• 대한두개안면성형외과학회지
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• 제16권1호
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• pp.17-23
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• 2015

Background: Treatment of skull base tumors is challenging due to limited access and presence of important neurovascular structures nearby. The success of a complete tumor resection depends on the extent of tumor exposure and secure field of view. While these tumors are often removed by transcranial endoscopic access, transfacial approach is sometimes required depending on the location and size of the tumor. This study describes various transfacial approaches in patients undergoing skull base tumor resection. Methods: From March to November 2013, 15 patients underwent skull base tumor resection via transfacial accesses at a tertiary institution. Data were reviewed for patient demographics, type of access used, completeness of tumor resection, surgical outcome, and postoperative complications. Results: Two clivus tumor patients underwent transmaxillary approach; three tuberculum-sellae and suprasellar-hypothalamus tumor patients underwent transbasal approach; three clinoid and retrobulbar intraconal orbital tumor patients underwent orbitozygomatic approach; and seven petroclival-area, pons, cavernous sinus, and lateral-sphenoid-wing tumor patients underwent zygomatic approach. In all cases, the upper and lower margins of the tumor were visible. Complete tumor removal consisted of 10 cases, and partial tumor removal in 5. There were no immediate major complications observed for the transfacial portion of the operations. The overall cosmetic results were satisfactory. Conclusion: Plastic surgeons can use various transfacial approaches according to the location and size of skull base tumors to secure a sufficient field of view for neurosurgeons.

• 전자공학회논문지
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• 제49권11호
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• pp.118-131
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• 2012

기존 전자발찌 시스템은 GPS 위성 및 휴대폰 기지국 통신을 통해 성범죄자의 위치를 추적하고 재범을 방지하는 장치이다. 하지만 GPS 위성통신 방식은 위성 신호 수신이 어려운 도심 건물의 실내나 지하철에서는 제대로 작동하지 않는다. 이러한 경우 휴대폰 기지국 통신을 통해 위치추적을 할 수 있다. 그러나 휴대폰 기지국은 설치범위가 수백 미터 간격으로 넓기 때문에, 위치추적을 할 경우 오차범위가 최대 2 km일 만큼 정확도가 떨어진다. 만약 도심의 5층 건물에서 유치원이 2층에 위치해 있고 커피숍과 성범죄자가 3층에 위치해 있다면, 기존 전자발찌는 건물 내부로 인해 GPS 위성통신으로 위치추적이 안되고 휴대폰 기지국 통신으로도 정확한 층에 대한 위치인식이 안 된다. 전자발찌는 위치인식 기반의 시스템으로 이러한 현상은 커다란 문제가 된다. 따라서 본 논문은 이런 위치인식 불가의 극한환경에서 USN을 이용하여 성범죄자들을 감시할 수 있는 스마트 전자발찌 시스템을 제안한다.

• 한국농공학회지
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• 제41권3호
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• pp.51-58
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• 1999

It is necessary to evaluate the location suitability of protected horticulutre facilities to guide and/or plan new protected horticulture facilities in rural areas. In this study, as one of methodological approaches for objective and systematic evaluation of location suitability for protected horiculture, the evaluation model of location sutitability for protected horticulture was formulated using AHP (Analytic Hierarchy Process) as a base technique. The evaluation model was made in three different selected regions ; suburban, plain, and mountainous, The results showed that there were significant differences in evaluation model of location suitability for protected horticulture among three regions.

• Journal of Electrical Engineering and Technology
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• 제5권1호
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• pp.36-44
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• 2010

This paper presents the design of an algorithm to detect, identify, and locate faults in radial distribution feeders of Provincial Electricity Authority (PEA). The algorithm consists of three major steps. First, the adaptive algorithm is applied to track/estimate the system electrical parameter, i.e. current phasor, voltage phasor, and impedance. Next process, the impedance rule base is used to detect and identify the type of fault. Finally, the current compensation technique and a geographic information system (GIS) are applied to evaluate a possible fault location. The paper also shows the results from field tests of the automate fault location and illustrates the effectiveness of the proposed fault location scheme.

