# Yearly Archives: 2007

7 posts

## What is Operations Research?

The term Operations Research is not so well-known in Denmark. I found this video with Vijay Mehrotra about the subject that give a good description and why managers should care about OR.

## Five days at KU Life

The last days 5-9 November I have been visiting Professor Anders Ringgaard Kristensen at KU Life. We have been working on a package in R “MDP” which will provide tools for solving Markov decision processes and their extension multi-level hirarchic Markov decision processes. The package will be based on a solver made by Anders in Java.

## New publication

The paper “Bicriterion shortest paths in stochastic time-dependent networks” have been accepted for publication in Lecture Notes in Economics and Mathematical Systems.

## EURO XXII conference

July 8-11, 2007 I participated in EURO XXII in Prague. Here I gave a talk “Embedding Dynamic Statistic Prediction (DSP) Models into a Markov Decision Process (MDP)”. Afterwards I spend a few days enjoying Prague.

## New publication

The paper “An algorithm for ranking assignments using reoptimization” have been accepted for publication in C&OR.

## Creating an animation (gif/mpeg) in R using intermediate files

I recent had a discussion with Søren about how one could create an animation of some plots in R. After searching the mail-list it seems that the best way to do it is using ImageMagick which is a free set of tools to create, edit, and compose bitmap images. To use the following guide you must install ImageMagick. Creating an animated gif We create an animated gif file in two steps. First, we save all the plots used in the animation as png files (vector file format) and second, we merge them into a gif animation. Lets try a simple example: > x<-1:10 > y<-runif(10,1.5,2.5) > xlim<-c(0,10) > ylim<-c(0,4) > png(file=”plot%02d.png”, bg=”transparent”) > plot(x, y, type=”n”, xlim=xlim, ylim=ylim) > title(“Create 10 uniform distributed samples”) > for (i in 1:10) plot(x[i], y[i], axes=F, xlab=””, ylab=””, xlim=xlim, ylim=ylim) > dev.off() We have now created intermediate files plot01.png to plot11.png. Note Plot plot01.png […]

## First Nordic-Baltic Biometric Conference

The Nordic-Baltic Biometric Conference 2007 (NBBC07) is the first conference arranged by the Nordic Regional and Baltic National Biometric Societies. The conferences aim at to supplement the series arranged by the International Biometric Society and are held in order to strengthen the collaborative efforts of the Nordic researchers interested in biometry and statistics in general. NBBC07 is hosted by the Research Unit of Statistics and Decision Analysis, Department of Genetics and Biotechnology, Faculty of Agricultural Sciences, University of Aarhus situated at Research Centre Foulum. For more information see the conference web-site.