An academic study suggests that long-standing habits are difficult to break for a reason. It attributes this chronic and dangerous entity to physiology. This might, at least in part, explain why so many of us struggle to change recurring activities or rid ourselves from addictions.

Old habits don’t die. They hibernate.

Habitual activity–smoking, eating fatty foods, gambling–changes neural activity patterns in a specific region of the brain when habits are formed.

A week back I became familiar with the World Community Grid. Described in their own words,

World Community Grid’s mission is to create the world’s largest public computing grid to tackle projects that benefit humanity.

Our work has developed the technical infrastructure that serves as the grid’s foundation for scientific research. Our success depends upon individuals collectively contributing their unused computer time to change the world for the better.

I am hoping for my medical imaging research to become part of a localised research grid. Fortunately, this may actually happen sooner than I had anticipated. Yesterday I handed over C/C++ code to become a Web service.

I also have particular intersting in the way grid computing can assist the Web. My recent initiative called Iuron, once resumed, might rely on available, idle computer resources.

As an arbitrary set of useful links:

• An academic homepage provides a description and listing of mathematical symbols in HTML.

Nice examples like the following equations have been put together:

∆u  =  Δu  =

n ∑ i = 1

∂2u/∂xi2

+∞ ∫ −∞

exp(−x2) dx

=  √π

The above is valid HTML, but as expected, it makes heavy use of tables although data is not truly tabular. From a standards perspective, this may be frowned upon.

While on the issue of rarely-used symbols, below lie my related ‘pocket links’:

• HTML accents table
• HTML symbols

An older Web-based presentation (April 2005, London)

received some encouraging news last night. My submission to the MIAS-IRC annual symposium has been accepted for an oral presentation. To make matters even better, a paper of my colleague, in which I am among the authors, has been accepted as well.

This maintains a good record of consecutive oral presetations (rather than posters). At the moment I continue working towards two looming deadlines for international conferences. I have also begun to prepare the upcoming presentation, the Ph.D. thesis and I foresee the possibility of supercomputing in the near future.

Appearance model of the brain, ±2.5 standards deviations shown

T is difficult to submit a reasonably decent paper to an international conference. It is also rather unfortunate when two papers need to be completed before strict submission deadlines that are only one day apart.

I am planning to submit a paper on image registration assessment to ISBI 2006 and another on appearance model evaluation to CVPR 2006. Both deadlines have been set to the beginning of next week. That possibly, if not probably, warrants scarce blog activity. Both conferences will take place in the States and I will wind up attending at least one of the conferences.

As the documents adhere to IEEE-styled templates, I have finally descended to the level of raw L^AT_EX. I preferred to have avoided it for the past 4 years as I discovered the front-end L_yX, which has its pros and cons. L^AT_EX. feels like a step back nonetheless as failed attempts to compile a document are time-consuming. This is just one among the many deficiencies I could list.

HIS item is about my personal research and, in particular, its recent development and progression, which may take it in a different and exciting direction. I currently work on assessment of registration algorithms, which I have described in some depth over at MARS — my research-related publishing platform. The latest item discusses everything at a more technical level.

Below lies the diagram which describes a possible framework, which is still at its ‘propsal stage’. The ultimate aim is to provide an e-Science workbench for medical image analysis. My experiments account for a mere subset, where image/volume sequences need be aligned.

Click image for full-sized version

Dozens of remote sessions occupying a cluster. Terminals shaded on the left monitor (click to enlarge)

HATEVER operating system we use, the idea of using remote terminals should not be foreign to us. These days, it is rather common to log on to a computer remotely and manage it from afar as if we were actually there.

Inter-Platform Connections

Windows users frequently stick to VNC, which requires a high-bandwidth connection and grabs the entire desktop/workspace metaphorically ‘across the wire’. Nonetheless, there are some smart algorithms (c/f Citrix clients), which only re-draw elements once they change, so speed/bandwidth might not be the utmost concerns.

Linux users, on the other hand, are capable of establishing transparent connections with Windows machines via VNC, for which there are many applications in existence (Remote Desktop or rdesktop among several more variants). Linux also takes a different approach in its most natural method for remote access. Take, for example, SSH connections wherein individual windows get ‘grabbed’ and communicated over the network, only upon demand. Everything else should be managed from the command-line interface (CLI), e.g. bash and xterm. This might be less natural to the majority of users nowadays, especially to those unfamiliar with CLI’s.

Windows connectivity to *nix protocols can be established using the renowned PuTTY. In the case of Telnet or RLogin, applicability might be slightly different, but merely all protocols seem to have been covered. In fact, Windows typically supports telnet at its core (Start » Run... » telnet » ENTER). This establishes a somewhat mutual relationship. Windows users can remotely log in to Linux machine (might need a commercial X-session if not CygWin) and Linux users can connect to Windows hosts. In modern Linux distribution, all necessary toolsets are already pre-installed from what I can gather.

Extreme Use of Remote Access

When carrying out some computer vision experiments, I was at times using over 30 Pentium 4′s. These were used for quite a considerable overnight resource hogs. The communication barrier was merely inexistent; I an fortunate enough to work upon a 100Mbit Ethernet backbone. To give some indication of how fast the connection actually is, I can transfer an entire CD (~650 MB) across campus in less than a minute. That unbelievable speed is at times truly needed. I estimate that I use up bandwidth of over 100 GB per month, mainly due to backup necessities.

As regards extreme use of remote login, this is one of the most exciting experiences, to me at least. Rather than conducting large-scale experiments over the period of one month on a single CPU, they can be distributed, thus completed within a day. Nothing can beat that in terms of productivity. AI is known to be resources-greedy. Our computer vision methodology falls under that branch too. I will soon write about the use of supercomputers to run my experiments, albeit this is still under negotiation.

Traffic Chain

I could no longer resist my geek spirit so I decided to experiment with the idea of SSH chaining. The dependency of one machine upon another is something that intrigues me, so often I log in remotely to one machine, which in turn connects to another.

I decided to set up a larger SSH chain wherein I connect to my own computer via an entire ‘ring’ of machines, using SSH. I wanted to see how this affects speed and responsiveness in applications that ‘travel’. Needless to mention, this also cripples all computers in that ring. This observation has some interesting implications on its own. These intermediatory machines can be perceived as purposeless routers. If one computer in the chain is reset, the whole chain collapses and the connection is lost. It may also take a while to re-build, which to me at least, is amusing.

Cluster Control

On to some more extreme uses of SSH, some time ago I read about use of SSH to control entire computer clusters in parallel. In essence, the user will be sending any given command to an ‘army’ of computers (clients or computational hosts). The tool is not very flexible, but can be valuable under particular circumstances.