中间件与联机事务处理

一般,按照功能把中间件分为以下几大类: 终端仿真/屏幕转换中间件数据库访问中间件远程过程调用中间件消息中间件交易中间件对象中间件其中,对象中间件代表了中间件技术未来的发展方向。     

中间件技术比较研究

本文归纳了中间件的定义,描述了中间件的分类方法和体系结构,比较了中间件的典型实现机制,论述了服务的共享机制和新型中间件,总结了中间件与系统性能的关系,最后展望了中间件的发展趋势及面临的挑战。     

中间件技术与J2EE平台综述

随着IT产业技术的发展,中间件技术应运而生。本文从中间件的概念、分类等方面对中间件做了全面的论述,分析了构件和中间件的关系,并主要介绍了J2EE中间件平台。     

中间件技术研究

介绍了中间件技术,讨论了中间件的分类,比较了不同中间件技术之间的特色和不足。重点介绍了基于PRC和面向对象技术的中间件机制的工作原理。     

中间件技术研究

中间件技术屏蔽了底层分布式环境的复杂性和异构性，简化了分布式应用程序的开发，使分布式应用程序的健壮性、可扩展性、可用性更好。介绍了面向对象中间件、面向消息中间件、面向大规模分布式系统中间件、服务质量中间件等当前各种中间件技术发展的现状，分析了中间件技术面临的挑战，提出了中间件技术研究的几个发展趋势，即网格技术、面向移动计算、面向服务质量等。     

中间件及其评估方法研究

对中间件及其评估方法进行了研究。首先给出了比较普遍被接受的中间件的定义，根据中间件的功能和用途对其进行分类，对每种分类进行了简要的解释，并对中间件的作用进行了的阐述；其次研究了中间件的评估方法，分析了中间件评估中涉及到技术、厂商实力、提供的服务、价格等相关要素及其权重；然后介绍了一种从功能性特征、非功能性特征与技术标准三个方面评估中间件的方法，并对其进行了比较详细的阐述；最后根据中间件的发展速度及其现况，展望了中间件的发展前景。     

PC八年之惑 第七幕:信息化带来大市场

中间件渐受青睐随着互联网应用和电子商务发展的不断深入,中间件开始为越来越多的企业所采用。到90年代中期,发展成为企业应用的主流技术,并形成各种不同类别,如交易中间件、消息中间件、专有系统中间件、面向对象中间件、数据存取中间件、远程调用中间件等。其实在二十世纪九十年代初期的时候,现代中间件的概念和产品便逐渐开始形成,随着不断的应用和发展到了九十年代中期开始风行起来,人们也越来越多地听到中间件这个词。到了1998年的时候情况发生了一些变化,企业应用对中间件提出了更为广泛的需求,于是迎来了应用服务器的时代。它们以面…     

普适计算中间件技术的研究

普适计算作为新的计算模式对中间件技术有一些特殊的要求。该文从普适计算的特点出发，分析了普适计算中间件硬解决的有关问题和需求，提出了构建普适中间件的4个设计原则，分析了c0TS中间件技术和典型普适计算中间件的技术特点并指出了普适计算中间件技术的发展趋势。     

中间件及其评估方法研究

对中间件及其评估方法进行了研究。首先给出了比较普遍被接受的中间件的定义,根据中间件的功能和用途对其进行分类,对每种分类进行了简要的解释,并对中间件的作用进行了的阐述;其次研究了中间件的评估方法,分析了中间件评估中涉及到技术、厂商实力、提供的服务、价格等相关要素及其权重;然后介绍了一种从功能性特征、非功能性特征与技术标准三个方面评估中间件的方法,并对其进行了比较详细的阐述;最后根据中间件的发展速度及其现况,展望了中间件的发展前景。     

支持Internetware的中间件技术演化模型(英文)

随着网络的发展,中间件在应用的开发、部署和管理中扮演着越来越重要的角色。因为中间件的类型复杂,关于中间件的认知众说纷纭,而新一代计算环境和技术又对中间件提出了新的要求。针对中间件技术的演化提出了一种观点,并阐述了支持Internetware的下一代中间件系统的演化模型。     

