Tech That..

Android development - Part I

2012-01-23T06:10:00.000-08:00

Since the time I bought my first Android phone, I have been wanting to tinker with it at code level. Now that I have too much time to kill (I am on vacation in India), the timing seems perfect to delve into it.

To describe an Android application architecture in a nutshell:

An application runs within a VM with a unique Linux user Id provided by Android OS.

An application is composed of activities, services, broadcast receivers and content providers.

An activity is a some meaningful action performed on screen. For e.g. composing an email, or sending an email are activities for an email client application. An application can access other functions available on a phone using an Intent. An application will choose to use a phone camera. For this, it will let Android OS know about its intent to use camera capture activity.

An application can choose to subscribe to system activities. For e.g. battery low, or screen blank etc. This is delegated to application's broadcast receiver component.

Content providers basically handle data layer abstraction for an application. content resolver is an additional abstraction between an application and content provider for security purposes.

Service is a background process component in an application.

This application architecture is described in a semi-structured XML format in an application manifest. For example:

<?xml version="1.0" encoding="utf-8"?>
<manifest ... >
    <application android:icon="@drawable/app_icon.png" ... >
        <activity android:name="com.example.project.ExampleActivity"
                  android:label="@string/example_label" ... >
        </activity>
        <service android:enabled=["true" | "false"]
        ...
        </service>
        <receiver android:enabled=["true" | "false"]
          android:exported=["true" | "false"]        
        . . .
        </receiver>
        <provider android:authorities="list"
          android:enabled=["true" | "false"]
          . . .
         </provider>
         ...
    </application>
</manifest>

Unlike iOS platform, the number and supported functions by a given device vary a lot for android powered devices. For e.g. not all the phones can come with a camera or only HTC phones will have special touchscreen component. To set the expectations for an application (so that Android OS can decide if an application can be installed on a given device), application requirements like <uses-sdk>, <supports-screens>, <uses-feature>, or <uses-configuration>.

Sources: http://developer.android.com/guide/topics/fundamentals.html

Entrepreneurship

2012-01-22T06:48:00.000-08:00

Today so many youngsters are trying their luck at that one new idea that (they think) can change the world. It makes me wonder what is really required to be an entrepreneur? and why would you want to be one?

Entrepreneurship (in my mind) is about being resourceful, insightful, passionate and a risk-taker. You have an insight about something that you find worth giving your attention to. You choose to (maybe not right away) get out of your comfort zone and devote your time, money and energy towards something. And once you jump into it, you make the most of given resources, find ways to get around your constraints.

Why would you want to be an entrepreneur? I think there is a gene or keedaa within us that makes us curious, seeks excitement, wants something different, or believes in or sees something that others do not. It is the very thing that made homo sapiens the conquerors of the world. Being an entrepreneur is a modern day equivalent of an exploration of a kind.

In my last trip to India, I came across couple of books on Indian entrepreneurs by Rashmi Bansal: Stay Hungry Stay Foolish and Connect the Dots. The first one is about MBA graduates who chose to go an unconventional path and develop their ideas into business, rather than going for a lucrative job. The second one is about entrepreneurs who had no business background, but still made it big based on their grit, intuition, keenness, and adaptability. It is really inspiring to see the struggles these people went through before making it big.

Although entrepreneurship is romanticized many times by the media, it is really a hard and risky way to take. The chances of success are very low. For every successful and sustained business idea, there might be hundred ideas before that could not last long. It is one thing to believe in some idea that you think is cool, but you have to convince others: your sponsors, VCs, and more importantly your customers. You might have to sustain losses for some time before you can make profit, or maybe break even. You should know when and where you should stop pursuing an idea and move onto other things as well. It maybe your tenth attempt that would really become a success, but if you are stuck with the first unsuccessful idea for long period, you might run out of time, money and resources.

Anyways, all this blabbering was a result of meeting couple of friends who have dared to try out something different: Desta, Estate Lister, Mirraw to name a few ventures. I hope their ventures grow big and grow fast to inspire others around them.

Image Source: Thinking Man

Annoying PuTTY keyboard beeps

2011-05-08T20:55:00.000-07:00

Get rid off them by selecting "None(bell disabled)"

Welcome to peaceful PuTTY time :)

Source: PuTTY bell configuration window

App ideas

2011-04-17T22:31:00.000-07:00

For many days now I have been yearning to work on some of the ideas in my head. I am going to put them down here, then start thinking more about them.

1. An App to bookmark news items on Facebook and share,star, like them like Google Reader. Maybe there's a way of doing it somehow that I am unaware of.

2. A website or app that takes as an input number of possible travel destinations, date ranges, and limit price you would like to spend on airfare and/or rental. It will update you when you are matched, else it will tell you when a new low price is registered, along with some price information. Often times, travel portals come across as unintelligent applications that focus on one of the two aspects mentioned. Again, there might be something like this out there. I need to look deeper.

