• The KIPS Transactions:PartB
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• v.11B no.5
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• pp.581-586
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• 2004

In this paper, we proposed a content-based image retrieval using a color feature for central region and its optimized comparing bin method. Human's visual characteristic is influenced by existent of central object. So we supposed that object is centrally located in image and then we extract color feature at central region. When the background of image is simple, the retrieval result can be bad affected by major color of background. Our method overcome this drawback as a result of the human visual characteristic. After we transform Image into HSV color space, we extract color feature from the quantized image with 16 level. The experimental results showed that the method using the eight high rank bin is better than using the 16 bin The case which extracts the feature with image's central region was superior compare with the case which extracts the feature with the whole image about 5%.

• Proceeding of EDISON Challenge
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• 2015.03a
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• pp.347-349
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• 2015

본 연구에서는 MOSFET 제작방법중 하나인 이온주입법에서 다양한 변수로 작용하는 도핑농도, 에너지주입, 바탕농도의 역할에 대해서 알아보고 채널길이가 감소함에 따른 단채널효과를 억제할 수 있는 최적점에 대하여 분석하였으며 Ion Implant 이차원 시뮬레이션값과 비교하였다. 결과적으로 농도와 에너지주입 그리고 채널길이에 따른 MOSFET의 최적화된 모델을 분석하였다.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.18 no.1
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• pp.71-78
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• 2005

Rescaled Simulated Annealing(RSA) has been devised for improving the disadvantage of Simulated Annealing(SA) which requires tremendous amount of computation time. RSA and SA have been for optimization of truss and satellite structures and for comparison of results from two algorithms. Ten bar truss structure which has continuous design variables are optimized.. As a practical application, a satellite structure is optimized by the two algorithms. Weights of satellite upper platform and propulsion module are minimized. MSC/NASTRAN is used for the static and dynamic analysis. The optimization results of the RSA are compared with results of the classical SA. The numbers of optimization iterations could be effectively reduced by the RSA.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.6
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• pp.147-154
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• 2013

To provide a method for optimizing the variation range of the received power is applied to Adaptive Genetic Algorithm in a LED communication environment. By optimizing the power distribution dynamically for mobile or fixed using a genetic algorithm, to eliminate the need for a system design that is customized to be independent of the movement pattern of the user's adaptability, and environmental properties. It is possible to improve easily the convenience of the user. The room power deviation from any location can be reduced by reducing the energy. the simulation results, the proposed method does not exist obstacles in an empty room with power deviation $10.5{\mu}W$ decreased 10 percent to reduce the deviation of the received power is shown that. In comparison with conventional methods, convergence to the optimal value is improved, the genetic algorithm proposed was confirmed to be efficient in terms of energy savings.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.1
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• pp.26-32
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• 2005

In this paper, the effect of various regression models is investigated on structural optimization using the central composite method. Three bar truss and the upper platform of a satellite are optimized using various regression models that are polynomial, exponential and log functions. Response surface method is non-gradient, semi-global, discrete and fast converging in optimization problem. Sampling points are extracted by the design of experiments using the central composite method. Response surface is generated using the various regression functions. Structural analysis for calculating constraints is executed to find static and dynamic responses. From this study, it is verified that the response surface method has advantage in optimum value and computation time in comparison to other optimization methods.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.5
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• pp.477-483
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• 2013

The widlass base frame which is currently used is designed by lots of volume and costs so as to obtain high rigidity in spite of the greatly external load. The purpose of this research is to draw conceptual design of optimal design which can satisfy high rigidity existing windlass base frame has and lessening the body at the same time. Therefore, it progressed conceptual design by applying Topology optimization and Size optimization based on the finite-element analysis for the early model and indicated the result by comparing the early model with optimized model. As the result of Topology optimization, its stress was increased by about 6MPa and weight was decreased by about 560kg in comparison with the early model. In addition, in case of Size optimization, its stress was increased by about 7MPa and weight was decreased by about 1,560kg in comparison with the early model.

• Proceedings of the KIEE Conference
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• 1999.07d
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• pp.1830-1832
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• 1999

