Caltech

One *Final* Time

 

AHHH it’s FINALS WEEK!!! And yes, unlike at Caltech where I have been known to take the occasional 100 mile trip to go to the beach and get Korean-American fusion during finals week, I am STRESSED.

 

Actually though, this has been quite likely the most stressful week of my life since my last week of IB exams in high school. Granted though, I had reason for that. I had four exams this season, three of which were this week, and two of which were yesterday. A normal Edinburgh student usually takes three classes and only has one or two of those with exams. So let’s just say it was a bit of a heavy load for me this term. Even my other caltech friends didn’t have 4 tests.

 

And it’s further stressful because the testing format is about as dissimilar from Caltech’s as one could physically get. All but one of my exams were closed book. I already learned the hard way on hydrogeology that that doesn’t mean that the exams are any less comprehensive on material, they just expect you to memorize legitimately everything (which is something I am historically bad at). Furthermore, the exams are all held in lecture halls in very strict, proctored exams. The sort of place where you have to raise your hand if you want to go to the bathroom.

 

Actually it really is funny how much these tests resembled my IB tests. Even the pink paper they used for the answer books was exactly the same. I was even able to recreate my high school pre-test ritual, with a new Scottish twist. Usually in high school I would drink an energy drink and listen to pump-up tunes ending with Eminem’s ‘Till I Collapse (dorky, I know). In Scotland I’ve now added the LIDL brand chocolate chip muffin as the healthy and nutritious breakfast that I need to fuel my brain through an exam. Realistically, they’re pretty mediocre muffins, but I’ve had a minor addiction to chocolate muffins and they’re the most price-per-quality-efficient option given my rate of consumption. Anyways, I have one more exam tomorrow: Land-Atmosphere Interactions. This is going to be my second hardest test, but luckily I only need a 31 on it to pass, so I’m luckily a bit less stressed. But also, I have to finish packing today (which is what I’ve procrastinated). So cheers to that haha. Also enjoy the assortment of random Edinburgh pictures. They wouldn’t let me take selfies in the exam room.

 

To passing all my classes! And thank goodness I’ll never have to sit finals like this again.

 

— Chandrew

 

 

It’s Studying Time

Well, the week before finals week is finally here. And I spent that studying, but also, doing the ever-important finishing of reports, and honestly, taking a couple of much-needed naps to catch up on everything else.

Studying is a bit different here in Edinburgh. The biggest difference is that every single lecture is usually recorded. This means it’s very easy to have a lazy day of staying in bed and re-watching the lectures you missed or that you zoned out during. The most helpful part of this is that you can repeat parts of the lecture you don’t understand. So instead of getting pointlessly lost, you can repeat the same 5-second clip until the cows come home. The other major difference is that every past exam from any year this course has been taught is posted online. They change the exams significantly every year, so they’re able to put up all the past papers for you to do. This is quite helpful, as the exams have certain trends that allow you to pick out what the instructors think are important topics, and thus hone the area you’re studying around those subjects.

And, as with any good week of studying, David and I decided to take a bit of a study break and spend some time at the holiday Christmas party. The student union (basically the student government) runs this giant venue that got out a snow machine and some sick early 2000s tunes. And free santa hats. We have a lovely photo of us sipping water and looking up and to the left. I don’t know why they felt the need to post that but who knows ahahaha.

And I designed a guitar body! Just for fun aha.

Oh! And we got free tickets to see the dress rehearsal of The Lion King in Edinburgh. This amazing experience was courtesy of the Singapore society, and we got to go out see it just a few days before anyone else. It was a wonderfully put on show, beautiful puppets (which weirded me out for most of the time) and generally great singing – although the kids did pronounce the “can’t” in “just can’t wait to be king” with an extremely heavy London accent which was a bit odd.

More theater soon! (we just got tickets to Les Mis in London – the dream of my theater life to see.)

