• Journal of Korean Society of Transportation
• /
• v.34 no.5
• /
• pp.421-436
• /
• 2016

Public-Private-Partnerships tend to be committed high project development cost and recover the cost through future revenue during the operation period. In general, long-term concession can bring on more revenue to private investors, but short-term concession less revenue due to the short recovering opportunities. The concession period is usually determined by government in advance or by the private sectors's proposal although it is a very crucial factor for the PPPs. Accurate traffic forecasting should be most important in planing and evaluating the operation period in that the forecasted traffic determines the project revenue with user fees in PPPs. In this regards, governments and the private investors are required to consider the traffic forecast risk when determining concession period. This study proposed a model for the optimal concession period in the PPPs transportation projects. Monte Carlo simulation was performed to find out the optimal concession period while traffic forecast uncertainty is considered as a project risk under the expected return of the private sector. The simulation results showed that the optimal concession periods are 17 years and 21 years at 5.5% and 7% discount level, respectively. This study result can be applied for the private investors and/or any other concerned decision makers for PPPs projects to set up a more resonable concession period.

• Convergence Security Journal
• /
• v.10 no.3
• /
• pp.9-14
• /
• 2010

The network architecture and analysis model for evaluating the information security are presented to distribute the reliable and secure multimedia digital contents. Using the firewall and IDS, the function of the proposed model includes the security range, related data collection/analysis, level evaluation and strategy proposal. To develop efficient automatic analysis tool, the inter-distribution algorithm and network design based on the traffic analysis between web-server and user are needed. Furthermore, the efficient algorithm and design of DRM/PKI also should be presented before the development of the automatic information security model.

• ETRI Journal
• /
• v.39 no.1
• /
• pp.116-123
• /
• 2017

Message-locked encryption (MLE) is a widespread cryptographic primitive that enables the deduplication of encrypted data stored within the cloud. Practical client-side contributions of MLE, however, are vulnerable to a poison attack, and server-side MLE schemes require large bandwidth consumption. In this paper, we propose a new client-side secure deduplication method that prevents a poison attack, reduces the amount of traffic to be transmitted over a network, and requires fewer cryptographic operations to execute the protocol. The proposed primitive was analyzed in terms of security, communication costs, and computational requirements. We also compared our proposal with existing MLE schemes.

• Tunnel and Underground Space
• /
• v.23 no.5
• /
• pp.347-352
• /
• 2013

Recently, due to the gravitation of the population and traffic congestion, the land supply tends to be short. Underground space development is considered positively as a countermeasure. This study was to review the basic principles of underground space, to find out problems, and to propose the direction for the effective development of underground space.

• Proceedings of the Korea Contents Association Conference
• /
• 2004.05a
• /
• pp.234-240
• /
• 2004

Now that the e-commerce users are explosively increasing, there is always followed by a sharp increase in load from the e-commerce system and the heavy traffic on the network, where leads to the delayed service for the client's request. The natural consequences contain decreasing customer satisfaction and weakening the business's competitive position in markets. Therefore, we'll need to study the e-commerce system in due consideration of the operational efficiency and response speed. This study includes a design of e-commerce system, with a hierarchical structure based on the local server, which has the capability of caching necessary to distribute the system load, makes a proposal concerning a split web-cache algorithm devoted to the local web server to finally give an analysis of the performance through the appropriate trial.

• Journal of Korean Society for Quality Management
• /
• v.19 no.2
• /
• pp.158-165
• /
• 1991

The Q-cost has been used in the manufacturing company to decide the optimal level of company's product quality, and to evaluate the effect of company's quality control system since the advent of Q-cost theory. In spite of the following costs are generated in the user side, owing to an unsuitable level of product quality and inadequacy of company's quality control system, these costs are not usually included in the company's Q-cost : (1) the cost generated in relation to a claim proposal as traffic expeneses and transpotation of the product. (2) the cost of maintenance through the useful life of the product, especially accured after quality warranty period. (3) the cost related to the economical efficiency in using the product. (4) the cost ralated to a customer dissatisfaction for the product quality. In this point of view, the contents of user side Q-cost, and the relations between the user side Q-cost and the level of company's product quality are discussed. And then the importance of user side Q-cost in order to determine the optimal quality level is discussed.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 1996.04a
• /
• pp.202-211
• /
• 1996

A number of typical type of steel-box pedestrian bridges are constructed in the metropolitan highway or heavy traffic urban area. Although it has the advantage of speedy construction because of its simple structural form and prefabricated erection method, it has been reported that many of these bridges are deteriorated or damaged and thus are in the state such that it would give unsafe and uncomfortable feeling to pedestrians. In the paper, for the realistic assessment of safety and residual earring-capacity of deteriorated and/or damaged steel box pedestrian bridges, an interactive non-linear limit state model are formulated based on the von Mises' combined stress yield criterion. It is demonstrated that the proposal model is effective for the reliability-based safety assessment and residual carrying-capacity evaluation of steel-box pedestrian bridges. In addition, this study suggests an effective and practical field load test method for pedestrian bridges.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2003.11c
• /
• pp.1355-1358
• /
• 2003

본 연구는 공군에서 운영하고 있는 ASIS2000(공군보급정보체계)의 활용과 효과적인 창고관리를 위한 의사결정시스템의 설계 및 구현에 적용할 OLAP엔진을 설계 및 구현하고 창고운영자의 동선을 최소화 할 수 있는 알고리즘을 제안하는 것이다. 창고운영자의 다차원질의를 처리하여 창고운영전반에 대한 분석을 제공의 기반이 되는 OLAP엔진과 동선을 최소화하는 알고리즘의 목적 및 구성요소를 중심으로 동선최소 알고리즘을 제안한다.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.7 no.5
• /
• pp.926-929
• /
• 2006

In this paper, I propose a load balancing algorithm based on the traffic characteristics of a software streaming service, and implement the proposed algorithm on the large scale software streaming server platform which provides a software streaming service to geographically dispersed internet users. By showing that the large scale software streaming server platform fuctions correctly, we know the proposed load balancing algorithm is operating properly and efficiently.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2007.05a
• /
• pp.1031-1034
• /
• 2007

다양한 유무선 단말의 등장과 함께 원하는 곳에서 시간에 제한없이 네트워크에 접속할 수 있는 유비쿼터스 세상이 눈앞으로 다가왔다. 네트워크 접속이 현대인 생활의 일부분이 된 현실에서 과다 트래픽 발생으로 인한 급작스런 네트워크 상의 장애는 유비쿼터스 환경에서 무엇보다도 큰 위협이라 할 수 있다. 따라서 비정상적으로 발생한 과다 트래픽을 빠르게 탐지하여 대응하는 것은 유비쿼터스 환경을 안전하게 보호하기 위한 필수 요소라 할 수 있다. 본 논문에서는 기존의 트래픽 분석과는 달리 흐르는 네트워크 패킷의 5 tuple 정보를 실시간으로 수집하여 과다/이상 트래픽을 즉각적으로 탐지하고, 이를 자동으로 제어하는 메커니즘에 대해서 소개하고 있다. 실시간으로 8초마다 트래픽 정보를 수집하고 이를 분석하여 트래픽의 특성을 구분 및 위협도를 분석하여 이를 바탕으로 트래픽 제어 정책을 생성 및 적용하는 전반적인 과정에 대한 것이다. 여기에는 본 메커니즘을 실제 테스트망에서 시험한 결과도 포함하고 있다.