This is quite cool – now only if MS hurry’s up and incorporated this to Bing Maps.
MS Street Slide
Jun 20 2010
Hardware Chart
This computer hardware chart is quite cool. Not sure why, where and who would want to use this. But, it does beg the question – can things get any geekier? 
![907479120_5ZgiC-S[1]](http://bahree.smugmug.com/Computers/Amits-Blog-Pictures/computer-hardware-2/907479120_5ZgiC-O.jpg "907479120_5ZgiC-S[1]")
Mar 26 2010
Analysis of Algorithms
If you were interested in algorithms and interested in some mathematical foundations for algorithm analysis? For example if you are interested in proof techniques, probability, Amortization analysis techniques, Case studies and Asymptotic notions (such as Big-Oh, Big-Omega, Little-oh, little-omega, Big-Theta) then check out these lecture notes (in ppt, 224kb) from California State University.
Mar 09 2010
Ubuntu on a HTC Touch Pro 2
Well this is the phone I have maybe some day I will try this – pretty geeky albeit useless.
Dec 19 2009
Allowing remote desktop with blank passwords on Win7
I finally got the time to upgrade my MCE with the RTM bits of Win7 (was running an old RC build until now). Given this is a dedicated MCE with nothing else on it and an on an isolated part of the network, I don’t have a password set for the Account I use to login (of course not a recommended practice). Now, I wanted to RDP to the machine and I realised then that Win 7 does not allow RDP with blank passwords by default (Vista behaves in the same fashion). The workaround is a simple fix – to update the group policy as Dan shows in this post. Even though that post is for Vista, its the same steps for Win 7.
Dec 06 2009
BizTalk Flat File schema optional attribute issue
I encountered this interesting issue and thanks to Colin we were able to resolve it. There will be situations you will encounter when adding additional optional attributes to a Flat File (FF) schema in BizTalk will cause problems. To get around this you basically will need to set the following properties to relax the parsing of the attributes which break.
- parser_optimization="complexity"
- allow_early_termination="true"
- early_terminate_optional_fields="true"
This got me thinking more and wanting to understand what does changing these attributes mean under the covers. Below is what I found out on each of these.
On parser_optimization:
- Setting the parser_optimization to complex essentially generates a more complicated grammar (it uses both a top down and bottom up parsing); this grammar is then used to parse the FF.
- The complicated grammar is better when parsing records with more optional nested options – however it still cannot handle all the layout conditions and can still break in some situations.
- And given the runtime is doing more things, this will be slower than the other option called ‘speed’ (yeah no kidding Sherlock!).
- The reason the ‘speed’ option is faster is because it uses top-down parsing only.
- In addition you should also set lookahead_depth to zero (more on this below) to avoid validation failures (against a schema) when there are many optional nodes in the same group/record.
Changing the lookahead_depth itself is trivial but you need to be a little more aware of what this means:
- This essentially tells the parser when making a parsing prediction how far ahead to look in the token stream.
- Setting this to Zero essentially means ‘infinite lookahead’ which in turn means more memory will be consumed.
- Depending on how busy your BizTalk servers are and how much memory pressure you already experience processing various files (and their sizes), this might be an issue.
Basically, the FF parser is a streaming parser and implemented as a leftmost derivation which takes in a CFG. Essentially when we change the lookahead_depth to zero we change do not restrict this and the parser can recognize tokens using DFA perhaps (of course we don’t know the real implementation).
For those old school like me, and have played with yacc – that is a LL(1) parser – essentially parse the grammar with one token lookahead.
On allow_early_termination="true":
- When working with FF’s BizTalk expects that every line is of the same length (either because of the data contained padded with spaces). However if it finds a newline (CR + LF) character then it breaks and you get an error something along the lines of “Unexpected data found while looking for: \r\n”.
- Adding the allow_early_termination setting helps fix this. Read more here.
- Also note that only the right-most positional field is allowed to early terminate.
Lastly, the early_terminate_optional_fields attribute enables early termination of optional trailing fields. A couple of points to note on this:
- If your schema does not have this annotation and you open that in the BizTalk editor, then it will automatically add this annotation explicitly and set it to the default value of False.
- This only takes affect if you also have the allow_early_termination annotation set to True.
- More details on this here.
And in case you were wondering this is a supported option by Microsoft as shown in this KB article.
