The Blog of Ian Mercer.

Topic: commentary

Cover Image for Time Series Data Compression

Time Series Data Compression

This new technique to compress the time series data collected by my home automation system seems to be working really well.

Ian Mercer
Ian Mercer
Cover Image for Digital Twins are never identical

Digital Twins are never identical

Digital Twin are an online representation of a real world object, a copy of its properties in the digital world and a way to send updated and commands to it. In effect I've been making them for years but now they have a trendy name.

Ian Mercer
Ian Mercer
Cover Image for Why smarthomes are hard

Why smarthomes are hard

Why automated learning is hard for a smart home. The perils of over-fitting, under-fitting and how the general unpredictable nature of life makes it hard to build a system that learns your behavior.

Ian Mercer
Ian Mercer
Cover Image for Collinearity test for sensor data compression

Collinearity test for sensor data compression

One way to reduce the volume of sensor data is to remove redundant points. In a system with timestamped data recorded on an irregular interval we can achieve this by removing co-linear points.

Ian Mercer
Ian Mercer
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Event blocks

Home automation systems need to respond to events in the real world. Sometimes it's an analog value, sometimes it's binary, rarely is it clean and not susceptible to problems. Let's discuss some of the ways to convert these inputs into actions.

Ian Mercer
Ian Mercer
Cover Image for Logistic function - convert values to probabilities

Logistic function - convert values to probabilities

Another super useful function for handling sensor data and converting to probabilities is the logistic function 1/(1+e^-x). Using this you can easily map values onto a 0.0-1.0 probability range.

Ian Mercer
Ian Mercer
Cover Image for ATAN curve for probabilities

ATAN curve for probabilities

In a home automation system we often want to convert a measurement into a probability. The ATAN curve is one of my favorite curves for this as it's easy to map overything onto a 0.0-1.0 range.

Ian Mercer
Ian Mercer
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Home Construction Advice

Several years ago we did a major remodel. I did all of the finish electrical myself and supervised all of the rough-in electrical. I also put in all of the electrical system and water in our barn. I have opinions ...

Ian Mercer
Ian Mercer
Cover Image for T-Mobile home internet

T-Mobile home internet

I'm testing a T-Mobile Home Internet device as a backup to XFinity and a way to offload half our monthly traffic to avoid the XFinity 1.2TB cap

Ian Mercer
Ian Mercer
Cover Image for iBeacon meetup in Seattle - January 2015

iBeacon meetup in Seattle - January 2015

My notes on the iBeacon meetup in Seattle held in January 2015

Ian Mercer
Ian Mercer

Finally got the 1U Atom Server racked up

Ian Mercer
Ian Mercer

Timelapse video using the GoPro HD Hero

Ian Mercer
Ian Mercer

I should have created Four Square ...

Ian Mercer
Ian Mercer
Cover Image for How can I tell if my house is smart?

How can I tell if my house is smart?

Ian Mercer
Ian Mercer

Asian Gadgets

Ian Mercer
Ian Mercer

A great video explaining the Semantic Web

Ian Mercer
Ian Mercer

Interesting Twitter Posts March 15th-

Ian Mercer
Ian Mercer

Twitter links for Week beginning March 8th

Ian Mercer
Ian Mercer

Facebook, social gaming and points

Ian Mercer
Ian Mercer

Useful Twitter links Feb 8-Feb 15 2010

Ian Mercer
Ian Mercer

When will people learn to backup?

A rant about RAID

Ian Mercer
Ian Mercer

Future proof your home with a new conduit system?

Running conduit can be expensive but maybe you don't need one to every room

Ian Mercer
Ian Mercer

Balloon Boy was much ado about nothing - Twitter

Some of the more witty comments on Twitter about the Balloon Boy hoax

Ian Mercer
Ian Mercer

Shortened URLs should be treated like a Codec ...

Expanding URLs would help users decide whether or not to click a link

Ian Mercer
Ian Mercer

Tagging File Systems

Isn't it time we stopped knowing which drive our file is on?

Ian Mercer
Ian Mercer

WMPnetwk.exe started using 50% of my CPU

Uninstalling Windows Media Player - the end of an era

Ian Mercer
Ian Mercer

Introducing Jigsaw menus

A novel UI for menus that combines a breadcrumb and a menu in one visual metaphor

Ian Mercer
Ian Mercer

Amazon Instance vs Dedicated Server comparison

Some benchmark performance for Amazon vs a dedicated server

Ian Mercer
Ian Mercer

Agile Software Development is Like Sailing

You cannot tack too often when sailing or you get nowhere. Agile is a bit like that.

Ian Mercer
Ian Mercer

AntiVirus Software is the Worst Software!

When your anti-virus software starts stealing your personal data, it's time to remove it!

Ian Mercer
Ian Mercer

It's all about disk speed

Why disk speed is the most critical aspect for most modern PCs and servers

Ian Mercer
Ian Mercer
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Giving up on Internet Explorer

Ian Mercer
Ian Mercer
Cover Image for New Home Automation Server

New Home Automation Server

Ian Mercer
Ian Mercer

Dell upgrades - a pricey way to go

Ian Mercer
Ian Mercer
Cover Image for Preparing for death

Preparing for death

A friend died last year, it wasn't unexpected. He left a lot for his friends to cleanup. Maybe these notes can help someone else prepare better.

Ian Mercer
Ian Mercer