Augmenting Agent Platforms to Facilitate Conversation Reasoning

Within Multi Agent Systems, communication by means of Agent Communication Languages (ACLs) has a key role to play in the co-operation, co-ordination and knowledge-sharing between agents. Despite this, complex reasoning about agent messaging, and specifically about conversations between agents, tends not to have widespread support amongst general-purpose agent programming languages. ACRE (Agent Communication Reasoning Engine) aims to complement the existing logical reasoning capabilities of agent programming languages with the capability of reasoning about complex interaction protocols in order to facilitate conversations between agents. This paper outlines the aims of the ACRE project and gives details of the functioning of a prototype implementation within the Agent Factory multi agent framework

Can the world cut poverty in half ? how policy reform and effective aid can meet international development goals

More effective development aid could greatly improve poverty reduction in the areas where poverty reduction is expected to lag: Sub-Saharan Africa, Eastern Europe, and Central Asia. Even more potent would be significant policy reform in the countries themselves. The authors develop a model of efficient aid in which the total volume of aid is endogenous. In particular, aid flows respond to policy improvements that create a better environment for poverty reduction and effective use of aid. They use the model to investigate scenarios-of policy reform, of more efficient aid, and of greater volumes of aid-that point the way to how the world could cut poverty in half in every major region. The fact that aid increases the benefits of reform suggests that a high level of aid to strong reformers may increase the likelihood of sustained good policy (an idea ratified in several recent case studies of low-income reformers). The authors find that the world is not operating on the efficiency frontier. With the same level of concern, much more poverty reduction could be achieved by allocating aid on the basis of how poor countries are as well as on the basis of the quality of their policies. Global poverty reduction requires a partnership in which"third world"countries and governments improve economic policy while"first world"citizens and governments show concern about poverty and translate that concern into effective assistance.Poverty Monitoring&Analysis,Services&Transfers to Poor,Poverty Reduction Strategies,Environmental Economics&Policies,Health Economics&Finance,Achieving Shared Growth,Environmental Economics&Policies,Poverty Monitoring&Analysis,Services&Transfers to Poor,Poverty Assessment

Computational complexity and memory usage for multi-frontal direct solvers in structured mesh finite elements

The multi-frontal direct solver is the state-of-the-art algorithm for the direct solution of sparse linear systems. This paper provides computational complexity and memory usage estimates for the application of the multi-frontal direct solver algorithm on linear systems resulting from B-spline-based isogeometric finite elements, where the mesh is a structured grid. Specifically we provide the estimates for systems resulting from $C^{p-1}$ polynomial B-spline spaces and compare them to those obtained using $C^0$ spaces.Comment: 8 pages, 2 figure

Nicotine treatment decreases food intake and body weight via a leptin-independent pathway in Psammomys obesus

It has been reported previously that leptin may be involved in nicotine\u27s ability to reduce body weight. Our aim was to investigate whether the anorexic action of nicotine is related to the actions of leptin by utilizing lean leptin-sensitive and obese leptin-resistant Psammomys obesus. Lean and obese P. obesus were assigned to receive nicotine sulphate at 6, 9 or 12 mg/day or saline (control) for 9 days (n = 6-10 in each group), administered using mini-osmotic pumps. Food intake, body weight, plasma leptin concentrations, plasma insulin and blood glucose were measured at baseline and throughout the study period. Nicotine treatment reduced food intake by up to 40% in lean and obese P. obesus. Plasma leptin levels fell significantly only in lean nicotine-treated animals, whereas no changes were observed in obese nicotine-treated animals. However, both lean and obese nicotine-treated animals had similar reductions in body weight. Our results show that nicotine has dramatic effects on food intake and body weight, however, these changes appear to be independent of the leptin signalling pathway.<br /

The cost of continuity: performance of iterative solvers on isogeometric finite elements

In this paper we study how the use of a more continuous set of basis functions affects the cost of solving systems of linear equations resulting from a discretized Galerkin weak form. Specifically, we compare performance of linear solvers when discretizing using $C^0$ B-splines, which span traditional finite element spaces, and $C^{p-1}$ B-splines, which represent maximum continuity. We provide theoretical estimates for the increase in cost of the matrix-vector product as well as for the construction and application of black-box preconditioners. We accompany these estimates with numerical results and study their sensitivity to various grid parameters such as element size $h$ and polynomial order of approximation $p$. Finally, we present timing results for a range of preconditioning options for the Laplace problem. We conclude that the matrix-vector product operation is at most \slfrac{33p^2}{8} times more expensive for the more continuous space, although for moderately low $p$, this number is significantly reduced. Moreover, if static condensation is not employed, this number further reduces to at most a value of 8, even for high $p$. Preconditioning options can be up to $p^3$ times more expensive to setup, although this difference significantly decreases for some popular preconditioners such as Incomplete LU factorization

Squatter settlements and the incorporation of migrants into urban life : the case of Lima

"April 1976.""#2075"--handwritten on coverIncludes bibliographical references (p. 59-62