• Proceedings of the Korea Information Processing Society Conference
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• 2011.11a
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• pp.483-484
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• 2011

본 내용은 이동성이 큰 해상 이동형 기지국 상에서 최적 라우팅을 하기 위해서는 이웃 기지국들 중 상대적으로 출력 정보 및 위치 정보와 같은 벡터 값이 가장 큰 기지국을 선택하는 방법과 같은 최적 조건을 찾는 최적 라우팅 방법이다.

• 한국지형공간정보학회:학술대회논문집
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• 1996.11b
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• pp.2-14
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• 1996

• Proceedings of the Korea Multimedia Society Conference
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• 2002.05d
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• pp.574-578
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• 2002

층 단위로 가공하는 RP(Rapid Prototype) 시스템에서 가공되는 물체의 표면에서는 계단형의 윤곽이 나타난다. 이러한 문제점을 보완하기 위해 경사절단 방법으로 3D 모델을 가공하여 기존의 가공방법에 의해 발생하는 계단형 윤곽 모습과 표면 왜곡 둥의 문제를 보완할 수 있다. 최적의 경사선분의 집합을 구하기 위해 경사절단 선분의 길이와 중간층 점의 거리를 정의하여 이를 최소화하는 에너지 함수를 구현한다. 그러나 이 방법은 경사절단 선분이 에너지가 작아지는 방향으로만 움직이기 때문에 레이어의 윤곽이 복잡한 경우 최적의 위치가 아닌 다른 위치에서 더 이상 움직이지 않는 국부적 최적해(Local Minima)가 발생할 수 있다. 본 논문에서는 국부적 최적해를 벗어나기 위해 경사절단 선분 추출 알고리즘에 시뮬레이티드 어니얼링(Simulated Annealing) 방법을 적용하였다. 제안된 방법으로 테스트한 결과 복잡한 레이어 윤곽에서 생길 수 있는 국부적 최적해가 어느 정도 해결되었다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.2
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• pp.271-275
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• 2006

In STP, network performance differs depending on topology configuration. Therefore, we need to configure right topology for the optimal efficiency of networking. This paper suggest the optimal topology configuration for efficient networking between ethernet switchs. It finds out the best topology configuration by calculation mathematical model which uses transmission time between root switch and other switchs in the same domain. And it also analysed performance difference on locations of root switch. Through the performance analysis, we could conclude that placing the root switch in the center is the most efficient.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.9 no.1
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• pp.76-90
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• 2010

Location Service is required in position-based routing for VANET to provide position information. We propose Grid-based Location service spot(GLSS) scheme for optimized routing path to improve accessibility and load balance in location service. Specific area is defined as Location service spot(LSS) on each grid in this scheme, and all nodes in the grid geocast its location update message and location request message to each LSS. Location request messages are flooded throughout LSSs, location reply messages establish optimized route from the source grid to the destination grid. We evaluated GLSS which establishes optimized route on the grid comparing GPSR in consideration of road condition and geographical features.

• Journal of Korea Water Resources Association
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• v.52 no.10
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• pp.719-728
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• 2019

Valve in water distribution network (WDN), that controls the flow in pipes, is used to isolate a segment (a part of WDN) under abnormal water supply conditions (e.g., pipe breakage, water quality failure event). The segment isolation degrades pressure and water serviceability in neighboring area during the water service outage of the segment. Recent hydraulic and water quality failure events reported encouraging WDN valve installation based on various abnormal water supply scenarios. This study introduces a scenario-based optimal valve installation approach to optimize the number of valves, the amount of undelivered water, and a shortest water supply path indicator (i.e., Hydraulic Geodesic Index). The proposed approach is demonstrated in the valve installation of Pescara network, and the optimal valve sets are obtained under multiple scenarios and compared to the existing valve set. Pressure-driven analysis (PDA) scheme is used for a network hydraulic simulation. The optimal valve set derived from the proposed method has 19 fewer valves than the existing valve set in the network and the amount of undelivered water was also lower for the optimal valve set. Reducing the reservoir head requires a greater number of valves to achieve the similar functionality of the WDN with the optimal valve set of the original reservoir head. This study also compared the results of demand-driven analysis (DDA) and the PDA and confirmed that the latter is required for optimal valve installation.