• 한국멀티미디어학회논문지
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• 제17권4호
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• pp.458-465
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• 2014

In this paper, we propose a strategy to distribute the energy consumption over the network. The proposed strategy is based on geographic routing. We use a smart base station that maintains the residual energy and location information of sensor nodes and selects a head node and an anchor node using this information. A head node gathers and aggregates data from the sensor nodes in a target region that interests the user. An anchor node then transmits the data that was forwarded from the head node back to the smart base station. The smart base station extends network lifetime by selecting an optimal head node and an optimal anchor node. We simulate the proposed protocol and compare it with the LEACH protocol in terms of energy consumption, the number of dead nodes, and a distribution map of dead node locations.

• 전기학회논문지
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• 제56권9호
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• pp.1543-1548
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• 2007

This paper reports a study on determination of the adequate location of 100 MVA STATCOM regarding the transfer capability enhancement on the metropolitan interface as well as the economy in system operation. The base case in the study was established considering a scenario of the energy support to North Korea from the KEPCO (Korea Electric Power Corporation) system through a HVDC interconnection. In the base case, the energy support was approximately modeled with a load of 1500 MW, and by the load addition, the system was weakened in terms of voltage stability and transfer capability. After a thorough investigation on the case, the location of the STATCOM was decided to compensate the reactive deficit of the modified system and to maximize the operational benefit which can be estimated by FV analysis.

• Journal of Communications and Networks
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• 제8권1호
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• pp.85-92
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• 2006

In this paper, we study a wireless cellular network design problem. It consists of selecting the location of the base station controllers and mobile service switching centres, selecting their types, designing the network into a tree-topology, and selecting the link types, while considering the location and the demand of base transceiver stations. We propose a constraint programming model and develop a heuristic combining local search and constraint programming techniques to find very good solutions in a reasonable amount of time for this category of problem. Numerical results show that our approach, on average, improves the results from the literature.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2008년도 하계종합학술대회
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• pp.271-272
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• 2008

TD-SCDMA combines TDMA and CDMA components to provide more efficient use of radio resources, and includes a new feature called HSDPA (high-speed downlink packet access) in the R5 stage. The TD-HSDPA supports high-speed traffic with a shared channel, but its uplink mechanism causes feedback problem for scheduling. Since the base station of TD-SCDMA can estimate the location of mobile terminals precisely, it can also estimate the possible path loss. In this paper, the base station utilizes the estimated path loss for scheduling, which is related with CQI (channel quality indicator) values. The proposed mechanism can provide the TD-HSDPA scheduler with an intial CQI value for efficient transmission.

• 한국IT서비스학회지
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• 제22권3호
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• pp.85-100
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• 2023

The development of Airside Vehicle Control System(AVCS) at Gimpo Airport aims to reduce ground safety accidents in movement area and improve airport operation efficiency and safety management service quality. The vehicle is controlled by a brake controller RTK-antenna and On-Board Diagonostics(OBD) module. Location data is transmitted to a nearby communication base station through a Wi-Fi router and the base station is connected to the AVCS by an optical cable to transmit location data from each vehicle. The vehicle position is precisely corrected to display information using the system. The system allows airport operators to view registered information on aircraft and vehicles and monitor their locations speeds and directions in real time. When a vehicle approaches a dangerous area alarm warnings and remote brake control are possible to prevent accidents caused by carelessness of the driver in advance.

• 한국통신학회논문지
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• 제40권11호
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• pp.2148-2150
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• 2015

본 논문은 셀 가장자리에서의 적응적 협력 전송 기법을 제안한다. 제안된 기법은 사용자의 위치를 고려하고, 그에 알맞은 협력 전송 기법을 적용한다. 셀룰러 시스템들에서, 사용자가 셀의 경계에 위치하게 되면 통신의 성능의 열화가 발생한다. 기존의 기법에서는 두 개의 기지국들이 다이버시티 이득을 얻기 위하여 사용된다. 하지만 사용자와 기지국 사이의 거리는 여전히 멀기 때문에, 기존의 방법만으로는 성능이 충분히 향상되지 않는다. 따라서 릴레이들을 사용하고 사용자의 위치에 따라 협력 전송 기법을 적응적으로 적용하는 기법을 제안한다. 시뮬레이션 결과들을 통해, 제안된 기법의 성능이 기존의 기법보다 좋다는 것을 확인할 수 있다.