Thursday, April 9, 2015

How to make your presentation effective - 10/20/30 rule

 Have you ever presented yourself in front of an audience ? Then you may have use slides for your talk to make it better.

But did it really improve or destroy your talk?

 Lets find out few facts that may be things you will not like to see if you are in an audience. Because that is the best place to give a verdict about a presentation.

Here are few common errors that i have observed in the presentations which you should avoid. 

1) Too much text in the presentation

How often have we seen the entire wikipedia or at least close to that in slides? Slides are not meant to be read. Believe me if you let the audience read slides you loose attention. You loose some of the audience. Once they are out of your story it is not easy to grab them back.  Maximum 10 words would be ideal. If you can find a single picture which gives the idea at once fantastic use that..

2) Too much slides in the presentation

Do not try to overload the presentation. Usually if have lots of slides then you are at the risk of going out of your time limits.  Be careful not to give lots of ideas in your presentation. Usually i follow a rule of 3. Which means pitch 3 key ideas to the audience and make sure they remember that 3 even after the presentation.

3) Slide formatting.

If you have letters in the slides the text size and the text formatting matters a lot. Text should look great in the presentation screen and not only on your laptop/desktop screen. Use bigger fonts as possible and make sure everyone can see without any effort. Use a proper standard font which looks neat ,well spaced and easy on eyes.

Following video describes a better way to optimize your slides or a good framework. Using 10/20/30 rule.

1) 10 -  slides
2) 20 - minutes
3) 30 - minimum font size.

Just watch this short video and you will understand it better.

Thursday, April 2, 2015

What you should know if you travel in Paris

 I had  a dream to visit Paris , City of love with a breeze of Romance. It is a lovely city to explore lots of things. But if you are a traveller knowing few things i have experience will make your journey much nicer :).

1) If you arrive in Beauvais airport and you need to find a way to go to Paris city center you can get Bus tickets from here. Because Ryan air which is most of the time cheaper will land only in this airport. Most of the people suggest other airports which is near to Paris but if you can spend one extra hour you can land in Beauvais and come to city center by bus. Because it (flight + bus) may be cheaper than some flight options.
2) Paris city metro is little bit complicated but it covers almost all the areas. It may be cheaper to get Paris 10 tickets options which will give you 10 tickets at once at a discounted price.

3) Get a metro map and correctly identify zones and lanes. Because there are some connecting lanes which can be confusing a bit. And also make sure you are not going through an exit when changing lanes or metros, Because once you do you ticket become void and have to use another ticket. Some routes combine rail and metro and may be cumbersome to find them. So to make things easier i opted only to use metro even though the ticket is valid for both to make my journeys hassle free.

3) You should visit paris by night which is more beautiful than the day time. I am posting few pics below and you can decide :)

4) Louvre is an amazing place to visit. But it takes time to explore since it is massive. Plan to spend at least  5 to 6 hours of the day there. Make sure you check the timetable as they closes the Museum on time

Monday, March 30, 2015

How does the confidence look like?

"John Carpenter (born c. 1968)[1] became the first millionaire on the United States version of the game show Who Wants to Be a Millionaire on November 19, 1999" [1].

The most important part of the show is the last question where he attempted to claim the final prize. Watch the following video which is too good for being a contestant at his final question for 1 million dollars.


Sunday, March 29, 2015

How to build Open JDK 9 on Mac OSX Yosemite

I have been struggling lately to find good resources to compile and change OpenJDK. There is a problem with Mac OS Yosemite as it uses Clang as the compiler. But Open JDK 9 builds without a problem. I am adding useful resources here just incase someone finds it useful.

How to build it

1) hg clone jdk9

2) cd ./jdk9

3) bash ./ (This will take sometime to download the sources so be patient. May be few hours sometimes)

4) when you try to issue command ./configure you will get the following issue.

configure: error: Could not find freetype! configure exiting with result code 1

5) You need install Xquartz to eliminate the above issue.

6) type make all to build the system. In the make file you can see different options to build the system.

