Extended Self Organizing Feature Map: A Tagged Potential Field Approach

This paper proposes an escape methodology to the local minima problem of self organizing feature maps generated in the overlapping regions which are equidistant to the corresponding winners. Two new versions of the Self Organizing Feature Map are derived equipped with such a methodology. The first approach introduces an excitation term, which increases the convergence speed and efficiency of the algorithm, while increasing the probability of escaping from local minima. In the second approach, we associate a learning set which specifies the attractive and repulsive field of output neurons. Results indicate that accuracy percentile of the new methods are higher than the original algorithm while they have the ability to escape from local minima.     

Influence of a beacon on spatial learning based on the shape of the test environment.

In 5 experiments rats were required to escape from a triangular shaped pool by swimming to a submerged platform. The principal group of interest in each experiment received training with a beacon attached to the platform. The purpose of the experiments was to assess if the beacon overshadowed (Experiments 1–4) or blocked (Experiment 5) learning about the position of the platform with reference to the shape of the pool. The platform was located in the center of the pool for the first 2 experiments and in a corner for the remaining experiments. Although there was an overshadowing effect in Experiment 1, the remaining experiments failed to reveal any disruptive influence of the beacon on learning based on the shape of the pool. Moreover, in Experiments 3–5 there was an indication that the beacon facilitated such learning. The results suggest that spatial learning based on the shape of a test environment may not take place in the same way as that based on more discrete landmarks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Psychological science in cultural context.

When one understands psychological science to be a by-product of the Western tradition, fashioned by particular cultural and historical conditions, the door is opened to a fresh consideration of the practice of psychology in the global context. By using examples from experiences in Turkey, New Zealand, and India, the reader is sensitized first to the problems inherent in the unreflective exportation of Western psychology. To presume Western concepts of the mind, along with its methods of study, not only lends itself to research of little relevance to other cultures, but disregards and undermines alternate cultural traditions. Against these tendencies toward a univocal science, the authors argue for a multicultural psychology—one that celebrates the rich multiplicity of indigenous conceptualizations of the person along with varying means of acquiring knowledge. To realize such a psychology, new forms of dialogue must be sought and the sharing made relevant to ongoing challenges of practical cultural signiflcance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stability of Lactobacillus bulgaricus immobilized in K-carrageenan gels

The future application of immobilized microorganism techniques will depend on the development of systems which are technologically applicable on an industrial scale. These techniques must permit high microbial concentrations and must allow mass transfer to take place with low diffusional limitations. In addition, the mechanical separation of the immobilized microorganisms must be achieved economically, K-carrageenan was used as an ionotropic gel carrier for the immobilization of Lactobacillus bulgaricus (ATCC 11842), and the effects of gel stability on productivity and the rate of product formation were investigated. K-carrageenan gels had higher mechanical and chemical stability than alginate gels. The storage stability of microorganisms immobilized in K-carrageenan was good enough to retain biocatalytic activity during prolonged storage at 4°C.     

Investigation of luminescence centers inside InGaN/GaN multiple quantum well over a wide range of temperature and injection currents

Journal of Materials Science: Materials in Electronics - InGaN/GaN multiple quantum well-based light-emitting diode LEDs were investigated over a wide range of injection currents (0.04 mA–0.1...     

A Petri net approach to behavioural simulation of design artefacts with application to mechatronic design

A Petri net-based design inference network (PNDN) architecture is presented in this paper. The network models the logical behaviour of any design artefact developed by designers at the conceptual design level by representing the subfunctions and their inter-relationships to perform a required overall function. The theoretical framework in developing the PNDN is based on the improved theory of Petri nets and hybrid automata. The theoretical PNDN architecture was implemented in a C++ based software called the design network simulator (DNS). The logical behaviour of a design artefact is modelled through the token flow within the PNDN. The token flow model is developed both for deterministic and nondeterministic PNDN, which involves uncertainties. In this paper we present the mathematical formalism of the deterministic token flow through the PNDN. We also provide a conceptual design example in order to explain the application of our theoretical architecture for structuring the PNDN.