https://blog.diasdiaz.net/tags/study/Recent content in Study on dias DiazHugoen-usThu, 30 Mar 2023 00:00:00 +0000https://blog.diasdiaz.net/blog/dpv-8-14-clique-independent-set/Thu, 30 Mar 2023 00:00:00 +0000https://blog.diasdiaz.net/blog/dpv-8-14-clique-independent-set/Overview Problem Statement Prove that the following problem is NP-complete: given an undirected graph G=(V,E)G = (V, E) and an integer kk, return a clique of size kk as well as an independent set of size kk, provided both exist. Approach We call the problem CIS for brevity. First, we show that the problem is in the NP computational class. Next, we show we can reduce the known NP-complete problem Clique →\rightarrow CIS. Finally, we provide a bidirectional proof to prove that the reduction is correct, which also proves that CIS∈NPCIS\in NP-complete.https://blog.diasdiaz.net/blog/interning-at-google-first-reflection/Sun, 12 Jun 2022 00:00:00 +0000https://blog.diasdiaz.net/blog/interning-at-google-first-reflection/tl;dr There are great perks working for large tech companies, but there is a real threat of burnout. Tomorrow will be my fourth week since I’ve started working at Google for my summer internship. I’ll describe some of my experience, how I got here, and finally what I’ve learned so far. This article will likely be article 1 of a series of three going from beginning to end. This is the beginning to my reflection on the experience.https://blog.diasdiaz.net/blog/a-brief-introduction-to-classification-used-by-ai/Sun, 27 Feb 2022 00:00:00 +0000https://blog.diasdiaz.net/blog/a-brief-introduction-to-classification-used-by-ai/Have you ever gotten a captcha test that asks you to click all the busses or streetlights? Why such a specific question, like streetlights? You are actually training a machine to classify everyday objects! Classification allows a model to make assumptions. It is a generalization made to quickly make decisions using a precomputed set of rules and characteristics. For example, when a child mistakenly calls a cow a big dog, the child has just tried to classify the cow as a dog. A cow and a dog share traits (4 legs, fur, a mouth). However, when you point out that it is a cow, the child has to correct their model using narrowing techniques (dogs are small, cows are large, etc.).https://blog.diasdiaz.net/blog/human-like-ai-with-generate-and-test/Sun, 20 Feb 2022 00:00:00 +0000https://blog.diasdiaz.net/blog/human-like-ai-with-generate-and-test/tl;dr Generate-and-Test is a human-like AI method that can solve complex problems by creating plausible states intelligently Give an infant some shapes and a shape sorter and watch them try to fit each shape into a slot. We call this method generate-and-test. A machine can use generate and test to solve various problems, using simple, human-like AI. This article will discuss using generate-and-test to solve the Tower of Hanoi with the fewest moves possible.https://blog.diasdiaz.net/blog/framing-problems-and-answering-questions-human-thinking-and-ai/Sun, 13 Feb 2022 00:00:00 +0000https://blog.diasdiaz.net/blog/framing-problems-and-answering-questions-human-thinking-and-ai/tl;dr Representations are powerful problem-solving technique that provides perspective, and makes difficult problems easy Like humans, AI benefits from problem constraints and making abstract problems concrete We can make problems concrete using mental models. We make mental models by representing the problem How you frame a problem is everything. It can make a painless problem painful. However, a good mental model will make even complex, abstract problems concrete and simple to solve.https://blog.diasdiaz.net/blog/using-hci-to-supercharge-the-design-process/Sun, 06 Feb 2022 00:00:00 +0000https://blog.diasdiaz.net/blog/using-hci-to-supercharge-the-design-process/tl;dr You are not your users Always, always conduct needfinding with actual/ potential users before touching code! Avoid bias by planning before gathering data Evaluate your prototypes in front of users What is Human Computer Interaction (HCI)? Human-computer interaction (HCI) is a relatively new interdisciplinary field involving technology, psychology, and engineering. It is a broad field whose scope includes or overlaps with UI/UX design, “smart” devices, and VR technology. HCI advocates for a structured, iterative approach to design. Ideally, a product will go through multiple stages. These stages present the product to actual users for feedback and evaluation. Designers should then use this feedback to make or brainstorm adjustments. The most important lesson that HCI advocates and the one takeaway you should remember is that: You are not your