• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2016.06a
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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.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.1
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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.

• The Korean Journal of Emergency Medical Services
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• v.14 no.3
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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.

• Journal of Korea Multimedia Society
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• v.13 no.6
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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.

• Journal of KIISE:Information Networking
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• v.34 no.1
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• pp.33-40
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• 2007

A multihomed enterprise or AS(Autonomous System) improves reliability and performance by acquiring its Internet connectivity from more than two ISP(Internet Service Provider). Multihoming protocol must allow a multihomed site whose connectivity through one of the ISPs fails to keep its Internet connectivity As one of mechanisms to do this, tunneling mechanism through Non-direct EBGP(Exterior Border Gateway Protocol) is defined. This mechanism makes connectivity to the Internet more reliable, but causes the problem that makes the communication route non-optimal. In this paper, we propose the route optimization mechanism using an extension header in the IPv6 multihoming environment.

• Proceedings of the Korea Contents Association Conference
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• 2009.05a
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• pp.467-471
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• 2009

A road is a fundammental public traffic facility for transporting people and goods. Road designer should determine the best route considering various conditions to minimize environmental bad effect due to road construction and show road functions sufficiently. In this research, we tried to select the optimal route location by comparing candidate routes considering weights of various items such as land use, slope, aspect, land price and so forth. The candidate routes were analyzed and visualized from built data using a GIS software and then compared with the existing route.

• Journal of Communications and Networks
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• v.10 no.3
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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.

• Proceedings of the KIEE Conference
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• 2006.11a
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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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• v.1 no.1
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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.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.08a
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• pp.87-95
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• 2004

Economic development is remarkable in Asia and progress of industrialization of NIES, ASEAN, and China in East Asia has increased the international physical distribution in this area. However, an imbalance of trade becomes severe in these areas. The imbalance is especially big in the Asia-North America route and the Japan-China route. The imbalance in the Asia -North America liner route is 5.04 million TEUS in 2002.The transportation ratio of loaded containers between China and Japan route is approximately 3:1 in 2000. In other words, it means that the transportation of loaded containers from China to Japan is 3, the transportation of loaded containers from Japan to China is I. The imbalance at a port is generally obtained by subtracting export loaded container cargo volume from import container cargo volume. However, the imbalance and the empty containers at the port are not always same. Then, in order to evaluate rationalization and efficiency of maritime container transportation, we introduce the amount of empty containers at a port as an evaluation index. However, the past data of the amount of handling empty containers have a lot of lacking portions. Then, it is necessary to estimate the past amount of empty containers in order to grasp the amount of empty containers historically. So, we construct the model that estimates the amount of empty containers using the imbalance of main port statistics in Japan.