Visitar URL original

David’s blog

David’s blog

A decision tree asks whether a noun ends in -e or -ung, then -chen, and leads to die, das, or der.

How many rules does it take to guess a German noun’s gender?

r

machine learning

A compact decision tree predicts German noun gender from spelling, semantics, and subtitle frequencies—while staying small enough to memorize.

For independent metrics, the chance that any ordinary test rejects rises from 5% to 92% as the number of metrics grows from 1 to 50. The chance that every non-inferiority test passes falls from 5% to about 3%, with one metric at the harm threshold.

Controlling for multiple testing with non-inferiority tests

statistics

More metrics don’t always mean more false positives. Here’s why requiring every non-inferiority test to pass changes the multiple-testing problem.

A skewed treatment-effect distribution with the median and Hodges–Lehmann estimate below zero and the mean above zero.

Making sense of non-parametric tests

r

statistics

Explore how the mean, median, and Hodges–Lehmann estimator tell different stories about treatment effects—and why the question should guide your choice.

Timelines comparing the engagement of a habitual user and a user who bounced

Beyond DAU: How to Measure User Retention with Survival Analysis

r

Use survival analysis to measure whether a product feature creates durable engagement beyond a short-lived DAU spike.

How Are P-values Distributed Under The Null?

r

I sometimes use this fun interview question for aspiring data scientists:

Your Classifier Is Broken, But It Is Still Useful

r

When you run a binary classifier over a population you get an estimate of the proportion of true positives in that population. This is known as the prevalence.

Things I wish they taught in school

Before he became Spider-Man in the 1960s, Peter Parker was a chemistry and physics genius, an expert photographer, and–get this–even knew how to tie a tie. But he was also a…

How to set up a reverse SSH tunnel with Amazon Web Services

When the startup shut down there were still dozens of netbooks out there in the wild collecting data on the residential houses fitted with our adaptive heating control…

Deep silence or deep work

It’s Monday afternoon. It’s a holiday but I have a couple of things to catch up from last week that I didn’t finish. The rest of the family is either on holiday camp or…

Simulated ratio distributions: nearly symmetric when the denominator is far from zero, and right-skewed when it is nearer zero.

Is The Ratio of Normal Variables Normal?

r

Is a ratio of normal variables also normal? R simulations show when the approximation works and how the denominator can make it break down.

Working with that data scientist

In my current team we have decided to split up the work in a number of workstreams, which are in effect subteams responsible for different aspects of the product. One…

Controlling for covariates is not the same as “slicing”

r

To detect small effects in experiments you need to reduce the experimental noise as much as possible. You can do it by working with larger sample sizes, but that doesn’t…

Getting into data science

A while back I had the pleasure to address a team of user experience researchers at YouTube, and I got asked for a few resources that could help someone pretty good at…

The law of total probability applied to a conditional probability

Dear future self,

xkcd and Data Science

I’ve been collecting all xkcd comics related to Data Science and/or Statistics. Here they are, but if you think I’m missing any please let me know in the comments. Use at…

Quick note about bootstrapping

Cross-validation—the act of keeping a subset of data to measure the performance of a model trained on the rest of the data—never sounded right to me.

The most under-rated programming books

Ask any programmer what their favourite programming book is, and their answer will be one of the usual suspects: Code Complete, The Pragmatic Programmer, or Design Patterns. …

Feature standardization considered harmful

r

Many statistical learning algorithms perform better when the covariates are on similar scales. For example, it is common practice to standardize the features used by an…

No, you have not controlled for confounders

r

When observational data includes a treatment indicator and some possible confounders, it is very tempting to simply regress the outcome on all features (confounders and…

A/B testing my resume

r

Internet wisdom is divided on whether one-page resumes are more effective at landing you an interview than two-page ones. Most of the advice out there seems much opinion- or…

Unit testing SQL with PySpark

python

Machine-learning applications frequently feature SQL queries, which range from simple projections to complex aggregations over several join operations.