7) Built image will be available usually at at build/macosx-x86_64-normal-server-release/jdk/

If you are trying on Mavericks i could find the following resource which seems to be useful but did not verify whether it actually works 100%

Friday, March 20, 2015

What should you do when your mobile phone is lost?

Have you ever lost your mobile phone in your life? I have lost twice and yes it is not a great position to be. But these two incidents had two different implications. When i lost my first phone it was a nokia phone (N71 to be exact) which was quite a smart phone at that time around 2007. Yes i wanted to find the phone but could not the story was over and life went on. But...  Second time i lost a Nexus 4 which is android.

So what is the big deal?

"Oh my gmail account"

When i sensed for the first time that i have lost my mobile phone the first thing that came to my mind was "oh gosh all my accounts are there". But fortunately i have thought about this topic before i lost this phone so the next steps to be done was obvious to me. I think you might be interesting and you may have better suggestions as well. :)

Three important things

1) Android phone has your email account , If you use gmail as the primary account then you might use gmail for most of other online accounts as well. (Facebook , twitter, ebay so on...)

So if anyone can get hold of it then you are doomed, Because anyone can use forgot my username or password reset features to take control of other account.

2) Android phone has all your data :). In this what google does not back up. I think only your life which cannot be backed up restore later.

3) If your phone is not pin protected or not protected with any other mechanism then you are at the highest level of vulnerability.

So what I should do?

1) Change your email address password immediately. This is very crucial and the most important step

You can check login history here. If there is a recent login just after you

2) You should visit Using this you can erase your mobile phone data (or in other words do a remote wipe out of data).

This will only happen if the device is online.

If you need to locate the device you need to do it before the wipe out using the same above link.

3) You may register a police complaint at last.

Finding the phone is more important. But for someone who needs to protect data, other accounts and also privacy above mentioned steps becomes vital.

If you have other suggestions please do share in comments :)

Wednesday, February 25, 2015

When should you give up ?

 When should i give up something?

 So you should never give up something until you find something you really want. Yes... Until you find it.. :). We usually draw the give up line on what society believe, Not what we really believe. We often create boundaries on what society believes achievable. Until someone who really believe him or herself step in expand the limits.

We never thought someone could fly until wright brothers flew, We never imagined a world speaking with someone thousand of miles away until Alexander Graham Bell invented the first practical telephone. We may be prisoners of the society unless we brave enough to reach outside.

So When should we give up on something? We should give up on the day we win the game. It seems so simple, obvious but senseless.

Watch the following video if you need to breath a life into what i mentioned.

"It's Not OVER Until You Win! Your Dream is Possible - Les Brown"

Tuesday, February 17, 2015

How to use python BOTO framework to connect to Amazon EC2

 Python Boto framework is an excellent tool to automate things with Amazon. You have almost everything to automate Amazon EC2 using this comprehensive library.

A quick guide on how to use it in your project

1) Configure your EC2 credentials to be used by your application using one of the followings.

  • /etc/boto.cfg - for site-wide settings that all users on this machine will use
  • ~/.boto - for user-specific settings
  • ~/.aws/credentials - for credentials shared between SDKs

2) Refer the API and choose what you need to do.

3) Sample code for a simple autoscaler written using Boto framework. You may reuse the code in your projects quickly. This autoscaler spawn new instances based on the spike pattern of the load.

Tuesday, February 3, 2015

Perfect Memory.. A Skill developed or a gifted super natural ?

 In the previous post i discussed about the importance of developing a most important gift a human has inside his brain.... the memory.

In this world we have externalized most of the important stuff to external digital world. In a way it has made things evolving faster. We are gathering much more knowledge than earlier. Wait.. Is it knowledge or knowledge pointers?

The most suitable word is knowledge pointers using which we can retrieve knowledge easily. Imagine a world without internet or any other form of knowledge reference. How far can we survive.? We are loosing our capability of retaining information in our brains day by day and making the external storages cost effective at an similar pace.

I am striving to regain that capability if i have lost and see how far i can succeed. Because following video will be one of your eye openers if you are one of the crazy people how would like to travel back to history and master one of the key aspects of a perfect Human being.

