• Journal of KIISE:Information Networking
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• v.34 no.5
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• pp.305-315
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• 2007

Broadband Convergence Network (BcN) is the network which unifies telephone network, the Internet and broadcasting networks. Threats to each network can bring serious problems in BcN environment since the whole network can be damaged by various types of attack. The purpose of this study is to suggest the prototype of intrusion-tolerant network design of BcN to guarantee the continuous operation of BcN services against malicious attacks. First, BcN service components, selected by analysis of service time and coverage importance, are classified into three groups by their type: server type, gateway type and hybrid type. Second, the necessity of applying intrusion tolerance on BcN services is deduced by possible attack scenarios on BcN. Finally, we suggest the intrusion-tolerant network design suitable to BcN, using hardware redundancy and secure policies. Also, we present that the suggested network design can increase the intrusion tolerance of BcN.

• Journal of Internet Computing and Services
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• v.21 no.4
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• pp.1-8
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• 2020

In order to reach Ultra-Reliable Low-Latency communication, one of 5G aims, Multi-access Edge Computing paradigm was born. The idea of this paradigm is to bring cloud computing technologies closer to the network edge. User services are hosted in multiple Edge Clouds, deployed at the edge of the network distributedly, to reduce the service latency. For mobile users, migrating their services to the most proper Edge Clouds for maintaining a Quality of Service is a non-convex problem. The service migration problem becomes more complex in high mobility scenarios. The goal of the study is to observe how user mobility affects the selection of Edge Cloud during a fixed mobility path. Mobility-Aware Service Migration (MASM) is proposed to optimize service migration based on two main parameters: routing cost and service migration cost, during a high mobility scenario. The performance of the proposed algorithm is compared with an existing greedy algorithm.

• Journal of the Korea Convergence Society
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• v.3 no.3
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• pp.7-12
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• 2012

mVoIP (mobile Voice over Internet Protocol) service is a technology to transmit voice data through an IP network using mobile device. mVoIP provides various supplementary services with low communication cost. It can maximize the availability and efficiency by using IP-based network resources. In addition, the users can use voice call service at any time and in any place, as long as they can access the Internet on mobile device easily. However, SIP on mobile device is exposed to IP-based attacks and threats. Observed cyber threats to SIP services include wiretapping, denial of service, and service misuse, VoIP spam which are also applicable to existing IP-based networks. These attacks are also applicable to SIP and continuously cause problems. In this study, we analysis the threat and vulnerability on mVoIP service and propose several possible attack scenarios on existing mobile VoIP devices. Based on a proposed analysis and vulnerability test mechanism, we can construct more enhanced SIP security mechanism and stable mobile VoIP service framework after eliminating its vulnerability on mobile telephony system.

• Journal of Korea Society of Industrial Information Systems
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• v.7 no.5
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• pp.1-10
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• 2002

This study is based on user requirements before the implementation of B2B order and delivery systems. For accurate and easy understanding of the user's requirements I have expressed my specifications in graphical method and to make use of multiple diagrams, I have used UML. In these specifications, I have implemented B2B order and delivery systems with the use of XML, with company 'N' which is domestic aluminum manufacturer as the study object. The results of this study are as follows. First, both a developer and a user can understand the problems associated with specifying study objects through this system. Second, the communication between developers and users is more effective using this system. Third programming became easier because or the formalized specifications of this system. Fourth, this system facilitates the rapid handling of marketing department and stock management. Fifth, order and reservation management became more rapid and accurate through the use of this system. Sixth, this system can help nate B2B order and delivery systems that can be direct transactions. Seventh, this system helps to reduce purchasing costs by allowing for the rapid and simple order and delivery of raw materials. Finally, this study emphasized the advertising effect of an aluminum vessel.

• Journal of Korean Society of Transportation
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• v.24 no.3 s.89
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• pp.51-61
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• 2006

Interchanges are passages for vehicle and pedestrians and a gateway to nearby facilities, and a place to stay of vehicle and Pedestrians. Interchange traffic must be able to navigate well for safety and convenience. Traffic safety and efficiency are influenced by the interchange. In this study, relative delays of vehicles are compared by changing traffic interchanges. the volume of traffic, the number of lanes, the rate of left turns vehicle on the interchanges of urban arterial roads. The object of this study is to compare Grade crossing interchange, Diamond interchange. Roundabout interchange. SPUI(Single Point Urban Interchange), Echelon interchange). Echelon interchange. By VISSIM Simulation, this study drew the relative delay value of every scenario and compared the delay value of each vehicle considering construction expenses. Through this comparison study, ideal interchange is dependent on the volume of traffic, the number of lanes, and the rate of left turns.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.2148-2152
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• 2009

