A Multi-Agent System Using JADE for Simulation of Supply Chains

This paper proposes a prototype system for modeling and simulation of supply chains using a widely accepted agent platform Java agent development platform (JADE). A simple but practical coordination mechanism agent-based dynamic information network for supply chains (ADINS) is employed for the illustration of the suggested system and a simulation experiment is performed using a supply chain model of a Korean LCD manufacturing company. The result shows that the suggested mechanism is successful in reducing bullwhip effects and increasing service rates.     

Interference Coordination in Cellular OFDMA Networks

Orthogonal frequency division multiple access is the basis for several emerging mobile communication systems. Prominent examples are the 3GPP Long Term Evolution as the successor of UMTS high-speed packet access and the IEEE 802.16 system, advanced by the WiMAX forum. On a system level, OFDMA is basically a combination of time and frequency division multiple access. In cellular TDM/FDM systems, inter-cell interference is a major issue that traditionally has been solved by avoiding the use of the same frequency bands in adjacent cells. However, this solution incurs a waste of precious frequency resources. An attractive alternative is the use of beamforming antennas in combination with interference coordination mechanisms, where the transmission of adjacent base stations is coordinated to minimize inter-cell interference. Interference coordination is an important aspect of the system level, which influences many other issues, such as network planning or scheduling mechanisms. In this article, we give an overview of interference coordination as it would apply, for example, to IEEE 802.16e and review the relevant literature. We also discuss and compare interference coordination algorithms, which can be based either on global system knowledge or purely on local system knowledge.     

可信终端动态运行环境的可信证据收集机制

可信计算的链式度量机制不容易扩展到终端所有应用程序,因而可信终端要始终保证其动态运行环境的可信仍然困难.为了提供可信终端动态运行环境客观、真实、全面的可信证据,提出了可信终端动态运行环境的可信证据收集机制.首先,在可信终端的应用层引入一个可信证据收集代理,并将该代理作为可信平台模块(trusted platform module,简称TPM)链式度量机制的重要一环,利用TPM提供的度量功能保证该代理可信;然后通过该代理收集可信终端的内存、CPU、网络端口、磁盘文件、策略配置数据和进程等的运行时状态信息,并利用TPM提供的可信存储功能,保存这些状态信息作为终端运行环境的可信证据,并保障可信证据本身的可信性.该可信证据收集机制具有良好的可扩展性,为支持面向不同应用的信任评估模型提供基础.在Windows平台中实现了一个可信证据收集代理的原型,并以一个开放的局域网为实验环境来分析可信证据收集代理所获取的终端动态运行环境可信证据以及可信证据收集代理在该应用实例中的性能开销.该应用实例验证了该方案的可行性.     

动态特性可调的微动平台优化设计

针对目前柔性铰链主要靠局部变形来工作,其存在应力集中,且微动平台的动态特性受材料特性、设计制造等误差影响,难以满足变工况条件下的高精密位移输出。基于应力刚化原理,采用对称布置的带倒角的弹片式柔性铰链,设计张紧力调节机构,实现微动平台的动态特性可调。采用COMSOL Multiphysics和MATLAB联合仿真对张紧力调节机构进行参数优化,让调节机构保持线性调节关系,使柔性铰链的应力分布最小化。结果表明,所设计的微动平台能够进行高度线性固有频率调节,与有限元分析结果相比,频率调节范围相差2.55%,在理论设计范围内。     

基于非线性因子的改进鸟群算法在动态能耗管理中的应用

针对实时系统能耗管理中动态电压调节(DVS)技术的应用会导致系统可靠性下降的问题,该文提出一种基于改进鸟群(IoBSA)算法的动态能耗管理法。首先,采用佳点集原理均匀地初始化种群,从而提高初始解的质量,有效增强种群多样性;其次,为了更好地平衡BSA算法的全局和局部搜索能力,提出非线性动态调整因子;接着,针对嵌入式实时系统中处理器频率可以动态调整的特点,建立具有时间和可靠性约束的功耗模型;最后,在保证实时性和稳定性的前提下,利用提出的IoBSA算法,寻求最小能耗的解决方案。通过实验结果表明,与传统BSA等常见算法相比,改进鸟群算法在求解最小能耗上有着很强的优势及较快的处理速度。     

