• 한국멀티미디어학회논문지
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• 제12권9호
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• pp.1333-1341
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• 2009

컴퓨터 게임에서 전술적 경로 찾기란 캐릭터의 이동 경로를 결정할 때, 최단 거리나 최소 시간 등의 요소만이 아니라 주변의 전술 정보를 고려하여 경로를 선택해야 하는 경로 찾기를 말한다. 경로 찾기에 전술 정보를 포함하는 한 가지 방법은 게임에 필요한 전술 정보를 각 정보의 중요도에 따라 가중치를 부여하고 가중 합으로 휴리스틱 함수를 표현하는 것이다. 전술 정보의 가중치의 결정은 경로를 찾기 위한 탐색의 성능과 구해지는 경로의 특성을 결정짓기 때문에 매우 중요하다. 본 논문에서는 레벨 설계자가 캐릭터의 특성에 맞는 경로 표본을 제공하면 현재 가중치에 의해 탐색된 경로와 주어진 표본 경로와의 차이를 이용하여 더 나은 가중치로 조정함으로서 휴리스틱 함수를 개선하는 방법을 제안한다. 제안된 방법은 탐색 오차를 발견하여 휴리스틱을 학습하기 위해 수정된 탐색 알고리즘과 퍼셉트론-유사 가중치 갱신 공식을 포함한다. 시뮬레이션 결과를 통해 전술 정보를 이용한 경로 계획과 기존의 경로 찾기의 차이를 보여주며 학습의 성능에 영향을 주는 요인들에 대해 분석하고 실제 게임 환경에 적용한 예를 보여 준다.

• 벤처혁신연구
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• 제5권2호
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• pp.85-99
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• 2022

시판되고 있는 실험용 및 산업용 건조기는 일반 드라이오븐, 열풍 순환 건조기, 진공건조기, 동결건조기 등으로 구분되고 기능, 크기 및 용량 등에 따라 그 종류도 다양하다. 그러나 제품의 품질 제어 및 성능 개선을 위해 중요한 요소인 수분측정이 적용되지 않아 현재는 건조 종료 후 임의로 중량을 칭량하기 때문에 매우 수동적이다. 일반적으로 수분을 측정하기 위한 방법은 직접적인 측정법과 간접적인 측정법으로 구분되고 수분 분리 전.후의 질량 또는 부피 변화와 같은 직접적인 측정법이 주로 이용된다. 상대적으로 열전도도, 마이크로파 등과 같은 간접적인 측정법은 측정 장비를 활용하기 때문에 적용이 제한적이다. 본 연구에서는 오픈소스 기반의 아두이노를 이용하여 비교적 손쉽게 수분측정 시스템을 설계하여 외부 환경요인에 영향 받지 않고 수분 변화량 및 무게 변화를 실시간으로 모니터링 하였다. 구체적으로 수분 민감도 물질 및 식품 건조에 적합한 60℃와 80℃에서 작동할 수 있는 온.습도 및 로드셀 측정 센서를 건조기 내부에 패키징하여 각종 변화량을 측정하였다. 또한 바나나, 배, 톱밥의 유기 시료를 이용한 반복적인 실험을 통해서도 건조시간 및 온도에 따른 증발율 변화와 로드셀 측정값에 있어 안정적인 응답특성을 나타냄으로써 성능 안전성을 확보할 수 있었다. 향후 온.습도 범위의 확대와 CFD(Computational Fluid Dynamics) 프로그램과의 비교 분석을 통해 신뢰도를 더욱 향상시킬 수 있을 것으로 판단된다.