This is a Ted talk which you will be fascinated to watch.

"There are people who can quickly memorize lists of thousands of numbers, the order of all the cards in a deck (or ten!), and much more. Science writer Joshua Foer describes the technique — called the memory palace — and shows off its most remarkable feature: anyone can learn how to use it, including him"

Monday, February 2, 2015

Do we need to master memory in Google's Era ?

 If you need any information you just type Google. Simple is n't it? So do we have to bother about memorizing anything this world? Is there a pay back for what you memorize? Can we rely on internet and only just learn how to search and can we be successful?

 I am sure most of the people have forgotten the importance of memorizing things in this information age. But the people who master memorizing things excel more often than people who do not. The simple reason is you can apply only what you know.

As a Software Engineer and as a Masters student in computer science we often think for any problem we can just Google and find answers. But how fast? You may say within seconds you may have thousands of results before you.

But... You need to type go to the first answer and if you are lucky you have a hit.. If not repeat until you find the correct answer. Imagine you have things in memory.... It will not take fractions of a second to retrieve. It will be simply comparing to a cache retrieval to a Hard disk access.

People often think there are lots of information how can we memorize all these things? Yes it is true that in this digital world content is being produced super faster. But you have to be super smart to filter out what is important to you and memorize those things. We often underestimate the capability of retaining information in our brain and lazily forget techniques to master memory.

If you have not read following book is a great source of encouragement as well as a learning tool by a
Memory Champ Kevin Horsley.

Following video is one of his world record breaking videos [Successful World Record attempt in Pi matrix memorization]

Thursday, January 29, 2015

Learning Math and Science - Genius Mind

 Do you think learning math and science is something alien from outer universe ? Do you struggle to solve complex mathematics or science problems? If you keep on adding questions there will be a lot to add on. Because even i have some of those problems in my mind.

I excelled in college and was able to get into the top engineering University in Sri Lanka. At present i am reading for my Masters Degree in Distributed computing in Europe which involve Science and Mathematics heavily.

If you read my post Want to Learn anythin faster was a spark to ignite my habit of learning. Often i was comfortable at Theoretical subjects which needed rote memorization or comprehension. I wanted to understand the reasons so anyone who suffers the same can be benefit of it.  Further there is a common misunderstanding that maths is hard and complex even before attempting to realize the beauty of it.

As Human beings we are computing machines. We can do lot of maths in our head to survive in this world. To measure the distance by contrasting with other objects, Cross a road safely without being hit by a vehicle and the list is endless..So then why we cannot do it in the class room?

I often find the way we approach math and science is wrong. There are several observations that i have made why we think maths is complex.

1) If we relate a story to a problem and try to solve it will be easier than denoting it with x,y or any other mathematical notation. When we have a story we have solid mapping of the problems in our mind so understanding a problem and working towards a solution makes more realistic. Good mathematicians or scientists create problems more vivid in their minds. They live in it as real worlds. Symbols are just notation to express what they understood in common language.

2) In classroom or tests we try to rote memorize concepts. Maths and science is super easy when you understand the fundamentals about it. You need to feel or live with the concepts to solve problems. learning an equation will not give you the ability to solve problems unless it is just a substitution.
If you clearly observe an equation, it is a complete story. It is a story of how incidents of left side will come to a common agreement on your right hand side.

3) Connect what you learn with what you know. Our brain is structured as a web. If you do not want to lose newly learnt concepts you have to link and bind with what you know to avoid loosing them. Isolated memory islands disappears soon. Try to relate to whatever the concept you have really understood and try to construct on top of that. If you find anything hard at once try it repeatably in different ways but always have a break. Our brain needs to digest and it takes time to assimilate.

I am still researching and try to apply those concepts in practice to see how they work in real world. But it has been producing interesting results so far. I find myself learning more complex math or science problem than before as i changed the approach.

I am currently reading this book which is an excellent resource for who wants to develop a "mind for numbers". Happy learning.