• 한국건설관리학회논문집
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• 제10권4호
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• pp.101-110
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• 2009

본 연구는 기존 시공단계 중심의 VR시뮬레이션 활용체계를 설계단계까지 확장하여 도로의 최적 설계정보 지원을 위한 시각화 분석 기능을 개발하는 것이 목적이다. 연구에서는 설계지원을 위한 VR기능으로 도보 선형(alignment)에 의한 토공 시뮬레이션, 대안 노선 선정 시뮬레이션 구조물 타입 선정 시뮬레이션 및 지하시설물 분석 시뮬레이션 기능들을 제안하고 있다. 이러한 VR시뮬레이션 기능을 통해 노선 및 토공 상태의 시각적 확인이 가능하고, 대안 노선의 가상적인 모의 배치를 수행함으로써 최적 설계노선을 선정할 수 있다. 이를 위해 본 연구에서는 도로설계정보 지원을 위한 VR시뮬레이션 기능 개발 방법론 및 시스템(VR Presenter)을 구현하며, VR기능을 적용한 개선된 도로설계 프로세스를 제안하고 있다.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송∙미디어공학회 2016년도 하계학술대회
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• pp.46-47
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• 2016

본 논문은 북미의 차세대 지상파 방송 표준인 ATSC 3.0에서 고려하고 있는 ROUTE(Real-time Object Delivery over Unidirectional Transport) 및 MPEG-DASH(Dynamic Adaptive Streaming over HTTP)를 기반으로 자유시점 방송 서비스를 송 수신하기 위한 SLS(Service Layer Signaling)을 제안한다. 특별히 ATSC 3.0과의 역호완성을 위하여 기존의 ROUTE/DASH의 SLS는 그대로 유지한 채 자유시점 방송을 위한 정보만 추가하여 기존의 SLS와 상호동작이 되도록 설계하였다. 따라서 본 논문에서 제안하는 내용은 향후 ATSC 3.0와 같이 IP(Internet Protocol)을 기반으로 SLS을 수행하는 표준규격과 역호환성을 유지한 채 자유시점 방송서비스를 할 수 있을 것으로 기대된다.

• 한국정밀공학회지
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• 제28권1호
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• pp.80-88
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• 2011

The dental high-speed air turbine handpiece is one of the most popular devices that have been widely used as the main means of cutting tooth structure and restorative material in dentistry. In consideration of usage and marketability of the dental handpiece, it is obviously worthy of investigating it. The goal of this paper is to establish the relationship between the air turbine speed and the supply route inside the handpiece. To do this, the Computational Fluid Dynamics(CFD) tool, Fine$^{TM}$/Turbo is used and the optimal supply route position is suggested from the simulation results. In addition, as an attempt for domestic product, the reverse engineering process of a high speed dental handpiece by 3D X-Ray CT equipment and wire cutting is presented for the Mark II model in NSK. In doing so, the 3D modeling of the handpiece parts is carried out with CATIA V5, and the interference between parts is examined. Finally, the result of performance test for the prototype produced in this research is presented.

• 한국응급구조학회지
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• 제14권3호
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• pp.5-11
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• 2010

Purpose: This study was to clarify correlation between en route distance and role time on call received hours. Methods: Data on en route distance(dependent variable), role time(independent variable) from 387 prehospital care reports documented by EMS in Kyonggi Provincial Fire and Disaster Headquarters and Seoul Metropolitan Fire and Disaster Department between 21 and 10 June 2010 were randomly chosen for simple regression analysis using Windows SPSS 12. OK. This analysis was conducted nine times on unit hour divided to eight call received and overall. Results: Statistically significant regression equations( Y=2.414+1.206X for 09:00~11:59, Y=3.753+.662X for 12:00~14:59, Y=2.215+1.458X for 15:00~17:59, Y=2.600+.822X for 21:00~23:59, Y=5. 445+.263X for overall) were derieved from the data. Conclusion: These equations having linear relationship may be utilized as a method for system status management to effectively response to emergency call.

• 한국멀티미디어학회논문지
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• 제13권6호
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• pp.849-864
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• 2010

This paper proposes a multipath routing protocol called cross-layer multipath AODV (CM-AODV) for wireless ad hoc networks, which selects multiple routes on demand based on the signal-to-interference plus noise ratio (SINR) measured at the physical layer. Note that AODV (Ad hoc On-demand Distance Vector) is one of the most popular routing protocols for mobile ad hoc networks. Each time a route request (RREQ) message is forwarded hop by hop, each forwarding node updates the route quality which is defined as the minimum SINR of serialized links in a route and is contained in the RREQ header. While achieving robust packet delivery, the proposed CM-AODV is amenable to immediate implementation using existing technology by neither defining additional packet types nor increasing packet length. Compared to the conventional multipath version of AODV (which is called AOMDV), CM-AODV assigns the construction of multiple paths to the destination node and makes it algorithmically simple, resulting in the improved performance of packet delivery and the less overhead incurred at intermediate nodes. Our performance study shows that CM-AODV significantly outperforms AOMDV in terms of packet delivery ratio and average end-to-end delay, and results in less routing overhead.