• 한국발생생물학회지:발생과생식
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• 제15권4호
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• pp.373-383
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• 2011

성 호르몬과 유사한 기능을 하는 것으로 알려진 내분비교란물질은 흰쥐 흉선세포에 세포자연사를 일으켜 흉선의 기능을 감소시키는 것으로 보고되고 있으나, 그 작용 기전에 대해서는 잘 알려져 있지 않다. 따라서 본 연구에서는 내분비 교란물질 중 하나인 Tributyltin(TBT)를 흰쥐에 투여한 후 흉선의 상피세포가 지방세포로 분화되는지를 조사하고, 이로 인한 T 세포의 세포자연사와 연관성을 조사함으로써 TBT가 흉선기능에 미치는 영향을 알아보고자 하였다. 3주령 된 암컷 흰쥐에 각각 TBT 1, 10, 25 mg/kg/day를 1주일 동안 경구 투여한 후, 흉선을 획득하여 무게와 세포 수를 측정하였고, 파라핀 절편으로 H&E 염색, TUNEL 분석을 수행하였다. 또한 real-time PCR 방법으로 상피세포 표지 유전자들, 지방세포유도 유전자들과 세포자연사 관련 유전자들을 비교 분석하였으며, 유세포 분석기를 통해 세포자연사 정도를 조사하였다. 흉선의 무게와 세포 수는 대조군과 비교하여 TBT의 농도가 높을수록 유의하게 감소하였다. H&E 염색 결과, TBT의 농도가 증가할수록 흉선의 크기가 감소하고 피질과 수질의 경계가 흐려짐을 관찰하였다. TUNEL 염색 결과에서는 대조군에 비해 TBT를 투여한 군에서 세포자연사가 증가하였으며, 유세포 분석결과에서도 TBT 농도 의존적으로 세포자연사가 증가하였다. Real-time PCR 결과, 상피세포 표지 유전자인 EVA, IL-7, AIRE, KGF는 TBT의 농도가 증가할수록 발현양이 유의하게 감소한 반면, 지방세포 유도와 관련된 유전자인 $PPAR{\gamma}$, aP2, PEPCK, CD36은 TBT의 농도가 증가할수록 발현양이 유의하게 증가하였다. 세포자연사와 관련된 유전자인 $TNF{\alpha}$, TNFR1도 TBT의 농도가 증가할수록 발현양이 유의하게 증가하였다. 위의 결과를 종합하여 볼 때, 내분비교란물질인 TBT는 흉선 상피세포에 직접적으로 작용하여 지방세포로 분화 유도시킴으로써 흉선의 기능을 상실케 만들면서 T 세포의 발달에 영향을 미치는 것으로 보인다. 이러한 결과는 지속적으로 노출되는 TBT가 흉선의 기능을 떨어뜨림으로써 면역력 저하를 유발시킬 수 있음을 제시하고 있다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 춘계학술대회
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• pp.89-92
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• 2007

The metallic bipolar plate in PEMFC is widely used for automotive driving because of its advantages, i) high strength, ii) high chemical stability, iii) low gas permeability and iv) applicability to mass production. Especially, the metallic bipolar plate which is manufactured with the sheet metal stamping process can be applied in automotive PEMFC with less volume and weight because of its thin thickness but the formability and springback problems arise in real manufacturing process. The assessment for formability and springback of metallic bipolar plate should be performed before making stamping die sets. In this work, the methodology for determining the allowable draft angle of flow passage is introduced by using finite element analysis. In analysis results, as the draft angle of flow passage increase, the major strain and thinning is increase with exponential function. The allowable draft angle without fracture is presented by fitting the results. Additionally, the staking results with manufactured metallic bipolar plates by stamping process is presented.

• 대한안전경영과학회지
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• 제20권2호
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• pp.1-8
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• 2018

This study aims to provide a real-time information to the driver by effectively operating the advanced safety device attached to the freight vehicle, thereby minimizing insecure behavior of the driver such as speeding, rapid acceleration, sudden braking, And improve driving habits to prevent accidents and save energy. Advanced safety equipment is a device that warns the driver that the vehicle leaves the driving lane regardless of the intention of the driver and reduces the risk of traffic accidents by mitigating or avoiding collision by detecting a frontal collision during driving.The main contents of this report are as follows: In case of installing a warning device on a lane departing vehicle (excluding a light vehicle) and a lorry or special vehicle with a total weight exceeding 3.5 tonnes, the driver must continue to operate unless the driver releases the function.In addition, when the automatic emergency braking system is installed, the structure should be such that the braking device is operated automatically after warning the driver when the risk of collision with the running or stopped vehicle in the same direction is detected in front of the driving lane.

