Data Science Preparing data for a machine learning model. Before you're ready to feed a dataset into your machine learning model of choice, it's important to do some preprocessing so the data behaves nicely for our model. In an ideal world, you'll have a perfectly clean dataset with no errors or missing values
Data Science Machine learning overview. Preface: this post is for the complete novice in the field of machine learning in an attempt to orient readers for my other posts on machine learning. This is a high-level view of machine learning. What the heck is machine learning? The whole concept of machine learning is figuring out
Data Science Linear regression. Linear regression is used to predict an outcome given some input value(s). While machine learning classifiers use features to predict a discrete label for a given instance or example, machine learning regressors have the ability use features to predict a continuous outcome for a given instance or example. For
Data Science Decision trees for classification. In this third post on supervised machine learning classifiers, I'll be talking about one of the oldest and most widely used techniques - decision trees. Decision trees work well with noisy or missing data and are incredibly fast at runtime. They're additionally nice because you can
Spring Break in Silicon Valley This past week I was invited to spend my Spring Break in Silicon Valley meeting with startups founded or connected with NC State alumni. Here's a short description of each visit and my takeaways. General Remarks One of my favorite things about the Valley was a culture of
Life On thinking critically and skepticism. It really clicked for me sophomore year of high school. I had gained an interest in eating healthy and was doing a lot of research online to figure out the optimal healthy lifestyle. Now, the area of health can be quite a confusing one seeing as almost every food in
Life A guiding principle for life. One day, when I was a freshman in college, I walked into my mentor's office and he clasped his hands together at his fingertips, moving both hands forward as one. He asked me, "what am I doing?" to which I replied, "I don't
Resolutions New Year's Resolutions 2017 Be more intentional with my time. When reading On the Shortness of Life by Seneca, I came across the following passage: It is not that we have a short time to live, but that we waste a lot of it. Life is long enough, and a sufficiently generous amount has
Life Strategies for understanding a concept. In my last post on learning (found here [https://www.jeremyjordan.me/on-learning-and-intrinsic-motivation/]), I presented a different way to think about the learning process. In this post, I'll focus mainly on the struggle phase and detail strategies for reaching your "a ha" moment. Think like a
Data Science Grouping data points with k-means clustering. K-means clustering is a simple method for partitioning $n$ data points in $k$ groups, or clusters. Essentially, the process goes as follows: 1. Select $k$ centroids. These will be the center point for each segment. 2. Assign data points to nearest centroid. 3. Reassign centroid value to be the calculated
Life Featured On happiness in life. Life isn’t about happiness. Life is about feeling the full range of emotions. Life is about exploring the human capacity. Convenient happiness is a facade. Life presents its attributes in a dualistic nature. Pushing through pain allows us to experience bliss. Challenging ourselves, feeling weak and vulnerable, allows us
Materials Science Harvesting energy from vibrations for powering small electronics. Here's a paper I wrote examining piezoelectric vibration energy harvesters. Enjoy! Further reading (papers I didn't have time to read before turning this assignment in but would like to revisit): * Power transfer of piezoelectric generated energy [https://www.google.com/patents/US5703474] * Strategies for increasing the
Materials Science Atomic force microscopy for studying surface topology. Ever wonder what a surface looks like at the microscale? Atomic force microscopy is commonly used in materials science to visualize surface topology. While it is often considered to be quite slow, it is often a useful materials characterization technique. Image credit [http://staff.ustc.edu.cn/~bxlin/harvest_e.
Materials Science Ductile to brittle transitions in materials. Understanding of fracture behavior is useful in selecting materials for product designs, and it is incredibly valuable to know if a material will experience a ductile-brittle transition and what temperature this transition occurs. Knowledge of a material's ductile-brittle transition temperature can prevent catastrophes such as the WW2 Liberty
Life On learning and intrinsic motivation. During a tutoring session last week, I was working with one of my students and could tell that while she could solve most of her homework problems, she still didn't feel confident with the subject. I encouraged her to take some time to dissect the concepts and try
Materials Science What is x-ray diffraction? X-ray diffraction is a common materials characterization technique that allows for identification of crystal orientations and interatomic spacing. X-rays are used for this because the wavelength is on the same length scale as interatomic spacing and lattice parameter values. What's going on? An x-ray is generated in a
Materials Science How does scanning electron microscopy work? Ever wonder how we can see things so small, the human eye doesn't even know it exists? Today I'll be writing about how scanning electron microscopes allow us to see far beyond what traditional microscopes can provide. You see, optical microscopy (which uses visible light waves
Data Science Identifying related bodies of text using TF-IDF vectorization. Term frequency-inverse document frequency (TF-IDF) vectorization is a mouthful to say, but it's also a simple and convenient way to characterize bodies of text. Due to its simplicity, this method scales better than some other topic modeling techniques (latent dirichlet allocation, probabilistic latent semantic indexing) when dealing with
Life Rejection is not a setback, it's a redirection. I decided to write this post after I found out that I was not selected to go on a trip sponsored and subsidized by my school. It was a really great opportunity to visit startups in New York that I was looking forward to, but there were only a limited
Materials Science The lotus leaf: how nature makes water-repellent materials. Ever wonder what makes a material water-repellent? Hydrophobic materials can be useful in a myriad of applications, basically anywhere where you don't want your things to get wet. To figure out how to engineer materials with better hydrophobic properties, scientists have turned to nature (specifically, the lotus leaf)
Life Personal reflections on self-confidence. This past Friday night I went home to cook dinner with my mom and spend some time with her as the school semester is winding down. After dinner, we were chatting and I told her that I see myself following the entrepreneurial path after graduating college. I said, "You
Life Life is not a linear progression. Rather, it's a grand adventure. All too often during my college career, I find both my peers and myself under great pressure and stress trying to figure out what we want to do and how we want to live our lives. It's easy to find ourselves
Projects My whiteboard stand-up desk. As a student who frequently spends long hours at my desk studying and doing homework, I often wish I could get up and move around or at least not be sitting all day. You've probably seen a number of articles detailing the negative health effects of sitting. So,
