SOFTWARE AND PERFORMANCE MEASURES FOR EVALUATING MULTI-AGENT FRAMEWORKS

ABSTRACT

Nowadays, multi-agent frameworks allow to implement very complex systems by means of agent technology. However, this complexity makes it more difficult to evaluate software and runtime characteristics of multiagent systems (MAS). Our aim is to define and study some quantitative measures to measure MAS aspects like development time, reusability, scalability, etc. These measures could be used by engineers to guide the selection among several MAS frameworks. Our study has been carried out in several MAS frameworks like JADE, JATLite, SkeletonAgent, and ZEUS, which have been used to build a MAS application for news retrieval.     

An optimal expansion of Volterra models using independent Kautz bases for each kernel dimension

A new solution for the problem of selecting poles of the two-parameter Kautz functions in Volterra models is proposed. In general, a large number of parameters are required to represent the Volterra kernels, although this difficulty can be overcome by describing each kernel using a basis of orthonormal functions, such as the Kautz basis. This representation has a Wiener structure consisting of a linear dynamic generated by the orthonormal basis followed by a non-linear static mapping represented by the Volterra series. The resulting Wiener/Volterra model can be truncated into fewer terms if the Kautz functions are properly designed. The underlying problem is how to select the arbitrary complex poles that fully parametrize these functions. This problem has been approached in previous research by minimizing an upper bound for the error resulting from the truncation of the kernel expansion. The present paper goes even further in that each multidimensional kernel is decomposed into a set of independent Kautz bases, each of which is parametrized by an individual pair of conjugate Kautz poles intended to represent the dominant dynamic of the kernel along a particular dimension. An analytical solution for one of the Kautz parameters, valid for Volterra models of any order, is derived. A simulated example is presented to illustrate these theoretical results. The same approach is then used to model a real non-linear magnetic levitation system with oscillatory behaviour.     

Immigration and the psychodynamics of class.

Numerous psychoanalytic contributors have theorized about the substantive role played by cultural factors in organizing individual identity. In addition to individual and family dynamics, issues related to class, race, religion, and other cultural themes also exert a vital presence in the treatment setting. These social forces define experience in profound ways from which it is impossible that form an inextricable part of an individual's psychology. Societal values, norms, and forces are carried and represented, forming an ever-present backdrop to our psychological lives. They thus become, perforce, part of the treatment process whether or not the therapist or analyst is aware of their presence. In prior work I have explored the topic of the immigrant's construction of self as it relates to social class (Ainslie, 2009). I argue that one of the variables that shape an immigrant's psychology is his or her social class position in his or her country of origin. In the present contribution, I seek to extend this exploration of the topic of social class and the psychology of immigration through three vignettes that capture aspects of how social class becomes represented in the experience and therapeutic treatment of immigrants. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

A FE/BE coupling for the 3D time-dependent eddy current problem. Part I: a priori error estimates

In this paper the discontinuous Galerkin method in time for the coupling of conforming finite element and boundary element methods is established. We derive quasi-optimal a priori error estimates. Numerical examples prove the new scheme to be useful in practice. A posteriori error control and an adaptive algorithm are studied in Part II of this paper.     

Chemical changes in the volatile fractions of Brazilian honeys during storage under tropical conditions

The chemical transformations of the volatile fractions of two different Brazilian honeys (cashew and marmeleiro) were monitored during storage under tropical conditions. Five systems, namely: 1 – fresh samples; 2 and 3 – samples heated for 3 and 6 months at 35 – 40 °C; 4 and 5 – samples kept under similar conditions to systems 2 and 3, but containing sodium metabisulphite, were tested. The transformations noted in the volatile fractions of these honeys could be mainly associated to acid or enzymatic hydrolysis of glycosides, volatilization, oxidation or esterification processes. The formation of furan derivatives, linalool derivatives and esters appears to be quite affected by the sodium metabisulphite. The concentrations of most powerful odorants increased during the storage (e.g.: benzenemethanol and isovaleric acid) or remained unchangeable (e.g.: vanillin, furfuryl mercaptan, 2-methoxyphenol).