• The Journal of Engineering Geology
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• v.25 no.1
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• pp.67-81
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• 2015

A FORTRAN program was developed to determine the optimal locations of multiple recharge wells in an aquifer with different arrangements of pumping wells. The simulated annealing algorithm was used to find optimal locations of two recharge wells which satisfied three objective functions. The model results show that locating two injection wells inside the cluster of pumping wells is efficient if the recovery rate only was taken into account. In contrast, placing injection wells to the side of the cluster is desirable if the simulation considers aggregate objective function. Therefore, installing an injection well on each side of the cluster seems to yield the maximum recovery rates for the existing pumping wells, and it yields similar increases in pumping rate for all wells in the cluster. The locations of recharge wells can be arranged in numerous configurations, because there are multiple near-optimal local minima or maxima. These results indicate that the simulated annealing can yield effective evaluations of the optimal locations of multiple recharge wells. In addition, the suggested aggregate objective function can be utilized as an appropriate multi-objective optimization.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.6
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• pp.32-40
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• 2015

In this paper, the optimum antenna placement is analyzed by considering the interference between airborne antennas mounted on the unmanned aerial vehicle(UAV). The analysis is implemented by selecting the antennas that the distance and operational frequency band between airborne antennas is close to each other among the omni-directional antennas. The analyzed antennas are the control datalink, TCAS(Traffic Collision & Avoidance System), IFF(Identification Friend or Foe), GPS(Global Positioning System), and RALT(Radar ALTimeter) antennas. There are three steps for the optimum antenna placement analysis. The first step is selecting the antenna position having the optimum properties by monitoring the variation of radiation pattern and return loss by the fuselage of UAV after selecting the initial antenna position considering the antenna use, type, and radiation pattern. The second one is analyzing the interference strength between airborne antennas considering the coupling between airborne antennas, spurious of transmitting antenna, and minimum receiving level of receiving antenna. In case of generating the interference, the antenna position without interference is selected by analyzing the minimum separation distance without interference. The last one is confirming the measure to reject the frequency interference by the frequency separation analysis between airborne antennas in case that the intereference is not rejected by the additional distance separation between airborne antennas. This analysis procedure can be efficiently used to select the optimum antenna placement without interference by predicting the interference between airborne antennas in the development stage.

• Water for future
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• v.28 no.1
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• pp.133-144
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• 1995

The subject of the paper is the selection of the number and location of rainguage stations among existing ones, which will be part of real-time data collection system, for the computation of mean areal precipitation and for use as input of real-time flow forecasting models. The weighted average method developed by National Weather Service was used to compute MAP. Two different searching methods were used to find local optimal solutions as a function of the number of rainguages. An operational rainfall-runoff model was used to determine the optimal location and number of stations for flow prediction.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1581_1582
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• 2009

본 논문에서는 T형 분기 도파관 내 Septum의 최적설계를 위하여 상용 전자파해석 소프트웨어의 API(Application Program Interface) 기능을 활용하는 VBA(Visual Basic Application) 기반 설계 인터페이스를 개발 하였다. 최적설계의 설계 변수는 도파관 내에서 Septum의 위치와 크기로 하였고, 목적 함수는 도파관의 반사계수($S_{11}$)를 가장 작게 하면서 T형 분기 도파관에서 출력되는 에너지를 2:1로 분배하도록 설정하였다. 목적함수는 본 논문에서 정한 함수이며 설계 목표에 따라 인터페이스 내에서 변경이 가능하다. 설계 인터페이스는 마이크로소프트사의 엑셀을 이용하였고 인터페이스 내에서는 사용자가 원하는 T형 분기 도파관의 크기 설계가 가능하며, 입력 port의 입력 모드를 설정하고, 해석 주파수를 선택하여 사용자가 정한 목적 함수에 맞는 최적화된 Septum의 크기와 도파관 내에서의 위치를 찾을 수 있게 하였다. 또한 사용자가 원하는 위치에서의 E Field, H Field, 전류 밀도를 크기 또는 복소수 형태의 수치 데이터로 획득할 수 있도록 설계하였다.