--Chandrew

Building a BLDC Motor Controller

EE91 is a lab course that all electrical engineering majors have to take. Typically, everyone takes it in their senior year, but I have some hardcore friends who took it as a junior. I am taking the class this quarter, and for it, I am building brushless DC motor control with my partner.

This class is a project based class with presentations and lectures sprinkled through out. This means that the bulk of our grade is attributed to our final project. However, we have to hit various milestones along the way like completing block diagrams and schematics. For each of the milestones we have to present to the class. The goal is to simulate an industry setting where we can get our designs reviewed by our peers for improvement.

So far, we are only at the stage of simulating the circuits we are designing. We broke down our circuit into multiple sub-circuits that we are testing independently. We are running our circuits in LTSpice to see what the responses are for frequency sweeps. In a sense, we are testing to make sure that our circuit runs properly under a range of conditions. After verifying that it could theoretically work, we need to build them out on breadboards. If we are really confident, we can order the PCB right away and test there.

This would be my first time making an actual PCB. Last quarter, when we built function generators, I had the opportunity to make a PCB. However, PCBs are expensive and the project was self-financed, so I chose to solder instead. This time around, our circuits are too complex to solder properly. Furthermore, I feel like I won't feel like a true electrical engineer until I've designed a built a whole system from scratch. PCBs are a large component of that.

For the next two weeks, we will test our circuits then finalize them for PCB production. Then, our final task would be creating documentation. I am pretty excited for how the motor controller will turn out. I will keep you all posted on the progress and the final product.

 

 

 Image courtesy of Nidec.com.

Netflix Competition (CS156b)

If the Netflix competition was one in which we competed to see how many consecutive episodes of Netflix originals we can watch in one sitting, I'd be a touch competitor. Unfortunately, that is not the case for CS156b. The class is about machine learning and is revolved around the Netflix competition. Basically, we are given 15GBs of data of users, movies, rating times and ratings. We have to create models that train on this data to predict future ratings for the users. We make presentations every two weeks about our progress, and we compete with each other to see who can get the lowest Root Mean Squared Error (rmse) on the test set.

This class is pretty open ended in that we can try any model of our choice, but there are packages that are off limits. This meant that we have to write model classes from scratch in C++. As someone who prefers python, I was not so keen to use C++, but since the data files are so big, we have to use a language that allows for faster computations. One thing to note about the data is that all the user and movie information is encoded with IDs. As such, you cannot bin it into age groups or genres. You have to use models with latent factors that you hope can learn these groupings implicitly.

Most groups go with SVD (singular value decomposition) and its variants. This is linear algebra where you convert the data into a giant matrix and perform various factorizations. Of course, on the subject of matrix factorization, there are so many possibilities: probabilistic matrix factorization, generalized matrix factorization etc. Other models we included are clustering (K-Means, K Nearest Neighbors) and a restricted Boltzmann machine (RBM). We wanted to use neural nets and auto-encoders as well but ran out of time to debug them. Finally, with all these different models, we blend their predictions using a validation/probe set using gradient descent and boosting.

We actually started out at the very bottom of the rankings. We were the only group to not have met the first milestone. However, we met with a lot of TAs to debug code and eventually, we ended up the middle of the pack. We were 10th out of 19 groups (We were team TBD because there was a lot To Be Done). I am pretty proud of our progress and of everything I learned along the way. I think this is my favorite class this term and would highly recommend it to anyone interested in data science and/or machine learning.

 

Building a Function Generator (EE90)

EE90 is a project class. Every year the theme is different. Two years ago it was to build a mouse trap. This year, it is to build an analogue function generator. There are minimum requirements that we have to achieve, like generating three types of waves: sine, triangle and square. We also needed to achieve a certain frequency range and have an adjustable amplitude. The rest of the design is flexible. This can include wave modulation, DC/phase offsets, or even packaging. The goal of the course is to simulate an industry setting where we are asked to create a prototype of a product with certain features.

