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In this paper, we propose a synchronous communication mechanism that can be used with asynchronous communication in an event-based communication framework (CM). The proposed synchronous communication mechanism supports directly synchronous communication between client and server, indirectly synchronous communication between two clients through server mediation, and indirectly one-to-many synchronous communication with multiple clients. In order to support synchronous communication, the CM uses the synchronization mechanism between the main thread and the processing thread while maintaining the multi-thread structure. The application can utilize both the asynchronous and the synchronous communication service of the CM together according to its requirements. For performance analysis, we compared the CM synchronous and asynchronous communication methods with qualitative and quantitative experiments, respectively. Through qualitative analysis, developing applications using synchronous services can more intuitively design application logic than asynchronous services. From the quantitative experiment, we also verified that the response delay time in the synchronous method is shorter than that in the asynchronous method although the difference in the response delay is not large.

The article is devoted to the development of a client-server application for detecting road infrastructure objects. The main architectures of neural networks are considered, a database for collecting the necessary data is developed. A feature of the developed application is the binding of road infrastructure objects with geo-position and the formation of a map with the display of recognizable objects.

Looking at the current ERP scenario, the market is dominated by a few big names such as SAP, Microsoft Dynamics and Odoo. To avoid the hefty installation and maintenance cost, smaller businesses are turning towards homegrown ERP systems. In these, there is need for a tool that will shift the entire business process designing to the business team from the technical team. This paper proposes ERPL which is an easy, intuitive language that assists the business personnel to sequence tasks written by the technical team according to the their needs. This paper gives the implementation and a working example of ERPL.

Taking the technical requirements for the dynamicity and flexibility of software system in open network environment as cut-in points, this paper put forward a novel dynamic component model named SoftMan component (SMC) which was well-formed and evolvable. And then a distributed multi-task collaboration mechanism based on game theory in SoftMan component dynamic evolution system is put forward in order to maximize the utilization of computing resources and resolve multi-tasks collaboration problem. Three kinds of experiments are designed to test the feasibility, robustness and performance of distributed multi-tasks collaboration mechanism. Results show that distributed multi-tasks collaboration mechanism based on game theory has a higher success rate and accuracy with good algorithm stability and reliability.

Displaying geo-referenced data in web mapping systems has become popular. However, most existing systems suffer from three annoying problems: (1) clutter when trying to visualize large amount of data; (2) slowness of transferring data over internet; (3) lack of support for dynamic queries. To solve these problems, we propose a real-time system using server-side clustering, transferring only the clustered data, and client-side visualization using existing map tools. As far as we know, there is no other scientific paper describing such real-time system that allows dynamic database queries without limiting to predefined queries. Experiments show that it can handle up to 1 million objects whereas all existing systems are either limited to pre-defined queries, or they support only a very small number of free parameters in the query whereas the proposed system has no such limitations.

In this paper, we have proposed a new approach to evaluate the response time of Networked Control Systems (NCS) working under client/server protocol. For this, we have used two tools of dis...

This article about the system of remote accesscontrol to the premises on the basis of Mesh-network. Theoperating principle of the system and the MESH network aredescribed here. It will also talk about the MESH network andcompare it with other network topologies.

Data-driven mobile applications are becoming increasingly popular in civilian and law enforcement. RapidGather, for instance, is an smartphone application that collects data from individual, and spreads rapid emergency responses. Image data is widely used in such applications, and machine learning methods could be utilized to analyze the image data. However, people would hesitate to share the data without protecting their privacy. In this paper, we propose to utilize dimensionality reduction techniques for privacy-preserving machine learning in face recognition for the image data. To demonstrate the proposed approach, we implement a client server system, FRiPAL. With extensive experiments, we show that FRiPAL is efficient, and could preserve the privacy of data owners while maintaining the utility for data users.

Computers are still lab and class oriented but now as tablets and mobiles have an advanced technology, which is advancing day by day. Computers can be used for learning beyond classroom through mobile devices which leads to a more practical and logical learning. This is based on group learning which takes place through a mobile device. Most of the mobiles are based on android technology and support collaborative learning. Collaborative learning using mobile devices can make users to learn the particular subject or language through their mobile phones they can take test and result will be displayed after the test held, the notes and the details of the user will be stored in the database where space will be taken in the cloud which is used to store the data, it focus on collaborative learning and peer-review learning both are related concepts where they can share education resources and information and feedback can be taken by the students and result will be displayed . Client server system is used to provide for all these feature.

In this paper, we present a client-server system for 3D scene change detection. A 3D scene point cloud which stored on the server is reconstructed by (structure-from-motion) SfM technique in advance. On the other hand, the client system in tablets captures query images and sent them to the server to estimate the change area. In order to find region of change, an existing change detection method has been applied into our system. Then the server sends detection result image back to mobile device and visualize it. The result of system test shows that the system could detect change cor- rectly.

