort.
The ongoing research is concerned with creating a fingerprint for this unique ambience and using this fingerprint it can detect the place you're in, people you're meeting and they type of the event happening now.
How are they doing that?
Our mobile phones became a very good set of sensors that are widely spread everywhere on earth. It's capable of detecting most of the data needed for creating the fingerprint needed through it's microphone, cameras, GPS and accelerometer with very good accuracy and the accuracy is still moving forward.
So in the future just by waving you mobile phone around it will be able to decect exactly where you are and what you're doing because that's exactly what the two researches are suggesting; SurroundSense detects the lights, colors, sounds, movement and wifi and creates a fingerprint using the collected data and then compares it the fingerprints database, that way it'll be able to know exactly where you are after of course having an approximation using the GPS. You can review the paper for more details.
It might sound like science fiction but it'll soon be in your pockets!

DNIS in SRC: Second Place but What a feedback!

2009-09-26T08:16:00.003+02:00

I couldn’t blog about what happened in the presentation right after it because I had places to go and things to do on my last day in China but in short it was amazing.
I asked my new friend Ari to record it in video for me and he did. As you’ll see I was terrible. I was tattering and I paused for a very long time searching for the word ORDER in my head. The bottom line I have not been worse in a presentation. The explanation is simple; my knees were shacking of fear. I was so nervous and I couldn’t help it. As I went last I got to see how all the judges asked questions and how hard these questions were. Also I got to know who the judges were and that made me even more nervous. So at the beginning I was pretty bad but I did good I think in the questions.
Even before the results were announced I knew that we’ll come second as the other guys, no matter how terrible he was on his presentation had some really solid Game Theoretic proofs behind his work and our idea was fairly simple. I was a little sad because I knew I could do better in my presentation and so I went to ask prof. Suman (posters Co-Chair and one of my judges) about my presentation and he told me that the judges liked it a lot but the idea of our project was fairly simple. Also I got to meet prof. Romit afterward and he encouraged me and told me he liked the presentation. That really meant a lot for me coming from those professors.
We came in Second in Mobicom’09 SRC Undergraduate Category. I am really proud of what we’ve did and I hope that we (as in Egyptian students) will have more of this kind of representation in major conferences in the following years

Before my MobiCom presentation: Fears and Doubts

2009-09-24T07:48:00.001+02:00

I want to blog this whole experience to be able to share and also have a good documentation about it. Now it's about 4 hours to my presentation, I am worried and nervous. Also I got this unimaginable pressure of what I am representing, usually I am representing myself, my social community or even my company. This time I thought I was only representing Egypt. But I got this assuring and motivative comment "Remember that you're representing, not only Egypt, but the entire Muslim and Arab countries. You may have noticed that very few, if any one, from an Arab or Islamic university is attending, not to mention presenting." (No Pressure :D).
Well, today I talked with some people I met here and I got this very nice comment, "Enjoy it! You know about your work more than anyone else, so just go there teach and enjoy".
So I am still a little bit worried, but I hope I'll do OK.
Ed3oly!

Egypt's Undergraduate Research is Rocking the WORLD!

2009-09-23T08:49:00.002+02:00

Yesterday was my big day, I had to present both the demo and the poster. I had judges coming for SRC and for demo evaluation, and a huge load of scientists and professionals coming to check our work. I started asking new friends I met during MobiCom about the work, and got some very helpful feedback about how to present and also they gave me a heads up one some questions I'll need to answer. But they all thought the work was great.

Now it's time for presenting the work to EVERYONE!

At first people just passed me by not asking nor talking, only more people I met on earlier days. After a while I started getting people asking me about the work. After a while I got to move my poster to be next to my demo and that's when all the action started.
I had Microsoft Research people, professors, PhD students and masters students asking questions about DNIS and discussing what we've done and how we did it. The demo helped A LOT in showing them how real the work is and its significance in terms of network performance.

That's not the only news:

We are SRC (Student Research Competition)Undergrad Finalists

Being SRC Finalists we'll get to present our work to ALL of the MobiCom audience. So, ed3oly!
We're rocking the world guys!
This is to every Egyptian undergrad: YOU CAN ROCK THE WORLD TOO, JUST START WORKING ON IT
For more information about SRC check here and here

First day of MobiCom: New People and New Experiences

2009-09-21T16:48:00.003+02:00

It's finally MobiCom!
I woke up a little late and wandered to the conference's venue using a bus and in 3 minutes I was there. The sign in procedure was pretty easy, the registration volunteers are pretty friendly and soon enough I had my package and name tag.
I started worrying about socialization a little after that. It seemed like everyone knew someone and was sitting with each other. But soon after the launch break I got to know one of the organizers due to a problem I had with my network connection. And one after another I started meeting new people from the opposite sides of the world doing research in different and interesting areas.
What I got to learn after some short conversations that it's really a big deal to be an undergraduate and present work in MobiCom. Also that our work is really something impressive as I got a lot of great feedback from everyone I talked to about our DNIS.
WE REALLY DID SOMETHING GUYS!
Here are some picture from my day:

A map of the posters and the demos, I am 16 and 59:

MobiCom Updates: DNIS got into SRC

2009-09-19T04:02:00.003+02:00

I am almost done with my tourist visit to China and back to work work work!
Before I left for China I got some very bad news, "we didn't get into SRC".
Let me first introduce SRC or Student Research Competition which is an international ACM competition for students (graduate and undergraduate). You can check its official webpage here.
The process of the competition in MobiCom goes as follows, the committee chooses a subset of the qualified posters to compete for the final places then select one of those depending on their presentations to be finalists and give a presentation on the fourth day of MobiCom. Until yesterday our DNIS wasn't selected to compete. Which was a real bummer for us.
Yesterday we got an e-mail saying that we got into SRC!
Ed3olna :D
You can check our names in the SRC Page and the Demos Page.
Wait for my future updates on MobiCom!