MAWS: A platform-independent framework for mobile agents using Web services

This paper proposes a framework for a multiplatform mobile agent system based on Web services. The framework includes a mobile agent factory, the mobile agents, and the host Web services. The mobile agents are created at the factory, migrate between Web services-enabled hosts, and execute at the destination hosts through invocation by XML-RPC. The transfer of mobile agents is accomplished through the employment of SOAP attachments where service handlers are used at the source and destination hosts to attach and detach agent files, respectively. The framework was implemented using the Java Web Service Developer Pack (JWSDP) and tested on 20 Linux and Windows hosts within a Wide Area Network (WAN). The system worked seamlessly on all designated hosts (proving interoperability) while comparing well in terms of throughput to three well-known mobile agent systems, namely, Voyager, Aglets, and Concordia. This paper demonstrates how the proposed system can interoperate with existing systems and serve as a model for interoperability among them. The paper also illustrates how the mobile agent can be secured against confidentiality and integrity attacks during transport and suggests ways for protecting it from malicious hosts as well as guarding hosts from malicious agents.     

A Note on Non-Closure Property of Sublogarithmic Space-Bounded 1-Inkdot Alternating Pushdown Automata with Only Existential (Universal) States

1-inkdot alternating pushdown automaton is a slightly modified alternating pushdown automaton with the additional power of marking at most 1 tape-cell on the input （with an inkdot） once. This paper investigates the closure property of sublogarithmic space-bounded 1-inkdot alternating pushdown automata with only existential （universal） states, and shows, for example, that for any function L（n） such that L（n） ≥ log logn and L（n） = o（log n）, the class of sets accepted by weakly （strongly） L（n） space-bounded 1-inkdot two-way alternating pushdown automata with only existential （universal） states is not closed under concatenation with regular sets, length-preserving homomorphism, and Kleene closure.     

Bursty Behaviour of Turbulent Particle and Energy Fluxes in Edge Plasma of HT-7 Tokamak

High time resolution measurements of the electrostatic fluctuations and the turbulent particle and energy fluxes have been performed with a Langmuir probe array in the edge plasma in HT-7 tokamak. Bursty behaviour was observed in the time resolved turbulent fluxes with positive skewness and large kurtosis. The contribution of the large sporadic bursts to the transport losses were estimated. The analysis shows that the turbulent fluxes have different behaviour in different frequency domains and the probability distribution functions （PDFs） of the particle and energy fluxes present two distinct scaling ranges. All these are essentially consistent with the predictions of the self-organized criticality （SOC） model, though further studies are needed.     

基于VB的山东省高速公路工程地质信息查询系统的建立

截至2003年底，山东省高速公路总里程已经位居全国第一位。建设覆盖全省高速公路工程地 质状况信息查询系统，不仅有利于该地区高速公路建设管理的信息化 |而且对未来该地区高 速公路维护、建设、规划开发具有良好的指导作用。在系统建设中，采用地理信息系统软件 ArcInfo7.1.1作为数据采集、处理的主要工具 |以地理信息系统软件ArcView3.2二次开发语 言Avenue、COM组件MapObjects2.1、通用软件开发平台Visual Basic6.0为平台 |结合DDE技 术，实现软件平台之间的通讯，从而实现了对高速公路工程地质样点分析信息的图像查询。 通过创建使用Excel的Active对象，实现对路段工程地质信息、地质灾害、路段基本信息空 间叠置查询。该查询系统设计思路新颖，适用于高速公路工程地质信息的管理、查询、分析 与计算，是一个较有实用价值的公路查询信息系统。     

Stable auto-tuning of hybrid adaptive fuzzy/neural controllers for nonlinear systems

In direct adaptive control, the adaptation mechanism attempts to adjust a parameterized nonlinear controller to approximate an ideal controller. In the indirect case, however, we approximate parts of the plant dynamics that are used by a feedback controller to cancel the system nonlinearities. In both cases, “approximators” such as linear mappings, polynomials, fuzzy systems, or neural networks can be used as either the parameterized nonlinear controller or identifier model. In this paper, we present an algorithm to tune the adaptation gain for a gradient-based hybrid update law used for a class of nonlinear continuous-time systems in both direct and indirect cases. In our proposed algorithm, the adaptation gain is obtained by minimizing the instantaneous control energy. Finally, we will demonstrate the performance of the algorithm via a wing rock regulation example.     

