• Journal of the Institute of Electronics and Information Engineers
• /
• v.52 no.5
• /
• pp.3-9
• /
• 2015

The wireless communication system adopts an appropriate retransmission scheme on each system protocol layer to improve reliability of data transmission. In each system protocol layer, the retransmission scheme operates in independently other layers and operates based on the parameters without reference to end-to-end performance of wireless communication system. For this reason, it is difficult to design the optimal system parameters that satisfy the QoS requirements for each service class. Thus, the performance analysis of wireless communication system is needed to design the optimal system parameters according to the end-to-end QoS requirements for each service class. In this paper, we derive the mathematical model to formulate the end-to-end performance of wireless communication system. We also evaluate the performance at the MAC and transport layers in terms of average spectral efficiency and average transmission delay. Based on the results of performance evaluations, we design the optimal system parameters according to the QoS requirements of service classes. From the results, the HARQ combined with AMC is appropriate for the delay-sensitive service and the ARQ combined with AMC is appropriate for a service that is insensitive to transmission delay. Also, the TCP can be applied for the delay-insensitive service only.

• Journal of Distribution Science
• /
• v.13 no.1
• /
• pp.57-70
• /
• 2015

Purpose - Open source software has high utilization in most of the server market. The utilization of open source software is a global trend. Particularly, Internet infrastructure and platform software open source software development has increased rapidly. Since 2003, the Korean government has published open source software promotion policies and a supply promotion policy. The dynamism of the open source software market, the lack of relevant expertise, and the market transformation due to reasons such as changes in the relevant technology occur slowly in relation to adoption. Therefore, this study proposes an assessment model of services provided in an open source software service company. In this study, the service level of open source software companies is classified into an enterprise-level assessment area, the service level assessment area, and service area. The assessment model is developed from an on-site driven evaluation index and proposed evaluation framework; the evaluation procedures and evaluation methods are used to achieve the research objective, involving an impartial evaluation model implemented after pilot testing and validation. Research Design, data, and methodology - This study adopted an iteration development model to accommodate various requirements, and presented and validated the assessment model to address the situation of the open source software service company. Phase 1 - Theoretical background and literature review Phase 2 - Research on an evaluation index based on the open source software service company Phase 3 - Index improvement through expert validation Phase 4 - Finalizing an evaluation model reflecting additional requirements Based on the open source software adoption case study and latest technology trends, we developed an open source software service concept definition and classification of public service activities for open source software service companies. We also presented open source software service company service level measures by developing a service level factor analysis assessment. The Behavior-Structure-Evolution Evaluation Model (BSEM) proposed in this study consisted of a rating methodology for calculating the level that can be granted through the assessment and evaluation of an enterprise-level data model. An open source software service company's service comprises the service area and service domain, while the technology acceptance model comprises the service area, technical domain, technical sub-domain, and open source software name. Finally, the evaluation index comprises the evaluation group, category, and items. Results - Utilization of an open source software service level evaluation model For the development of an open source software service level evaluation model, common service providers need to standardize the quality of the service, so that surveys and expert workshops performed in open source software service companies can establish the evaluation criteria according to their qualitative differences. Conclusion - Based on this evaluation model's systematic evaluation process and monitoring, an open source software service adoption company can acquire reliable information for open source software adoption. Inducing the growth of open source software service companies will facilitate the development of the open source software industry.

• Proceedings of the Korea Association of Information Systems Conference
• /
• 2003.05a
• /
• pp.169-181
• /
• 2003

As growth of the web-based applications, the requirements of the users who have been very familiar to the web-based user interfaces and customer-oriented services on the Internet would become more knowledge-intensive and higher technology involved in a more convenient and polite way of service delivery. Therefore, the service quality of information system department should be considered as a very important factor influencing success of information systems. The objective of this study is to provide the relationship between service quality of IS department and its impacts such as use, user satisfaction and job performance. For this purpose, we provide a research model for it and test it empirically for the users of the corporate portal in one of main telecommunication service providers in Korea. In result, our model with satisfiable validity and reliability shows not only importance of IS departments' service quality but also two-faced characteristics of service quality. That is, while technical competence which means with knowledge and expertise of IS department staffs is more related with user satisfaction on information systems, personal service which means the way and manner of service delivery is more related with use of it.