user.https://blog.diasdiaz.net/blog/writing-a-time-management-android-application-timetime/Sun, 30 Jan 2022 00:00:00 +0000https://blog.diasdiaz.net/blog/writing-a-time-management-android-application-timetime/Motivation and Overview TimeTime was my first large, independent project. My motivation was two-fold. First, I wanted a project to help build my understanding of software architecture and the Android framework. Second, I wanted an application centered on privacy and gathering personal and work metrics. TimeTime took inspiration from an already existing application on the Android App Store. However, this application lacked desired features, stored data remotely, and locked premium features behind a subscription model.https://blog.diasdiaz.net/blog/using-grpc-to-write-a-distributed-file-server/Sat, 08 Jan 2022 00:00:00 +0000https://blog.diasdiaz.net/blog/using-grpc-to-write-a-distributed-file-server/tl;dr we use gRPC to make a distributed file system which can “share” a directory among multiple clients, keeping the directory in sync. gRPC simplifies client-server applications by taking care of infrastructure How can we write a server-client application that behaves similar to dropbox, google drive, and other cloud storage solutions? In other words, how can we create a system where the changes in a client directory are propagated to the rest of the system, including the server and other clients?https://blog.diasdiaz.net/blog/coordinating-caching-in-multiprocess-applications/Mon, 03 Jan 2022 00:00:00 +0000https://blog.diasdiaz.net/blog/coordinating-caching-in-multiprocess-applications/tl;dr Caching makes huge performance improvements. Here we work on integrating a server-side caching application with a server To communicate between processes we have to use POSIX message queues, shared memory, and semaphores Motivation and Overview It is usually a good idea to cache the data a server will need in memory. The alternative is to always store data on storage or remotely. Retrieving from such secondary storage will take exponentially more time than retrieving from memory. Often this is counteracted by keeping frequently retrieved data in the main memory. However, our server program should not be monolithic. Instead, we can design our server to run a function when a request is made. The function will ask a caching process if the request is stored in memory. If the requested data is available, the caching process shares the data with the server process. Otherwise, the server can try to retrieve it from secondary storage.https://blog.diasdiaz.net/blog/building-a-concurrent-tcp-file-server/Thu, 30 Dec 2021 00:00:00 +0000https://blog.diasdiaz.net/blog/building-a-concurrent-tcp-file-server/tl;dr We start build-up from our starting point of a simple echo-client and server, to a file-server Make use of IPv4/IPv6 agnostic TCP sockets Create a simple HTTP-like protocol to standardize and parse client requests Overview Overall requirements: IPv4/IPv6 agnostic, TCP, multi-threaded (server can service multiple clients simultaneously, parse and respond to requests in C (i.e., memory management, buffer allocation, byte parsing), implement a simple HTTP RESTful client-server application. The server needs to receive and parse file requests from a connected client. Once the request is verified the server needs to serve the file’s data to the client. Moreover, the server should handle multiple, concurrent connections.https://blog.diasdiaz.net/blog/omscs-gios-review/Thu, 30 Dec 2021 00:00:00 +0000https://blog.diasdiaz.net/blog/omscs-gios-review/tl;dr OMSCS Graduate Introduction to Operating Systems will give you a wide breadth into modern operating systems Exams are over-weighted Projects were fun, but can be challenging coming from a less experienced background GIOS Fall 2021 Review Coming from an economics background with Java and Python experience, GIOS was a plunge into the deep end of the swimming pool. There are two parts to the course: Lectures (pretty good, but old, amended, and in some places confusing) Projects The projects are always tangent on the lectures, but you CANNOT solely rely on lecture material to complete them. They are challenging for someone with not much C/C++ experience, but they were also rewarding and enjoyable.https://blog.diasdiaz.net/blog/an-introduction-to-thread-concurrency-a-os-perspective-part-2/Mon, 01 Nov 2021 00:00:00 +0000https://blog.diasdiaz.net/blog/an-introduction-to-thread-concurrency-a-os-perspective-part-2/A readable summary of how an operating system facilitates multi-threading and how it works. This series of articles will cover key questions about how an Operating System works. After