Reliability assessment of multiple-agent cooperating systems

Multiple agent systems are being increasingly used in real-time applications, safety-critical systems, etc. Many of these applications have soft real-time constraints and imprecise correctness criteria for the output value. A principal characteristic of such systems is the tradeoff between using an efficient but less accurate strategy and a sophisticated but more time-consuming strategy. This paper develops methods for assessing the reliability of these systems in terms of the timeliness and accuracy of the output, to aid decision making. Two commonly used coordination structures, parallel and pipeline, are used. Some adaptive schemes are proposed, i.e., strategies can be selected dynamically by agents at the run-time according to the input encountered in order to enhance the reliability of the system. The applicability of this approach is demonstrated by a practical multimedia client-server example     

基于多智能体技术的城市智能交通控制系统

本文中提出一种城市交通智能控制系统,针对城市交通网络中相邻交叉口的交通流可能相互冲突,即局部交通流的优化可能引起其他区域交通状况的恶化的问题,采用多智能体协调控制方法来协调相邻交叉口处的控制信号消除网络中的交通拥塞.提出以一个智能体的方式实现一个信号灯交叉口控制,对多个信号灯交叉口形成的交通网络采用多智能体协调控制的方式实现网络流量优化来消除拥塞.文中提出由递归建模和改进的贝叶斯学习相结合的多智能体系统来使智能体可以确定其他智能体的准确模型并实时更新信息,并基于上述方法在简单的交通网络模型上建立了多智能体交通控制系统,仿真结果表明了方法的有效性,对实现智能交通系统有重要意义.     

认知无线网络中一种新的反压式传输控制机制

认知无线网络中资源动态变化,必须制定特别的传输控制机制来协调各节点间的传输.该文提出一种新的反压式传输控制机制,充分利用局部节点间的调整能力,将端到端传输中出现的不良网络状况尽量解决在局部,使得源节点可以较温和地做出端到端控制,从而保证端到端传输的高效与平稳.大量仿真证明,该文控制机制能有效适应认知无线网络的动态环境,保证较高效且平稳的端到端传输.     

Neural-Network-Based Path Planning for a Multirobot System With Moving Obstacles

Recently, a coordinated hybrid agent (CHA) framework was proposed for the control of multiagent systems (MASs). It was demonstrated that an intelligent planner can be designed for the CHA framework to automatically generate desired actions for multiple robots in an MAS. However, in previous studies, only static obstacles in the workspace were considered. In this paper, a neural-network-based approach is proposed for a multirobot system with moving obstacles. A biologically inspired neural-network-based intelligent planner is designed for the coordination of MASs. A landscape of the neural activities for all neurons of a CHA agent contains information about the agent's local goal and moving obstacles. The proposed approach is able to plan the paths for multiple robots while avoiding moving obstacles. The proposed approach is simulated using both MATLAB and Vortex. The Vortex module executes control commands from the control system module, and provides the outputs describing the vehicle state and terrain information, which are, in turn, used in the control module to produce the control commands. Simulation results show that the developed intelligent planner of the CHA framework can control a large complex system so that coordination among agents can be achieved.      

宽带OFDM系统的干扰协调技术

在基于OFDM的蜂窝移动通信网络中,影响系统性能的主要干扰来自小区间干扰。小区间的干扰协调技术是提高系统性能的有效手段之一。首先,给出了干扰协调的软频率复用原理。然后,按照资源在时域上调度粒度的不同将干扰协调技术分为三类,即静态干扰协调、动态干扰协调和半静态干扰协调,并分析了各自的优缺点。最后,通过两个干扰协调方案实例说明干扰协调在3G长期演进系统中的应用。     

一种新的仿生彩色图像增强方法

 基于人类视觉系统的全局和局部自适应特性,本文提出一种仿生彩色图像增强方法,用于增强不均匀光照或低照度情况下的图像.该方法主要包括全局自适应亮度调节、局部对比度增强和颜色恢复三个部分.即全局亮度调节主要用来增强暗区域的亮度和压缩图像的动态范围;局部对比度增强利用当前点与其邻域象素的双边滤波输出之间的关系,调节当前点的亮度,以增强图像局部对比度;再通过一种简单的线性颜色恢复算法恢复图像色彩.与文献 所提彩色图像增强算法相比,实验结果表明本文所提方法的效果更好.     

