Shawn Lankton Online

In this three-part series I’ll give you a how-to for getting an interview, preparing for it, and dazzling the interviewers once you’re across the table. These are the main topics we’ll cover:

• Part 1: Branding Yourself and Making Making a “Wow” Resume
• Part 2: Preparing for Your Case Interview to Get Bulletproof
• Part 3: Talking about Your Experience and Sounding like a Bad-ass

Leaving academia and joining consulting firms is a something many PhD students (myself included) are getting interested in. Firms like McKinsey & Company, Boston Consulting Group (BCG), and Bain & Associates once hired mostly MBAs but are now branching out to hire MDs, lawyers, and PhDs.

I wanted to make a big impact with the skill I learned during my PhD. I got excited when I heard about consulting because it promises just that. In the next three parts, I’ll take you through the big lessons I learned while preparing and interviewing: How to get an interview, how to nail the case, and how to dazzle them with your experience.

Part 1: Branding Yourself and Making Making a “Wow” Resume gives you pointers to polish that scruffy science look off your C.V. and generally control your “personal brand” so that interviewers are impressed with you long before you walk in the door.

Part 2: Preparing for Your Case Interview to Get Bulletproof talks about how to approach the case and how to practice so that you can shine while others look dull. I’ll give you some simple exercises that will improve the structure and creativity of the “case” portion of your interview.

Part 3: Talking about Your Experience and Sounding like a Bad-ass covers an important and often overlooked portion of a consulting interview… talking about yourself! I know you have some amazing stories to tell. This sections shows how to make your stories say the right things about you.

Please enjoy!

Disclaimer: I recently went through the application and interview process with a top firm, came out with an offer, and signed it! In this series, I share my experience and give some ideas for people on a similar path. However, at the time of writing (July 2009), I do not have any inside information on how any company conducts their hiring. These are just my thoughts!

Active contour methods for image segmentation allow a contour to deform iteratively to partition an image into regions. Active contours are often implemented with level sets. The primary drawback, however, is that they are slow to compute. This post presents a technical report describing, in detail, the sparse field method (SFM) proposed by Ross Whitaker [pdf], which allows one to implement level set active contours very efficiently. The algorithm is described in detail, specific notes are given about implementation, and source code is provided.

Fast Level Sets Demo

The links below point to the technical report and a demo written in C++/MEX that can be run directly in MATLAB. The demo implements the Chan-Vese segmentation energy, but many energies can be minimized using the provided framework.

Sparse Field Method – Technical Report [pdf]
Sparse Field Method – Matlab Demo [zip]

To run the MATLAB demo, simply unzip the file and run:
>>sfm_chanvese_demo
at the command line. On the first run, this will compile the MEX code on your machine and then run the demo. If the MEX compile fails, please check your MEX setup. The demo is for a 2D image, but the codes work for 3D images as well.

My hope is that other researchers wishing to quickly implement Whitaker’s method can use this information to easily understand the intricacies of the algorithm which, in my opinion, were not presented clearly in Whitaker’s original paper. Personally, these codes have SUBSTANTIALLY sped up my segmentations, and are allowing me to make much faster progress towards completing my PhD!

Thanks to Ernst Schwartz and Andy for helping to find small bugs in the codes and documentation. (they’re fixed now!)

For more information regarding active contour, segmentation, and computer vision, check here: Computer Vision Posts

Recently, I started looking at faster ways to perform dense stereo matching for some work with 3D video. After some experimentation, I found out that by using a selective mode filter paired with naive correspondence matching, I was able to get satisfactory results very quickly. Check out the slide show below for some results!

Here is a download-able Matlab demo, which should work on any pre-aligned stereo image pairs:

stereo_modefilt.zip

The entire code is written in Matlab/C++/MEX. The stereo matching is all in Matlab, and the selective mode filter is coded in C++ and callable from Matlab (meaning it must be compiled before it can run). Currently, the correspondence is the major bottleneck, so anyone who can improve this, please let me know! Enjoy.

With the easy availability of scientific papers through the internet, it is easy to quickly get your hands on tons of pdfs. Then what? I look through the pile very quickly and pick out the one or two papers that look the most relevant. This quick pass consists of glancing at the abstract and the figures.

Knowing that this quick and dirty scan is probably becoming the norm, I’ve started including a telling graphic right in the Sweet Spot. This is a term my colleagues and I have come up with for the top of the right column on the first page. Check it out:

Including the Sweet Spot graphic may get your paper read more, it may get your paper read less. Either way, it helps the reader make a snap decision about whether or not your paper is of interest to them. I feel like it makes the paper visually more attractive and inviting, too.

Any other Sweet-Spotters out there?

I want to share the lessons I learned recently when writing a paper. These were some revelations that helped me get over the procrastination hump and really set me on the writing fast-track.

1. Start with a thesis
2. Do all the experiments next
3. Recursive outlining
4. Finish it up

Read on for an explanation of each of these steps:

Start with a thesis

Before you do anything else, write a short, to the point thesis topic. It should be one or two sentences and the entire paper should be written to prove that thesis. I stuck mine to the wall above my desk to help keep me focused. They tell you to do this in grade school, and when you’re all grown up, the same rule applies. This will forever-on be the first thing I do when I sit down to write a paper.

Do all the experiments next

All of your experiments should be designed to support your thesis, and completed before you do anything else (so that you know your thesis is right). If your thesis turns out not to be right, then you have to go back to the beginning and pick a new thesis!

When I say experiments, here I mean the work that you’re writing about. In my case ‘experiments’ are figures showing the results of my computer vision algorithms. For someone else it may be analysis of a client’s financial data or a computer simulations of particle movement through a turbulent fluid field.

In any case, doing these with the thesis in mind, and before writing ensures that the experiments are relevant, and help to prove the thesis.

Recursive Outlining

In recursive outlining I start with an outline of sections: Introduction, Background, Novel Algorithm, Results, Conclusion. This takes no time because its the same for almost every paper. Next, go though and add sub-sections, then sub-sub sections.

At this point, most typical ‘outlining’ stops. However, keep going. Add sentence ideas to each sub-sub section, and start making rough guesses about where graphics will go. Add key words to those sentences ideas. All the time, keep the thesis in mind.

Now your paper has all of the ideas you want to present in a very rough form. Inevitably some sections will be sketchier than others, but now the process of refining the text can become very compartmentalized without sacrificing overall idea of the paper.

Finishing it up

What the process until now has done is to take apart the paper into these little tasks. The final steps are to turn your sketch for each sub-sub section into an concise, eloquent-sounding, finished piece of writing. Once you have done this for all the sections, give it a final read-over and its done.

Keep in mind that some of these steps may take days, but by following this process you always know what your next action is, and you don’t have to waste a lot of time doing pointless things or re-doing things that were directed towards the wrong point.

It’s true that I have precious little paper-writing experience, but these revelations have helped my writing considerably. I plan to post updates to this as my experience grows and my method evolves. If you have any good tips along these lines, please share them in the comments!