Start thinking..

Citrix receiver/ICAClient issues on Ubuntu 9.04

2010-11-21T15:54:00.000-08:00

Its a pure joy (OK, maybe not :P) to work on my office machine from Ubuntu. Obviously I need a remote desktop client, which is Citrix receiver in my case.

The installation part is quite tricky and might not be as straightforward as it is on Windows. I had to go through multiple sources to get the entire process right.

1. Download the latest citrix receiver from Citrix website.

2. tar xvzf linux*.tar.gz

3. sudo apt-get install libmotif3

4. sudo apt-get install libxaw6 or sudo apt-get install libxaw7

5. locate libXm.so*

6. sudo ln -s libXm.so_latest_version_location /usr/lib/libXm.so.4

7. Follow default installation

8. sudo ./wfcmgr This should run without any errors.

And you are done..

A useful shortcut to toggle b/w remote desktop and local machine is CTRL+F2 and then ALT+TAB as usual.

Update: Still facing one weird issue with remote desktop. After using it for a while, the keyboard stops functioning, only mouse works. I cannot type anything and the only way out is to log out of the remote machine and login again. Any solution?

Sources:

1. http://www.citrix.com/English/SS/downloads/details.asp?downloadID=3323
2. http://carlo-hamalainen.net/blog/?p=349
3. http://skarh.wordpress.com/2008/05/20/how-to-citrix-on-ubuntu/

technology defeats common sense

2010-08-16T19:26:00.000-07:00

I had my dinner at an Indian/Pakistani restaurant today. Before going I looked up this place on yelp, and found that it has got great reviews. As I was about to enter the restaurant, I noticed that the place was virtually empty. I went around the time when Muslims break their Ramadan fast. It was quite obvious that the place is not one of the best ones around. The food was just OK.

But all this time only one thing was humming in my brain. How can I keep my common sense aside and rely on online reviews? It is not the first time this has happened. In fact, our generation blindly believes what technology tells us. Sometimes it turns deadly - people driving off the cliff, just because their GPS shows an 'imaginary' road.

I know I would sound like a grey haired grandpa, but technology makes us dumb and unintelligent. I am not sure whether I can even perform my job as good, if there were no Google (the thought itself scares me :P ) Matrix or people plugging themselves to machine to live a virtual life doesn't seem like a far-fetched idea!

An intro to mobile and location aware social networks

2010-03-28T23:24:00.000-07:00

Today internet is swamped by social networking websites, applications like Facebook, MySpace, and Twitter. These applications form an overlay or virtual social network, one which is independent of physical location or proximity between its users.

Consider a scenario: You enter a pub and look around for familiar faces. Finding none, you pull out your smartphone to see whether your phone can help you finding your friends (on social networking websites) or somebody with whom you went to school with, or somebody who listens to same music as you do. Well, it ain't a figment of my imagination? Such applications already exist.

These applications focus on physical location of its users. Networks are ad hoc and are based on user's proximity. Such networks can be easily broken if connected users move away from each other. In short, these networks are formed based on user proximity and rely on user mobility for survival.

Some more examples could be:

1. a researcher at a research conference can find other researchers who have similar interests or can choose to exchange list of publications/contact information.
or
2. Shoppers passing by their favorite shops can automatically receive price discount or product information without even going inside the store.

To put it simply, mobile social networks are trying to tap into still unexplored aspect of social communication - autonomous information exchange/interaction among users physically closer to each other. The reason why this communication could be useful or even relevant is because often times people grouping at a place do have something to share with each other. Even when people don't know each other or are not related, such applications can help finding interesting information around.

One important distinction of mobile social networks from existing location-aware services like GPS is these networks will not be centralized and mostly ad-hoc. i.e. you don't really have to connect to a remote server to be a part of it. Communication between two parties can be completely isolated and independent.

If you would like to know more about this topic, you are welcome to browse through my master's thesis that talks about mobile social networking applications using ad hoc Wi-Fi technology. Although I must warn that theses or dissertations are not the most fanciest reads :)

Images:

1. http://www.infovark.com/blog/wp-content/uploads/2008/10/social-network.jpg

Is your home passive?

2010-03-06T11:30:00.000-08:00

With increasing energy consumption and its cost, it has become important to do some radical changes in our lifestyle. Passive home is one such concept that has come up in European countries like Sweden, Germany, Austria.

Some interesting ideas behind a passive home are:

1. To keep the house tightly insulated. Hence, using wood over concrete as main building material, which is a better insulator. Also, using very thick insulation like 40 cm thick walls and 30 cm thick floors, 50 cm thick roofs.

2. To trap and reuse the heat generated by house inhabitants and appliances. Heat exchange system in a passive home keeps it properly ventilated and warms the incoming air with trapped heat.

Results: 90% less energy costs as a compared normal houses.

