• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.12B
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• pp.1022-1036
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• 2004

In mobile cellular network the ever-changing location of a mobile host necessitates the continuous tracking of its current position and efficient management of location information. A database called Home Location Register(HLR) plays a major role in location management in this distributed environment, providing table management, index management, and backup management facilities. The objectives of this paper are to identify the p개blems of the current HLR system through rigorous analysis, to suggest solutions to them, and to propose a new architecture for the HLR system. In the HLR system, a main memory database system is used to provide real-time accesses and updates of subscriber's information. Thus it is suggested that the improvement bemade to support better real-time facilities, to manage subscriber's information more reliably, and to accommodate more subscribers. In this paper, I propose an efficient backup method that takes into account the characteristics of HLR database transactions. The retrieval speed and the memory usage of the two-level index method are better than those of the T-tree index method. Insertion md deletion overhead of the chained bucket hashing method is less than that of modified linear hashing method. In the proposed backup method, I use two kinds of dirty flags in order to solve the performance degradation problem caused by frequent registration-location operations. Performance analysis has been performed to evaluate the proposed techniques based on a system with subscribers. The results show that, in comparison with the current techniques, the memory requirement is reduced by more than 62%,directory operations, and backup operation by more than 80%.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.11b
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• pp.1547-1550
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• 2002

MANET은 전형적인 무선 네트워킹과는 다른 새로운 무선 네트워킹 파라다임으로써 기존 유선 망의 하부 구조에 의존하지 않고 이동 호스트틀로만 구성된 네트워크이다. Ad Hoc망에서 통신을 하기 위해서는 출발지 노드에서 목적지 노드까지 데이터 전송을 위한 라우팅에 관한 문제이다. Ad Hoc망에서는 모든 단말기의 위치변화가 가능하기 때문에 경로설정에 어려움이 따른다. 노드간에 정보를 보내고자 할 때 노트가 인접한 상태가 아니면 정보를 직전 보낼 수 없고 여러 중간 노드들을 거쳐서 정보를 보내는 다중-홉 라우팅 방식을 사용해야 한다. 따라서 중간 노드들은 패킷 라우터의 역할을 해야하는데 무선 통신 자체가 좁은 대역폭과 한정된 채널을 가지고 전송 범위가 제한되는 문제가 있다. 또한 노트 자체의 이동성과 전력 소모 등으로 인한 이탈은 망 위상을 수시로 변화시키므로 노트간에 정보를 전송하는데 가장 종은 경로는 수시로 변경될 수 있으므로 많은 어려움이 따르게 된다. 본 논문에서는 이러한 문제의 해결방안으로 경로유지 과정에서 Ad Hoc망 내의 노드들은 이동성의 특성으로 인해 현재 사용되는 경로 보다 더 짧고 효율적인 경로가 발생하고 중간 노트가 이동 될 때 새로운 경로로 갱신하여 솔기없는 최적의 경로를 유지할 수 있는 방법을 제안한다. 제안 방법은 ZRP의 IERP에서 감청모드를 통하여 사공중인 경로보다 최적의 경로를 감지하여 새로운 경로로 갱신하는 방법과 중간 노드가 이동하여 경로가 깨진 경우 부분적으로 경로를 복구하는 방법을 제시하여 항상 최적화된 경로를 유지함으로써 Ad Hoc망의 위상변화에 대한 적응성을 높일 수 있도록 한다. SQL Server 2000 그리고 LSF를 이용하였다. 그리고 구현 환경과 구성요소에 대한 수행 화면을 보였다.ool)을 사용하더라도 단순 다중 쓰레드 모델보다 더 많은 수의 클라이언트를 수용할 수 있는 장점이 있다. 이러한 결과를 바탕으로 본 연구팀에서 수행중인 MoIM-Messge서버의 네트워크 모듈로 다중 쓰레드 소켓폴링 모델을 적용하였다.n rate compared with conventional face recognition algorithms. 아니라 실내에서도 발생하고 있었다. 정량한 8개 화합물 각각과 총 휘발성 유기화합물의 스피어만 상관계수는 벤젠을 제외하고는 모두 유의하였다. 이중 톨루엔과 크실렌은 총 휘발성 유기화합물과 좋은 상관성 (톨루엔 0.76, 크실렌, 0.87)을 나타내었다. 이 연구는 톨루엔과 크실렌이 총 휘발성 유기화합물의 좋은 지표를 사용될 있고, 톨루엔, 에틸벤젠, 크실렌 등 많은 휘발성 유기화합물의 발생원은 실외뿐 아니라 실내에도 있음을 나타내고 있다.>10)의 $[^{18}F]F_2$를 얻었다. 결론: $^{18}O(p,n)^{18}F$ 핵반응을 이용하여 친전자성 방사성동위원소 $[^{18}F]F_2$를 생산하였다. 표적 챔버는 알루미늄으로 제작하였으며 본 연구에서 연구된 $[^{18}F]F_2$가스는 친핵성 치환반응으로 방사성동위원소를 도입하기 어려운 다양한 방사성의 약품개발에 유용하게 이용될 수 있을 것이다.었으나 움직임 보정 후 영상을 이용하여 비교한 경우, 결합능 변화가 선조체 영역에서 국한되어 나타나며 그 유