Scraping real estate for fun

Here’s a fun weekend project: scrape the real estate classifieds of the website of your choice, and do some analytics on the data. I did just that last weekend, using the Scr…

Testing Scientific Software with Hypothesis

python

Writing unit tests for scientific software is challenging because frequently you don’t even know what the output should be. Unlike business software, which automates…

Monty Hall: a programmer’s explanation

r

I take it we’re all familiar with the infamous Monty Hall problem:

Reading S3 data from a local PySpark session

python

To read data on S3 to a local PySpark dataframe using temporary security credentials, you need to:

Probability’s not fair

maths

I’m currently reviewing a book for a well-known tech publisher, in which the author discusses the assignment of probabilities to each face of a die, when the faces are not…

Math tests

\begin{align*} \int \frac{1}{(2x^{2}+4x-2){-\frac{3}{2}}} \textrm{d}x &= \frac{\sqrt{2}}{8} \int\frac{\sec{t} \cdot \tan{t}}{\tan^{3}{t}} \textrm{d}t \\ &= \frac{\sqrt{2}}{8}…

Machine Learning in R: Start with an End-to-End Test

r

As a data scientist, you will likely be asked one day to automate your analysis and port your models to production environments. When that happens you cross the blurry line…

Where to define S4 generics

r

You need to declare generic functions in S4 before you can define methods for them. If no definition exists you will see the following error:

Connecting to SQL Server from R on a Mac with a Windows domain user

r

Connecting to an SQL Server instance as a Windows domain user is relatively straightforward when you run R on Windows, you have the right ODBC driver installed, and your…

Learning Gregg shorthand

This piece is a writing assignment for the Learning How To Learn online class, in which we are asked to reflect on a recent learning challenge.

Notes from the “Learning How To Learn” course

“Learning How To Learn” (LHTL), an online course freely available on Coursera, teaches techniques for becoming a better learner and thinker. Given by Dr Barbara Oakley…

Why I (still) use C++

c

When I joined Neurobat in 2010, the company’s vision was to develop an add-on component that would compute optimal setpoints for your heating system. Such a device had to be…

Our first 3D game programming project

My son Nathan made this:

Predicting where the bugs are

Adam Tornhill’s Your Code as a Crime Scene (YCAACS) has lain open next to my laptop for several months now. I’m usually a fast reader and a technical book rarely lasts that…

How I review papers

Once you publish a paper in a journal, you are expected to regularly review papers for that journal. It’s part of the normal scientific process. Some may consider it a…

The DEBORAH project kick-off meeting

We are involved in DEBORAH, a Eurostars project nr E!10286, led by EQUA Simulation AB, the vendor of the highly regarded IDA ICE building simulation software. Together with …

Being blocked doesn’t mean you cannot work

agile

If you’ve been on a Scrum team for some time, you will inevitably hear someone at the stand-up say:

Was “Building Science” really the best we could come up with?

The big problem with Building Science is that we call it Building Science.

CARNOT has an official home

I’m pleased to report that CARNOT, the Simulink library of models for HVAC systems, has now an official home. You can find it by visiting its page on the MATLAB Central. On…

Linus Torvalds thinks like a chess grandmaster

I’ve uncovered evidence that Linus Torvalds, creator of Linux, may entertain a secret hobby.

Where all floating-point values are above average

When you just fix a programming bug quickly, you lose. You waste a previous opportunity to think and reflect on what led to this error, and to improve as a craftsman.

The one question not to ask at the standup meeting

agile

What is the very first question one is supposed to answer during a standup meeting? If your answer is:

The opinionated estimator

r

You have been lied to. By me.

The SIM4Blocks project kick-off meeting

The SIM4Blocks European project held its kick-off meeting on 5 and 6 April 2016 in Stuttgart, Germany. A consortium of 17 European partners (including 3 Swiss organisations)…

Biblical kings and boxplots

r

When you read through the biblical books of Kings, you may have been struck by a phrase that repeats itself for every monarch:

C++: when delete doesn’t delete

We once spent almost a week chasing after a mysterious memory leak in our application, built on top of the highly regarded eCos real-time operating system. The leak appeared…

Going for one-week sprints: a good wrong idea

agile

A few weeks ago, our team held a sprint retrospective (which I unfortunately couldn’t attend) during which it was decided to shorten our sprint length from two weeks to one.…

Scrum stories that are juuuust right

agile

On thing has been bugging me for quite some time now as I observe our team at Neurobat. Most stories on our sprint board are being worked on by one developer each, leading…

Running CARNOT models under OSX

CARNOT (Conventional And Renewable eNergy systems Optimization Toolbox) is a set of MATLAB & Simulink models for simulating buildings and building systems, e.g. boilers…

Book review: Advanced R

book-reviews

r

I would like to call this the best second book on R, except that I wouldn’t know what the first one would be. I learned R from classes and tutorials about 10 years ago, used…