The increasing diversity of end devices used by users to access their applications and systems strengthens the need for device-independent methods for implementing these applications. The Device-Independent Architecture (DIA) is one of the available approaches to this problem, but it does not directly address the issue of user interface (UI) device-independency. This issue can be addressed by runtime UI adaptation, but it is not clear whether the DIA architecture requires new UI adaptation methods or may use existing ones. Through theoretical model-based analysis of UI adaptation in various client-server systems and through case studies of practical UI adaptation solutions we came up with a conclusion that the DIA-based systems may use existing runtime UI adaptation methods. However, they have to be used with a different set of optimization criteria.

This paper introduces a new client-server messaging engine used to exchange clinical data between various medical software applications. Our portal uses the HL7 (Health Level Seven) messaging standard to provide translated clinical data to HL7 and non-HL7 client applications. We used HL7 because this standard is worldwide used to facilitate the communication between clinical applications.

Peer-to-Peer (P2P) architectures for Massively Multiplayer Online Games (MMOG) provide better scalability than Client/Server (C/S), however, they increase the possibility of cheating. Recently proposed P2P protocols use trusted referees that simulate/validate the game to provide security equivalent to C/S. When selecting referees from un-trusted peers, selecting non-colluding referees becomes critical. Further, referees should be selected such that the range and length of delays to players is minimized (maximizing game fairness and responsiveness). In this paper we formally define the referee selection problem and propose two secure referee selection algorithms, SRS-1 and SRS-2, to solve it. Both algorithms ensure the probability of corrupt referees controlling a zone/region is below a pre-defined limit, while attempting to maximize responsiveness and fairness. The trade-off between responsiveness and fairness is adjustable for both algorithms. Simulations of three different scenarios show the effectiveness of our algorithms.

Formal statistical analysis of defect databases for two commercial client-server products for disparate applications - C-language parsing and geophysical modeling - tests the hypothesis that defects in the graphical client mask more important underlying defects in the computational server. It also quantifies the benefit of continued testing after delivery in terms of reduced software defect densities apparent to end users.

We developed a peer-to-peer local area network client back-end buffering system module for video-on-demand (VoD) systems. Our aim is to minimize both the number and duration of stops experienced by users, thereby minimizing the cost while improving the performance. Simulations show that our module outperforms both typical and recently proposed VoD systems

This paper presents HotZone, an algorithm to place replicas in a wide-area network such that the client-to-replica latency is minimized. Similar to the previously proposed HotSpot algorithm, HotZone places replicas on nodes that along with their neighboring nodes generate the highest load. In contrast to HotSpot, however, HotZone provides nearly-optimal results by considering overlapping neighborhoods. HotZone relies on a geometric model of Internet latencies, which effectively reduces the cost of placing K replicas among N potential replica locations from O(N/sup 2/) to O(N /spl middot/ max(logN, K)).

This paper describes application system architecture using cellular phones as user interface devices, which enables users to interact with the system by graphic symbols on a client screen. Our approach has the following features: (i) divided interaction logics running on a server and a Java phone client; both interaction logics cooperate to accomplish a user's operation using a simplified script, (ii) local interaction which enables users to handle figures on a client screen without connecting to a server, and (iii) device-independent script which hides the differences of API sets among various cellular phones. By using this architecture, complicated figures including lots of graphic symbols can be displayed in spite of program-size limitation on a client device, and application programs including same interaction logics are just described once for various cellular phones. Our experiments show the advantage of the local interaction. A client program can respond immediately when handling complicated figures. The ratio of requests to the server is reduced to 23%. It takes less than 9 seconds to display typical contents, which is good enough for practical use. This method also reduces development costs at the second development or later.

We describe the concept and implementation of a decision support system for professional course scheduling which allows the planner to generate, evaluate, and compare different schedules obtained by different runs based on variations of the objective function and different strategies of blocking, i.e. pre-assigning certain subsets of courses. The core of the system is a population-based improvement heuristic, i.e. a specific genetic algorithm. We have implemented the decision support system as web-based service, i.e. a distributed client server system with a thin client, where communication between server and client is via the Internet. The approach has been developed for the specific planning situation at Ford Service Organisation in Germany and has shown to significantly improve the planning process with respect to quality of schedules, time-to-plan, and flexibility.

Adapting data transfer to network throughput enables real-time interactive Web-based navigation of large 3D anatomical data sets. This article focuses mainly on network performance and data encoding issues. We describe our implementation and the principles of slice and label extraction. Evaluating the proposed solution's performance and the server's behavior when serving multiple clients simultaneously points to several issues for further exploration.

