• Korean Journal of Remote Sensing
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• v.33 no.4
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• pp.391-400
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• 2017

Geo-based application services linked with the Open Geospatial Consortium (OGC) Web Processing Service (WPS) protocol have been regarded as an important standardized framework for of digital earth building in the web environments. The WPS protocol provides interface standards for analysis functionalities within geo-spatial processing in web-based service systems. Despite its significance, there is few performance tests of WPS applications. The main motivation in this study is to perform the comparative performance test on WPS standards. Test system, which was composed of WPS servers, WPS framework, data management module, geo-based data processing module and client-sided system, was implemented by fully open source stack. In this system, two kinds of geo-based image processing functions such as cloud detection and gradient magnitude computation were applied. The performance test of different server environments of non-WPS, synchronous WPS 1.0 and asynchronous WPS 2.0 was carried out using 100 threads and 400 threads corresponds client users on a web-based application service. As the result, at 100 threads, performance of three environments was within an adjacent range in the average response time to complete the processing of each thread. At 400 threads, the application case of WPS 2.0 showed the distinguished characteristics for higher performance in the response time than the small threads cases. It is thought that WPS 2.0 contributes to settlement of without performance problems such as time delay or thread accumulation.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.11
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• pp.5419-5436
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• 2016

Enhancing the performance of computing systems has been an important topic since the invention of computers. The leading-edge technologies of multicore and virtualization dramatically influence the development of current IT systems. We study performance attributes of response time (RT), throughput, efficiency, and scalability of a virtualized Web system running on a multicore server. We build virtual machines (VMs) for a Web application, and use distributed stress tests to measure RTs and throughputs under varied combinations of virtual cores (VCs) and VM instances. Their gains, efficiencies and scalabilities are also computed and compared. Our experimental and analytic results indicate: 1) A system can perform and scale much better by adopting multiple single-VC VMs than by single multiple-VC VM. 2) The system capacity gain is proportional to the number of VM instances run, but not proportional to the number of VCs allocated in a VM. 3) A system with more VMs or VCs has higher physical CPU utilization, but lower vCPU utilization. 4) The maximum throughput gain is less than VM or VC gain. 5) Per-core computing efficiency does not correlate to the quality of VCs or VMs employed. The outcomes can provide valuable guidelines for selecting instance types provided by public Cloud providers and load balancing planning for Web systems.

• Journal of the Korea Society for Simulation
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• v.14 no.4
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• pp.31-41
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• 2005

This paper proposes a novel Web Services enhancement method, which enhances XML based e-commerce and Web Services securely and efficiently. Recently, the ratio of XML Denial of Services (XDOS) is increased significantly However, XML data is visible only at the target application site or the application layer. Thus, an efficient and secure mechanism handling XML data on the network layer to provide fast performance on the server and protect XDOS at network level is strongly required basic component. This paper presents many issues and gives useful results from the various experiments to support an implemented XAN platform.

• Journal of KIISE:Computer Systems and Theory
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• v.30 no.7_8
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• pp.426-433
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• 2003

Management policies of Web Proxy Cache, for the QoS of Web users, are mainly focused on the page replacement and the data consistency policy. But the two subjects have been studied independently to each other regardless of its possibility of cooperation. In this paper, we introduce the performance improvement obtained by adapting the characteristic of LMF used in data consistency policy to LRU, thus taking the better performance synergy as a result of complementary cooperation. Various policies for the management of Web Proxy Cache are in progress, this study can be a way of performance guide to increase cache hit ratio and reduce the transmission overhead of Web Server.