The only problem with daily scrums

agile

Over the past five years, our team has attended more than 120 daily standup meetings, carefully following the “canonical” format and having each team member answer the usual…

You know you have a great tester on your team when…

… you find a wireless room temperature sensor in your fridge:

How to fix rotation problems with iPhone pictures

When I take a picture with my vertically-held iPhone, here is what happens when I insert it as-is in this blog:

Reviewer queue

agile

During a recent sprint retrospective we raised a problem with the way we assign code reviews. Not the formal, whole-team ones, but the regular ones we solicit for each pull…

How to test for floating point exceptions with CppUTest

Some programmers, when confronted with a problem, think “I know, I’ll use floating point arithmetic.” Now they have 1.999999999997 problems. // Tom Scott

Not prioritising architectural needs

agile

From Mike Cohn’s User Stories Applied, there was this little paragraph that I think many teams (including my own) tend to forget about:

Bayesian tanks

r

The frequentist vs bayesian debate has plagued the scientific community for almost a century now, yet most of the arguments I’ve seen seem to involve philosophical…

ISH 2015 – first impressions

ISH, held every two years in Frankfurt, describes itself as “The world’s leading trade fair The Bathroom Experience, Building, Energy, Air-conditioning Technology, Renewable…

How not to get hired by Neurobat

When I recruit software engineers I always ask them to first take a short online programming test. Following a recommendation from Jeff Atwood, we use Codility as an online…

Review: Growing Object-Oriented Software, Guided by Tests

book-reviews

Growing Object-Oriented Software, Guided by Tests by Steve Freeman

How to determine if a sample is drawn from a normal distribution

Suppose you’ve performed some experiment on a given population sample. Each experiment yields a single numeric result. You have also derived the usual statistics (say, the…

MATLAB Coding Conventions

Over the course of four years we have developed, at Neurobat, a set of coding conventions for MATLAB that I would like to share here. The goal of these conventions is…

How to install RPostgreSQL on OSX Mavericks

Even if you’ve installed the PostgreSQL client binaries via Brew (i.e., brew install postgres), you will run into problems if you try to install the RPostgreSQL package in…

Energy savings with Neurobat

The official video presenting our main product and explaining how it works:

Programming Wingmen

For the past few weeks we’ve been experimenting with a variant of the Pair Programming theme.

C’est “Test Unité”, m***e!

Most french-speaking professional programmers I’ve worked with will translate “Unit Test” by “Test Unitaire”. This is indeed the term used by the french translation of the…

When to disable software assertions

I’m currently taking the Software Testing class on Udacity. The instructor spent a couple of videos discussing the pros and cons of leaving software assertions turned on in…

The only statistical distribution you need to know

If you pick two people at random and measure their heights, what can you say about the average height of the population?

Review: RESTful Web Services

book-reviews

RESTful Web Services by Leonard Richardson My rating: 5 of 5 stars

Pair-programming girls did just as well as boys

For the past three years I’ve taught a freshman-level programming course at the Swiss Federal Institute of Technology in Lausanne. Students are asked to form groups of 2 and…

Statistically significant energy savings: how many buildings are enough?

From Neurobat’s website it is now possible to download a brochure with the 2012-2013 test results. It summarises the findings we published at the CISBAT 2013 conference…

Welcome back, Climate Charts & Graphs

I was happy to learn a few days ago that the Climate Charts & Graphs blog is being reactivated by its author. I used to subscribe to it back in the Google Reader days. In…

Review: The Thoughtworks Anthology: Essays on Software Technology and Innovation

The Thoughtworks Anthology: Essays on Software Technology and Innovation by ThoughtWorks Inc.
My rating: 3 of 5 stars

Review: Linkers and Loaders

book-reviews

Linkers and Loaders by John R. Levine

Review: Applying UML and Patterns: An Introduction to Object-Oriented Analysis and Design and Iterative Development

Applying UML and Patterns: An Introduction to Object-Oriented Analysis and Design and Iterative Development by Craig Larman
My rating: 5 of 5 stars

When climate change hits us, at least we’ll know where

climate-change-2

Switzerland is a small country in the middle of Europe, wedged between France, Germany, Austria and Italy (see below). In a previous post I have documented the above-average…

Climate change in Switzerland: skipping the waiting line

I live next to Geneva in Switzerland. If you come to Geneva, be sure to include in your visit the ramp leading up from the Parc des Bastions and running parallel to the edge…

Great moments in the history of CO2 mitigation

Foreigners make better programmers

We have recently been recruiting a couple of new programmers at Neurobat. This time we submitted the candidates to an online programming test, which consists of a couple of…

Phileas Fogg on Agile Project Management

I just finished reading Jules Verne’s Around The World In 80 Days, which I had never read before. It’s a great read and I highly recommend it to children and adults alike.…

ScrumMaster no more

The first thing we did this week was to hold a sprint retrospective. And one of the first things we decided was that I should step down as ScrumMaster.