The authors present Gridella, a Gnutella-compatible P2P system. Gridella is based on the Peer-Grid (P-Grid) approach, which draws on research in distributed and cooperative information systems to provide a decentralized, scalable data access structure. Gridella improves the highly chaotic and inefficient Gnutella infrastructure with directed search and advanced concepts, thus enhancing efficiency and providing a model for further analysis and research.

client/server(C/S) systems have revolutionized the systems development approach. Among the drivers of the C/S systems is the lower price/performance ratio compared to the mainframe‐based transaction processing systems. Data mining is a process of identifying patterns in corporate transactional and operational databases (also called data warehouses). As most Fortune 500 companies are moving quickly towards the client server systems, it is increasingly becoming important that a data mining approaches should be adapted for C/S systems. In the current paper, we describe different data mining approaches that are used in the C/S systems.

Using a sample of 350 companies, this paper investigates the benefits of client-server systems and links them to a set of implementation factors. The paper reveals that companies can expect competitive, operational, financial and technical benefits. It reports several important steps, activities and tasks that are positively related to those benefits, including defining clear organizational objectives and strategies, re-organizing corporate data and testing multiple levels of clients and servers. Furthermore, they list some of the problems that companies may encounter during a client-server implementation. The paper is relevant to managers and academicians who want to better understand the implementation of client-server.

Experience demonstrates the benefits and feasibility of supporting multimedia applications in distributed middleware architectures. However, deployment of multimedia-capable middleware platforms has not yet occurred on a large scale. This article describes designing such a platform and its attempts to maximize performance, predictability, and configurability in a standard workstation operating system environment.

Considerable research has gone into investigating networking and operating system mechanisms to support the transfer and playout of stored continuous media, but there is very little information available about how users actually interact with such systems. Developing a user workload characterization can help in the design and evaluation of efficient CM resource allocation and access mechanisms. The authors developed an interactive Web-based, multimedia, client-server application, known as the Multimedia Asynchronous Networked Individualized Courseware, or MANIC, which streams synchronized CM (currently audio) and HTML documents to remote users. This article presents empirical and analytic characterizations of observed user session-level behavior (for example, the length of individual sessions) and interactive behavior (for example, the time between starting, stopping, and pausing the audio within a session). The data come from a full-semester senior-level course given by the University of Massachusetts to more than 200 students who used MANIC to listen to the stored audio lectures and to view the lecture notes.

With the world rapidly changing into a global village, the necessity of interconnecting computers is exponentially increasing. The greatest hand in conjoining computers is the Internet. With rapid advancement development (RAD) tools, Internet programming has become a piece of cake for the developers. Now a novice programmer can develop applications encompassing common web protocols just by dragging and dropping. The API era has been washed out.

Client-server computing provides many corporations with the ability to build scalable, adaptive and cost-effective information systems. However, to design and implement an effective client-server system is not an easy job. The complexity due to the inherent heterogeneity in client-server platforms makes the performance evaluation an important issue. The main purpose of this paper is to provide an analytical model to evaluate the performance of a client-server system before it is implemented. It is shown in this paper that the Petri net model is a powerful technique used to study the client-server system performance. Besides using a numerical example to illustrate the solution procedure of the Petri net model, a case study is also given to show the applicability of the developed analytical model. This research concludes that, with the assistance of some software packages, the Petri nets are very useful tools for the information system manager to analyse a client-server system and to decide the appropriate ...

JICST新総合情報システム開発の一環として情報編成システム（LIRACSII）を開発した。情報編成システムは資料管理機能を包含するものであり，本報では，そのメイン機能である自動チェックインシステムについて，その特徴を紹介する。本システムはZ39.56（SICI）やSISACバーコードシンボル等の標準技術を採用し，書店の一括納入システムと連携して，雑誌受入管理業務の自動化を図っている。自動チェックインの機能概要，受入率向上のための手法などを中心に述べる。

One goal of information systems (IS) departments in business schools is to train IS professionals with the necessary technical skills to support the IS function in companies. This paper suggests that changes are needed for most current IS curricula to meet the technical requirements of the client/server (C/S) world of technologies. It is hoped that the ideas presented here will stimulate debate and discussions as to how this transition can be accomplished.

Queueing networks have been widely used to evaluation performance of mainframe computer systems. In contrast, few results have been reported for modern open systems, so it was not clear whether queueing networks are useful for modern systems or not. We think this situation has partly been due to lack of handy evaluation tools. This paper presents tow tools that we developed to evaluate open system performance. On is a measuring tool that is capable of accurately obtaining the service times of system resources requested by an application transaction. The other is an estimating tool which calculates various performance measures based on queueing network models. This paper also describes a case study in which the performance of a medium-sized UNIX client-server system (up to 24 clients) is estimated using the tools and these estimates are then compared with experimental results. The estimates closely agree with the measured results and are accurate enough for practical applications. Based on this, we conclude that queueing network models are also useful for modern systems.