• Proceedings of the Korean Information Science Society Conference
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• 2000.10a
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• pp.311-313
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• 2000

인터넷 E-Business를 위한 ASP를 이용한 웹사이트 구축이 급속도로 증가하는 추세로 대화형 서비스를 제공하기 위해 데이터베이스인 MS SQL Server의 적용이 많아졌다. 따라서 본 연구에서는 웹사이트 구축시 데이터베이스의 성능개선을 위한 임시테이블의 램 활용기법에 대한 효율적인 모델을 제안하고 성능을 평가하였다. 이와 같은 결과로 웹서버의 성능개선에 임시테이블의 램 활용에 대한 기법이 유익하게 활용될 것이다.

• Proceedings of the CALSEC Conference
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• 2003.09a
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• pp.249-254
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• 2003

Object caching is a desirable feature to improve the both scalability and performance of distributed application systems for information infrastructure, the information management system leveraging the power of network computing. However, in order to exploit such benefits, we claim that the following problems: cache server placement, cache replacement, and cache synchronization, should be considered when designing any object cache system. We are under developing DOC: a Distributed Object Caching, as a part of building our information infrastructures. In this paper, we show how each problem is inter-related, and focus to highlight how we handle cache server deployment problem

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1747-1750
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• 2003

The development of a Web-based powertrain performance simulation system is introduced. The development approach of system architecture and each module is introduced along with the H/W and S/W used. The interface with all users is developed via a JAVA applet. The powertrain modeling and other job history data of a user is managed systematically on the server by database to increase the reusability of the data. A self-developed program using object-oriented programming is used as a solver for the performance simulation. The graph tool for the analysis of simulation results has the collaboration support developed based on JAVA so that synchronous users can view the same result. As a result, the powertrain simulation is possible only with Web-browser for the user and the collaboration support among the relevant engineers is possible.

• Journal of Korea Society of Digital Industry and Information Management
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• v.5 no.3
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• pp.19-28
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• 2009

Computer system performance has always had the possibility of affecting business profitability, but with the advent of the World Wide Web where customers interact directly with Web servers, response time can have a direct and dramatic impact on business revenue. This paper is written in the operation environment and system analysis of HTS(Home Trading System) running K Securities. This paper also shows the method for performance improvement through investigation and analysis for the overall systems resources whether HTS has an appropriate performance or not. Performance analysis includes specially CPU analysis, Memory analysis, Disk Input/Output analysis and application analysis. Besides providing more detailed server specification for expansion from now on, system performance can be maintained with effect in the future. Through this study it is possible to manage the performance of HTS more easily and to solve problems such as a bottleneck more quickly.

• The Journal of Korean Association of Computer Education
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• v.18 no.3
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• pp.115-124
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• 2015

In this paper, we introduce a web-based scheduling toolkit(GridTool2), which can run simulation of scheduling algorithm in grid system. And we suggest new algorithms which apply additional communication costs to the existing MinMin and Suffrage scheduling algorithms. Since GridTool2 runs in web environment using server and database, it does not require a separate compiler or runtime environment. The GridTool2 allows variables such as communication costs on the web for performance evaluation, and shows simulation results on the web page. The new algorithm with communication costs was tested using GridTool2 to check for performance improvements. The results revealed that the new algorithm showed better performance as more workloads were incorporated to the system.

• The KIPS Transactions:PartA
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• v.11A no.5
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• pp.355-364
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• 2004

These days, various clustering technologies have been adopted to construct web sites. High performance hardware switches have good performance, but have disadvantage of high cost for constructing small and middle-sized web sites. Now a days, many sites have been constructed with the LVS (Linux Virtual Server), which is free of charge and has good performance. Having a centralized load balancing with one front-end, the LVS causes a bottleneck when it receives all at once. In the paper, we suggest a way to remove the LVS bottleneck by providing multiple front-ends. In this architecture, all of cluster nodes act as both a front-end and a back-end. When the load of a node receiving requests is not large enough, the node responds to the client directly. When the load of a node is large enough, the node send the request to a node which is selected by a scheduling algorithm. The scheduling algorithm is discussed to balance loads between servers. While single front-end cluster raises the throughput curvedly, the multiple front-end cluster raises the throughput linearly.