Numero

Veckobladet om forskning, undervisning och
administration, m.m.

Nummer 38 · 30 november 2000 · Årgång 30       

NADA

CAS Seminar

Thursday 7 December 2000, 10.30, Fiskartorpsvägen 15

Overview of Mobile Robotics research at PMA, K.U.Leuven
including Learning Force controlled assembly operations
Dr. Marnix Nutten, PMA, KU Leuven

In this talk I'll claim that learning approaches will become very
important in robotics, if at least these approaches can comply with real-world requirements. Let's focus on programming by demonstration. Imagine that you want the robot to execute a new task it hasn't performed yet. An intuitive approach is to "program" the robot by demonstrating the task. A three-phase approach is proposed: (1) Initial knowledge acquisition (2) Controller synthesis and (3) Controller refinement. Learning techniques are applied at all three levels. This approach is applied to two force-controlled assembly tasks. The first task is the insertion of a peg into a hole. The second task is the light switch test case.

Currently, we are moving towards mobile manipulation, where we will follow a behaviour-based approach. Some important research issues are (again): how to program a new task. This brings us then to a presentation of our mobile robots. LiAS (Leuven intelligent autonomous system) is a mobile platform equipped with a manipulator. Bert and Ernie are two cooperating Pioneer robots. Sharioto is a wheel chair for disabled people. I'll present an overview of various projects and results of our mobile robotics group.

Seminarium i Numerisk Analys

Klas Samuelsson, Chalmers University, Göteborg.
Rubrik: A posteriori error estimation of functionals using multi-grid and higher order elements.
Tid och plats: Onsdagen den 6:e December kl 11.15-12 i sal 4523, Lindstedsvägen 3, NADA, KTH.

Sammanfattning:
The error of a functional of a finite element computation can be represented by an error representation formula involving the residual of the finite element solution and the solution of a dual problem associated to the used functional. We show how this error representation formula can be used to obtain an asymptotically correct error and be used to provide data for the adaptive refinement strategy. Moreover, the computed error can efficiently be used to get an extrapolated value of the functional. The error estimates has been implemented for tetrahedral elements up to polynomial degree six. We present an efficient
method to assemble the equations when subparametric mappings are used.

The resulting linear system of equations are solved by using a multi-grid method. We report on numerical examples where the adaptive algorithm
is used to compute various functionals to an accuracy of more than 10 digits.

 

 
 
 

A position at the University of Haifa

The Department of Mathematics of the University of Haifa, Israel,
announces an opening for a tenure-track position beginning in October 2001. Candidates must hold a Ph.D. in either mathematics or computer science, and, also, a master degree, preferably in the other field among the two mentioned above. Candidates are expected to have an excellent record in research and teaching.

The position will require the continuation of a high level research work, and teaching of computer science courses and/or courses on applications of mathematics to high-tech industries in our bachelor programs: "Mathematics with Computer Studies" and "Mathematics and its Applications to High Technologies", and in a master program of "Mathematics with Computer Sciences". Thus, the
candidates must have a proven record of teaching such courses,
and a reasonable command of the Hebrew language.

Remark: the University of Haifa has an independent Department of
Computer Science which is not part of the above mentioned bachelor programs and has no connection to this announcement.
Please send a letter of application, which addresses your suitability for the position described above, a complete CV and a list of publications. In addition, please have three letters of recommendation sent directly to us. All should be sent by air mail to Professor Izu Vaisman, Chairman
Department of Mathematics
University of Haifa
Mt. Carmel, Haifa 31905, ISRAEL.

Numero är institutionstidningen vid Nada – institutionen för numerisk analys och datalogi, KTH. Numero utkommer normalt på fredags­förmiddagar under teminstid. Manus måste lämnas in före kl.16 på tisdagar.

Manus, tips, förslag och andra bidrag till Numero kan lämnas på något av följande sätt:

Bidrag för artiklar och notiser bör i största möjliga mån vara färdigformulerade och korrekturlästa.

Varje Numeronummer utkommer i två former:

Numeroredaktionen består av Rickard Buch. Ansvarig utgivare är Ingrid Melinder. Numeros innehåll uttrycker inte institutionens officiella ståndpunkt annat än då detta anges.

Ibland refereras till Numeropärmen. Det är en pärm som finns i bokhyllan i Nadas fikarum på plan 4, i vilken kompletterande information sätts in, försett med nummer på formen 99:NN-N.

 

Kalendarium

Ons. 6 december kl 11.15-12 Seminarium i Numerisk Analys. Klas Samuelsson, Chalmers University, Göteborg.
Rubrik: A posteriori error estimation of functionals using multi-grid and higher order elements.
Plats: i sal 4523, Lindstedsvägen 3, NADA, KTH.
Tors. 7 december kl. 10.30 CAS Seminar. Overview of Mobile Robotics research at PMA, K.U.Leuven including Learning Force controlled assembly operations. Dr. Marnix Nutten, PMA, KU Leuven
Tis. 12 december kl. 10.00 Licentiatexamen! Raul Tempone Olariaga. i sal E2, Lindstedtsv. 3, KTH, Stockholm. "Weak Approximation of Ito Stochastic Differential Equations and Related Adaptive Algorithms."

 

"Education is a progressive discovery of our own ignorance."

Will Durant