This paper investigates the (m,n) information dispersal scheme (IDS) used to support fault-tolerant distributed servers in a distributed system. In an (m,n)-IDS, a file M is broken into n pieces such that any m pieces collected suffice for reconstructing M. The reliability of an (m,n)-IDS is primarily determined by 3 important factors: n=information dispersal degree (IDD), n/m=information expansion ratio (IER), P/sub s/=success-probability of acquiring a correct piece. It is difficult to determine the optimal IDS with the highest reliability from very many choices. Our analysis shows: several novel features of (m,n)-IDS which can help reduce the complexity of finding the optimal IDS with the highest reliability; that an IDS with a higher IER might not have a higher reliability, even when P/sub s//spl rarr/1. Based on the theorems given herein, we have developed a method that reduces the complexity for computing the highest reliability from, O(/spl nu/) [/spl nu/=number of servers] to O(1) when the 'upper bound of the IER'=1, or O(/spl nu//sup 2/) to O(1) when the 'upper bound of the IER'>1.

The main objective of the Nymble system is to allow its users a responsible, secured anonymous online access to other networks. It provides a reliable mechanism for the server administrators to block misbehaving users while allowing the other users to stay anonymous and also in fact even the blocked users remain anonymous but only discarded from the system. The main aim is to implement a system for the server administrators to block anonymous misbehaving users by keeping the utilization of anonymizing networks more acceptable for the server administrators. All users remain anonymous and the misbehaving users can be blocked without deanonymization.

Many IaaS providers allow cloud consumers to define elasticity (or auto-scaling) rules that carry out provisioning or de-provisioning actions in response to monitored variables crossing user-defined thresholds. Defining elasticity rules, however, remains as a key challenge for cloud consumers as it requires choosing appropriate threshold values to satisfy performance and cost requirements. In this paper we propose novel analytical models that enable the study of application performance under different elasticity rules. Based on these, we develop algorithms for performing scale-in and scale-out operations. We simulate our models and algorithms using different thresholds, and validate the results against empirical data obtained using the same rules with the TPC-W benchmark on Amazon cloud.

Real-time online interactive application (ROIA) is an emerging large scale distributed application in recent years. To satisfy the high demands on performance, ROIA needs a highly robust and efficient architecture to cope with the huge concurrent users. Previous works are almost based on the C/S and P2P mode, and these architectures cannot be simply copied to cloud computing environment. In this paper, we propose an overlapping architecture for ROIA in cloud, which based on zoning technique. This new architecture provides redundancy to ensure the robust and enhance the scalability of ROIA. We focus on analyze the two merits of new architecture: seamless migration across zones and protecting against server crash. This paper sheds a little light to the related further research on ROIA.

The amount of data during OPC Client and OPC Server communications is an important parameter to design an equipment, a network and a system, but it has never been given in the theoretical calculations or tests. In this paper amount of data is tested, and the result of the test is analyzed by designing and making six groups of experiments, then recording, analyzing and operating the data. In the end, empirical formula is obtained for the first time in the OPC Client and OPC Server Communications. The empirical formula shows that relationship between the amount of data per second and the number of the data item is almost linear, and relationship between rate and the number of the data item is similar to the above-mentioned relations. Based on above-mentioned conclusions, the test will explain how much data every OPC Client or OPC Server can load.

The FM (Frame Manager) flight software module is responsible for maintaining the frame tree database containing coordinate transforms between frames. The frame tree is a proper tree structure of directed links, consisting of surface and rover subtrees. Actual frame transforms are updated by their owner. FM updates site and saved frames for the surface tree. As the rover drives to a new area, a new site frame with an incremented site index can be created. Several clients including ARM and RSM (Remote Sensing Mast) update their related rover frames that they own. Through the onboard centralized FM frame tree database, client modules can query transforms between any two frames. Important applications include target image pointing for RSM-mounted cameras and frame-referenced arm moves. The use of frame tree eliminates cumbersome, error-prone calculations of coordinate entries for commands and thus simplifies flight operations significantly.

The proliferation of client - server systems in business continues unabated, as applications are split into local tasks run on `client' workstations and resource-intensive computations run on a `server' mainframe. The complexity of such systems requires quantitative modelling for their efficient design and reconfiguration throughout their lifetime. The tools and techniques that are needed for the effective performance management of distributed client - server systems are discussed and illustrated by a case study taken from the financial sector.