Swedish Government is constructing buildings based on this concept and trying to commercialize it, so that the cost of construction can be made competitive. Also, scientists have come up with viable plans to convert an existing home to passive home.

Since internally generated heat is an important element in keeping passive homes warm, they say it is important that the inhabitants are active in a passive home :)

Do watch this CNN video to get some idea about passive home technology.

Sources:

1. Image: http://www.yourhome.gov.au/technical/fs45.html

2. Link to Video: http://www.cnn.com/video/#/video/tech/2009/07/09/gg.boulden.sweden.passive.houses.cnn

3. http://www.energysavers.gov/your_home/designing_remodeling/index.cfm/mytopic=10250

Dining philosopher with a twist..

2010-03-06T01:53:00.000-08:00

A funny incident had occurred during advanced software engineering class. Prof was talking about dining philosophers problem and asked about the causes of starvation.

Somebody answered without thinking - "When philosopher has both the chopsticks, but he can't eat!" :D

I somehow controlled from LMAO, but all I could picture at that point was a dining philosopher contemplating on how to eat with chopsticks. :)

The brain that changes itself

2010-01-20T21:14:00.000-08:00

Brain is undoubtedly the most complex and intriguing machine known to mankind. For years it is thought to be similar to supercomputer, where every single functionality is performed by a fixed part inside brain. Scientists have now refuted this belief and are proving that brain is much more dynamic and self-modifying than it was thought before.

The property of the brain to restructure itself is called neuro-plasticity. In past, it was believed that brain is only developed till certain age and after that it cannot be modified i.e. new faculty of senses or knowledge cannot be absorbed or learned. This has been proven wrong by people re-learning all sensory and learning skills, after they have suffered severe brain injury or damage due to stroke or accidents. It is also shown that different functionalities are not necessarily performed by particular parts inside brain and if a particular part in brain is somehow damaged, re-learned skills might be assigned to another place(s) inside brain. For e.g. when a person, who has lost his ability to speak due to damage to speech part of the brain learns to speak again, it might not be governed by the same part of brain as before.

Use it or lose it analogy holds true for brain too. Traits are formed by repetitive use of senses that form certain growing patterns in brain (similar to pathways being formed in jungles by repetitive use of same paths). Thus traits can be difficult to get rid off, but new traits can also be formed in similar way.

The ability of brain's neuro-plasticity depends on the process called neuro-genesis or the ability create new synapses, which help forming new neural networks. Interestingly, depression slows down the rate of neuro-genesis and activities like exercising or anti-depressant drugs increase this rate. No wonder, exercising is said to be good to kill depression.

Anyways, all this blabbering was inspired from following talk. If you want to explore more, do check out this book - The Brain That Changes Itself.

Part 1:

Part 2:

To conclude, do you remember the scene from Matrix - part 1, where confused Neo goes to see Oracle for the first time? Neo tries to imitate the kid who is trying to bend a spoon. The precocious child utters, "Do not try to bend the spoon — that's impossible. Instead, only try to realize the truth: there is no spoon." I am sure it would make better sense to Neo, if only he knew about neuro-plasticity ;)

Sources:

1. Neural Network Image: http://www.skeptic.com/eskeptic/07-11-20

2. Brain Image: http://staffpsychologist.com/

3. Matrix Image: http://cmcforum.com/

4. Documentary found at http://www.documentary-log.com/

What would you do if you have 5 dollars and 2 hours?

2009-10-30T22:36:00.000-07:00

Found a video of an amazing classroom exercise at Stanford technology venture program. Teacher poses a problem with its constraints and goal. The goal: Earn maximum benefits, The constraints: 2 hours and 5 dollars. What is the most you can get if you have above mentioned constraints?

What is your idea?

Wanna know the ideas that actually aced this exercise? Well, they simply ignored the constraints (both 5 dollars and 2 hours), because they actually posed as limitations to their profits. They focused on ideas and skills they have to get the best possible outcome. The best one was the group which focused on presentation of their idea and then sold it to a company to get hired :) (Smart!)

Conclusion:

Given a problem, you gotta look at the constraints and evaluate whether the constraints are real or not? Or whether they are just distractions to take your eyes of the best solution.

Interesting!! Do watch the video, leave comments if you like it.

Sources:
http://entrepreneur.venturebeat.com/2009/10/30/start-up-studies-a-pop-quiz/

Testing Revision

2009-10-18T20:26:00.001-07:00

Its been many days I read something about testing. So I am going to read from Code Complete and Software Engineering - A Practitioner's Approach. Following are some notes I jotted down while scheming through the text.

White Box Testing:

1. Basis path testing: Making sure every independent path in program is traveled at least once.
2. Condition Testing:
i. Branch Testing: Making sure every condition in a compound condition is executed.
ii. Domain Testing
iii. Branch and relational operations testing (BRO)
3. Data Flow Testing: Checking all defined-used pairs of variables
4. Loop testing: Testing loops, concatenated and nested ones.