하천수질보전을 위한 필요유량은 하천유지유량 항목 중 하나로써 환경기초시설 등으로 최대한 처리한 후 남는 오염부하량을 고려하여 적정 수질을 유지하는데 필요한 유량을 의미한다. 하천수질보전을 위한 필요 유량을 산정하는 절차는 (1) 수질특성 파악 및 평가대상 항목의 선정, (2) 목표연도 및 목표수질 기준 설정, (3) 오염부하량 조사 및 목표연도별 오염부하량 산정, (4) 수질예측모형의 선정 및 수질예측, (5) 목표수질과의 비교 및 필요유량의 설정으로 이루어질 수 있다. 현재 우리나라에서는 수질평가 항목으로 여러 가지가 제시되어 있지만 주로 생물화학적 산소요구량(BOD)만으로 목표수질을 설정하고 있는 실정이며, 수질예측 모형으로써 QUAL2E 모형이 주로 이용되고 있다. 현재까지 고시된 하천유지유량은 대부분 기준갈수량 또는 평균갈수량이며 몇몇 지점이 하천생태계 및 하천수질보전을 위한 필요유량으로 고시된 바 있다. 본 연구에서는 국내 하천수질예측에 많이 이용하고 있는 QUAL2E 모형의 단점을 수정, 보완하고 보다 사용자가 쉽게 사용할 수 있도록 개발된 QUAL2K 모형을 이용하여 용담댐 하류의 하천수질보전을 위한 필요유량을 산정하였다. 과거에 산정된 하천수질보전을 위한 필요유량 산정치와 환경부에서 최근 제시하고 있는 금강오염총량관리 기본계획과의 비교를 통해 산정한 결과의 타당성을 분석해 보았으며 장래 발생할 수 있는 여러 가지 상황들을 시나리오로 구축하여 분석함으로써 보다 합리적인 결과를 도출하도록 노력하였다. 하천수질보전을 위한 필요유량 산정 시 하나의 경우에 대한 분석보다는 발생할 수 있는 여러 상황을 시나리오로 분석함으로써 의사결정자나 일반대중에게 보다 다양한 정책 방향성과 유량에 따른 하천수질변화에 대한 다양한 정보를 제공할 수 있을 것으로 판단된다.

• The Journal of the Korea Contents Association
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• v.14 no.6
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• pp.11-25
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• 2014

In strong dramas, pot, character, and theme, three basic elements in dramatic structure, are effectively integrated forwards the same dramatic idea. Plot might be considered as the most important element to combine events and character. However, at some point of the script, the writer becomes less interested in the mechanics of the plot, and the characters take over, because audiences remember the characters or the situations more clearly than the plot. Therefore, the workshop of dramatic structure would be successful when it starts from excogitating the character and the situation, by improvising 'voices' of characters, building 'back story', and reconstructing 'outline from the antagonist's view'. With these exercises, the writer and the director understand the mechanics of dramatic plotting by characterization, which include the choice of the protagonist, and the description of plausible actions and the theme, and they consequentially find the way to obtain solidity and plausibility in the scenes.

• Journal of Advanced Navigation Technology
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• v.21 no.1
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• pp.36-42
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• 2017

An airport surface movement scheduler using first-come first-served (FCFS) algorithm is developed to efficiently manage surface traffic in an airport. It is based on the previously developed traffic flow management scheduler. Link directionality and intersection processing, which are additional constraints for ground movement, are added to the scheduler. To verify each of additional constraints, several simulations were performed by making simple scenarios, and the results show that all constraints were satisfied. Also, a simulation was performed by making a scenario based on flight operation information system (FOIS) data which is real departure and arrival flight data of Jeju airport. To determine the practicality of the developed scheduler, we compare the actual average delay time with the average delay time calculated by the scheduler.

• Journal of Korean Society of Transportation
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• v.31 no.4
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• pp.58-66
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• 2013

Due to the characteristics of urban freeways such as heavy traffic and high speed, work zone on urban freeways causes the increase of not only the likelihood of crash occurrence but also traffic congestion caused by lane drop, lane change, acceleration/deceleration, and etc. This paper aims to determine the proper length of transition area that satisfies two criteria, mobility and safety, to make the operation of work zone more efficient. For the analysis, three different scenarios were developed by the number of lanes and the proper length of transition area were determined by changing the length from 100m to 500m in 100m increments. The results showed that the proper length of transition area for 3- and 4-lane freeways is 300m, whereas the proper length of 2-lane freeways is 200m. The results indicated that the different length of transition area based on the number of lanes is more desirable and efficient.

• The Journal of Society for e-Business Studies
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• v.11 no.1
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• pp.69-89
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• 2006

Due to the technological developments and industrial changes , studying for the future has been attached great importance. According to the forthcoming ubiquitous computing environment or smart environment, it is necessary for a country and an enterprise to forecast the future or foresight the future technologies . Although many countries have been doing the foresight, it is difficult for the enterprise to try future foresight activity, because the foresight activity needs lots of the costs and time for good results. Also, almost methodologies used in foresight are suitable for country level foresight projects. In this research, a methodology is developed for an enterprise to use easily, and a case based on the proposed methodology is presented. The proposed foresight methodology is developed based on the traditional forecasting methods, FAR, Future Wheel, and Scenario. Especially, the methodology focused on the customers of a company.