It is getting late in the day for me. I am a believer in deep work so several months ago I decided to get up early morning and study for a couple hours. So far, it has worked very well for me. I have set a wakeup alarm for 05:00 AM 7-days a week. Typically I am awake between 04:30 and 05:00 so I just turn off the alarm and head down to my home office. Around 05:00 PM I feel the work day coming to an end and am ready to punt. I use EyeDefender to break every two hours. During my 5 to 10 minute breaks I walk and get some fresh water. What can I say; it works for me. On weekends I tend to just do two are three blocks. On work days I tend to do five. Continue reading “ACM and Coursera”
Author: JohnCanessa
Encrypted Store
This post has to do with encrypting data in a storage server. When the storage server in question was architected and implemented the data at rest and in transit were raw (unencrypted). The main reason was that clients and servers where deployed in the same facility.
Years when by and the requirements called for encrypting data in transit while the data at rest was left raw. Encrypting data in transit could be performed by using HTTPS, secure sockets or encrypting the data when retrieved from the servers and decrypting by clients when received. Storing data would be the opposite. The initial decision, given that the client and server where under control, was to encrypt transmissions using the Advanced Encryption Standard (AES) which was designed by Vincent Rijmen and Joan Daemen back in 1998. Continue reading “Encrypted Store”
Neo4j and Dijkstra’s SSSP
The workday is starting to wind down slowly. I have been doing some cosmetic changes and running tests on a medical storage server. No matter what you change you must always run tests to make sure all is well.
On my last post I covered Dijkstra’s algorithm for shortest path. Shortest path implies distance and not number of vertices traversed.
Graphs – Shortest Distance Paths
The motivation for this post is the Coursera class “Graph Analytics for Big Data” by the University of California San Diego I am currently taking. One of the algorithms that we briefly touched was shortest path between two nodes by Edsger Dijkstra.
The algorithm comes in different flavors. One can compute the shortest path between two nodes, the shortest paths between all nodes, among others. In this case I just went with the first approach. Continue reading “Graphs – Shortest Distance Paths”
BeautifulSoup
The past weekend was kind of cold in the Twin Cities area of Minneapolis and St. Paul. Seems like winter a somewhat ahead of time.
In the past few months I have been spending time learning and experimenting with machine learning (ML) and Big Data. Machine learning seems to require a lot of properly cleaned samples. This is one more case when garbage in implies garbage out. That said; the first step is to collect data. Data can come from different sources i.e., databases, files, public repositories, the Internet, etc. Data can be collected from the Internet in different ways. In general one can collect data from the internet using two main approaches: web scraping and via an API. I will cover both of these approaches in the following posts. Continue reading “BeautifulSoup”
Odd Occuring Number in Array
It is Sunday again, seems like last week came and went by faster than usual.
When I browse YouTube videos on my phone, I tend to run into some that I would like to watch and if possible experiment with the subject. This post is associated with a video by Irfan Baqui. It is nice to get a challenge, understand what it is required, solve it and see how a fellow developer comes to the same solution using a different and in some cases the same approach. Continue reading “Odd Occuring Number in Array”
Equal Stacks
While I was waiting for some tests to complete I checked my Gmail and found a message from HackerRank suggesting a challenge. The Equal Stacks challenge may be found under Practice > Data Structures > Stacks > Equal Stacks. I read the description for the problem and decided to tackle it using stacks; how creative of me. Continue reading “Equal Stacks”
Transform Strings
It is Sunday morning in the Twin Cities of Minneapolis and St. Paul. Woke up around 04:30 AM and spent the next couple hours working on Machine Learning with Big Data. It is a Coursera course. Have one more week to complete this course; so far so good. After preparing and having breakfast with my best half, return to my computer. Continue reading “Transform Strings”
Queue implemented with Stacks
Yesterday I was talking with a coworker about the time it takes (me) to produce a post in this blog. Towards the end of the day, after a nice walk with my wife, I developed the code for this post. My inspiration came from a YouTube video by Irfan Baqui. I am a firm believer that in order to verify you understand some subject, you need to write about it. The reason for writing is that one explains the subject to the reader. Continue reading “Queue implemented with Stacks”
Fibonacci Sequence
Lately I have not had the time to write in this blog. For the past several months I have been getting up seven days a week, no later than 04:30 AM. I am taking a specialization on Big Data and machine learning. Loving every minute but it does not leave time at the end of the day to sit down and do something in order to be able to write a post. Continue reading “Fibonacci Sequence”