Black Box Testing
1. Graph based methods: Examples- Finite state modeling (GUI Testing), Transaction modeling
2. Equivalence partitioning: Creating minimal test cases to cover all classes of errors.
3. Boundary Value Analysis: Testing at boundaries of capacities, lower and upper extremes of value ranges.
4. Orthogonal Array Testing: Testing limited parameter ranges by placing them in a cube and choosing test cases that are orthogonal in cube. Helps in finding and isolating single mode faults, also identifying double mode faults.

Testing Strategies: Testing strategies are important part of SQA activities. Starting from unit testing to system testing, software can be tested at different levels and at different times during SDLC.

Unit Testing: Testing individual component (class or method) for
1. Checking interface behavior
2. Checking all independent (basis) paths
3. Checking all boundary conditions
4. Checking consistency of local data structures
5. Checking data flow within unit.

Unit testing should cover
1. Common computational errors
2. Testing error handling code
3. Boundary conditions testing

Unit testing should be kept simple and if a component is highly cohesive with another component, unit testing can be delayed until that component is built.

Integration testing: Incremental approach is favored.
1. Top-down approach: Use of drivers and stubs
i. Breadth-First
ii. Depth-First.
2. Bottom-up approach: No stubs required. Create cluster of low level components. Create drivers to test these clusters and replace drivers by upper level components.

Generally integration testing incorporates both these approaches. Program is split in number of functional modules, which are tested in bottom-up fashion. These modules are then integrated and top-down approach is used.

Regression testing: Re-testing some of existing test cases, to see effects of introducing new or changed component. Can't test all existing tests. Followed by integration testing. We test:
1. Sample of tests that represent system functionality
2. Tests for software functions that are likely to change
3. Tests for changed component.

Validation testing: Checks whether program matches its functional requirements and behavioral characteristics, also performance requirements. Deficiency list is created for any deviations found and error resolution in phases after scheduled delivery.

Alpha and Beta testing ( aka Acceptance testing): alpha tests are performed on-site, whereas beta testing is based on end user feedback.

System testing: Once software is incorporated with other elements like hardware, people, information, a series of system integration and validation testing is performed.

Recovery testing: Tests fault-tolerance of the system.

Security testing: Security mechanisms work as required.

Stress, sensitivity and performance testing: Involves software and hardware integration.

Debugging: Art cum science
Methods:
1. Brute force: Memory dumps and print statements. Least efficient but most common.
2. Backtracking: Starting from point of error, trace back the source of error.
3. Cause elimination: Speculating over different reasons of failure and testing using data set corresponding each hypotheses.

This is a fast-track summary of testing and debugging concepts. I will add some more stuff when I read more. By the way, it was fun reading Software Engineering - A Practitioner's Approach again. This was our textbook for software engineering class, during bachelors. Brought back memories of engineering days :)

Visual Studio quirks

2009-09-22T08:55:00.000-07:00

Visual studio 2005/08 is one my favorite IDEs, but it does have some quirks. One of the quirks I frequently encounter is following deploy-time error:

The OutputPath property is not set for this project. Please check to make sure that you have specified a valid Configuration/Platform combination.

I have a visual studio solution with multiple projects that depend on one another. When I try to deploy one such dependent project on windows mobile device, sometimes I get above error. MSDN forums have given some detailed explanations and solutions to this problem.

Following works for me:

1. Clean and rebuild the solution.
2. Remove the project references from a dependent project and add them again. Now deploy.

Hope this helps!

IM + Email + Social Networking = digsby

2009-09-21T23:47:00.000-07:00

I guess IM, email and social networking sites are the three most used apps nowadays. These are highly interrelated apps and currently there is some level of integration between them. Chat clients come integrated with email clients (Gmail-chat) and social networking sites (Facebook, Orkut). Multiple IM clients are already merged into one by meebo.

What if all three come integrated in one package? You don't need different apps to access these functions. Digsby tries to solve this problem. It makes accessing IM, email and social networking sites a seamless experience. Check out their site and see the video demo.

P.S.: I haven't tried this app, but it immediately caught my attention, so I am blogging about it.

Segmentation fault :)

2009-07-03T02:51:00.000-07:00

Source: http://www.thinkgeek.com/tshirts-apparel/unisex/itdepartment/5b7e/

To go or not to go

2009-07-02T07:35:00.000-07:00

With tragic death of Michael Jackson, fans who bought tickets to his upcoming concerts are facing a dilemma. Whether to ask for refund or to keep the ticket as a valuable souvenir. This is an intersting problem. If too many people ask for refund, the ticket would actually become rare, incereasing its 'collector value'. Whereas, if everybody keeps the ticket as a souvenir, it would be a worthless piece of paper. This article talks more about this puzzling problem. The problem is roughly similar to El Farol Bar problem.

