Решение некоторых проблем защиты мультиагентных систем

In article the analysis of categories of the distributed systems and characteristic threats for them is carried out. The basic attention is given development of methods of protection in multiagent systems. Realization of platform methods of protection in multiagent systems is considered.Проводится анализ категорий распределенных систем и характерных для них угроз. Основное внимание уделяется разработке методов защиты мультиагентных систем. Рассмотрена реализация платформенных методов защиты мультиагентных систем

A Craniometric Perspective on the Transition to Agriculture in Europe

Debates surrounding the nature of the Neolithic demographic transition in Europe have historically centered on two opposing models: a demic diffusion model whereby incoming farmers from the Near East and Anatolia effectively replaced or completely assimilated indigenous Mesolithic foraging communities, and an indigenist model resting on the assumption that ideas relating to agriculture and animal domestication diffused from the Near East but with little or no gene flow. The extreme versions of these dichotomous models were heavily contested primarily on the basis of archeological and modern genetic data. However, in recent years a growing acceptance has arisen of the likelihood that both processes were ongoing throughout the Neolithic transition and that a more complex, regional approach is required to fully understand the change from a foraging to a primarily agricultural mode of subsistence in Europe. Craniometric data were particularly useful for testing these more complex scenarios, as they can reliably be employed as a proxy for the genetic relationships among Mesolithic and Neolithic populations. In contrast, modern genetic data assume that modern European populations accurately reflect the genetic structure of Europe at the time of the Neolithic transition, while ancient DNA data are still not geographically or temporally detailed enough to test continent-wide processes. Here, with particular emphasis on the role of craniometric analyses, we review the current state of knowledge regarding the cultural and biological nature of the Neolithic transition in Europe

Pyrus Base: An Open Source Python Framework for the RoboCup 2D Soccer Simulation

Soccer, also known as football in some parts of the world, involves two teams of eleven players whose objective is to score more goals than the opposing team. To simulate this game and attract scientists from all over the world to conduct research and participate in an annual computer-based soccer world cup, Soccer Simulation 2D (SS2D) was one of the leagues initiated in the RoboCup competition. In every SS2D game, two teams of 11 players and one coach connect to the RoboCup Soccer Simulation Server and compete against each other. Over the past few years, several C++ base codes have been employed to control agents' behavior and their communication with the server. Although C++ base codes have laid the foundation for the SS2D, developing them requires an advanced level of C++ programming. C++ language complexity is a limiting disadvantage of C++ base codes for all users, especially for beginners. To conquer the challenges of C++ base codes and provide a powerful baseline for developing machine learning concepts, we introduce Pyrus, the first Python base code for SS2D. Pyrus is developed to encourage researchers to efficiently develop their ideas and integrate machine learning algorithms into their teams. Pyrus base is open-source code, and it is publicly available under MIT License on GitHu

Gliders2d: Source Code Base for RoboCup 2D Soccer Simulation League

We describe Gliders2d, a base code release for Gliders, a soccer simulation team which won the RoboCup Soccer 2D Simulation League in 2016. We trace six evolutionary steps, each of which is encapsulated in a sequential change of the released code, from v1.1 to v1.6, starting from agent2d-3.1.1 (set as the baseline v1.0). These changes improve performance by adjusting the agents' stamina management, their pressing behaviour and the action-selection mechanism, as well as their positional choice in both attack and defense, and enabling riskier passes. The resultant behaviour, which is sufficiently generic to be applicable to physical robot teams, increases the players' mobility and achieves a better control of the field. The last presented version, Gliders2d-v1.6, approaches the strength of Gliders2013, and outperforms agent2d-3.1.1 by four goals per game on average. The sequential improvements demonstrate how the methodology of human-based evolutionary computation can markedly boost the overall performance with even a small number of controlled steps.Comment: 12 pages, 1 figure, Gliders2d code releas

Artificial Neural Network, Quantile and Semi-Log Regression Modelling of Mass Appraisal in Housing