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2003.05a
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• pp.181-186
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• 2003

The satellite navigation system is widely used for identifying a user's position regardless of weather or geographic conditions and also make effect on new technology of marine LBS(Location Based Service), which has the technology of geographic information such as the ENC. Generally, there are conceivable systems of marine LBS such as ECDIS, or ECS that use the ENC itself with powerful processor in installed type on ships bridge. Since the ENC is relatively heavy structure with dummy format for data transfer between different systems, we should reduce the ENC to small and compact size in order to use it in mobile platform. In this paper, we assumed that the mobile system like PDA, or Webpad can be used for small capability of mobile platform. However, the ENC should be updated periodically by update profile data produced by HO. If we would reduce the ENC without a consideration of update, we could not get newly updated data furthermore. As summary, we studied considerations for ENC reduction with update capability. It will make the ENC be useful in many mobile platforms for various applications.

• Journal of the Korean Association of Geographic Information Studies
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• v.14 no.3
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• pp.163-173
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• 2011

This paper, as a case study on the evaluation of nationwide-unit forest functions, targeting the entire Gyeongsangnam-do region, examined the integration measures for the evaluation of national, public and private forest functions, as well as GIS data problems and GIS data building methods. Also, the distribution and characteristics of Gyeongsangnam-do's forest functions were examined. First, as integration measures for forest function evaluation, evaluation unit was proposed as watershed unit, and GIS techniques were proposed to correct some patterns of errors shown in the watershed maps. Also, of GIS data used for forest function evaluation, maps of locations of saw mills to be revised, expressway interchange location maps, and population distribution maps were built nationwide. Based on watershed units, the forest functions of 20 cities and counties in Gyeongsangnam-do were evaluated, revealing that wood production function and forest recreation function potentials, high-ranking was high distributed throughout the site, while most functions potentials, low-ranking was low distributed. In forest function maps with the application of priority by city and gun, the area size was ranked in the order of forest recreation, timber production, natural conservation, water yield, living environment conservation, and prevention of natural disaster. Case analysis results for large areas can be used in evaluating nationwide forest functions.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.3
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• pp.469-477
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• 2017

Cloud computing is an IT resource providing technology to various users by using virtualization technology. Newly updated spatial information may not be used by other organizations since management authorities are dispersed for Korean public spatial information. Further, the national budget is wasted since each organization independently implements renewable GIS analysis function. These problems can be solved by applying cloud service. However, research related to the application of cloud service to Korea spatial information system has been proposed in the technology development direction, and no detailed development plan has been proposed. In this paper, we deal with the establishment of a technology development plan for national spatial information infrastructure cloud service. First, we deduct the implication to derive the technology development goals by analyzing the political and technical environment. Second, technology and critical technology elements are derived to achieve the goals of the specialist's analysis based on the evaluation elements. As a result, thirteen critical technology elements are derived. Finally, thirty-one research activities, which comprise the critical technology elements, are defined. Critical technology elements and research activities derived in this research will be used for the generation of a technology development road-map.