Standup meetings are not diaries

Very often I hear scrum standup meetings go something like this:

Selenium script to reset a ZyXEL NBG4115 4G Router

The ZyXEL NBG4115 is a small, cheap 3G router that can be used to build a wireless network where there is no access point available. You plug one of those 3G dongles into…

Floating-point woes, part 1

programming

You may have several decades of programming experience, certain classes of problems seem to repeatedly cause endless confusion. Floating-point computation is one such class.

Automatic data collection without FTP

I haven’t written anything in a while, so I thought I might begin by sharing some ideas on how we collect test site data at Neurobat without using FTP.

homeR: an R package for building physics

programming

tools

For the past few weeks we’ve been very busy here at Neurobat with the analysis of field tests results. In the process of doing that, we had to implement several functions in…

Saikoro game engine in Lisp

programming

Here at Neurobat we consecrate one day per sprint as a *Lab Day*, i.e. a day when, not unlike what Google does, we are free to work on whatever we want.

Pomodoro + Workrave = Well-being

I’ve been a big fan of the Pomodoro Technique for almost a year now. No, I don’t go as far as actually having a ticking timer in my office in front of my co-workers, and I…

Converting Sweave/R plots for inclusion in Word/OpenOffice

Just a quick note to myself:

Git and Scientific Reproducibility

research

tools

I firmly believe that scientists and engineers—particularly scientists, by the way—should learn about, and use, version control systems (VCS) for their work. Here is why.

Thou shalt save energy

energy

I’m not sure anyone else is saying this, so I will: I think **there is a clear and unambiguous scriptural mandate to reduce our current energy consumption**.

Neurobat, day one

announcements

Yesterday marked my first day as Chief Technology Officer at Neurobat AG, a young company formed in Switzerland to industrialize and market advanced building control…

Resources for building simulation

research

About two weeks ago I posed the following question on the Bldg-sim mailing list:

DB4ALL: reformatting the mess that Internet has become

announcements

I always try very hard to keep my posts within the main topic of this blog, namely computers in the context of building automation and simulation. Occasionally I fail, like…

Software engineering best practices in academia

announcements

As you might know, my primary background stems from the field of academia and research, but over the past years my interests have focused increasingly on software engineering.

Weird certificate verification error

programming

I spent most of the day today debugging a very mysterious error we encountered when trying to programmatically call a web service over SSL from Java.

MATLAB’s inane idea of time

programming

MATLAB seems to have a very peculiar notion on how to represent dates and times. Yesterday I spent a wonderful couple of hours debugging some code that’s supposed to compute…

Trying out new themes

general

I’m currently experimenting with new themes for this blog. I was not quite satisfied with the width that Typebased would leave me for giving code samples. So do expect some…

Installing ESP-r on Ubuntu 9.10

tools

ESP-r, is an integrated modelling tool for the simulation of the thermal, visual and acoustic performance of buildings and the assessment of the energy use and gaseous…

Alternatives to Java for home automation devices

programming

I think there’s no escaping this simple fact: the Java Virtual Machine (JVM) is definitely here to stay, and all the evidence shows that it has tremendous potential for…

Why I’m disabling MathML for now

tools

In a previous post I described how I tweaked my WordPress installation to support the display of MathML markup, for displaying mathematical equations.

Equivalent conductance due to air infiltrations

energy

Here is how you compute the thermal coupling between a room’s indoor temperature and the outdoor temperature due to infiltrations.

Event rate of arrival analysis with R

programming

Here is a very common problem: suppose you’re give a series of event timestamps. The events can be anything—website logins, persons entering a building, anything that recurs…

Book review: Agile Project Management with Scrum

book-reviews

I began reading Ken Schwaber’s ‘Agile Project Management with Scrum’ for two reasons: 1) it’s a book about Scrum, and 2) it’s from Ken Schwaber, one of the fathers of Scrum.…

How to include MathML in a Wordpress blog

tools

Project GreenFire mentioned on Java Posse

general

On a recent episode of The Java Posse they mentioned a project I had never heard about before: project GreenFire.

