Search results for "TACL"

Mass transport problems for the Euclidean distance obtained as limits of p-Laplacian type problems with obstacles

2014

In this paper we analyze a mass transportation problem that consists in moving optimally (paying a transport cost given by the Euclidean distance) an amount of a commodity larger than or equal to a fixed one to fulfil a demand also larger than or equal to a fixed one, with the obligation of paying an extra cost of −g1(x) for extra production of one unit at location x and an extra cost of g2(y) for creating one unit of demand at y. The extra amounts of mass (commodity/demand) are unknowns of the problem. Our approach to this problem is by taking the limit as p→∞ to a double obstacle problem (with obstacles g1, g2) for the p-Laplacian. In fact, under a certain natural constraint on the extra …

La Recherche d'Expériences dans la Consommation du Spectacle Sportif

2001

Free boundary methods and non-scattering phenomena

2021

We study a question arising in inverse scattering theory: given a penetrable obstacle, does there exist an incident wave that does not scatter? We show that every penetrable obstacle with real-analytic boundary admits such an incident wave. At zero frequency, we use quadrature domains to show that there are also obstacles with inward cusps having this property. In the converse direction, under a nonvanishing condition for the incident wave, we show that there is a dichotomy for boundary points of any penetrable obstacle having this property: either the boundary is regular, or the complement of the obstacle has to be very thin near the point. These facts are proved by invoking results from t…

Obstacle Detection in an Unstructured Industrial Robotic System: Comparison of Hidden Markov Model and Expert System

2012

Abstract This paper presents a comparison of two approaches for detecting unknown obstacles inside the workspace of an industrial robot using a laser rangefinder for 2-D measurements. The two approaches are based on Expert System (ES) and Hidden Markov Model (HMM). The results presented in the paper demonstrate that both approaches are able to correctly detect and classify unknown objects. The ES is characterised by low computational requirements and an easy setup when relatively few known objects are to be included inside the workspace. HMMs are characterised by a higher flexibility and the ability to handle a larger amount of known objects inside the workspace. Another significant benefit…

Mathematical analysis of the stimulus for the lateral line organ

1985

Behavioral studies have shown that a blind fish is capable of detecting and recognizing stationary objects in its surroundings. It is proposed that the displacement of water caused by the fish as it moves is the basis for this detection capability. Alterations in the displacement of water around the fish, caused by the obstacle, act as stimuli for the lateral line organ. The question of how these stimuli acting on the skin of the fish, image the environment and what information is thus made available to the fish is the concern of this paper. The stimuli for the lateral line organ are derived mathematically. Two cases are treated: that of a fish gliding past an obstacle and that of one appro…

Detection of explanation obstacles in scientific texts: the effect of an understanding task vs. an experiment task

2013

The aim of this study is to analyse the effect of tasks on the detection of explanation obstacles when secondary school students read scientific texts. Students were instructed to read short passages under different task conditions, and to ask questions if necessary. Obstacle detection was operationalised in terms of the type of questions asked by the students. The experiment examined the influence of goals associated with the task of reading to understand a text vs. reading to perform a procedure described by the text (a science experiment). Significantly, more explanation obstacles were found in the understanding condition than in the experiment condition. Scientific text also had an effe…

Towards a cumulative tradition in e-Government Research: Going beyond the Gs and Cs

2007

Published version of a chapter published in Lecture Notes in Computer Science, 4656, 13-22. Also available from the publisher at: http://dx.doi.org/10.1007/978-3-540-74444-3_2 The emerging research area of e-Government is gradually moving towards a level of maturity on the back of increasingly rigorous empirical research. Yet, there has been little theoretical progress and a cumulative tradition is not emerging. We argue that a principle reason for this is a lack of shared understanding about basic concepts and entities amongst scholars in the field. Specifically, the entities that form the bedrock of e-Government research, such as “Government” and “Citizen” are conceptualized at a very gen…

The Obstacle Problem in a Non-Linear Potential Theory

1988

M. Brelot gave rise to the concept harmonic space when he extended classical potential theory on ℝn to an axiomatic system on a locally compact space. I have recently constructed1 a non-linear harmonic space by dropping the assumption that the sum of two harmonic functions is harmonic and considering some other axioms instead. This approach has its origin in the work of O. Martio, P. Lindqvist and S. Granlund2,3,4, who have developed a non-linear potential theory on ℝn connected with variational integrals of the type ∫ F(x,∇u(x)) dm(x), where F(x, h) ≈ |h|p.

Studies regarding supported housing and the built environment for people with mental health problems : A mixed-methods literature review

2019

Abstract Places where people live are important for their personal and social lives. This is also the case for people with mental health problems living in supported housing. To summarise the existing knowledge, we conducted a systematic review of 13 studies with different methodologies regarding the built environment in supported housing and examined their findings in a thematic analysis. The built environment of supported housing involves three important and interrelated themes: well-being, social identity and privacy. If overregulated by professionals or located in problematic neighbourhoods or buildings, the settings could be an obstacle to recovery. If understood as meaningful places w…

Evolution of mica fish in mylonitic rocks

2003

Abstract Mineral fish are lozenge-shaped porphyroclasts, single crystals in a finer grained matrix, which occur in ductile shear zones and which are commonly used as shear sense indicators. Mineral fish of biotite, tourmaline, K-feldspar, garnet, hypersthene and quartz occur in mylonites but most common are white mica fish. These mica fish can be subdivided into six morphological groups that develop by different mechanisms determined by different initial shapes and orientations. The principal mechanisms of formation are intracrystalline deformation combined with rigid body rotation. Concomitant selective grain size reduction occurs by recrystallisation, cataclastic separation, pressure solu…