Oct 25 2009
Installing OpenSceneGraph on Ubuntu
If you use the Synaptic Package Manager in Ubuntu 9.04 to install OpenSceneGraph, by default it will install version 2.4.x. However if you want to install OpenSceneGraph 2.8.1 then you need to do the following in a terminal:
- Modify the file /etc/apt/sources.list (make sure you run it via sudo something like: sudo gedit /etc/apt/sources.list)
- Add the following two lines in the end and save the file:
- deb http://openscenegraph.dachary.org/packaging-farm/openscenegraph/gnulinux/debian/unstable/src ./
- deb-src http://openscenegraph.dachary.org/packaging-farm/openscenegraph/gnulinux/debian/unstable/src ./
- Run in the terminal: sudo apt-get update
- And finally run: sudo apt-get install openscenegraph
Jun 17 2009
Major Network Attack
Wow! Looks like a lot of bots suddenly woke up – major attack in progress.
Grrr … b**tards!
Jun 02 2009
Image detection – how, what, where – any insights?
I don’t have much experience with image detection in a video, and wanted to understand what options are possible – all I know it is not as simple as “CSI” makes it out to be – yet. 
Here is the scenario:
Say I have a remote controlled aircraft (a mini helicopter) which among other things has a camera fitted which is filming over a certain area. I use a training set and somehow “train” the camera to look for certain objects and recognise data points of that object and learn it to recognize that object (for example a human in Pink). Now once this is trained, if the helicopter is over another area and recording I want it to be able to recognise these pre-trained images in that video feed and do something if something is found (e.g. a human in pink).
The closest “CSI” analogy I can think of is – the facial recognition which they show to be iterating through hundreds of photos comparing data points (which of course as we all know this is mostly fiction – but that is a discussion point for another day).
So the question:
What does it take to compare objects in video feeds? I am not really interested in knowing how to “train” and find a pink human – but rather how to reliably and possibly quickly (within reason of course) compare and see if two are the same of the pattern. This should also reduce the false positives – e.g. a pink table might look like a human in pink with the environmental factors (shadows, sunlight, rain, angle of camera, etc.). I have read a little online but don’t have any experience in the subject.
Has anyone done this (or something similar) in the past or have any pointers for me?
May 19 2009
Creating an Event Source via a Reg File
If you ever tried to write to the event log, without an event source for that application created you will get an exception saying something along the lines of that you do not have permissions to create the event source.
If an event source does not exist, it is automatically created. The creation of the event source is a privileged operation and requires elevated privileges (a.k.a admin privileges) which of course might not always be possible if running a web application.
The easiest way to create this event source is via a reg file. An example is below (credit goes to my colleague Dominic to provide me the original sample).
Note: you need all the lines below including the “Windows Registry Editor Version 5.00”.
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Eventlog\Application\YOUR-APPLICATION-NAME-GOES-HERE]
"EventMessageFile"=hex(2):43,00,3a,00,5c,00,57,00,49,00,4e,00,44,00,4f,00,57,\
00,53,00,5c,00,4d,00,69,00,63,00,72,00,6f,00,73,00,6f,00,66,00,74,00,2e,00,\
4e,00,45,00,54,00,5c,00,46,00,72,00,61,00,6d,00,65,00,77,00,6f,00,72,00,6b,\
00,5c,00,76,00,32,00,2e,00,30,00,2e,00,35,00,30,00,37,00,32,00,37,00,5c,00,\
45,00,76,00,65,00,6e,00,74,00,4c,00,6f,00,67,00,4d,00,65,00,73,00,73,00,61,\
00,67,00,65,00,73,00,2e,00,64,00,6c,00,6c,00,00,00
May 18 2009
Upgrading Enterprise Edition to Ultimate (Vista or Win7)
If you are ever in a situation where you want to upgrade say from Vista Enterprise edition to Win 7 Ultimate edition – by default you cannot do this. When you insert your Win7 disc you won’t find the upgrade option available and the only way you see forward is to do a complete fresh install (after backing up your data of course). However, that is very time consuming and of course generally a lot of pain.
So here is a tip to get you to upgrade without doing a complete fresh install where you “fool” the installer in thinking you have a different version to allow you to upgrade.
You need to do the following steps, before inserting the Windows DVD
- Go to, Start, Run: and type: regedit.exe
- Go to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion
- Change the key: ProductName from "Windows 7 Enterprise” to “Windows 7 Business” or to “Windows 7 Ultimate”
- Change the key: EditionID from "Enterprise" to “Business” or to “Ultimate”
- Do not restart!
- Now insert Windows DVD and start upgrading (the option Upgrade will not be graded out anymore)
Of course you will need the appropriate licences and still need to activate, etc.
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