고에너지 이온주입(1)에 기인한 격자 손상 발생 및 열처리에 따라 이들의 회복이 어느정도 가능한지에 대하여 측정 및 분석방법을 통하여 조사하였다. 그리고 본 실험에서는 이온주입시 형성되는 빈자리 결함(Vacancy defect)과 격자간 결함(interstitial defect)의 재결할(recombination)을 이용 점결합(point defect)를 감소 시킬 수 있는 effective RTA조건을 설정하여 well 특성을 개선하고자 하였다. 8inch p-type Si(100)기판에 pad oxide 100A을 형성한 후 NMOS 형성하기 위해 vtn${\sim}$p-well과 PMOS 형성을 위해 vtp$\sim$n-well을 이온주입 하였다. Mev damage anneal은 RTA(2)(Rapid Thermal Anneal)로 $1000\sim1150C$ 온도에서 $15\sim60$초간 spilt 하여 실험후 suprem-4 simulation data를 이용하여 실제 SIMS측정 분석결과를 비교하였으며 이온주입에 의해 발생된 격자손상이 열처리후 damage 정도를 알아보기 위해 T.W(Therma-Wave)을 이용하였으며 열처리후 면저항값은 4-point probe를 사용하였다. 이온주입후 열처리 전,후에 따른 불순물 분포를 SIMS(Secondary ion Mass Spectrometry)를 이용하여 살펴보았다. SIMS 결과로는 열처리 온도 및 시간의 증가에 따라서 dopant확산 및 활성화는 큰차이는 보이지 않고 오히려 감소하는 경향을 볼 수 있으며 또한 접합깊이와 농도가 약간 낮아지는 것을 볼 수 있었다. 결점(defect)을 감소시키기 위해서 diffusivity가 빠른 임계온도영역($1150^{\circ}C$-60sec)에서 RTA를 실시하여 dopant확산을 억제하고 점결점(point defect)의 재결합(recombination)을 이용하여 전위 (dislocation)밀도를 감소시켜 이온주입 Damage 및 면저항을 감소 시켰다. 이와 같은 특성을 process simulation(3)(silvaco)을 통하여 비교검토 하였다.

• Convergence Security Journal
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• v.11 no.1
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• pp.11-18
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• 2011

Wireless mesh network technology with transmission speeds similar to wired and wireless technology means to build, compared with wired networks, building a more efficient network to provide convenience and flexibility. The wireless mesh network router nodes in the energy impact of the mobility is less constrained and has fewer features entail. However, the characteristics of various kinds due to network configuration settings and the choice of multiple paths that can occur when the system overhead and there are many details that must be considered. Therefore, according to the characteristics of these network routing technology that is reflected in the design and optimization of the network is worth noting. In this paper, a multi-path setting can be raised in order to respond effectively to the problem of the router node data loss and bandwidth according to traffic conditions and links to elements of the hop count evaluation by using a genetic algorithm as a workaround for dynamic routing the routing metric for wireless mesh network scheme is proposed.

• The KIPS Transactions:PartC
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• v.18C no.3
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• pp.179-186
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• 2011

Wireless Mesh Network technology refers to the technology which establishes wireless network whose transmission speed is similar to that of the wire system, and provides more enhanced flexibility in the building of network, compared to the existing wired network. In addition, it has the feature of less mobility and less restriction from the energy effect. However, there follow many considerations such as system overhead in the case of setting or the selection of multi-path. Accordingly, the focus is on the design and optimization of network which can reflect this network feature and the technology to establish path. This paper suggests the methods on the programming of path in Wireless Mesh Network routing by applying the evaluation value of node service, making use of the loss rate of data, the hop count of bandwidth and link and the traffic status of node, considering the performance of link and load in the fitness evaluation function, in order to respond to the programming of multi-path effectively.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.31-31
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• 2018

본 연구는 내수침수에 의한 침수면적 예측을 위하여 1차원 유출모형의 유출특성을 이용하여 침수면적 예측방법의 최적화이다. 2017년 강우의 초기강우와 첨두강우 특성을 적용한 경우에 정확한 침수면적 추정이 가능한 것을 확인한 바가 있다. 이러한, 결과에 추가적으로 SWMM 모형의 유출결과 자료의 특성인자를 이용하여 침수DB를 선택한 경우에 침수면적 예측 정확도를 분석하였다. 강우지속시간 및 강우량의 변화에 따른 유출결과의 변화를 분석하여 강우특성에 따른 SWMM 모형의 노드별 유출결과의 특성인자 변화를 분석하여 침수DB에서 실제 침수면적 선정방법을 정리하였다. 정리된 방법을 이용하여 유출결과 자료 특성인자를 이용한 최적의 침수DB 선정방법을 돌출하였다. 강우 특성 인자에서 침수DB를 선정하는 방법과 비교하여 강우유출모형의 모의결과를 이용한 경우에 약 6,000여개 노드를 기준으로 5~10분의 모의시간이 추가적으로 소요되어 실시간 침수 DB 선정에는 어렵지만, 준실시간 실제 유출량을 고려한 침수DB 선정이 가능할 것이다. 따라서, 강우특성 도출에 따라 1차적으로 침수DB를 선정하고, 강우유출모형의 유출 특성에 따라서 2차적으로 침수DB를 선정한다면, 예경보 시스템에서 대응시간 확보와 예측 정확도 유지에 긍정적인 방안으로 도입될 수 있을 것이다. 침수DB 구축은 많은 침수면적 산정연구에 이용하였던 TUFLOW 모형을 이용하여 침수DB를 구축하였다. SWMM 모형을 이용하여 강우유출을 모의하고, 침수면적을 TUFLOW를 이용하여 구축한 다양한 호우사상에 대한 침수DB를 이용하여 준실시간 침수면적 예측하는 방법은 향후, 예경보 시스템 구축에 이바지 할 수 있을 것입니다.