Complex networks and SOA: Mathematical modelling of granularity based web service compositions

Service Oriented Architecture (SOA) can be defined as a way of defining and implementing enterprise applications that deals with the intercommunication of loosely coupled, coarse grained (business level), reusable artifacts (services). In this paper, we attempt to mathematically model the preliminary steps in the larger problem of providing an optimal architecture. The problem is treated as a complex network, particularly a process-task-network. We employ statistical and graph-theoretic methods namely, Jaccard’s distance analysis, Multiple Correspondence method and the Minimum Spanning Tree method, to find appropriate clusters. These methods are used to cluster tasks across business processes to propose services. Additional properties and features of these clusters are discussed. We propose a leverage factor which demonstrates the importance of a task within the service and its impact on service composition.     

A restful web notification service

With the rapid growth of mobile applications or web services, many users are using the same service at the same time which leads to the need for scalable application services. To enlarge the capability of handling large volumes of concurrent requests, server-side push technologies have been then introduced recently. Server-side push technology tries to eliminate unnecessary client requests by sending notification messages to clients when a data change event is triggered on the server side. There are two famous server-side push frameworks used today, and they are services using the Pub/Sub protocol, and the Ajax Push Model. These two mechanisms need middleware between clients and servers which result in complex and heavy-weight system architectures for application developers. To simplify development and increase ability to accommodate the growth in application users, a RESTful notification service is proposed in this paper. The notification service leverages the event-driven characteristic of JavaScript, and pushes response data asynchronously to different requests. Based on the RESTful software architecture style, the proposed notification service is not only a lightweight system but also has impressive performance.     

可信服务组合的马尔可夫链模型及其应用

基于马尔可夫链建立了服务组合的形式化模型--马尔可夫链模型,此模型可以在已知组合服务定义规格的情况下由组合服务的定义规格转换得到,也可以在未知组合服务定义规格的情况下由组合服务的执行历史信息得到.不同于多数服务组合形式化模型仅有用于验证组合服务正确性的单一功能,组合服务的马尔可夫链模型具有多种用途,例如可以用来评估组合...     

基于Web Service构建分布式虚拟地理环境系统

在研究了分布式虚拟地理环境系统的特征和基于Web Service、GI Web Service实现分布式虚拟地理环境系统的优势的基础上,建立了基于Web Service的分布式虚拟地理环境系统的体系结构,最后开展了原型系统试验.结果证明,系统实现了在异构环境下的资源共享和协同工作,基本解决了以往C/S、B/S结构的系统中共享资源只能集中存储在服务器端等难点问题.     

基于Web服务的分布式仿真系统的双重访问控制

随着分布式仿真系统与Web服务技术的结合日益紧密,以及功能与资源分离的愈加明显,导致大量仿真资源暴露于网络中,传统、单一的访问控制模型已无法应对.为此提出了一种基于属性的针对功能和资源的双重访问控制模型,采用证书代理机制实现功能端单点登录,采用XACML实现资源端多属性的访问控制.详细描述了该模型的访问控制流程,目前已应用到虚拟采办系统中.通过对性能的分析和测试,证明了该双重访问控制模型的可用性和有效性.     

Allocation of advertising space by a web service provider using combinatorial auctions

Advertising is a critical process for promoting both products and services in global trade. Internet has emerged as a powerful medium for trade and commerce. Online advertising over the internet has increased more than hundred-fold since 2001. In the present work, we address problems faced by online advertisement service providers. In this paper, we propose a multi-slot and multi-site combinatorial auction for allocating scarce advertisement slots available on multiple sites. We observe that combinatorial auctions serve as effective mechanisms for allocating advertising slots over the internet. We resort to “ant” systems (ant — social insect/intelligent agent) to solve the aboveNP- hard combinatorial optimization problem which involves winner-determination in multi-item and multi-unit combinatorial auctions.     

Optimization of the procedure of formation of high-strength compositions based on the relationship between technological and service parameters of plasma spraying

On the basis of the investigation of physical and chemical processes accompanying the process of plasma spraying, we propose new approaches to the solution of the problem of control over the parameters responsible for the formation of coatings and adhesive and strength properties of compositions. We establish a relationship between the technological and service parameters of plasma spraying and the fine structure of subsurface layers of the base material. Ukrainian Scientific Research Institute of Standardization, Certification, and Information of the Ukrainian State Committee of Standards, Kiev, Ukraine. Translated from Problemy Prochnosti, No. 1, pp. 68–75, January–February, 1999.     

Stability of delay compositions

The degradation and stability of delay compositions are explored under various temperature and humidity environments. Delay compositions investigated include D-16 (manganese/lead chromate/barium chromate) and T-10 (boron/barium chromate) delays which are components of cartridges for cartridge actuated devices (CADs) used in automated aircrew escape systems, and tungsten-viton delay, a relatively new composition which has found application in the igniter for the 5″/54 gun fired rocket assisted projectile (RAP). Comparison of trends indicates the superiority of T-10 and tungsten-viton delay compositions over D-16 delay.     

Rubber-modified polystyrene compositions

The physical and mechanical properties of polystyrene compositions, prepared by blending high impact polystyrene (HIPS) with different types of elastomer, are studied. The results obtained show a considerable increase in HIPS impact strength when modified with isoprene and butadienestyrene elastomers. This increase in impact strength is due to factors such as lowT _g and the flexibility of macromolecules of the elastomer phase and adhesion at the interphase boundary. An optimal elastomer concentration of 12.5 parts per hundred of resin is observed. A multi-directional influence of the elastomer additive on the impact strength and on the tensile and flexural strength has been found, due to different mechanisms of fracture.