I started out quite ambitious. I wanted to do AM and FM modulation, and add a DC offset to mine. However, I spent too long debugging other parts of my circuit that I ran out of time. Don't worry, I did not procrastinate until the very end. This isn't a class where we get the syllabus and just checks back in with our final product. We have a project proposal as well as two midterms. The project proposal makes us think about what we hope to achieve and the modules we would need to achieve it. The first midterm requires us to present a schematic of exactly what circuitry we will use. We can still make changes afterwards, but it's just a checkpoint to make sure that we have thoroughly thought through the logic. For the second midterm, we present a breadboard with a working circuit that achieves the minimum criteria. As such, we can then move on to packaging and so forth.

I remember showing up to the second midterm with my circuit like "hello Professor, I am done." He replied "great, now you can work on packaging it". I was slightly confused. Do we just stick it in a box and call it a day? I think he kind of scoffed at me. He asked if we can just present someone with a breadboard with wires. After some back and forth, I realized that we have to either create a PCB or solder the components to a perforated PCB board. Unfortunately, I missed the deadline to order a PCB with regular shipping. I did not want to waste money on rush shipping, so I decided to solder instead. I am quite glad I went with the second option because I ended up changing my circuit a little at the very end.

For most people, building the circuit was the most fun part. For me, it was the packaging. I got to use the laser cutter in the machine shop for the first time since freshman year, and I am pretty proud of the results. There are a few bugs in my circuit. For example, the system switch I bought was from a cheap supplier on Amazon and doesn't always work. However, in general, I met the criteria.

Finally, I'll share a blooper ... I purchased some fancy components to enhance the performance of my function generator. However, I was too lazy to read the instruction manuals. As such, the moment I added them to my breadboard, they blew up. It is quite a waste of money, but a learning experience never the less.

 

Design-er? I Have to For a Final Grade!

Hello hello party people! I designed my dream house. Or at least, I guess I did. So, with that great expectation, let’s talk about my English 110 final portfolio. The culmination of all the work that I did throughout the term.

My teacher, dear teacher, recommended that I stick with the black pen on white paper aesthetic that I had maintained through several projects this term. Little did she know the angsty route of poetry and mis-mashed phrases that form a semblance of poetry. Basically, I created a photo book. I took all my photos of Los Angeles. From class this year, from my photo outings with friends, and the ones I imagined and drew myself. I converted them all to black and white by desaturating and then running a threshold filter on them until they looked suitably black and white and scary. And then I used a typewriter font and added a few lines here. A phrase there. And every now and then, something meaninglessly deep that forms the way my mind has developed to think about the city in which I live.

So, my house design. An unfinished basement. An unfinished tunnel that connects the house to the garage. A two-car garage. Even if by a miracle I end up rich enough to build this, there’s still no reason to have more than two cars protected from the weather. After all, I’m not really planning on living anywhere with weather serious enough to snow me in more than once or twice a year. And the base of it is a cube. This is attached to another cube on the upper level that’s offset. Not for any particular reason except for that I’ve always liked offsetting cubes and things that don’t match exactly like they’re supposed to.

The weirdest part is the pool cantilevered over nowhere. Somehow, I’ve always wanted to have some kind of crazy cantilever in my designs. Then there’s the rooftop garden. The flower-shaped solar panel to provide enough energy for the house in some strange hypothetical world. And then tress. Tall trees. An oak. Maybe a maple. And some tall conifers. Maybe a Ponderosa pine, I haven’t decided quite yet. A ponderosa pine would be fitting though, those trees have been with me throughout my entire childhood. And if you eat their needles, or smell their bark, something sweet comes out too. Maybe that’s a metaphor for life.

Interpret things how you will,

-- Chandrew

The 80s Called: They Want Their Hairstyle Back

It’s that time of the year again. The one glorious night in June where for once everyone seems calm, at least in the department of Geological and Planetary sciences (GPS). That’s right, it was Zilchbrau 2019, and the theme?? The 80s. Zilchbrau is an annual party held by our GPS department to celebrate undergraduate and graduate achievement, in addition to just providing a nice venue for us to relax and take a Friday night off before finals.