Looking up an EJB from a Web Service under JBoss 4.x

programming

EJB injection in Web Services does not work with JBoss (yet), so when you want to use an EJB from your @WebService annotated POJO you have no choice but to look it up…

7 numbers why building automation can save the world

energy

home-automation

Automating buildings costs money. Lots, lots of money. The return on investment (ROI) is usually very low, and it takes a long, long time (on the order of 5 to 10 years) for…

Enjoying a NO energy home

general

There’s a nice little article about green energy homes over at Greenprofs.com. The author makes a nice point that home owners have many options when it comes to choosing carb…

5 Java logging frameworks for building automation software

programming

Back in 2005, when I was writing Java software for an embedded home automation controller, we ran into a little unforeseen problem. The embedded virtual machine we were…

When I hear the word “Entity” I reach for my thesaurus

programming

According to Eric Evans, the author of Domain-Driven Design: Tackling Complexity in the Heart of Software, one of your first goals as domain analyst is to define what he…

Book review: “Hot, Flat and Crowded”

book-reviews

I’ve read Thomas Friedman’s “Hot, Flat and Crowded”, and firmly believe this book belongs on the shelf of anyone involved in making buildings more energy-effective.

Polyphasic sleep

Wikipedia defines polyphasic sleep as the practice of sleeping multiple times in a 24-hour period. Proponents of this practice argue that it results in a much reduced total…

Largest palindromic long long int that is also the product of two integers

programming

Just to practice my C skills I’ve begun doing the Project Euler exercises in that language.

Default welcome page with Tomcat and Spring MVC

programming

In my professional development, I felt that I had always neglected the field of web aplication development. To correct this I’ve started a little side project with Spring MVC…

Source code filtering with Maven

programming

Today I searched for a Maven plugin that would filter some of my source files before compiling them. An equivalent to the resources plugin with filtering turned on, but for…

Ubuntu fonts problem after reboot

My screen fonts under Ubuntu are occasionally completely screwed up. They show up in blue with overstrikes:

Strongest chess program money can (not) buy

Kinda offtopic, but I’m also an avid chessplayer, so…

Don’t unit test JavaBeans

programming

Should unit tests cover JavaBeans just to get a higher code coverage?

Trends in Smart Buildings Meeting, March 2009

research

trends

Several home automation enthusiasts met again at LESO-PB to discuss recent developments in the field. There were four of us this time, Adil, Friedrich, David and yours truly.

Software Engineering Radio

general

People often ask me what podcasts I regularly listen to. Well there are many of them and I won’t enumerate them all here, but I wanted to mention one that I listen to almost…

Spring for structure, property files for parameters

programming

Spring is a great framework for externalizing the object graph of your application. Typically you write an XML config file that defines a number of Java objects (or “beans”)…

Trends in Smart Buildings Meeting, January 2009

trends

I just realized how late I was with a summary of our last Trends meeting, which we held on Tuesday January 27th at LESO. So here follow my distant recollections of the event.

Wordpress shortcode for syntax highlighting

tools

There’s a nice feature in Wordpress for including source code in your blog posts, but the Codex is not crystal-clear on how to activate it.

A unit test that Could. Not. Fail. (but did)

programming

I am now convinced that even the most trivial pieces of code must be unit-tested.

Canonical data formats, middleware and GCC

programming

tools

These days I’m working on a middleware application that bridges a company’s ERP and its warehouses. The ERP posts messages in a given XML schema, our application reads these…

Article watch: Solar Energy vol 82 issue 11, 2008

articlewatch

research

From Solar Energy vol 82 issue 11, 2008:

Remotely editing files as root with Emacs

programming

tools

I often need to edit files on remote machines or on embedded devices, that is, machines without a monitor and on which a proper editor might not necessarily be installed.

Presentation checklist

book-reviews

This week I started reading Garr Reynolds’ Presentation Zen, the well-known book on presentation design and guidelines. (I’ve borrowed it from our library after waiting for…

MATLAB, Java, Spring and dynamic classloading

home-automation

programming

I have sort of a love-hate relationship with MATLAB, and always had since I read its tutorial in January 2003.

