postgres

• Magic SQL

  Ever wanted to find the number of days between two dates without counting weekend (Saturdays and Sundays)? In PHP you typically needs to do a lot of calculation and a lot of factors needs to be considered. Therefore, in the end you will end up having a whole bunch of code that you will probably start asking yourself whether you are programming a web-calendar or something similar.

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Random Posts

• Revisiting semantic web (plus wheel building with Poetry)

  Back then, when I was still working on my postgraduate degree research, I used RDF, which was the preferred format in the world of Semantic Web to represent data. I eventually dropped the degree, and stopped following the development of the related technology and standards. Until I volunteered to update the import script for popit when I was looking for the next job/project.

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• Creating a new daemon script for Meego 1.2 Harmattan

  Call me a cheapskate, as I still have not subscribe to a mobile data plan after purchasing my second smartphone, namely Nokia N9. There’s this ‘allow background connections’ option but it doesn’t care whether the connected network is a WLAN network or mobile data network. After finding out that Nokia has no interest in creating another separate option so that each type of network has their respective ‘allow background connections’ switch, I decided to make one for my own.

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• Approximate Neighbour Search in Multiple Dimensions

  In the previous post, I re-implemented Annoy in 2D with some linear algebra maths. Then I spent some time going through some tutorial on vectors, and expanded the script to handle data in 3D and more. So instead of finding gradient, the perpendicular line in the middle of two points, I construct a plane, and find the distance between it and points to construct the tree.

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• Building problock – my personal experience

  A few years ago, I was asked to build a game or simulation (alongside 2048) as a part of a job application. Being very impressed with Explorable Explanations, I implemented Conway’s Game of life with Javascript and jQuery (that was before ES6 became popular). Then I made a very simple grid maker jQuery plugin to dynamically generate a grid of divs. If you check the source code, you may realize I rely on Underscore.js a lot back then.

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• Collaborative Tagging & Folksonomy

  Folksonomy is a neologism of two words, ’folk’ and ’taxonomy’ which describes conceptual structures created by users ^{[4, 5]}. A folksonomy is a set of unstructured collaborative usage of tags for content classification and knowledge representation that is popularized by Web 2.0 and social applications ^{[1, 5]}. Unlike taxonomy that is commonly used to organize resources to form a category hierarchy, folksonomy is non-hierarchical and non-exclusive ^[3]. Both content hierarchy and folksonomy can be used together to better content classification.

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