Two of my papers have been accepted for publication. “Optimal Replacement Policies for Dairy Cows Based on Daily Yield Measurements” have been published in Journal of Dairy Scienc. Abstract: Markov decision processes (MDP) with finite state and action space have often been used to model sequential decision making over time in dairy herds. However, the length of each stage has been at least 1 mo, resulting in models that do not support decisions on a daily basis. The present paper describes the first step of developing an MDP model that can be integrated into a modern herd management system. A hierarchical MDP was formulated for the dairy cow replacement problem with stage lengths of 1 d. It can be used to assist the farmer in replacement decisions on a daily basis and is based on daily milk yield measurements that are available in modern milking systems. Bayesian updating was used […]
Research
From the first of November 2009 I will be working as a Associate Professor at CORAL, Aarhus School of Business, University of Aarhus. I will be doing both research and teaching.
I oktober nummeret af Ny Kvægforskning er der på side 8 en artikel om vores udskiftningsmodel baseret på daglige ydelsesmålinger.
The 16th of October I gave a presentation to a group of students at KU Life about optimal replacement policies for dairy cows based on daily yield measurements. A hierarchical Markov decision process is used to solve the problem. The following downloads are available: presentation – handouts (2×2) – animation 1 2 3
Erratum to “An algorithm for ranking assignments using reoptimization” [Computers and Operations Research 35 (2008) 3714-3726] is now available on-line. As pointed out by Dr. A. Volgenant, we unfortunately missed one available implementation written by Miller et al. in IEEE Transactions on Aerospace and Electronic Systems.
The paper “Time-adaptive versus history-adaptive strategies for multicriterion routing in stochastic time-dependent networks” have been published in OR letters.
Aim of ESI 2009 is to bring together young scientists with academic experts on OR methods besides the development of applications for Agriculture, Forestry and related industries of the primary sector. Anders Ringgaard Kristensen and I will the first day talk about Markov decision processes (MDPs) for sequential decision problems in agriculture and forestry. First the theory of MDPs will be presented and next I will give an introduction to my new MDP package in R. The files needed for the exercises can be found here.
NorFor Plan, der er et system til rationsoptimering, inddrager ikke de økonomiske sammenhænge på den enkelte bedrift og dermed optimering af fodringsøkonomien i den enkelte besætning. Økonomisk optimering er vigtig i en tid, hvor der er stigende fokusering på effektivisering i malkekvægsbesætninger og større udsving i priser på foder og mælk. I 2008 har jeg været involveret i et udredningsarbejde, som skulle opstille en anbefaling for udvikling af et beslutningsstøtteværktøj til økonomisk foderoptimering i den enkelte besætning baseret på NorFor Plan. Resultatet af arbejdet er en intern rapport.
Today I am participating in a kick-off meeting of the project ‘The intelligent Farrowing Pen’. The four-year project is supported by Højteknologifonden, The Faculty of Agricultural Sciences, Skov A/S and Danish Pig Production. The goal is to develop a system whereby the condition and activity of the animals will be registered. For example, previous studies have shown that the sow is very active in the 24 hours prior to farrowing. She stands up and lies down often and spends time building a nest. This knowledge can be used to predict when she will farrow within a narrow margin. When the system predicts when the sow is expected to farrow, a message is given to the farmer and to a climate control system that ensures that there is more heat in the pen. Not only does this save piglets. It could perhaps also save heating bills in the farrowing barn, which […]
Den 25 november 2008 afholder DORS en dag om anvendelser af OR på Handelshøjskolen i Århus, hvor jeg deltager med en præsentation. Sted: R –Bygningen, ASB – det gamle Musik Konservatorie Program 9:30 – 10:00 Ankomst, kaffe og rundstykker 10:00 – 10:15 Velkomst ved DORS formand Julie Groth 10:15 – 11:00 Niels Christian Petersen, Institut for Sundhedstjenesteforskning, SDU: “Håndtering af forskelle i omgivelserne i Data Envelopment Analysis” 11:00 – 11:45 Johan Kjeldgaard‐Pedersen, PA Consulting: “OR IRL” 11:45 – 12:15 Lars Relund, Research Centre Foulum: “En Markov beslutningsproces anvendt til beregning af optimale udskiftningsstrategier for malkekøer” 12:15 – 13:00 Frokost 13:00 – 14:00 Arne Andersson, Trade Extensions: About OR in Game Theory 14:00 – 14:30 Jørgen Bang‐Jensen, imada, SDU: ”Eksempler på praktiske anvendelser af kombinatorisk optimering” 14:30 – 15:00 Jakob Skov, B&O: ” Skedulering af et Anodiseringsanlæg” 15:00 – 15:30 Kaffe og kage 15:30 – 16:00 Rune Larsen, imada, SDU: ”Optimaring […]