Keeping the Math aside, I think an ardent MJ fan would go to the concert and keep the ticket as a souvenir.

Sources:

1. http://timesonline.typepad.com/science/2009/07/will-your-michael-jackson-tickets-be-worth-more-than-a-refund.html

2. http://en.wikipedia.org/wiki/Minority_game

Quote of the day!

2009-05-12T04:15:00.000-07:00

Inefficiencies and problems don’t persist because we lack the appropriate technology to fix them - they persist because we lack the appropriate psychology to fix them!

From Blog Said Svec

Courtesy: http://www.saidsvec.com/2009/05/11/technology-vs-psychology/

Subversion Lock is based on both working copy and user

2009-05-02T05:34:00.000-07:00

Scenario: User 'sankalp' locks a file in his working copy and tries to commit some changes to the locked file from another working copy that was checked out under same username.

Result: Commit would fail, because the later working copy doesn't get the file lock, only the first one does.

I stumbled upon this while locking a file via URL path, using FinalBuilder Subversion file lock (Actually 'Subversion Generic' action). Although the lock is successful and can be seen from repository browser client, the working copy didn't reflect it. So I had to lock the file based on its working copy path, and not based on its URL path. This made me realize that locks are specific to working copies, apart from being exclusive to users.

Also, if somehow you delete the working copy that had locked a file and cannot restore it back, the only way out seems to be breaking a lock on that particular file. Or is there any other way out?

Sources:

1. http://groups.google.com/group/tortoisesvn/browse_thread/thread/dbf3269ae304761d
2. http://tortoisesvn.net/docs/release/TortoiseSVN_en/tsvn-dug-locking.html

Looking for free online private subversion repositories

2009-04-26T05:36:00.000-07:00

Any suggestions???

Found this article on StackOverflow. But it doesn't show any clear winner for free, private or personal and online subversion repositories.

So your suggestions are most welcome...

PS: I think I found one: http://beanstalkapp.com/ . They provide 100MB storage and one repository that can be accessed maximum 3 users. Cost none.. Not bad huh?

How version control changed me!

2009-04-19T08:08:00.000-07:00

I know that the title is little corny, but little corny is OK some times :) I was looking back at the version control strategies I have been using to store my personal information/documents etc.

First there was no version control. I had many of my important documents stored at multiple places on same disk. Then I started changing the titles of the files to describe the purpose of a particular version. It worked fine when there were few versions and fewer files. Until last year, my usage of any kind version control system was only related to source code management. Although, I have worked on SourceSafe, CVS and Subversion for quite time now, I never delved into or even thought about it apart from source code management. There was a time when I would be freaked out to see a CVS conflict, and would become miserable just by the thought of merging conflicts. When I was in school doing internship, I had to perform source code migration from SourceSafe to Subversion, while preserving version history and SourceSafe labels. I took this application, modified it suit my needs - converting labels to tags and building more fault-tolerant and faster application. I had successfully migrated SourceSafe databases having 70-80 versions of each file. Also, I added a simple GUI to make the application usable. During this process, I was hooked to Subversion, for obvious reasons. Then I started taking versioned backup of all my important stuff. For a moment I thought I was the only one, until I saw this .

Anyways, it was nice to look back and realize how far I had come, as far as version control is concerned. Nowadays I am using git - brainchild of Linus Torvalds, and it seems only a matter of time I would incorporate it in personal document management system.

P.S.: One might argue why not use cloud file system that can be accessible from anywhere. Well, that might be next thing on my list (if it manages to provide the level of version control typical VCS provides)

Combining paths in .Net

2009-04-04T20:30:00.000-07:00

Whenever you are combining paths using Path.Combine(path1, path2), watch out for a subtle but deadly pitfall.

path1 should not have a front slash at the end and path2 should not have a front slash in the beginning. Things get really bad otherwise. I have realized this after wasting 5-6 hours of precious weekend sleep. I can't help cussing myself, because I have a feeling that I had made this mistake before. @#$@#!$@#$%@#!@#@!$. :)

i.e.

string path1 = "c:\\tempdir";
string path2 = "subdir\\";
path3=Path.Combine(path1, path2)
/*path3 = c:\\tempdir\\subdir\\*/

But,

string path1 = "c:\\tempdir";
string path2 = "\\subdir\\";
path3=Path.Combine(path1, path2)
/*path3 = \\subdir\\*/

In my defense, I strongly feel that the library function should have taken care of this subtle variation. (Blame .Net :) )

Anyways, find more information about this function here.

Different version formats for .Net & win32 components

2009-03-09T14:16:00.000-07:00

For a win32 dll or exe , the fileversion attribute means following:

majorversion.minorversion.releaseversion.buildversion

Whereas, a .Net component has different interpretation of these numbers. i.e.

majorversion.minorversion.buildnumber.revision

This means, if you have an exe or dll with fileversion 1.0.0.2 from a vc++ project, then corresponding assemblyversion for a .Net exe or dll for same build would be: 1.0.2.0.

