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Showing posts from 2015

See You Again

This piece is another "download-and-read" piece (sorry) with a little practice. I dedicate it to one of my colleagues who just resigned. He taught me a bunch of invaluable stuff at work. We will really miss him. :'(

Theme of Tears

Took a short break due to a big project at work. Hope this is okay. Thanks for watching. ^_^

You are my Love and Hishoku no Sora

You Are My Love

Hishoku no Sora

River Flows in You by Yiruma and Butter-Fly

These pieces aren't really part of my repertoire [i.e. I just printed the music sheets and read the notes] but I found the mellow melodies quite enticing. I like playing this kind of stuff when I'm down in the dumps. It is my first time playing it and my note reading skills aren't that honed but I hope it is okay anyway. Yiruma has produced other nice mellow songs which are worth listening to so don't be afraid to look him up on Youtube too. 

Climate Change: Adaptation and Mitigation

I live in a city not far from the coast. The effects of climate change in my local community are not visually evident due to the city being one of the primary nests of business enterprises and economic ventures (the heart of the region is also the capital of the country). However, if we continue to have a loose grasp on our activities that greatly affect climate, one of the many significant changes that will occur would be increase in mean annual temperatures effectuating a further proportional increase in cyclone frequency. (Climate Change Impacts in Philippines)

More cyclones exacerbate an already impoverished community

Firstly, stronger and more frequent tropical cyclones on a city would mean more suspended working days. Every suspended working day approximately cost the industry hundreds of millions to a billion dollars (for the years 2012-2014). (Monteiro & Del Rosario, 2014) This kind of economic damage is harrowing to a third world country. It not only impedes growth and d…

What are all these Nanogenerator stuff, Anyway?

Was there a time when you were introduced to the piezoelectric effect in one of your Physics classes and wondered, “If piezoelectric crystals generate voltage when subjected to vibration, can’t we harness this voltage to power our electronics?” It was a pretty interesting afterthought. What about the voltage developed from the Seebeck effect? There are a lot of naturally occurring temperature gradients in our environment such as the thermal gradient between our body, the engines we use, even our gadgets and ambient temperature. It would feel wasteful to watch all the energy from these potential sources dissipate to the empty void. Apparently, such sources would only yield power just enough for the mobile phone of an ant. But recent developments in materials science as well as improvements in power consumption of modern electronics have aroused interest anew. Thus, in 2006 the first nanogenerator emerged drawing energy through the piezoelectric and semiconductor characteristics of a …

What Ifs? Sigmoid Function vs. Error Function in Machine Learning through Logistic Regression

While brushing up on some study materials in Mathematics, a familiar function piqued my interest. It was the error function, the solution to the non-elementary integral exp(-x^2) and whose complement is used in determining the conditional probability of bit error due to noise:

Or quite simply, the probability of error due to noise.

But the real point of interest was the nature of the curve of the function shown below.

Now, why be so interested in such a function? When I compared erf(x) with the sigmoid function commonly used in defining the decision boundary in machine learning algorithms, it returned a steeper slope. Then the thought came to me. What would be the differences of using the error function instead of the sigmoid function? Would the cost improve? Would the training accuracy improve?

And so my curiosity got the better of me and I played around with both of the functions to see what would happen.

Sigmoid vs. Error
First of all, replacing the sigmoid function with the error…

Sonata Pathetique [Allegro di molto e con brio - Part 2]

Took quite a while to upload part 2 of Sonata Pathetique given the schedule of an engineer in the industry (still an amateur video)... The entire piece would've cost me a 1 Gb upload! Current focus of practice is only on Hanon, as typical classical and concert pieces gravitate on the exercises it contains. Hope it doesn't sound to bad. Hehehehe... ^_^

Inconspicuous Pitfalls in Datasheet Analysis

A chess grandmaster, who also happens to be an electronics hobbyist, decides to design his own chess clock. The LEDs, normally-open push-button switches, and microcontrollers are all in place, driven by a pair of 1.5V AA batteries. But the clocks only last for a few hours. So he checks online for a power management IC to extend the battery life, and finds one promising an efficiency of 94%. After purchasing the chip and ramming it onto a prototype, he becomes puzzled when the operating lifespan doesn’t change much. He then checks the wires and solders and connections again in a vain effort to find a solution.

Let us take this to the industry level. Apple is designing its 23rd Iphone. The company producing the processor for the Iphone23 is looking for a PMIC that can deliver a transient response of around 10mV with a 10A shifting load (Absurd!). They contract a semiconductor company to design the chip. After numerous tedious design reviews, the PMIC becomes ready. When the chips are t…

Honest Reviews: FAN48610 - Fairchild Semiconductor's Not-Programmable TinyBoost Regulator

It is nice not to hear any unreferenced superlatives in the short description of Fairchild Semiconductor's TinyBoost regulator, the counterpart of their TinyBuck regulator. For completion, I review FAN48610, being even smaller than TinyBuck but with a lower output current capacity (as expected from a boost)  and no trimming feature.

FAN48610 or TinyBoost (mind if I call it by its family name for the rest of the article) is "a low-power boost regulator designed to provide a minimum voltage regulated rail from a standard single-cell Li-ion battery and advanced battery chemistries" according to FS. A boost regulator, which serves the opposite function of a buck regulator, steps up the input voltage by essentially taking advantage of the inductor's ability to resist current change. It is available in a 1.215mm by 1.215mm WLCSP package, with 0.4mm pitch (datasheet available for download by following the link below).
Download TinyBoost's DataSheet 

DataSheet Analysis Base…