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3 hints for Excel excellence

July 20th, 2011 No comments

Excel is the go-to tool for business calculations. Simple or complex, weeks of work or merely minutes, you’ll use Excel eventually. As with any tool, knowing a few tricks can transform the output from a clunky mess to a useful, beautiful creation.

  • Learn before you hack
  • Make it pretty
  • Document everything

These three hints apply to lots of life’s endeavors,
but let’s talk about how they apply to Excel.

   Click to continue →

A PhD’s Guide Getting Consulting Jobs

August 1st, 2009 11 comments

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:

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!

Sparse Field Active Contours

April 21st, 2009 95 comments

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!)

This code can be used according to the MIT license. As long as this work is appropriately cited and attributed, and not being used for proprietary or commercial purposes, I’m fully supportive of you using it. Please drop me a line if it helps you!

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

Fast 3D Stereo Vision

April 14th, 2008 47 comments

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!



[red indicates close, blue indicates far away]

 

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.

This code can be used according to the MIT license. As long as this work is appropriately cited and attributed, and not being used for proprietary or commercial purposes, I’m fully supportive of you using it. Please drop me a line if it helps you!