• Journal of Digital Contents Society
• /
• v.3 no.1
• /
• pp.101-111
• /
• 2002

Lately development of network around Internet expands range of data traffic to multimedia information, and so for the guarantee of multimedia services end-to-end QoS(Quality of Service) must service because comparing with existing Internet service can not support For satisfying those QoS requirements, network have to guarantee not only network on parameter, such as delay, jitter, throughput but also system resources like CPU utilization, memory usage. Therefore it is urgent to develop QoS based middleware to distribute multimedia data and maximize network utilization in the limited resource environment. And it must be necessary of network to provide end-to-end QoS(Quality of Service) for multimedia applications. Multimedia applications want that QoS which satisfy their own service properties be guaranteed Then, We must analyze those necessary QoS requirements md define QoS parameter which specify as two viewpoint, user's and network's perspective. Therefore network provider supplying network for usual user and university, enterprise must want to find about their own network performance and problem. It is essential for network manager to want to use a tool like this. On the basis of technique about QoS test-bed in the AIM network, We studied on the method of QoS measurement and management about end-to-end connection in the Internet. We measured network status about end-to-end connection and analyze the result of performance.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.17 no.5
• /
• pp.1160-1167
• /
• 2013

Web based simulation service is utilized to computationally analyze various phenomena in real world according to the progress of network and computing technology. In this paper, we present an improvement and utilization of e-AIRS (e-Science Aerospace Integrated Research System). e-AIRS, has been utilized to support web based CFD simulation service since 2008. has some problems such as stable system, pre processing, post processing. To solver this problem, we improved e-AIRS such as distributed service processing, personal simulation job assignment control, and faster data loading. After improvement, although users increase from 110 to 606, the priority of user requirements is changed from stable system to pre/post processor. User requirements and statistics about e-AIRS simulation service for each semester is analyzed to support more stable and comfortable service.

• Journal of Korea Port Economic Association
• /
• v.25 no.3
• /
• pp.339-360
• /
• 2009

In recent years, the quality and safety requirements in the shipping industries have been more stringent than the previous requirements. It is essential to effective quality management system which can cope with a change in shipping business environment and improve shipping service performance to get competitiveness in the international shipping market. This study on the focus of the Korean shipping company which provides shipping transportation service examined following issues. First, how each of the key factors of ISO 9001 quality management affects service performance, internal customer satisfaction and customer orientation. Second, how the internal customer satisfaction affects service performance and customer orientation. Third, customer orientation affects service performance.

• Proceedings of the Safety Management and Science Conference
• /
• 2006.04a
• /
• pp.355-362
• /
• 2006

This paper is to introduce guidelines for automotive and food quality management system. International standards such as ISO/TS 16949 and ISO 15161 are considered. This study is to discuss particular requirements for the application of ISO 9001 : 2000 for automotive production and relevant service part organization , and guidelines on the application of ISO 9001 : 2000 for the food and drink industry.

• Proceedings of the KIEE Conference
• /
• 2015.07a
• /
• pp.1595-1596
• /
• 2015

This study presents the review of technical requirements of safety and security for the developed high-speed freight train which will be serviced on the existing route of the high-speed line. There is no any experience to make a system design of high-speed freight train in Korea until now. We need to make a new regulations of commercial service.

• Journal of Industrial Technology
• /
• v.11
• /
• pp.99-106
• /
• 1991

In this paper the functional requirements of a B-ISDN access network based on MAN are investigated. Firstly, criteria of designing access network for the B-ISDN is studied. Secondly, the types of subscribers and their service requirements are defined. Thirdly, various architectures of CPNs(Customer Premises Networks) are considered and their characteristics are studied, Finally, the interworking functions of a DQDB MAN as an access network are investigated.

• Proceedings of the Society of Korea Industrial and System Engineering Conference
• /
• 2002.05a
• /
• pp.497-505
• /
• 2002

This paper is a report on the user requirements analysis based on the survey performed during the February and March, 2002. The survey constitutes the preliminary stage of our research on the design of advanced public transportation system(APTS) in ITS service. A random sample of 60 responses were selected from the total of 300 replies that were received for our statistical analysis. We were able to identify what kind of information content Is mostly required by the public transportation users. Some useful guidelines as to how to design the APTS are provided as the conclusion.