This was causing little confusion while I was working with FinalBuilder to version all project executables before applying MSBuild. Right now, I have kept consistent version format for all project types and am interpreting them as win32 style version information.

Any opinions?

MS Word 2003 cheat sheet & quick reference

2009-03-02T14:39:00.000-08:00

Since I am not a superuser of MS Word, many times I need a quick reference or a cheat sheet.

Following are some quick references and cheat sheets you can easily find on www.

MS Word 2003 cheatcheet & MS Word quick reference

Sources:

1. http://www.customguide.com/pdf/word-quick-reference-2003.pdf

2. http://www.its.qut.edu.au/assist/userguides/exfiles/word.pdf

Windows mobile device platform not found

2009-03-01T11:51:00.000-08:00

If you are trying to load a windows smart device project set to .Net CF v3.5 in Visual Studio 2005, you might get this error message:

the project could not be opened because it refers to a device plaform that does not exist in your datastore

The reason being VS 2005 cannot work with .NET CF v3.5.

The workaround is to set project file's .NET CF target framework to v2.0. i.e.

<TargetFrameworkVersion>v2.0</TargetFrameworkVersion>

Sources:

http://social.msdn.microsoft.com/Forums/en-US/netfxcompact/thread/f51d6fdb-2758-4b60-9527-149a18498481/

http://groups.google.com/group/microsoft.public.pocketpc.developer/msg/8df085eaffb916a5

Remote install of DVD/CDs without any hassles

2009-02-24T15:16:00.000-08:00

This is a really simple but useful trick. If you have access to a remote machine via Remote Desktop Connection. But you are wondering how to run CD/DVD setups without having to create ISO images or virtual drives on remote machines and considering that you don't have physical access to the remote machine, do the following:

Share your local CD/DVD drive over the network.
Right Click on CD/DVD Drive icon, go to Properties > Sharing and share the drive on network. Allow only one remote access.

Map local CD/DVD drive to remote machine.
In Windows Explorer, go to Tools > Map Network Drive. Enter network location of your local drive as \\local_machine_ip\shared_drive_name .

Installation
Insert installation DVD/CD in local drive & installation window will appear on remote machine.

I have tried installing Visual Studio 2005, and Crystal Reports this way, and it worked just fine.

Good Luck!

A revelation: C# doesn't allow default parameters

2009-01-11T12:35:00.000-08:00

Wondering why?

Check out: http://blogs.msdn.com/csharpfaq/archive/2004/03/07/85556.aspx.

Quoting their reasons below:

1. The first one is that the correlation between the code that the user writes and the code the compiler generates is less obvious. We generally try to limit magic when possible, as it makes it harder for programmers.

2. The second issue has to do with things like XML doc comments and intellisense. The compiler would have to have special rules for how it generates doc comments for the overloaded methods, and intellisense would need to have smarts to collapse the overloaded methods into a single method.

The first reason kind of makes sense. Allowing default parameters is like forcing the programmer to know about default parameters before using them. Although, default parameters can make your program look magical(!) (initializing something without doing anything), it makes it harder to read.

It sucks if you are used to default parameters.

Check out this link for more How To's or FAQs in C#.

Sources:

1. http://blogs.msdn.com/csharpfaq/archive/2004/03/07/85556.aspx

2. http://blogs.msdn.com/csharpfaq/default.aspx

Cool Tool - Photosounder

2009-01-06T10:38:00.000-08:00

Check out this tool : photosounder. It converts image into sound & vice versa. Immediate question that would come to your mind is why would you wanna do that?

Well, there are many things you can actually do with this.

1. Converting image to sound could be an unconventional form of encryption.

2. You can draw music on screen. Of course, complicated the music gets, difficult (or impossible?) it will become to actually draw it. But nonetheless, you can create simple beats this way. check out various sounds made using this tool on http://photosounder.com/ (There is a small jukebox player on the right side.)

I found it interesting because I haven't seen anything like this before, so there is that WOW factor.

Lemme know if you think of any cool application of this tool..

Dell wireless connection with LinkSys routers

2008-12-25T02:38:00.000-08:00

Whenever I try to connect to a LinkSys wireless router from my dell laptop, I cannot even see the list of connected networks.

Solution:

1. Enable WZC (Wireless Zero Configuration, that provides automatic configuration to wireless adapters) service.

Go to system services (control panel -> administrative tools -> services). Go to Wireless Zero Configuration Service & start it. Also, select automatic start-up type.

2. Let Windows configure the wireless settings.

Go to wireless Connection Properties and check 'use windows to configure my wireless network setting' . Now click on 'Wireless Networks'. You will immediately see available network connections around..

