• 한국정보통신학회논문지
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• 제26권5호
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• pp.786-792
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• 2022

최근 클라우드 환경의 서비스 지연문제 해결을 위하여 응용서비스의 사용자 근접성 확보 및 계산 오프로딩을 위한 FEC (Fog/Edge Computing) 패러다임에 대한 연구가 활발하다. 엣지 디바이스 (이동객체)들의 동적 위치변화 패턴 예측방법은 FEC 환경에서 컴퓨팅 리소스의 효율적 분배 및 배치를 위하여 중요한 역할을 한다. 본 논문은 엣지 디바이스들의 이동 빈발패턴에 대한 지지도의 임계값을 적용하여 선택된 경로들을 대상으로 임의의 가중치 (거리, 시간, 혼잡도)를 추가적으로 적용한 최적 이동패턴 추출방법을 제안한다. 실험을 통하여 제안 알고리즘은 빈발도만을 적용한 OPE_freq [8] 알고리즘과 A^* 및 Dijkstra 알고리즘 등과 비교한 결과, 수행시간과 노드 접근횟수를 감소시키고 보다 정확한 경로를 추출함을 알 수 있다.

• 정보처리학회논문지D
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• 제13D권7호
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• pp.985-996
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• 2006

인터넷 기술의 발전에 따라 분산 지리정보 시스템 환경이 웹 기반 서비스로 변화되고 있는 추세이다. 기존의 웹 지리정보 서비스의 지리정보는 다양한 지도 포맷을 지원하여 상호운용하지 못하도록 독립적으로 개발되어 왔다. 동일한 지리정보임에도 불구하고 이러한 정보는 서로 다른 목적에 따라 개별적인 지리정보 시스템에 의해 중복된다 이는 중복된 지리정보 객체를 식별하는 문제와 중복된 지리정보 객체들 중에 클라이언트에게 가장 적합한 복사본을 선정하기 위한 지능적인 전략이 요구되고 있다. 그리고 중복 객체를 관리하기 위해 OMG와 GLOBE 그리고 GRID 컴퓨팅에서 관련 프레임워크를 제안하고 있다. 그러나 지리정보 객체에 대한 연구는 미흡하다. 따라서, 본 논문에서 이름 또는 속성으로 중복된 서비스 객체들의 효율적인 관리와 중복 서비스 객체들 중 가장 적합한 객체를 선정하기 위한 위치 서비스 모델을 제시하였다. 위치 서비스 모델은 세 개의 주요 서비스로 구성되어 있다. 첫 번째로 바인딩 서비스는 사용자가 객체의 이름과 속성으로 정의하여 서비스 오퍼 단위로 저장하고 클라이언트가 서비스 오퍼를 검색 할 수 있다. 두 번째는 위치 서비스로 컨택 레코드를 갖는 위치 정보를 관리한다. 그리고 컨택 주소를 갖는 독립적인 시스템상의 LSF에 의해 성능 정보를 획득한다. 세 번째는 지능형 선정 서비스로 바인딩/위치 서비스로부터 기본/성능 정보를 획득하고, 러프집합 기반의 지능형 모델에 의한 규칙에 의해 보다 빠르게 접근하고 성능이 우수한 특징을 제공한다. 본 논문에서 제시한 위치 서비스 모델에 대한 검증을 위해 그래픽 사용자 인터페이스를 통해 위치 서비스의 처리 과정을 보였다.효과를 나타냈다.\alpha}-amylase$ 활성을 고려한 적정 종자수분 함량은 단옥수수는 15%, 초당옥수수는 12%이었다.미관련(食味關聯) 미질특성(米質特性)을 이용한 토요식미치 추정(推定) 중회귀식(重回歸式)에 채택(採擇)된 주요 특성은 단백질함량, 알칼리붕괴도 및 최저점도(最低粘度)였으며 결정계수(決定係數)로 보아 약 49%의 적중율(的中率)을 나타내었다. 생물학적 기능의 상관관계를 이해하는데 활용될 수 있을 것이다.V는 앞으로 바이러스와 기주의 다양한 상호관계를 이해하는데 있어서 중요한 병원학적 성질을 가지고 있는 것으로 생각되었다.>$300^{\circ}C$ 이하, 공정압력 1 Torr, 그리고 bias전압과 기체 혼합비를 변화시키면서 증착하였다. 증착시 in-situ OES 분석결과 플라즈마 내의 질소종의 함유량 변화에 따라 증착속도가 크게 변화됨을 알 수 있었고, 많은 질소기체를 인입하면 질소종이 많아지지만 증착률은 급격히 감소하였고 박막내 탄소의 함량이 커지면서 막질이 비정질로 바뀌고 미세경도 또한 감소함을 알 수 있었다. 이는 in-situ 플라즈마 진단분석이 전체 PEMOCVD 공정에 있어서 대단히 중요하고, Ti(C,N)과 Hf(C,N) 코팅막의 탄소함량과 미세경도는 플라즈마내의 CH과 CN radical종의 세기에 크게 의존함을 의미한다. 그리고 Hf(C,N) 박막의 경우도 Ti(C,N) 박막의 경우와 유사하게 최대 미세경도값$(2460\;Hk_{0.025})$이 -600 V bias 전압과 10% 질소기체 혼합비를 사용한 경우에 얻어졌고, 이는 박막이 주로(111) 방향으로 성장됨에 기인한 것으로