Of course, for a theme party I had to make my annual Goodwill hunting trip to find affordable clothes that matched the theme. Molly and I decided to go for the greaser look, and ended up matching with Shaelynn, a grad student who was in our intro to geology course first term. The leather jacket apparently looked so natural on me that several of the new grad students I met though that it was just my everyday look. So I guess that’s a good thing?

A couple things were different this year to last though (I posted about the same event last year when I was but a wee little freshman). The first big difference is that this year I actually knew people. Not just the assorted small group of undergraduates who happened to be free this Friday, but professors, grad students, and everyone in-between who came out to the Dabney Gardens to have a good old fashioned 80s time. This made it a lot more fun. Molly and I got roped into having two lines in the graduate student skit, which posited that Caltech caused Chernobyl and the Mount Saint Helens Eruption (both facets of the 80s) and that a grad student had turned into a monster and had been living under Caltech since the 80s.

Other highlights include the pie eating contest (only one slice, but I lost horribly to a grad student and Professor Eiler, among others) and the amazing Thai food from catering. After all the inside skits were all done, we all just went outside and talked for a while. I met lots of new people and had a great time and truly felt like a part of my department. I joined the GPS softball team too for these first couple of weeks before I go to Singapore. GPS is a true home.

Strike, or slip?

--Chandrew

Cooking Final: 3/42

It’s the beginning of the end (for now): the last round of finals that I’m going to take at Caltech before I leave the country for 6 months. I’ve officially finished my first class for the semester: cooking! I took cooking this term so that I could TA it in the future and I had a complete blast. The final was no different.

The cooking final is structured like a reality cooking competition, only on a much smaller scale. Our four teams (we’ve had the same team throughout the term) had to cook a five-course meal using a special ingredient. Only there was a little twist to the secret ingredient. It wasn’t just one ingredient; it was an entire themed cooking challenge!

The theme: INDIA. This was beyond exciting for me; junior year of HS I went to one of my friends’ house and her mother taught me how to make South Indian curries, so I guess you could say I was more or less a pro. Not actually, but I did make a killer curry.

We started off with a deep-fried spinach dish (palak chaat).

The second dish was a bit of a play on a wonton – two members of our team really wanted to potstickers, so we made an Indian spiced filling and put them in wonton wrappers because we were unable to procure potsticker wrappers.

The third dish was a saag paneer. We used my mom’s recipe and apparently made a great dish, but somehow, we managed to forget to salt it and then narrowly lost best dish which was a little heartbreaking.

My curry was the fourth dish. It was good, definitely had some solid heat and well-developed flavor, but there was just something missing for the judges. I was still in love though; I love my friends.

 

Finally, we made Gulab Jamun (a traditional donut-like dessert) and served it over homemade ice cream. This was a delicious finish to the meal. A great meal overall. We tied for second, but it was definitely a success for our team all around. And a fun way to spend a day to boot!.

Apparently, it’s the weekend of many courses. That would make a funny short story title.

Real action Aladdin was kinda a letdown,

--Chandrew

Huntington Gardens with H132

This past weekend, our Humanistic Ecology class had a field trip to the Huntington Gardens. Our professor, Dan Lewis, also works as a curator there and has access to its incredible archives. Although the class is about the impact of humans on ecosystems, the field trip was more of an opportunity to learn about the development of ideas in ecology, and to gush over the important manuscripts.

 

We started off the day looking at printing blocks made of lime stone. Apparently, these block leverage the separation between oil and water to transfer oil-based ink onto paper. To use them, an artist would have to scrape off the surface of the stone, draw the design, then transfer  it onto paper. It is mostly used for images, but also for text before type setting existed.