Developing a vision-based auto-recharging system for mobile robots

This article describes a vision-based auto-recharging system that guides a mobile robot moving toward a docking station. The system contains a docking station and a mobile robot. The docking station contains a docking structure, a control device, a charger, a safety detection device, and a wireless RF interface. The mobile robot contains a power detection module (voltage and current), an auto-switch, a wireless RF interface, a controller, and a camera. The controller of the power detection module is a Holtek chip. The docking structure is designed with one active degree of freedom and two passive degrees of freedom. For image processing, the mobile robot uses a webcam to capture a real-time image. The image signal is transmitted to the controller of the mobile robot via a USB interface. We use an Otsu algorithm to calculate the distance and orientation of the docking station from the mobile robot. In the experiment, the proposed algorithm guided the mobile robot to the docking station.     

Biomechanical analyses of paramedics simulating frequently performed strenuous work tasks

Firefighters performing emergency rescue functions are at an elevated risk of musculoskeletal injuries. The objective of the current study was to analyze the biomechanical stresses placed on the body based on simulations of the following strenuous and frequently performed emergency rescue tasks: (1) transferring a patient from a bed to a stretcher using bedsheets, (2) transferring a patient from the ambulance stretcher to a hospital gurney, (3) carrying a victim down a set of stairs and through a landing using a stairchair, (4) carrying a victim down a set of stairs and through a landing using a backboard, and (5) carrying a victim down a straight set of stairs using a stretcher. Postural data were analyzed using the University of Michigan's Three-Dimensional Static Strength Prediction Program and the relative risk of low back disorder (LBD) was quantified using the trunk motion model published by Marras et al. (1993, spine 18, 617-628). Peak compression values and the probabilities from the Marras et al. (1993) model indicated that the most hazardous tasks performed as part of this simulation included pulling a victim from a bed to a stretcher, the initial descent of a set of stairs when using the stretcher, and lifting a victim on a backboard from the floor. Overall, the two models were well correlated in their assessment of the task components modelled (r = 0.78). These data indicate where engineering changes to equipment regularly used by emergency rescue personnel would have the greatest impact in reducing the risk of musculoskeletal injury.     

Chemical reaction and mixing inside a coalesced droplet after a head-on collision

We investigated the phenomena of a chemical reaction inside a coalesced droplet after a direct (head-on) collision. A droplet containing an alkaline solution collided with a droplet containing a pH indicator on a surface with a wettability gradient. We used a high-speed camera to observe the color-changing reaction inside the coalesced droplet. Compared with a traditional dye-mixing test, the chemical reaction inside the coalesced droplet facilitated the mixing of two counter-reactive fluids and was more than 100 times as efficient as for unreactive fluids mixing inside the coalesced droplet. Instead of mere mixing, a chemical reaction inside a coalesced droplet is valuable for applications in a digital microfluidic open system. In droplet coalescence, the characteristics of the fluids and the ratio of volumes of two droplets caused a varied profile of the droplet coalescence, especially the neck curvature that affects the shape of the material interface between the two droplets at an initial phase. We observed the evolution of the chemical reaction with a varying radius of neck curvature inside the coalesced droplet. For the case of a small radius of neck curvature, the small interfacial area between two reactive fluids accumulated an intense heat of reaction and induced a rapid growth of the fingers. For the case of a large radius of neck curvature, the growth of fingers was slight and the interface was uniform across the large interfacial area. Our work illustrates a correlation between the rate of chemical reaction and the profile of a coalesced droplet, which is a significant reference in droplet-based microfluidic systems for biochemical applications.     