Wireless power transfer

2008-10-11T16:42:00.000-07:00

Today, during wireless networking lecture my professor was talking about wireless USB drives. They are based on UWB protocols. I can understand wireless data transfer, but I still need wire to charge my USB device so that it can transmit data to my computer.

It is a coincidence that immediately after the lecture I stumbled upon one article from Technology Review that talks about wireless energy transfer. Here is the link to the article:

Emerging Technology: Wireless Power

A professor in MIT has come up with the method of generating wireless power using magnetic resonance. Also, to my surprise, I came to know that there are already some wireless adapters and pads by which you can charge your cellphone, mp3 player etc.

Hmm.. thats pretty interesting.... so do you think finally wireless world is here???

Naah, I don't think so. All current technologies work best over small range. Also, it is bit risky to be exposed to wireless energy radiations all the time. With so much radiation around, I guess scientists will come up with special type of clothings that will reflect all harmful radiations. so cloth specifications will read '100% microwave proof' or something like that. :)

Just kidding...

Sources:

1. http://beta.technologyreview.com/read_article.aspx?ch=specialsections&sc=emerging08&id=20248

Addition to SunSPOT Emulator - Solarium

2008-10-08T07:03:00.000-07:00

I am very impressed by solarium - SunSPOT emulator tool available with SunSPOT SDK V4.0.
Using this tool you can run almost all your programs on virtual SPOTs. It is real boon if you don't have sufficient number of sensor nodes.

However it currently lacks all radio monitoring, configuration functionalities. It would be wonderful, if we can emulate various environment conditions & add distance dimension to Solarium. This way, we could monitor & configure networks of virtual SPOTs, conduct radio based experiments on Solarium.

To further that, different sensing environments like day or night time, dry or humid weather, hot or cold weather etc.

What I am saying is, add to this emulator a simulator that would make virtual SPOT quite 'real'.

Makes developer feel good :)

2008-10-07T04:25:00.000-07:00

Byte Array to String and vice versa - Java

2008-09-17T04:00:00.000-07:00

This is little stupid, but I wasted some time on this. The problem is

String s = "abc123";
byte[] b = s.getBytes();
System.out.println(b.toString());

Output: [B@3e25a5

You don't get back the original string when you use toString().

If you want to get back the original string, you will have to use string constructor:

String s = "abc123";
byte[] b = s.getBytes();
System.out.println(new String(b));

Output: abc123.

Hot, Flat, and Crowded

2008-09-13T16:05:00.000-07:00

Few days ago, I attended Thomas Friedman's promotion lecture for his new book - Hot, Flat, and Crowded: Why We Need a Green Revolution--And How It Can Renew America.

Personally, I am not a great fan of his books. I have read his previous book - The World is Flat in which he describes the phenomenon of globalization in his bit of a sensationalizing style. But I liked few points he made during this lecture.

He starts his presentation with -

"German engineering, Swiss innovation, American nothing."

He says that US has has lost its edge in post cold-war era, because of the absence of a worthy competitor like USSR . He also speaks about the emergence of middle-class to affluence, everywhere in the world. Lot of countries have come up with their own niches - German technology, Chinese manufacturing, Indian service sector etc. This has led to affluent centers - small Americas (that is his term) all around the world like Doha of Qutar, Dalian of China. This in turn has led to enormous energy consumption all over the world. Now all these small Americas will lead to scarcer energy resources. More energy consumption has given rise to pollution, global warming. This coupled with exponential population growth is going to make Earth a terrible place to live. In short, the world is becoming hot - due to global warming, flat- due to globalization, and crowded - due to population growth.

He predicts the future superpower will be the one that has supremacy over 'Energy Technology' i.e. cost-effective ideas, resources, and infrastructure to generate pollution-free power sources at very large scale. I liked the point where he says that although the World has moved into 21st century, we still hopelessly rely on 19th century energy resources - thermal & hydro power, fossil fuels. Needless to say, he emphasized the dire need of nuclear power reactors in 21st century.

An innovative concept (not his) that came during his lecture was of Carbon Trading. Each manufacturing firm is given limits & license for x amount of carbon emissions. Less pollutant the firm is, more carbon credit it has. This credit can be sold to other companies thus prompting companies to be less pollutant by luring them with credit-carrot.

He also makes us the modern Noahs. We are the first generation that has to seriously care about Earth's diminishing biodiversity - rapid extinction of animal & plant species.

He openly criticizes Al Gore for not seriously publicizing his environmental activism until now. It sure makes you wonder what this man has done for environment apart from writing a book in year 2008.

Anyways, I feel that not only America but entire world needs to care about issues like these. Its no more about one country's supremacy over others, it is about saving the Earth - our only home in the entire universe.