 

 

Then, to our surprise, Professor Lewis bring out one of Charles Darwin’s original letters. The most shocking part was that he was holding it in his bare hands, without gloves. He told us that this paper is made from cotton fibers and is quite study. Gloves can make the handling process more tedious,  as it involves more fumbling, which means that paper manuscripts can be more easily damaged. Although the letter is impressive, Darwin’s handwriting is not. We had an exercise where we tried to  read the letter. Unfortunately, most of us can nearly distinguish the words on the page. It requires special understanding of Darwin’s language and of the letter’s potential content to decipher it.

 

 

As if we need to be even more impressed, Professor Lewis showed us the first 7 drafts of Walden’s texts and an volume of the Audubon. The Audubon is the most impressive thing I have seen in a long time. It is the largest commercially available book, with each volume weighing as much as 60 pounds. The book is massive because it is full of vivid images of birds, which the editor wanted to have be life sized. For some more context, the Audubon is about the Great Birds of America. It is filled with images of birds in their natural habitat and has images of many extinct species as well, like the passenger pigeon and the Carolina parakeets.

 

In relation to modern culture, the Audubon is like a 19th century Pinterest. Except, there are only limited copies available. It’s also one of the first subscription services. For $1000 (a fortune at the time), subscribers would get 5 drawings of birds a month. There would be 3 small, 1 medium and 1 large drawing. The drawings are extremely intricate, and are completed by hand. Once a subscriber collects all the drawings, they can choose to get it bound into a book. Today, the collection with all the images is worth $12 million.

 

After appreciating the rare art, we went to check out the publicly available display on heart of science. The display is permanent, and was curated by our professor. It touches on a couple of main themes, including astronomy, light and medicine. My favorite part of it was the 170 different editions of the Origins of Species on display in the bookshelf. The proliferation of ideas is truly fascinating.

 

We were granted free passes to explore the park’s grounds afterwards. I didn’t have time to stay, although I would love to checkout the desert gardens again. This field trip is a great conclusion to a great class and I would highly recommend it to anyone.

Watercolor Workshop by the Visual Cultures Program

This past Saturday, the Caltech Visual Culture program invited a guest instructor for a watercolor workshop. There was a lottery for the workshop as it was in high demand and the art house is too small to fit everyone who wanted to attend. Although I did not get the lottery at first, I was able to get off the waitlist.

The workshop began with a technical component, where we learned the wet on dry and the wet on wet techniques. The wet on wet technique is more forgiving. It involves wetting the paper first, then applying water colors. This allows colors to blend more easily. The wet on dry technique leads to bolder colors, but it can be difficult to blend colors if the previous layer has already dried. Of course, it is possible to blend colors in the palette instead of directly on paper. Also, we can achieve bold colors with wet on wet if we allow the previous layer to dry first before applying another layer of water, and another layer of color. We explored these techniques in painting a sunset scene.

After painting a gradient background, we could go back in with a smaller brush and water to remove some color to bring out features like clouds. You know that stain like pattern when you spill coffee on paper? Some times, that "splatter" is desired, and you can create it by either removing or adding color.

PC: Ruoyun Zheng

The technical portion took around 45 minutes. Then while our sunset scenes dried, we went outdoors to paint either the flowers in the Art House garden or a photo/picture of our choice. A lot of the participants chose to paint the still life. I, on the other hand, chose to paint a picture of a chameleon that I saw on Pinterest.

Painting the chameleon was slightly more challenging than expected. I am used to painting with acrylics, which involves clearly defined lines and bold colors. Since acrylics are much thicker, you don't have to worry about colors mixing with each other in an unwanted way. For water colors, I would forget that a part of the paper still needs to dry before I can apply the next layer, so there were a few sections that I had to "remove" with water before painting over it again. I also ended up repurposing some water color paint by making it more pigmented than usual for more defined lines. I guess this makes it less traditional, but hey, the paint is just a medium for expression.

The water color class was a super fun way to relax in between working in sets and projects. I hope the Visual Cultures program continues to have to more events like this. I really miss painting and drawing for fun, so when opportunity arises, I am eager to jump on it.