We used a large sample of 188,652 properties, which represented 4.88% of the total housing stock in Catalonia from 1994 to 2013, to make a comparison between different real estate valuation methods based on artificial neural networks (ANNs), quantile regressions (QRs) and semi-log regressions (SLRs). A literature gap in regard to the comparison between ANN and QR modelling of hedonic prices in housing was identified, with this article being the first paper to include this comparison. Therefore, this study aimed to answer (1) whether QR valuation modelling of hedonic prices in the housing market is an alternative to ANNs, (2) whether it is confirmed that ANNs produce better results than SLRs when assessing housing in Catalonia, and (3) which of the three mass appraisal models should be used by Spanish banks to assess real estate. The results suggested that the ANNs and SLRs obtained similar and better performances than the QRs and that the SLRs performed better when the datasets were smaller. Therefore, (1) QRs were not found to be an alternative to ANNs, (2) it could not be confirmed whether ANNs performed better than SLRs when assessing properties in Catalonia and (3) whereas small and medium banks should use SLRs, large banks should use either SLRs or ANNs in real estate mass appraisal

Intention Reconciliation by Collaborative Agents

Research on resource-bounded agents has established that rational agents need to be able to revise their commitments in the light of new opportunities. In the context of collaborative activities, rational agents must be able to reconcile their intentions to do team-related actions with other, conflicting intentions. The SPIRE experimental system allows the process of intention reconciliation in team contexts to be simulated and studied. Prior work with SPIRE examined the effect of team norms, environmental factors, and agent utility functions on individual and group outcomes for homogeneous groups of agents. This paper extends these results to situations involving heterogeneous groups in which agents use different utility functions. The paper provides new illustrations of the ways in which SPIRE can reveal unpredicted interactions among the variables involved, and it suggests preliminary principles for designers of collaborative agents.Engineering and Applied Science

Roles Played by the Na+/Ca2+ Exchanger and Hypothermia in the Prevention of Ischemia-Induced Carrier-Mediated Efflux of Catecholamines into the Extracellular Space: Implications for Stroke Therapy

The release of [3H]dopamine ([3H]DA) and [3H]noradrenaline ([3H]NA) in acutely perfused rat striatal and cortical slice preparations was measured at 37 °C and 17 °C under ischemic conditions. The ischemia was simulated by the removal of oxygen and glucose from the Krebs solution. At 37 °C, resting release rates in response to ischemia were increased; in contrast, at 17 °C, resting release rates were significantly reduced, or resting release was completely prevented. The removal of extracellular Ca2+ further increased the release rates of [3H]DA and [3H]NA induced by ischemic conditions. This finding indicated that the Na+/Ca2+ exchanger (NCX), working in reverse in the absence of extracellular Ca2+, fails to trigger the influx of Ca2+ in exchange for Na+ and fails to counteract ischemia by further increasing the intracellular Na+ concentration ([Na+]i). KB-R7943, an inhibitor of NCX, significantly reduced the cytoplasmic resting release rate of catecholamines under ischemic conditions and under conditions where Ca2+ was removed. Hypothermia inhibited the excessive release of [3H]DA in response to ischemia, even in the absence of Ca2+. These findings further indicate that the NCX plays an important role in maintaining a high [Na+]i, a condition that may lead to the reversal of monoamine transporter functions; this effect consequently leads to the excessive cytoplasmic tonic release of monoamines and the reversal of the NCX. Using HPLC combined with scintillation spectrometry, hypothermia, which enhances the stimulation-evoked release of DA, was found to inhibit the efflux of toxic DA metabolites, such as 3,4-dihydroxyphenylacetaldehyde (DOPAL). In slices prepared from human cortical brain tissue removed during elective neurosurgery, the uptake and release values for [3H]NA did not differ from those measured at 37 °C in slices that were previously maintained under hypoxic conditions at 8 °C for 20 h. This result indicates that hypothermia preserves the functions of the transport and release mechanisms, even under hypoxic conditions. Oxidative stress (H2O2), a mediator of ischemic brain injury enhanced the striatal resting release of [3H]DA and its toxic metabolites (DOPAL, quinone). The study supports our earlier findings that during ischemia transmitters are released from the cytoplasm. In addition, the major findings of this study that hypothermia of brain slice preparations prevents the extracellular calcium concentration ([Ca2+]o)-independent non-vesicular transmitter release induced by ischemic insults, inhibiting Na+/Cl--dependent membrane transport of monoamines and their toxic metabolites into the extracellular space, where they can exert toxic effects