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제55권11호
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• pp.532-537
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• 2006

Lightning induced faults accounts for more than 66% at the transmission lines of KEPCO. The lightning causes damages to power system equipments including transmission line, the blackout of electricity and the electro-magnetic interference. Because of this reason, we need the real time lightning information for the optimal operation of power system. And, it is required to obtain and accumulate the lightning current parameters for the insulation design. In 2005, KEPRI constructed a lightning detection network, the KLDNet (i.e. Kepco Lightning Detection & Information System) and launched a lightning information service for KEPCO customers. It is intended to provide data service on the operation of transmission lines and collect lightning-related data, which is the most important factor regulating power system design and operation. The new system will replace LPATS, the old detection system, which has been operating since 1995 and is rapidly failing in terms of both detection performance and location accuracy. The purpose of this paper is to explain the work performed and the results of that work in performing a site survey of several locations. The purpose of the site survey is to find locations acceptable for the installation of a lightning location receiver in support of a Lightning detection system(LDS). A restriction was placed on the surveyed locations, as they must belong to the Korea Electric Power Company. This requirement was made to facilitate the communication needs of the LDS network. Total of 15 sites were evaluated as possible LDS sensor sites. Some of the sites were rejected for physical reasons and therefore no electrical testing was performed. Of the 15 sites, total of 10 sites were considered acceptable and 5 sites were rejected for various reason. In this paper, we would like to explain the site survey and detection efficiency for LDS.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제5권10호
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• pp.1862-1878
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• 2011

With the advances in wireless communication technology and the advent of smartphones, research on location-based services (LBSs) is being actively carried out. In particular, several spatial index methods have been proposed to provide efficient LBSs. However, finding an optimal indexing method that balances query performance and index size remains a challenge in the case of wireless environments that have limited channel bandwidths and device resources (computational power, memory, and battery power). Thus, mechanisms that make existing spatial indexing techniques more efficient and highly applicable in resource-limited environments should be studied. Bitmap-based Spatial Indexing (BSI) has been designed to support LBSs, especially in wireless broadcast environments. However, the access latency in BSI is extremely large because of the large size of the bitmap, and this may lead to increases in the search time. In this paper, we introduce a Selective Bitmap-based Spatial Indexing (SBSI) technique. Then, we propose an Adaptive Bitmap-based Spatial Indexing (ABSI) to improve the tuning time in the proposed SBSI scheme. The ABSI is applied to the distribution of geographical objects in a grid by using the Hilbert curve (HC). With the information in the ABSI, grid cells that have no objects placed, (i.e., 0-bit information in the spatial bitmap index) are not tuned during a search. This leads to an improvement in the tuning time on the client side. We have carried out a performance evaluation and demonstrated that our SBSI and ABSI techniques outperform the existing bitmap-based DSI (B DSI) technique.

• 대한안전경영과학회지
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• 제14권4호
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• pp.153-168
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• 2012

It has been recognized as an important issue to design optimally a firm's logistics network for minimizing logistics cost and maximizing customer service. It is, however, not easy to get an optimal solution by analyzing trade-off of cost factors, dynamic and interdependent characteristics in the logistics network decision making. Although there has been some developments in a system which helps decision making for logistics analysis, it is true that there is no system for enterprise-wise's on-site support and methodical logistics decision. Specially, E-biz process along with information technology has been made dramatic advance in a various industries, there has been much need for practical education closely resembles on-site work. The software developed by this study materializes efficient algorithm suggested by recent studies in key topics of logistics such as location and allocation problem, traveling salesman problem, and vehicle routing problem and transportation and distribution problem. It also supports executing a variety of experimental design and analysis in a way of the most user friendly based on Java. In the near future, we expect that it can be extended to integrated supply chain solution by adding decision making in production in addition to a decision in logistics.

• 한국환경복원기술학회지
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• 제24권2호
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• pp.115-126
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• 2021

Strategic Environmental Impact Assessment (SEA) is a decision-making process taking into account the environmental impact, economic and social impact of policies, plans, and programs at the higher stage prior to the project plan for promoting sustainable development. In this study, we analyzed the process and criteria for selecting appropriate alternatives when establishing development plan in SEA. First, the criteria for estimating changes in ecosystem services following the implementation of development project of industrial complex were presented. Second, alternative evaluations were conducted through an analysis of ecosystem service scenarios to explore suitable alternatives in Anseong. As a result, the environmental quality of selected area as the existing project site deteriorated according to the implementation of the project, and the dimensional reduction technique confirmed that the change in ecosystem service factors in project area was the optimal location. In addition, the results of the scenario assessment to explore suitable alternatives in Anseong City showed that the existing site had large capacity in terms of water quality control services (scenario 1), scenario 2 in terms of preconditioning services, and scenario 3 in terms of water supply services. The guidance of Ecosystem service assessment is expected to be available in decision-making of large-scale strategies (e.g., SEA) and projects by presenting more quantitative criteria for determining the adequacy and location feasibility of development plans and policy plans. This is expected to require various support, including legislation and revision of related laws, believed to be supported by advanced research.

