A formal architectural model for logical agent mobility

The process of agent migration is the major difference between logical code mobility of software agents and physical mobility of mobile nodes in ad hoc networks. Without considering agent transfer, it would make little sense to mention the modeling of strong code mobility, which aims to make a migrated agent restarted exactly from the state when it was stopped before migration. From the perspective of system's architecture, this paper proposes a two-layer approach for the formal modeling of logical agent mobility (LAM) using predicate/transition (PrT) nets. We view a mobile agent system as a set of agent spaces and agents could migrate from one space to another. Each agent space is explicitly abstracted to be a component, consisting of an environmental part and an internal connector dynamically binding agents with their environment. We use a system net, agent nets, and a connector net to model the environment, agents, and the connector, respectively. In particular, agent nets are packed up as parts of tokens in system nets, so that agent transfer and location change are naturally captured by transition firing (token game) in Petri nets. Agent nets themselves are active only at specific places and disabled at all the other places in a system net. The semantics of such a two-layer LAM model is defined by transforming it into a PrT net. This facilitates the analysis of several properties about location, state, and connection. In addition, this paper also presents a case study of modeling and analyzing an information retrieval system with mobile agents.     

基于神经网络的图像来源识别方法比较研究

随着手机等便携式智能电子设备的普及,图像已成为最重要的信息载体之一,在新闻、社交及司法等领域发挥着重要作用.在享用电子图像带来便捷性的同时,图像处理工具给不法分子通过篡改电子图像实施诈骗等犯罪活动提供了可能,识别图像来源、辨别图像真伪已成为遏制和惩罚此类犯罪活动的重要技术手段.该文讨论了神经网络在图像源识别中的应用方法...     

基于设计模式的软件重用

针对软件重用。提出应用设计模式来记录软件设计知识。这可以使软件重用从构架重用提高到软件开发各阶段知识的重用。此外结合通用仓库／销售系统的实际对设计模式的用法进行了讨论。     

大型铝合金机车顶盖焊接工艺

介绍了大型铝合金顶盖的焊接工艺,并根据DIN6700体系要求分析顶盖结构,确定焊接方法及焊接材料,通过将顸盖分为四部分,详细介绍了顶盖的组装工艺及过程,并得出了大型铝合金结构件的焊接顺序,以及在整个顶盖的制造过程中采用的一些简单实用的工装与夹具.提出了如何在大型铝合金结构件生产过程中避免内应力集中的方法,从而有效避免了大量焊接裂纹的产生.     

Sensing mechanism of Ag/α-MoO3 nanobelts for H2S gas sensor

Sensing mechanism is still a big problem in the field of gas sensor.In-depth study of the sensing mecha-nism can provide better ideas for the design of sensing ...     

Influences of harmonic cavities on single-bunch instabilities in electron storage rings

Harmonic cavities (HCs) are widely used in electron storage rings, mainly to increase the Touschek lifetime by lengthening bunches. HCs have become critical com...     

Biological analysis of woodpecker’s brain after impact experiments

Woodpeckers can withstand a fierce impact during pecking. Previous studies have focused on the biomechanical analysis of the pecking process, the properties of the beak and hyoid bone of woodpecker; however, the biological characteristics of the woodpecker brain are also important in resisting impact injuries. We employed impact experiments and biological analysis in normal and injured brains to reveal the impact-resistant biological characteristics of woodpecker brains, as well as the impact energy's biological effects on the woodpecker brain. The hoopoe, which has a similar size but only a slight pecking behavior, was selected as the control group to compare brain morphology and neuronal cells differences in normal brains between woodpecker and hoopoe by sectioning and staining. A loading device was designed to conduct a quantifiable impact energy to the woodpeckers' head. Four groups of woodpeckers were impacted with the same energy on the forehead, beak, tempus and occiput,respectively. Biological changes in the injured brains were evaluated by Nissl staining and enzyme-linked immunosorbent assay.The results showed that:(1) woodpeckers had a larger cerebellum and a higher density of Nissl bodies than hoopoe;(2) Nissl apoptosis appeared in the brain samples after the forehead and the occiput impact experiments, but no obvious Nissl body apoptosis was observed after impact on the tempus and the beak;(3) β-amyloid protein accumulated in the normal status woodpecker brain. This study reveals that: woodpecker brain morphology is well-adapted to impact, woodpecker heads display location-dependent protective performance, with beak and tempus regions having a better protective performance than the forehead and occiput, Nissl apoptosis appears in injured woodpecker brains, and that the accumulation of β-amyloid protein does not show a direct relationship with the injury state of woodpecker's brain tissue in our study.     

浅谈零缺陷与质量成本

阐述零缺陷在工作中的行动准则和零缺陷管理所要达到的最终目标,分析了零缺陷在实际生产中对质量成本的影响。     

ptp通讯在锌电解供电优化系统中的研究与应用

以提高锌电解供电系统的自动化程度、实现网络控制为目的,在分析了系统总体结构和控制原理的基础上,重点讨论了ptp通讯在系统中的研究与应用;ptp通讯网络以S7-300PLC为主站,以两台晶闸管数字触发器为从站,实现电流给定和触发角反馈等信号的传输,其通讯协议简单,开发成本低,与Profibus网一道组成的控制网抗干扰能力强,可靠性高,有力地保证了锌电解供电优化系统安全运行,为锌电解提高整流效率、节约电能提供了保障.     

Learning capability of the truncated greedy algorithm截断贪婪算法的学习性能

Pure greedy algorithm (PGA), orthogonal greedy algorithm (OGA) and relaxed greedy algorithm (RGA) are three widely used greedy type algorithms in both nonlinear approximation and supervised learning. In this paper, we apply another variant of greedy-type algorithm, called the truncated greedy algorithm (TGA) in the realm of supervised learning and study its learning performance. We rigorously prove that TGA is better than PGA in the sense that TGA possesses the faster learning rate than PGA. Furthermore, in some special cases, we also prove that TGA outperforms OGA and RGA. All these theoretical assertions are verified by both toy simulations and real data experiments.