you read it, you will walk away knowing what the OS does behind the scenes to make your life easier when creating multi-threaded applications. You won’t need much of any background to read this article, but it will help if you are familiar with a low-level language, like C. If you want to learn more, the end of this article provides my sources and what you can use in your own studies. Make sure to check out part one.https://blog.diasdiaz.net/blog/an-introduction-to-thread-concurrency-a-os-perspective-part-1/Sun, 10 Oct 2021 00:00:00 +0000https://blog.diasdiaz.net/blog/an-introduction-to-thread-concurrency-a-os-perspective-part-1/A readable summary of how an operating system facilitates multi-threading and how it works. This series of articles will cover key questions about how an Operating System works. After you read it, you will walk away knowing what the OS does behind the scenes to make your life easier when creating multi-threaded applications. You won’t need much of any background to read this article, but it will help if you are familiar with a low-level language, like C. If you want to learn more, the end of this article provides my sources and what you can use in your own studies. Make sure to check out part two.https://blog.diasdiaz.net/blog/a-look-at-the-flat-tax-and-progressive-tax/Wed, 23 Jun 2021 00:00:00 +0000https://blog.diasdiaz.net/blog/a-look-at-the-flat-tax-and-progressive-tax/This article will argue that the progressive tax system is more equitable than a flat-rate tax system. First, we describe each tax system in the simplest terms possible. Flat Tax In a flat tax system, everyone, no matter their background, pays the same tax rate. In the USA, a real-life example is a sales tax for a region. In a flat tax system, no matter how much money you spend at a store or how much money you make, you will pay the same flat percentage. For example, if the tax rate is 10% you would owe $10 on a taxable amount of $100.https://blog.diasdiaz.net/blog/sockets-in-c/Wed, 16 Jun 2021 00:00:00 +0000https://blog.diasdiaz.net/blog/sockets-in-c/A high-level introduction to sockets, or what I’ve been reading for the past week. Introduction When computer networks (the prelude to the internet) were conceived, it was up to programmers at the time to create an architecture that was reliable and future-proof. Sockets came about as a middle layer between the metal of the machine and software applications. The nice thing about this layer is that it lends to abstracting away details. Abstracting the hardware and software layer means that these layers of independent of one another. That is, software applications are unaffected by hardware architecture and vice versa. In fact, we’ve seen this happen many times already with the transition from dial-up to broadband (and from Netscape to Chrome). The convenience of the abstraction allows programmers to not worry about the underlying hardware. So, what exactly is a socket? And why are they important?https://blog.diasdiaz.net/blog/the-inflation-question/Sun, 23 May 2021 00:00:00 +0000https://blog.diasdiaz.net/blog/the-inflation-question/There has been more and more talk about the fear of rising inflation. That is, a fear of prices increasing because of an increase of the money supply. This topic is fueled by recent decisions from entities like Jerome Powell’s Federal Reserve and their policy of increasing the money supply through buybacks on US Treasuries and “alternative” means. Here, I will pitch my view on modern inflation and why you needn’t fear talks of soaring prices.https://blog.diasdiaz.net/blog/weekly-check-in/Thu, 13 May 2021 00:00:00 +0000https://blog.diasdiaz.net/blog/weekly-check-in/Takeaways Finished the KBAI and HCI courses offered by GA TECH with A’s! takeaways Completed Head First C by David Griffiths Had the first session of my new D&D campaign latex Courses and life takeaways I posted my thoughts and review for Knowledge-Based AI and Human-Computer Interaction offered by Georgia’s Institute of Technology last week. This week I received final grades. I was cheered to see that I scored As in both classes. I don’t like to give myself much fanfare for accomplishments, but here I want to say with solid emphasis that I’m excited to start the program with a 4.0.https://blog.diasdiaz.net/blog/kbai-review/Sat, 08 May 2021 00:00:00 +0000https://blog.diasdiaz.net/blog/kbai-review/Takeaways The course covers classic AI algorithms like generate and test and case-based learning A fantastic introduction to the program, the coursework is lighter on programming than others. There is a lot of writing, with weekly deliverables What is Knowledge-based AI (KBAI)? Knowledge-based AI (KBAI) is a course offered by GATECH’s OMSCS. The course deals with applying human-like cognitive techniques to develop artificial intelligence. The class provides two goals: Understand the basic architectures, representations, and techniques for building knowledge-based AI agents issues and methods of knowledge-based AIhttps://blog.diasdiaz.net/blog/hci-review/Wed, 05 May 2021 00:00:00 +0000https://blog.diasdiaz.net/blog/hci-review/Takeaways Human computer interaction (HCI) is a course offered by GA Tech’s OMSCS Taking the course will equip you with design principles and techniques established in the field of HCI What is HCI? The past decade has revealed a trend of embedding microprocessors in non-traditional applications. For example, a CPU in a refrigerator would be unheard of only a decade ago. The growing ubiquity of processing power has fueled the growth of the field of Human-computer interaction.https://blog.diasdiaz.net/blog/initial-thoughts-on-the-omscs/Thu, 29 Apr 2021 00:00:00 +0000https://blog.diasdiaz.net/blog/initial-thoughts-on-the-omscs/Takeaways My initial experience as an entrant in the Online Master’s in Computer Science (OMSCS) offered by the Georgia Institute of Technology (GA TECH) The program is tough: expect 20 hours per course. For my first semester, I fully immersed myself in academic literature, project documentation, and analysis Introduction A shipwreck of fear. An incredible sense of hopefulness. I completed my first semester at the Georgia Institute of Technology as a candidate for the Master’s program in Computer Science. I grew up somewhere where statistically, I did not have much of a chance of escaping poverty. Few friends from high school attended or completed college. I was the first and only one in my family to achieve a bachelor’s. My father started working as a pre-teen in Mexico to support his family. The only man in a family of six sisters. My mother only years later received a GED. I am considerably thankful but have also been self-absorbed in some level of doubt. Who do I look to for advice? Was I even supposed to get this far? Maybe you feel this way too.https://blog.diasdiaz.net/blog/starting-omscs-at-gatech/Sun, 10 Jan 2021 00:00:00 +0000https://blog.diasdiaz.net/blog/starting-omscs-at-gatech/TL;DR: Spring Semester 2021 begins Jan 14th An overview of the registration process has been like An assessment of how prepared I feel after the last few months of studying What I hope to get out this Semester I won’t be able to commit to any sort of regular schedule on the site. I would like to do some sort of update post-midterms and post-finals. Thank you for your understanding.https://blog.diasdiaz.net/blog/weekly-check-in-11-02-20/Mon, 02 Nov 2020 00:00:00 +0000https://blog.diasdiaz.net/blog/weekly-check-in-11-02-20/An update from the last time we spoke. I want to get some in depth articles up, but I’ve only been putting time into mathematics in preparation for more theory based courses I am expecting this upcoming semester. Working on I was able to finish Hefferon’s Linear Algebra. I am now working on the labs provided in the book. On my efforts in cpp: Completed Udacity’s free C++ for Programmers About a fifth through Bjarne’s excellent book Programming Principles and Practice Using C++ finished up Hackerrank’s relevant cpp exercises and obtained the gold badge. Exercism.io Found an excellent and noteworthy site thanks to reddit. It’s called Advance Projects for Beginners and currently working on the life project. Started diving into Al Doer and Ken Levasseur’s Applied Discrete Structures but Dropped it in favor of Lehman’s Mathematics for Computer Science along side MIT Opencourseware’s Mathematics for Computer Science I found these sources too convoluted. Instead, I switched to a recently published THIN and excellent introduction by Harry Lewis and Rachel Zax on the subject. Hitting 60 wpm consistently since my last post. Touch typing is proving to be fruitful. For resources check out: Typing Club keybr Goals for the Upcoming Week Aiming to finish Hefferon’s Lab modules by mid-December. Hit 80-90 WPM using touch typing. A medium sized C++ program on my git. finish exercism’s C++ course. Finish intro level Discrete Mathematics textbook (and exercises) by the New Year. Reflections Since last Post It has been a month since I’ve really done the morning routine bit. That is, waking up at ~04:30. I found the hump was the first two weeks, but it has been rewarding. I get at least 4-6 hours of studying in every day because of it.https://blog.diasdiaz.net/blog/weekly-check-in-10-19-20/Mon, 19 Oct 2020 00:00:00 +0000https://blog.diasdiaz.net/blog/weekly-check-in-10-19-20/An