Trends in Smart Buildings Meeting, November 2008

research

trends

We met again on November 3 to discuss recent events in the field of building simulation and automation. This time we were joined by Adil Rasheed, a PhD student at LESO-PB…

Article watch: Journal of Building Physics vol 32 nr 2

articlewatch

research

The following articles from the last issue of Journal of Building Physics will probably be of interest to building simulationists and automationists.

Article watch: Energy and Buildings vol 40 nr 12

articlewatch

research

The following articles from the last issue of Energy and Buildings are probably of interest to building simulationists and automationists.

Schema validation with LXML on Ubuntu Hardy

programming

tools

LXML is an amazing Python module that picks up where the standard xml.dom(.minidom) left off.

Trends in Smart Buildings Meeting, October 2008

research

trends

After a two-month hiatus, we resumed our monthly meetings at LESO-PB to discuss recent developments in building automation and simulation. Frédéric Haldi, David Daum and…

The OpenRemote.org project

announcements

home-automation

Recently I stumbled upon a blog entry by Marc Fleury, whom I believe is one of the lead developers on the JBoss Application Server project. In this post he describes his new…

Article watch: Lighting Research and Technology vol 40 nr 3

articlewatch

research

Lighting Research and Technology vol 40 nr 3 has a couple of articles that sound interesting for anyone involved in visual comfort.

Article watch: Energy and Buildings vol 40 nr 11

articlewatch

research

One article in the last issue of Energy and Buildings is of particular relevance to the field of home automation, particularly where daylight control is involved:

Low energy, low cost linux box

home-automation

tools

There’s a great discussion on StackOverflow going on, when someone asked for suggestions for a low power, low cost and high availability linux box. Exactly the kind of…

Article watch: Building Simulation vol 1 nr 3

announcements

articlewatch

research

Two articles from new new issue of Building Simulation sound particularly interesting:

Java GNU Scientific Library 0.2 released

announcements

programming

tools

I have released version 0.2 of the Java GNU Scientific Library (JGSL) project, its second public alpha release. Please visit the JGSL project website for more information.

Article watch: Building and Environment, December 2008

announcements

articlewatch

research

The following papers from Building and Environment Volume 43, Issue 12, December 2008 are relevant to the field of building automation and simulation.

Journal of Building Performance Simulation - Volume 1 Issue 2 article watch

announcements

articlewatch

research

More papers directly relevant to the main topic of this blog:

Trends in Smart Buildings Meeting, August 2008

home-automation

research

trends

Four people again attended this second meeting, the purpose of which is to share information among people interested in home and building automation. As previously, here are…

Smart houses discussed in New York Times

home-automation

A fun online article in the New York Times discusses the current public perception of smart houses.

Interview: H. Michael Newman

bacnet

home-automation

interviews

I have just come across a short but interesting interview with H. Michael Newman, the “Father” of BACnet. The interview can be downloaded from here.

Computing sustainability and building automation

energy

home-automation

research

The energy demand of computers—including PCs, peripherals, and corporate data centers—produced about 830 million tons of CO2 in 2007, according to a report by the the Global…

Trends in Smart Buildings Meeting, July 2008

home-automation

research

trends

On 4 July 2008 we held at LESO-PB the first of (hopefully) a series of meetings for people interested in home/building automation. The idea is to give people of widely…

Donald Norman on user interface design issues with smart houses

home-automation

Let’s face it: us geeks do have a tendency to accept computer interfaces barely more user-friendly than, say, a shell. And that’s all right for me; it doesn’t really matter…

Monitoring a home automation PC

home-automation

tools

Lesson learned today: always monitor a machine you intend to let run without interruptions for a long time. And that includes home automation hardware.

Bayesian optimization of visual comfort: thesis defense videos

energy

home-automation

research

At long last I’ve pasted together the videos taken during by PhD defense. Here they are, raw and unedited.

ZigBee’s unkept promises

home-automation

The Guardian carries an interesting story about yet another alternative to ZigBee: Ultra-low Power Bluetooth.

X10 CM11A controller programming specs

home-automation

x10

The CM11A X10 controller (or its various incarnations, such as the CM12CH model for Switzerland), made by X10 Pro, is one of the most ubiquitous (and cheapest) X10…

Debian installation on a Soekris embedded PC

home-automation

programming

tools

Ubiquitous home automation will never become a reality unless cheap embedded PCs are available to be the “brains” of the home. Some time ago I came across a company called So…

Wattwatt, a community for individuals interested in electrical energy efficiency

energy

Wattwatt is a user-contributed website related to the efficiency of electrical energy in all its forms. It’s a place to read blog entries, share ideas, and more generally…

Monitoring home electricity usage

announcements

energy

home-automation

If you can measure it you can control it, and that is also true of your energy consumption.

