An implementation of collaborative adaptation of cognitive radio parameters using an ontology and policy based approach

The main objective of this paper is to demonstrate the feasibility of the ontology and policy based approach to realize collaborative, automatic adaptation of cognitive radio parameters in the transmitter and receiver. The ontology and policy based approach features the following three aspects. First, all the internal and external information of the radio is represented in the Web Ontology Language (OWL). The transmitter and receiver share the same core ontology and thus can communicate with each other using this common language. Second, the policy rules are written in a declarative form and interpreted by a reasoner. Third, in order to exchange the OWL represented information between the radios, we adopt a more flexible signaling plan, which is different than the conventional protocol-predefined signaling plan, i.e. the control messages are added to an extendable payload, rather than embedded in the predefined protocol-dependent header or trailer. The paper discusses the implementation and shows some examples of radio behaviors resulting from the execution of the policies.     

Reinforcement learning: Architectures and algorithms

This article is related to the research effort of constructing an intelligent agent, i.e., a computer system that is able to sense its environment (world), reason utilizing its internal knowledge and execute actions upon the world (act). the specific part of this effor presented in this article is reinforcement learning, i.e., the process of acquiring new knowledge based upon an evaluative feedback, called reinforcement, received by tht agent through interactions with the world. This article has two objectives: (1) to give a compact overview of reinforcement learning, and (2) to show that the evolution of the reinforcement learning paradigm has been driven by the need for more efficient learning through the addition of more structure to the learning agent. Therefore, both main ideas of reinforcement learning are introduced, and structural solutions to reinforcemen learning are reviewed. Several architectural enhancements of the RL paradigm are discussed. These include incorporation of state information in the learning process, architectural solutions to learning with delayed reinforcement, dealing with structurally changing worlds through utilization of multiple models of the world, and focusing attention of the learning agent through active perception. the paper closes with an overview of directions for applications and for future research in this area. © 1993 John Wiley & Sons, Inc.     

Survival of salmonellae in skimmilk powder during storage at 20–35°C

Effect of 1-, 2-, 3-, 7- and 14-day storage of skimmilk powder at 20, 25, 30 and 35°C on the survival of S. typhimurium, S. anatum and S. dublin was examined. Salmonellae were always recovered in all experimental variants when the samples were inoculated with high numbers of these bacteria. When small inoculum was applied it was found that the rates of salmonellae destruction increased as the temperature and the time of storage was increased. It is concluded that storage of skimmilk powder at ambient temperature may, depending on the level of contamination, considerably or completely eliminate these bacteria from the product.     

LIMITATIONS OF AVERAGE STRUCTURE DETERMINATION FOR HEAVY ENDS IN FOSSIL FUELS

This paper provides a critical analysis of the average molecular structure determination For high boiling and nondistll-lahle fractions in fossil fuels. The emphasis is on molecular weight distribution and compound-class composition. The wide molecular weight distribution, resulting from the different volatility of the various chemical classes of compounds comprising these complex mixtures, is demonstrated to be the major limitation.     

Investigations on Romashkino asphaltic bitumen. 3. Fractionation of asphaltenes using ion-exchange chromatography

The fractionation of asphaltenes originally separated¹ from Romashkino asphaltic bitumen has been achieved by means of stepwise anion- and cation-exchange chromatography through macroreticular resins. The fractionation procedure and yields of the fractions are given. A detailed structural analysis has been made of original asphaltenes and their acid- and base-free fraction using elemental and densimetric analyses, gel-permeation chromatography and proton magnetic resonance spectroscopy. Inverse gas-liquid chromatography has also been used to detect the chemical functionality of the asphaltene fractions. Results are presented to show the effect of ion-exchange resins treatment upon the composition of asphaltenes, noting that molecular weight as well as chemical structure changes appreciably.     

A Survey of Several Root-Finding Methods in the Complex Plane

In this paper a few classes of root-finding iterative methods are presented and used in the complex plane to solve the equation  z⁴− 1 = 0  . These methods are studied using computer graphics techniques.     

Self Controlling Tabu Search algorithm for the Quadratic Assignment Problem

This paper addresses the application of the principles of feedback and self-controlling software to the tabu search algorithm. We introduce two new reaction strategies for the tabu search algorithm. The first strategy treats the tabu search algorithm as a target system to be controlled and uses a control-theoretic approach to adjust the algorithm parameters that affect search intensification. The second strategy is a flexible diversification strategy which can adjust the algorithm’s parameters based on the search history. These two strategies, combined with tabu search, form the Self Controlling Tabu Search (SC-Tabu) algorithm. The algorithm is implemented and tested on the Quadratic Assignment Problem (QAP). The results show that the self-controlling features of the algorithm make it possible to achieve good performance on different types of QAP instances.     

Using UML and OCL for representing multiobjective combinatorial optimization problems

This paper describes the results of a preliminary feasibility study of an approach to representing multiobjective combinatorial optimization problems in UML (structural constraints) and OCL (procedural constraints) and then automatically translating the representations to a constraint satisfaction solving language (Oz) for execution. The paper presents two examples of the application of the approach—a job scheduling problem and a (fixture) design problem. The main goal of this paper is to investigate directions towards a standard, graphical language for representing combinatorial optimization problems. The paper shows that for the two selected problems it is easy to represent structural constraints in UML and that procedural constraints are representable in OCL. The results also show that a developed translator automatically converts the UML/OCL representations to Oz and that the resulting Oz program performs very reasonably, in some cases outperforming the hand-written benchmark programs.     

Defect Structure of Cobalt Monoxide: I, The Ideal Defect Model

The nonstoichiometry and electrical properties of Co_1-YO are considered in terms of an ideal defect model. Both intrinsic and extrinsic regions are analyzed. Interrelationships between the oxygen partial pressure and the oxide composition are derived. It has been shown that the p _O2 exponent resulting from the deviation from stoichiometry (l/ n _Y ) differs substantially from the exponent determined by measurements of electrical conductivity (1/ n _σ) The limitations of the ideal defect approximation are discussed.