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Christopher J. MacLellan
HCI Institute
Carnegie Mellon University
cmaclell@cs.cmu.edu

Curriculum Vitae
Research Statement
Teaching Statement

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  • Problem OverviewMany machine learning applications require the use of both nominal (e.g., color="green") and numeric (e.g., red=0, green=255, and blue=0) feature data, but most algorithms only support one or the other. This requires researchers and data scientists to use a variety of ad hoc approaches to convert troublesome features into the format supported by their algorithm of choice. For example, ...

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  • Problem OverviewStatistical models of student learning, such as the Additive Factors Model (Cen, 2009), have been getting a lot of attention recently at educational technology conferences, such as Educational Data Mining. These models are used to estimate students' knowledge of particular cognitive skills (e.g., how to compute the sum two numbers) given their problem-solving process data. The learned estimates can ...

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  • Problem OverviewFor one of my projects, I need to generate a random permutation (without repetition) of the integers from 0 to n. In my particular situation, I am generating permutations for large n and I am only using a small portion of the values at the beginning of sampled permutation (e.g., generating a permutation of a shorter length k, where ...

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  • I have been struggling over the past week to come up with a solution to read a 10k NTC thermistor for my work. I eventually purchased a USB Bit Whacker (UBW) to perform my A/D conversion as well as satisfy my needs for gpio. Hardware in hand I had to figure out how to measure resistance with a analog input. ...

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  • Insight problems, or problems that are nearly impossible to solve without the crucial insight (with which they become trivial), are an interesting class of problems lead individuals to interesting conclusions about the subconscious mind. Namely, the experience of insight hints at our subconscious autonomously solving problems for us and magically making the solution aware to our conscious mind after the ...

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  • I recently watched Randy Pausch's lecture on time management and, like many time management gurus, he emphasized the need to keep track of how you are spending your time. Once you have an idea of how your time is being spent you can make some adjustments to focus on the most important things first (see "The 7 Habits of Highly ...

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  • For my social media mining project on twitter sentiment aggregation I need a working version of University of Pittsburgh's Opinion Finder 1.5.I went to the website here: http://www.cs.pitt.edu/mpqa/opinionfinder_1.html and requested version 1.5.First unpackage the download and enter the directory:tar -zxvf opinionfinder.tar.gz cd opinionfinder Installing SundanceThe first part of the install is installing sundanceTo do this you'll need cshsudo aptitude install ...

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  • This article is a continuation of my last one and focuses on the topic of Bitcoins. Instead of how to mine bitcoins on your computer I am going to discuss how you can use other people's computers to do all the hard work using Javascript and PHP.Mining for Bitcoins with JavascriptA recent development in the bitcoin community is Javascript Bitcoin ...

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  • I have been hearing about bit coins a lot lately (here and here) and so I decided to check them out and give a basic overview of how to get a bit coin system running on Ubuntu. It was much more confusing then I thought it would be but I eventually got it working. Of course I immediately saw a ...

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  • Twitter has become an international web phenomena where people report their everyday ideas and opinions. Along these lines sentiment analysis of tweets has been seeing a lot of attention lately. There have been articles in Wired Magazine and Bloomberg about using twitter to predict stock market trends. Work by economists at Technische Universitaet Muenchen (TUM, the Technical University of Munich) ...

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  • I recently purchased a UBW (premade) and a UBW PTH kit (both 18f2553) from the Sparkfun website for a project that I am doing at my work. For this project I need to be able to read a thermistor (ADC), communicate with a Pololu Qik 2s9v1 motor controller (UART), and interface with an home brewed LED controller card which is ...

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  • I just finished the first chapter of Machine Learning (Mcgraw-Hill International Edit) by Tom M. Mitchell. This chapter discusses the very basics of how to write a learning system and serves as an introduction to the rest of the book. As part of reading the chapter I decided to do exercise 1.5: Implement an algorithm similar to that discussed for ...

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© Christopher J. MacLellan