Sources:

1. http://tinyurl.com/noah-ark

2. http://en.wikipedia.org/wiki/The_World_is_Flat

3. http://en.wikipedia.org/wiki/Hot,_Flat,_and_Crowded

4. http://en.wikipedia.org/wiki/Emissions_trading

5. http://www.goma.demon.co.uk/eco/carbon-trading.jpg

6. http://tinyurl.com/friedman-book-cover

Store for ideas!

2008-09-11T08:02:00.000-07:00

Ever thought something out-of-the-box and wondered whether that is possible or not?

Well, I am sure that happens with everybody. I guess thinking out-of-the-box is something peculiar to mankind.

Here's a thought: Why don't we have sensors in parking lots that could tell us the location of a free parking spot, if available. Imagine how much time & fuel (this one is very important now a days) we could save if we didn't have to make endless rounds of parking lot just to find out that it was full.

On googling a bit, I found some serious research going on in this field at Rensselaer Polytechnic Institute.

Also, I found a very interesting site that allows its users to publish such ideas & to vote on present ideas. Here is the link.

Actually, I was not expecting to find any site like this, so it was a pleasant surprise for me too.

Sources:

1. http://tinyurl.com/research-proposal

2. http://kimskorner.zed1.net/blog/wp-content/parking-for-the-future.jpg

3. http://www.whynot.net/

Particle Accelerator & UTA

2008-09-10T10:48:00.000-07:00

My university - University of Texas at Arlington, is a part of the much talked physics experiment - Large Hardon Collider, happening at CERN, Switzerland. Here is a news article about it. This experiment is supposed to biggest particle physics experiment by far. Its purpose is to validate & explore current theoretical claims about particle physics. Here's the list of questions that might be answered with this experiment.

University's physics department was actively involved in building the particle detector - ATLAS. Now, the department is instrumental in building PanDA - the software for managing the computer grid that will handle enormous amount of data generated by particle detectors. These Experiments are believed to generate 1 petabyte (10^15 bytes) of data in the first year.

The experiment kicked off today - September 10, 2009. You might have noticed the Google Doodle for the same.

First results of these experiments are expected to come out by late 2009 or early 2010. As I write this blog, experiments have already started successfully.

Sources:

1. http://news.nationalgeographic.com/news/bigphotos/3205477.html

2. http://www.fwweekly.com/content.asp?article=6963

3. http://atlasexperiment.org/

4. http://en.wikipedia.org/wiki/Large_Hadron_Collider

5. https://twiki.cern.ch/twiki/bin/view/Atlas/Panda

HTTP PUT Vs POST

2008-06-09T08:10:00.000-07:00

A nice post on difference between PUT and POST HTTP methods, and when to use which one.

http://tinyurl.com/post-vs-put

Amazing webcasts

2008-02-26T18:50:00.000-08:00

After long long time I touched my Google reader. And I found one really nice article about course webcasts from UC Berkeley. After surfing a bit I found many freely available webcasts from premier institutes like MIT & UC Berkeley.

For example:

Algorithms courses from MIT, webcast courses from many other universities & organizations

Now you can enjoy MIT experience at your home!!! :)

Following article speaks about how MIT's move of knowledge-sharing is having worldwide impact.

http://www.wired.com/wired/archive/11.09/mit_pr.html

Something for tooltip text

2008-02-08T15:07:00.000-08:00

While coding for CNM website I stumbled upon this cool JavaScript code that shows different types of tool-tip text .

Here's a link to it : http://www.walterzorn.com/tooltip/tooltip_e.htm

SOAP or REST

2008-02-07T19:57:00.000-08:00

For the uninitiated, SOAP & REST are web service development standards ( REST is more of a style than a standard)

I have been working on REST based web services for past 2 months now. Here's an article that talks about suitability of a particular web standard depending on application.

http://www.ibm.com/developerworks/webservices/library/ws-restvsoap/

I personally find REST pretty cool over SOAP. Its simple, no need of libraries, and is stateless. Authentication and authorization is URL based. Its more like HTTP.

Anyways, both have their pros & cons and both are suitable for different requirements. SOAP works great for a complex web service like bank transaction. Whereas REST is good for resource based push & pull services. In my case, the later was true. So, opting for REST was obvious choice for me.

sun SPOT

2007-12-24T00:25:00.000-08:00

Currently I am working on Sun's latest Wireless Sensors kit called sun SPOT. It is pretty cool thing. It contains couple of sensor nodes with one base station node. All of them have motion, temperature, light sensors built in. And most fascinating part about it is you can program them in Standard Java. No embedded programming and all. You can do lot of funky stuff with it. Go to YouTube and search for "sun SPOT" .

Pretty cool, huh???

For me, its nice way to kill time in vacations ;). Lets hope I come up with something constructive and useful.

Hello world!

2007-09-08T14:35:00.000-07:00

Welcome All!!! Howdy?

Watch this space if you are interested in random chitchat about technology, coding, science & philosophy.