A Petri nets semantics for data flow networks

This work presents a truly concurrent operational semantics for nondeterministic data flow networks. We introduce a model, the df-process, which is a notion similar to that of non-sequential process for a Petri net: a df-process is defined as a mapping from an occurrence net K to a data flow net N, such that the places and the transitions of K are mapped onto the channels and the nodes of N. A df-process contains, by means of some labelling of the places, information on the value and the order in which data flow through the channels during a computation. Df-processes for a data flow network are characterized in an abstract way by a set of properties and in general a df-process corresponds to a set of computations of the network. We give a way to build the df-process corresponding to a computation incrementally at each event occurrence: a main result of the paper is that the incremental construction yields exactly the same set of df-processes as abstractly defined. We also show that df-processes are compositional. The model is intended to be used by distributed systems designers: it contains enough information to be a guideline for the designer and to be a base to develop dynamic checking tools. We outline how df-processes can be used in the design phase of a system.Research supported in part by Progetto Coordinato CNR ANATRA     

Detection and replacement of a failing node in the wireless sensors networks

The lifetime in a wireless network, in particular a wireless sensor network, depends strongly on the connectivity factor between nodes. Several factors can be at the origin of a connectivity rupture such as: lack of energy on a significant node level, infection of a vital node by a malevolent code and a logical or physical failure of a primary node. This rupture can lead in some cases to a reconfiguration of the network by generating a prejudicial overhead or in other cases to a failure of the mission assigned to the network. In this paper, we propose a DRFN approach (Detection and Replacement of a Failing Node) for the connectivity maintenance by carrying out a replacement chain according to a distributed algorithm. Through simulation, we have shown our approach efficiency. Compared with similar work, our proposed approach consumes less energy, and improves the percentage of reduction in field coverage.     

Possibility-based fuzzy neural networks and their application toimage processing

This paper describes the foundations for a class of fuzzy neural networks. Such a network is a composite or two-stage network consisting of a fuzzy network stage and a neural network stage. It exhibits the ability to classify complex feature set vectors with a configuration that is simpler than that needed by a standard neural network, Unlike a standard neural network, this network is able to accept as input a vector of scalar values, or a vector (set) of possibility functions. The first stage of the network is fuzzy based. It has two parts: a parameter computing network (PCN), followed by a converting layer. In the PCN the weights of the nodes are possibility functions, and hence, the output of this network is a fuzzy set. The second part of this stage, which is a single layer network, then converts this fuzzy set into a scalar vector for input to the second stage. The second stage of the network is a standard backpropagation based neural network. In addition to establishing the theoretical foundations for such a network, this paper presents sample applications of the network for classification problems in satellite image processing and seismic lithology pattern recognition.     

Self-Replicating Structure as an Artificial Multicellular Organism

Two models of an artificial biological cell are constructed in a fine-grained structure in the form of a self-reproducing loop. The models are developed on the basis of a parallel substitution algorithm, i.e., a system for modeling spatial fine-grained parallel algorithms and architectures. A model of a biological cell is constructed from a one-dimensional artificial genome written on the input tape. The proposed model contains a phenotype in the form of a set of fixed data and a genotype in the form of a set of mobile data. Such a cell can be an element of an artificial multicellular organism that simulates the following properties of living organisms: growth, self-reproduction, and self-repair.     

A case study of a difficult refinement: a fast dictionary for a spell-checking program

We present a difficult refinement of a dictionary for a spell-checker. It represents a realistic problem and shows how a calculational approach using a relation known as a coupling invariant can improve the process of refinement over the conventional posit-and-prove approach. The paper concludes with a brief discussion of the advantages of the approach we adopt. We also hope that the paper will contribute a difficult refinement to the rather sparse corpus of such case studies in the literature—especially those using the calculational approach.     

A game-theoretic approach to integration of modules

This paper offers a new approach to integration of modules in an intelligent sensor system. Such a system requires that a set of modules-each doing a smaller portion of the overall task-be integrated within a unifying framework. From the perspective of computational systems, this problem holds a considerable interest because it is characterized by a set of coexisting mathematical objectives that need to be optimized simultaneously. In this sense, the design considerations necessitate the introduction of problem solving with multiple objectives. This paper explores these issues in the instance when each module is associated with a mathematical objective that is a function of the outputs of other modules. The integration problem is formulated and what is required of a good solution is presented. This examination interprets the decentralized mediation of conflicting subgoals as promoting a N-player game amongst the modules to be integrated and proposes a game-theoretic integration framework. We model the interaction among the modules as a noncooperative game and argue that this strategy leads to a framework in which the solutions correspond to a compromise decision. The application of this framework in image analysis motivates the hope that a framework such as game-theoretic integration will facilitate the development of general design principles for “modular” systems