• Journal of Environmental Policy
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• v.12 no.3
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• pp.3-20
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• 2013

Recently, impacts and damages of extreme climate change have already affected on worldwide. Thus adaptation and action plan are essential concepts in minimizing the impacts of climate change. In order to introduce climate change adaptation decision-making measure, the need for high-quality and integrated information system within adaptation policy has increased enormously. However, most of adaptation information is based on different sources and various backgrounds. Currently, domestic climate change information is disseminated from about 132 internet sites and most of them are limited to general information of climate change, rather than information that are based on scientific evidence. Also, there are some difficulties in updating new resources. Reliable climate change information is provided from different agencies, which makes users difficult to locate right information they need. As a progress to overcome the limitations of these problems, we carried out a feasibility research on integrated information system for climate change adaptation. For the objectives, our solutions are as follows. First, we analyzed definition of climate change adaptation and climate change adaptation information. Second, we suggested integrating the information system for adaptation and phased implementation plan for establishing integrated information system for climate change. Finally, we verified the establishment of integrated support system based on policy applications of integrated information system. This system will provide an integrated climate change information and be a very useful tool to support the decision making process of effective climate change adaptation policies.

• Journal of the Korean Association of Geographic Information Studies
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• v.18 no.1
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• pp.105-119
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• 2015

A case study to test the open API service functions of Geographic Information Open Platform(Vworld) for Environmental Impact Assessment was carried out for improving the function of Environmental Impact Assessment Geographic Information System(EIAGIS) which is one of Environmental Impact Assessment Supporting System(EIASS) used for current Environmental Impact Assessment. Followings are the summary of the study. First, utilization of EIAGIS was low since DB renewal was limited and the quality of 2D based topographic information was low. A new service which could respond to practitioners' needs could be developed to use a open API service of Vworld provided by the Ministry of Land, Infrastructure and Transport to make up those disadvantages. EIASS with Vworld could provide a consulting service from the beginning stage of business plan and make improvements of confidence as well as fast agreements since both consultation agencies and assessment agencies are using a same program during Environmental Impact Assessment process with customized information.

• Journal of the Korean Association of Geographic Information Studies
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• v.22 no.3
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• pp.120-132
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• 2019

As a key infrastructure for positioning autonomous vehicles, HD maps are making efforts to equip autonomous vehicles and connect them with services worldwide. Global companies like Here and TomTom have contracted an agreement with three German automobile companies(BMW, Audi, Daimler) by establishing systems including from the production of HD maps to loading autonomous vehicles. Japan has organized a DMP(Dynamic Map Platform) by collaborating public and private section and performing establishment of HD map on private section-oriented. Korean companies related with autonomous vehicles are also cooperating with various companies such as vehicles, sensors and maps. But public and private sections are establishing HD maps respectively. Accordingly, Ministry of Land, Infrastructure and Transport implemented and signed memorandum for private and public cooperation in April 2019, Joint establishment council of HD map has launched in August 2019. This study performed domestic and foreign trend analysis about HD map and interviewed to related companies. And analyzed solutions for interactive cooperation of private and public section in HD map industry, purposed step-by-step strategy for operation and operation plan for joint establishment council of HD map.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.49 no.6
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• pp.1-7
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• 2012

Due to the increasing demand of network convergence, in future, hybrid/integrated satellite and terrestrial systems will play an important role. In that case, compatibilities between the satellite and terrestrial systems are very important for efficiency of the systems. 3GPP Long Term Evolution (LTE) is one of the 4G system. Therefore, in this paper, we introduce the design of interleaver for mobile satellite system based 3GPP LTE specification. The 4G system including the LTE specification adopted adaptive modulation and coding (AMC) schemes for efficient usage of resources, and the updating interval of resource allocation is an order of msec. However, because of the long round trip delay of satellite systems, we cannot employ the same AMC scheme specified for the terrestrial system, and thus it cannot effectively counteract to short term fadings. Therefore, in order to overcome these problems, we propose an interleaver scheme combined with AMC. We present the interleaver design results considering mobile satellite system based on the LTE and analyze the simulation results.

• Journal of the Korean Association of Geographic Information Studies
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• v.23 no.1
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• pp.41-50
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• 2020

The National Geographic Information Institute of Korea takes digital aerial photograph images every two years to make and modify/renew the digital map. The cameras for aerial photogrammetry to capture these digital aerial photographs are divided into frame types and line types. Computer vision analysis of aerial photograph images was only possible for frame type. Thus, in this study, Line type aerial photograph images was intended to generate geospatial information through computer vision analysis, and forest geospatial information was created as a method for the utilization of aerial picture images. As a result, geospatial information generated by computer vision analysis of line type aerial photograph images showed that RMSE of horizontal and vertical position errors was less than quadruple that of GSD. Forest geospatial information was generated using geospatial information generated by computer vision analysis. It was confirmed that extraction of the crown of tree and calculation of tree height are possible. Through this study, it is expected that utilization of aerial photograph images will be improved.