update from the last time we spoke. I want to get some in depth articles up, but I’ve only been putting time into mathematics in preparation for more theory based courses I am expecting this upcoming semester. Working on Linear algebra is still taking up most of my day. Hefferon’s Linear Algebra is still serving me well. What’s more is I discovered his recently uploaded lectures that follow the textbook. A blessing of the lockdown Switched my efforts from C to C++ just because of the STD. The syntax is a little boggling compared to Java. I am Using: Udacity’s free C++ for Programmers Bjarne’s excellent book Programming Principles and Practice Using C++ Hackerrank + Exercism.io Speaking of exercism.io, I’ve started mentoring on their Java track. Started diving into Al Doer and Ken Levasseur’s Applied Discrete Structures but Dropped it in favor of Lehman’s Mathematics for Computer Science along side MIT Opencourseware’s Mathematics for Computer Science Bought a Ducky One mini with Silent Cherry Red’s to replace my blue’s. (basically was too loud at sensitive times. I wanted too keep typing at 5am without waking my SO). Alongside that last point, I am converting to touch typing currently hitting around 30 WPM which is terrible, but I will keep it up and see how it does. If you’re interested I am using: Typing Club keybr Goals for the Upcoming Week Aiming to finish Hefferon’s textbook early the middle November. Hit 80-90 WPM using touch typing. A medium sized C++ program on my git. finish exercism’s C++ course. Reflections Since last Post I was able to limit my caffeine and have been regularly hitting the 6-8 hour range studying. I did it by keeping a strict schedule, up by 4:30AM and in the Linear algebra a cup of coffee later (around 5am). Let’s figure out on avoiding burn out now. Naps have really helped.https://blog.diasdiaz.net/blog/weekly-check-in-9-27-2020/Sun, 27 Sep 2020 00:00:00 +0000https://blog.diasdiaz.net/blog/weekly-check-in-9-27-2020/A quick post to the site to let people know I am alive for the week of 9/21/2020 to 9/27. I hope to get an article out sometime in October on my current project involving oAuth1 &oAuth2. Since I’ve gotten accepted into GA Tech I’ve been brushing up on my math and C / C++. Working on Linear algebra. Currently neck deep in Hefferon’s excellent and free Linear Algebra Lots of low-level C programming. Never realized how much higher-level languages took care of string manipulation for you. Hacker rank has been an excellent tool for practice. Besides that, I have been giving exercism.io a try. Built a CLI hangman game in C with 1000+ word bank. Finished Unix Workbench course on Coursera. Focused on command line stuff and Bash. Android phone screen gave out on me (from flicker to dead). Have switched to iPhone. On that note I’ve had to change my time management application from my android based app to a Linux based CLI Watson. Has been pretty clean so far. Goals for the upcoming week Trying to limit my caffeine to a healthy amount from the copious amounts I have been drinking. I am doing 1 cup a day. Aiming to get 8+ hours a day studying. Switching between C/ C++ Still working on using only VIM or VIM style interfaces. Checkpoint my Linear algebra to prepare for the first midterm. etc. Excited about my special someone. Trying to get them a gift that won’t suck. Have been using a vertical second monitor at my dock. Been getting some power issues. Not enjoying iOS, but it’s workable.https://blog.diasdiaz.net/blog/2020-c-programming-barriers-to-entry/Sat, 12 Sep 2020 00:00:00 +0000https://blog.diasdiaz.net/blog/2020-c-programming-barriers-to-entry/C is one of the oldest programming languages still in use today. It’s attributed success comes from its “simplicity.” Weird to hear that when the likes of Python exisits. But it’s true, C for its time was one of the easier, and more robust languages available for developers. This grandpappy of language originates from 1972. It picked up steam from IBM’s decision to support it on its PC line of consumer computers.https://blog.diasdiaz.net/blog/jekyll-introductions/Tue, 08 Sep 2020 00:00:00 +0000https://blog.diasdiaz.net/blog/jekyll-introductions/Jekyll is a great tool if you want the simplicity of a static website but with more complicated functionality. It offers a load of plugins and maintenance saving methods. The primary advantages are: templating variables and loop functionality support for GitHub pages (a free webhosting platform for anyone with a GitHub account) plugins, database free solutions, and niche cases If this is tempting strap in and I’ll describe my weekend setting up Jekyll.