Detecting and measuring rings in banknote images

Various intelligent systems show a rapidly growing potential use of visual information processing technologies. This paper presents an example of employing visual information processing technologies for detecting and measuring rings in banknote images. The size of the rings is one of parameters used to inspect the banknote printing quality. The approach developed consists of two phases. In the first phase, based on histogram processing and data clustering, image areas containing rings are localized and edges of the rings are detected. Then, in the second phase, applying the hard and possibilistic spherical shell clustering to the extracted edge pixels the ring centre and radii are estimated. The experimental investigations performed have shown that even highly occluded rings are robustly detected. Several prototypes of the system developed have been installed in two banknote printing shops in Europe.     

基于CPLD技术的PC104总线多功能扩展卡设计

介绍了一款PC104总线多功能扩展卡设计。采用了复杂可编程逻辑器件(CPLD)技术,集成了多路模拟量输入/输出、带光电隔离的开关量输入/输出及一个正交解码电路,接口协议与台湾研华PC工控机ISA总线板卡兼容,满足了嵌入式控制系统高集成度的设计要求,在实际应用中获得了良好的效果。     

An improved interface element with variable nodes for non-matching finite element meshes

Extensive improvements of the interface element method (IEM) are proposed for the efficient treatment of non-matching finite element meshes. Our approach enables us to establish the master element via the moving least-square (MLS) approximation, and so to remove the cumbersome process of constructing interface elements. The values of shape functions and their derivatives are therefore mapped from the master element, as in the conventional finite element method. For the assurance of convergence and compatibility condition, a patch test is demonstrated. Through several examples of 2D linear elasticity, the convergence rate is compared between the present interface element and the previous version.     

A spectrally formulated plate element for wave propagation analysis in anisotropic material

A new spectrally formulated plate element is developed to study wave propagation in composite structures. The element is based on the classical lamination plate theory. Recently developed method based on singular value decomposition (SVD) is used in the element formulation. Along with this, a new strategy based on the method of solving polynomial eigenvalue problem (PEP) is proposed in this paper, which significantly reduces human intervention (and thus human error), in the element formulation. The developed element has an exact dynamic stiffness matrix, as it uses the exact solution of the governing elastodynamic equation of plate in frequency–wavenumber domain as the interpolating functions. Due to this, the mass distribution is modeled exactly, and as a result, a single element captures the exact frequency response of a regular structure, and it suffices to model a plate of any dimension. Thus, the cost of computation is dramatically reduced compared to the cost of conventional finite element analysis. The fast Fourier transform (FFT) and Fourier series are used for inversion to time–space domain. This element is used to model plate with ply drops and to capture the propagation of Lamb waves.     

A simple displacement-based 3-node triangular element for linear and geometrically nonlinear analysis of laminated composite plates

A simple displacement-based 3-node, 18-degree-of-freedom flat triangular plate/shell element LDT18 is proposed in this paper for linear and geometrically nonlinear finite element analysis of thin and thick laminated composite plates. The presented element is based on the first-order shear deformation theory (FSDT), and the total Lagrangian approach is employed to formulate the element for geometrically nonlinear analysis. The deflection and rotation functions of the element boundary are obtained from the Timoshenko’s laminated composite beam functions, hence convergence to the thin plate solution can be achieved theoretically and shear-locking problem is avoided naturally. The plane displacement interpolation functions of the Airman’s triangular membrane element with drilling degrees of freedom are taken as the in-plane displacements of the element. Numerical examples demonstrate that the present element is accurate and efficient for linear and geometrically nonlinear analysis of thin to moderately thick laminated composite plates.