A Study of Applications of Multiagent System Specifications and the Key Techniques in Automatic Abstracts System

A Study of Applications of Multiagent System Specifications and the Key Techniques in Automatic Abstracts System     

Agent cloning: an approach to agent mobility and resourceallocation

Multi-agent systems are subject to performance bottlenecks in cases where agents cannot perform tasks by themselves due to insufficient resources. Solutions to such problems include passing tasks to others or agent migration to remote hosts. We propose agent cloning as a more comprehensive approach to the problem of local agent overloads. Agent cloning subsumes task transfer and agent mobility. According to our paradigm, agents may clone, pass tasks to others, die, or merge. We discuss the requirements of implementing a cloning mechanism and its benefits in a multi-agent system, and support our claims with simulation results     

On an aperiodic stochastic resonance signal processor and its application in digital watermarking

In this paper, an aperiodic stochastic resonance (ASR) signal processor for communication systems based on a bistable dynamic mechanism is proposed for detecting base-band binary pulse amplitude modulation (PAM) signals in communication systems. All parameters in the processor can be adjusted when needed. The adjustment mechanism is explained from the perspective of the conventional noise-induced nonlinear signal processing. To demonstrate this processor's usability, a digital image-watermarking algorithm in the discrete cosine transform (DCT) domain is implemented. In this algorithm, the watermark and the DCT alternating current (ac) coefficients of the image are viewed as the input signal and the channel noise, respectively. In conventional watermarking systems, it is difficult to explain why the detection bit error ratio (BER) of a watermarking system suffering from certain attacks is lower than that of the system not suffering from any attack. In the new watermarking algorithm, this phenomenon is systematically analyzed. It is shown that the DCT ac coefficients of an image as well as the noise imposed by the attacks can cooperate within the bistable system to improve the performance of the watermark detection.     

仿真系统和实装系统集成设计及应用

为了满足仿真系统和实装系统的集成需求,提出以基于高级体系结构（High level architec-ture,HLA）的运行支撑环境（Release to the internet,RTI）仿真代理系统作桥接,实现系统间互连互通和协同工作的系统集成方案,针对不同系统间信息交互机制不同及时间管理策略不同的问题,仿真代理系统设计实现了联邦代理、通信代理、数据转换、同步代理四大功能模块,给出了应用实例,并对系统扩展性和通用性进行了初步探讨。     

一种网络设计动态调整方法的设计与实现

针对新的网络设计需求变化不大的情况,本文设计了一种网络设计的动态调整方法,实现了对已有网络设计的参数进行更改设置,完成了相似网络的调整设计.通过具体实例详细讲解了该网络设计动态调整方法的实现过程.本网络设计方法易于实现,调整过程简洁、直观、可操作性强.     

MAS系统中迁移机制的研究与实现

该文分析了现有移动代理系统的几种代表性的迁移技术,阐述了在作者设计的移动代理系统(Mobile Agent System,MAS)中代理迁移机制的具体实现,着重解决了代理的动态路由和与迁移相关的安全要素的改变,并提出了一种扩展的代理迁移机制,最后给出了应用实例分析。     

Collaborative color calibration for multi-camera systems

This paper proposes a collaborative color calibration method for multi-camera systems. The multi-camera color calibration problem is formulated as an overdetermined linear system, in which a dynamic range shaping is incorporated to ensure the high contrasts for captured images. The cameras are calibrated with the parameters obtained by solving the linear system. For non-planar multi-camera systems, we design a novel omnidirectional color checker and present a method for establishing global correspondences to facilitate automatic color calibration without manual adjustment. According to experimental results on both synthetic and real-system datasets, the proposed method shows high performance in achieving inter-camera color consistency and high dynamic range. Thanks to the generality of the linear system formulation and the flexibility of the designed color checker, the proposed method is applicable to various multi-camera systems.