Interview: Jessen Page

interviews

research

You are a model of predictability. You come to your office every day of the week at 8 am sharp, never one minute late. You take no breaks until noon, when you instantly…

Running Apache Felix on the UNC90 platform

osgi

programming

We have made Apache Felix run successfully on the UNC90 embedded platform and here I’d like to share our experience.

OptiControl project website

announcements

home-automation

research

Recently I got this email from Dr. Dimitrios Gyalistras of ETH Zurich:

Java GNU Scientific Library 0.1.0 released

announcements

programming

tools

I have released version 0.1.0 of the Java GNU Scientific Library (JGSL) project, its first public release. You can download it from here.

OSGi Community Event, Munich 26-27 June 2007

home-automation

osgi

programming

tools

I have already mentioned elsewhere that the OSGi technology is likely to play an important part in the computerization of current and future buildings. It is a very…

Energy Usage in Cities and Buildings

energy

Philip Greenspun has written a nice report on a MIT meeting whose theme was energy. You can find it here.

LaTeX to Word format conversion how-to

tools

Grant that I will never ever have to submit a paper in Word format again…

Java GNU Scientific Library project update

announcements

programming

tools

The GNU Scientific Library (GSL) is a rich state-of-the-art C library of mathematical routines. Pretty much everything you could think of—special functions, linear algebra…

International Building Physics Toolbox

tools

Too much choice can sometimes be just as bad as not enough. Market research has shown that there is an optimal number of jam flavours a supermarket should have on shelf for…

CO2 concentrations and global temperature correlation

energy

CS Lewis called this person the “embarassing enthusiast”. A person very committed and very verbal about your common religion, yet someone who occasionally discredits your…

KNX is world standard

announcements

eib

home-automation

knx

KNX, the home- and building automation standard that grew out of the fusion of Batibus, EIB and EHS, has now become international standard ISO/IEC 14543-3. The press…

Choice of new programming language

programming

tools

If you are regularly programming in your work you should invest some time to keep your programming skills sharp. And one of the best ways to do that is to master a new…

Bug finding tools for Java

programming

tools

I came across an article in the 15th International Symposium on Software Reliability Engineering (2004) titled “A Comparison of Bug Finding Tools for Java”. The authors…

“Ecobilans” software presentation

tools

IBPSA-CH, the newly created regional affiliate of IBPSA for Switzerland, hosted on 19 October 2006 in Geneva a software presentation of so-called “Ecobilans” programs.

IBPSA Swiss regional affiliate created

announcements

tools

The first General Assembly of IBPSA-CH took place on 1 September 2006 in Lucerne, Switzerland, at the University of Applied Sciences. International Building Performance…

Energy-efficient appliances in Switzerland

energy

Top Ten is a well-designed and user-friendly website that carries information on energy-efficient appliances and other equipment. It is mainly targeted at the swiss audience…

Review: Decompiling Java

book-reviews

I just finished reading through Decompiling Java by Godfrey Nolan. You might ask, why would I mention a book on reverse-engineering bytecode in a weblog dedicated to smart…

Vampires in the home

energy

Referring again to the power consumption of “stand-by” appliances discussed earlier, I recently stoborrowed a WSE Wattmeter, made by Messtechnik Schaffhausen GmbH, from our…

Raclette machine control with X10

home-automation

This Saturday I turned on our new raclette machine at our flat from my computer.

“Standby” appliances waste of energy

energy

The BBC carries a story on the energy waste represented by household appliances kept on standby mode instead of being switched off. The UK alone wastes enough energy to send…

Tools that anyone can use

tools

I heard once a senior researcher criticize a doctoral student for having chosen a particular software tool to do his data analysis.

Building Energy Software Tools Directory

tools

The U.S. Department of Energy maintains on their website a fairly comprehensive directory of building energy software tools. From their website: “The energy tools listed in…

Eye movement tracking of office workers

research

Our laboratory hosted this morning a seminar given by Sylvia Hubalek, of the Environmental Ergonomics department of the Center for Organisational and Occupational Sciences in…

Welcome to the Computing & Smart Buildings blog

announcements

Welcome to the Computing & Smart Buildings blog. In this column I will provide insights on a regular basis on how computers in all their forms are used to make the home or…