• 대한기계학회논문집A
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• 제26권2호
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• pp.406-414
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• 2002

A new approach, referred to as a successive zooming genetic algorithm (SZGA), is Proposed for identifying a global solution for continuous optimization problems. In order to improve the local fine-tuning capability of GA, we introduced a new method whereby the search space is zoomed around the design point with the best fitness per 100 generation. Furthermore, the reliability of the optimized solution is determined based on the theory of probability. To demonstrate the superiority of the proposed algorithm, a simple genetic algorithm, micro genetic algorithm, and the proposed algorithm were tested as regards for the minimization of a multiminima function as well as simple functions. The results confirmed that the proposed SZGA significantly improved the ability of the algorithm to identify a precise global minimum. As an example of structural optimization, the SZGA was applied to the optimal location of support points for weight minimization in the radial gate of a dam structure. The proposed algorithm identified a more exact optimum value than the standard genetic algorithms.

• Archives of Plastic Surgery
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• 제35권5호
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• pp.545-552
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• 2008

Purpose: The transaxillary approach for breast augmentation has been advocated for patients and surgeons for several decades. However, this blind technique had many disadvantages including, traumatic dissection, difficult hemostasis, displacement of implants, and ill-defined asymmetrical location of inframammary crease. In the present study, the precise endoscopic electrocautery dissection was applied to eliminate the limits of blunt dissection throughout the procedures. Methods: From December 2006 to December 2007, a total of 103 patients with an average age of 29.5 years underwent endoscopic assisted transaxillary dual plane augmentation mammoplasty. The mean implant size was 243 cc with the range between 150 and 350 cc. Through a 4 cm axillary incision, electrocautery dissection for submuscular pockets was carried out under the endoscopic control. The costal origin of pectoralis muscle was completely divided to expose subcutaneous tissue and to make type I dual plane. Results: Using the endoscopic dissection, we achieved good aesthetic results including a short recovery period, less morbidity, and symmetrical well-defined inframammary crease. Type I dual plane procedure could support the consistent inframammary fold shape and be applied to most patients without breast ptosis. Minor complications did not occur, however, four major complications of capsular contracture occurred. Conclusion: In contrast to the era of the blind techniques, endoscopic assisted transaxillary dual plane breast augmentation can now be performed effectively and reproducibly. With Its advantage, the axillary application of endoscopy for augmentation mammaplasty is useful to achieve the optimal cosmetic outcomes.

• 한국통신학회논문지
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• 제25권5A호
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• pp.602-610
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• 2000

본 논문에서 무선 ATM LAN 환경에서 기지국 기반 기법의 루프 제거 및 경로 최적화 알고리즘을 제안한다. 제안하는 경로 최적화 알고리즘은 다각 루프 제거법과 삼각 루프 제거법의 두 단계로 이루어져 있다. 단말기의 이동각을 고려한 순서쌍의 기념을 도입하여 핸드오버하는 단말기의 위치를 표현하고, 계산된 순서쌍을 이용하여 경로 최적화를 수행한다. 우리는 핸드오버 지연 시간, 통신 단절 시간, 버퍼 요구량, 그리고 총시그널링 교환 시간 등을 이용하여 제안하는 기법과 앵커 재라우팅 기법을 비교하였다. 이러한 비교 평가를 통하여 제안하는 기법이 경로 확장 기법의 장점인 빠른 핸드오버를 보장하면서 경로 상에서 발생하는 루프의 제거와 경로의 최적화를 효과적으로 수행할 수 있음을 보였다.

• 한국태양에너지학회 논문집
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• 제34권5호
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• pp.11-22
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• 2014

It is usual to determine silver-town location by people's experienced knowledge or intuition considering many different type of thematic variables simultaneously. This paper is primarily intended to locate sunny silver-town according to catchment-wide solar radiation as single key variable. GIS based solar simulation realistically identified catchment-wide solar radiation in the study area using large scale spatial precision. More than 90% over the worst catchment were identified shadow surfaces while the optimal catchment was heavily covered by sunny radiation surfaces. It is confirmed that standard GIS technology can offers the viable method of measuring and comparing the catchment-wide solar radiation. Guidelines for a replicable methodology are presented to provide a strong theoretical basis for the standardization of factors involved in locating the sunny silver-town; delineation of catchment boundary, solar simulation, catchment-wide comparison etc. They could be used as an evidence to determine sunny catchment in comparison with other catchment, based solar simulation. It is anticipated that this research output could be used as a valuable reference to confirm the potential of introducing the new concept of "catchment specific solar radiation" to support more scientific and objective decision-making in the process of locating silver town.