• 한국정보과학회논문지:정보통신
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• 제34권1호
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• pp.33-40
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• 2007

멀티호밍은 하나의 기업 혹은 자율 시스템(AS, Autonomous System)이 둘 이상의 인터넷 서비스 제공업체(ISP, Internet Service Provider)로부터 인터넷 연결 서비스를 제공받는 메커니즘이다. 멀티호밍 메커니즘을 사용하는 AS는 망 내의 호스트들에게 여러 ISP를 통하여 좋은 성능과 신뢰성을 가지는 인터넷 연결을 제공할 수 있다. IPv6 멀티호밍에서는 멀티호밍 사이트가 하나의 ISP하의 연결에 문제가 발생하였을 경우 멀티호밍 사이트로 전송되어야 하는 패킷을 손실 없이 목적지로 전달할 수 있도록 하기 위하여 Non-direct EBGP(Exterior Border Gateway Protocol)를 통한 터널링 메커니즘이 정의되었다. 그러나 이 메커니즘의 경우 신뢰성 있는 인터넷 연결은 제공하지만 통신 경로가 최적화되지 못하는 문제점을 가진다. 본 논문에서는 IPv6 멀티호밍 환경에서 IPv6 확장 헤더를 사용함으로써 멀티호밍 사이트가 하나의 ISP와의 연결에 문제가 발생하였을 경우에 최적화된 경로를 통하여 신뢰성 있는 인터넷 연결을 제공할 수 있는 메커니즘을 제안한다.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2009년도 춘계 종합학술대회 논문집
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• pp.467-471
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• 2009

도로시설은 사람과 물자를 수송하는데 있어서 가장 기본적인 공공교통시설이고 도로 건설시 환경파괴를 최대한으로 감소시키고 그 기능을 충분히 발휘할 수 있도록 대상지역의 여러 가지 조건을 고려하여 가장 적합한 노선의 위치를 결정하여야 한다. 본 연구에서는 연구대상지역의 토지이용, 지형경사, 사면방향, 지가 등을 분석하여 각각의 경중률을 고려한 후보노선들을 비교분석함으로서 최적노선을 선정하고자 하였다. 각 항목별로 경중률을 분류하여 구축된 자료들은 GIS 프로그램을 이용하여 후보노선을 선정하고 시각화하였으며 기존노선과 비교하였다.

• Journal of Communications and Networks
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• 제10권3호
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• pp.351-361
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• 2008

This paper presents a delay-margin based traffic engineering (TE) approach to provide end-to-end quality of service (QoS) in multi-protocol label switching (MPLS) networks using differentiated services (DiffServ) at the link level. The TE, including delay, class, and route assignments, is formulated as a nonlinear optimization problem reflecting the inter-class and inter-link dependency introduced by DiffServ and end-to-end QoS requirements. Three algorithms are used to provide a solution to the problem: The first two, centralized offline route configuration and link-class delay assignment, operate in the convex areas of the feasible region to consecutively reduce the objective function using a per-link per-class decomposition of the objective function gradient. The third one is a heuristic that promotes/demotes connections at different links in order to deal with concave areas that may be produced by a trunk route usage of more than one class on a given link. Approximations of the three algorithms suitable for on-line distributed TE operation are also derived. Simulation is used to show that proposed approach can increase the number of users while maintaining end-to-end QoS requirements.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 추계학술대회 논문집 전력기술부문
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• pp.63-65
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• 2006

These days, it is not easy to construct the transmission line because of the environmental association activity, a civil appeal, etc. To solve these kinds of difficulties, the program with leading-edge IT technology, such as GIS, 3 dimensions CAD, computer graphic, etc., is developed to be more transparent and objective in the design stage of the transmission line and the selection stage of the transmission line route. Comparing this program with previous methods, this program is composed of the environmental evaluation program, data producing program for analysis and selecting line route program because it is not possible to conduct those kinds of work without any help from the computer and well-developed program. To confirm the performance of the program, the result from the program and the human were compared. Therefore, the result from the program was same as the result conducted by human. In addition, the program makes the selection of the transmission line route easier by checking the mountainside, lumbering, the estimated cost of the tower construction, etc. in real-time.

• Acta Via Serica
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• 제1권1호
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• pp.105-117
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• 2016

The Silk Road named by Ferdinand von Richthofen was not designated as a specific route. A lot of East-West trade routes had already existed across the continent and the geographical scope and definition of the Silk Road is still expanding. In particular, the claim that the Eastern end of the Silk Road reaches Gyeongju is an example of this expansion. Burial treasures from tombs on the Korean Peninsula have already been identified as products from the Sassanian Dynasty of Persia, and various archaeological and epical evidences support this finding. However, the specific route where these exchanges were made, around the 6th-8th centuries, has yet to be identified. Maritime as well as inland routes can easily be hypothesized. The Silk Road was largely activated by the Yam postal system with the expansion of the Mongol Empire. It not only served as an effective pathway for the Yuan to rule over the Goryeo, but also connected the Eastern end of the Silk Road to Gyeongju. This can explain the situation since the 13th century. Therefore, this paper claims that the Yeokcham system had been operating on the Korean Peninsula since the Unified Silla Kingdom, the previous period of Goryeo, or perhaps even before then. The Yeokcham should thus be regarded as a prototype of the Mongolian Yam, and the Korean peninsula should be recognized as another route which contributed specifically to the development of the Silk Road, not just as a user or a beneficiary.