• 전자공학회논문지SC
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• 제37권2호
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• pp.16-28
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• 2000

In this paper, we propose a navigation algorithm for a mobile robot, which is intelligently searching the goal location in unknown dynamic environments using an ultrasonic sensor. Instead of using "sensor fusion"method which generates the trajectory of a robot based upon the environment model and sensory data, "command fusion"method is used to govern the robot motions. The major factors for robot navigation are represented as a cost function. Using the data of the robot states and the environment, the weight value of each factor is determined for an optimal trajectory in dynamic environments. For the evaluation of the proposed algorithm, we peformed simulations in PC as well as real experiments with ZIRO. The results show that the proposed algorithm is apt to identify obstacles in unknown environments to guide the robot to the goal location safely.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
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• pp.612-615
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• 2007

Water quality modelling is an ideal tool of simulating physical, chemical and biological changes occurring in water systems. It has been utilized in a number of GIS-based water quality management and analysis applications. However, there is a need of a decision making process to translate the modelling result into an understandable form thereby implement the modelling results to the real world. This paper outlines a new water quality index called the QUAL2E's water quality index (QWQI) based on the water quality modelling using QUAL2E. The development mainly includes four steps: variable selection, sub-index development, weight assignment and sub-index aggregation. An experiment of applying the index and GIS to the Sapgyo River in Korea was implemented. Different from other water quality indices for general water uses, the index is specifically used for the simulated water quality indicators. The index can provide a simple and easy-to-understand decision support. Furthermore, interfacing with GIS, the decision analysis can be performed within a spatial environment. However, more study needs to be made in the future including the improvement of aggregation function.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1998년도 봄 학술발표회 논문집
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• pp.262-271
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• 1998

Recent, more and more steel deck bridges are adopted for the design of long span bridges and the upgrading of existing concrete deck bridges, mainly because of reduced self weight, higher stiffness and efficient erection compared to concrete decks. The main objective of this study is to propose on formulation of the design optimizations to develop an optimal desist program required for optimum desist for orthotropic steel-deck bridges. The objective function of the optimization is formulated as a minimum initial cost design problem. The behavior and design constraints are formulated based on the ASD and LRFD criteria of the Korean Bridge Design Code(1996). The optimum design program developed in this study consists of two steps. In the first step the system optimization of the steel box girder bridges is carried out. And in the second step the program provided the optimum design of the orthotropic steel-deck with close ribs. In the optimal design program the analysis module for the deck optimization is based on the Pelican Esslinger method. The optimizer module of the program utilizes the ADS(Automated Desist Synthesis) routines using the optimization techniques fuor constrained optimization. From the results of real application examples, The cost effectiveness of optimum orthotropic steel-deck bridges designs based on both ASD and LRFD methods is investigated by comparing the results with those of conventional designs, and it may be concluded that the design developed in this study seems efficient and robust for the optimization of orthotropic steel-deck bridges

• 대한간호학회지
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• 제24권2호
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• pp.216-225
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• 1994

The cost of hospice care should be covered by the insurance system if it is to be promoted in our country and this, in turn, requires a proper method to the estimate of this cost. The purpose of this study was to set up the method to estimate the cost of hospice care. First the cost effectiveness of hospice care were studied. By tracing the activities of hospice nurses for a given period, all the relevant data such as the scope and load of activities as well as the cost were collected. Then these were analysed and compared with the data obtained from hospice and home care. The results showed that the cost of hospice care was the most economic, and indicate its qualification as .1n in-dependent system. The main part of the cost of hospice care was found to be the labor cost which was up to 83% of the total. Therefore a method to estimate the cost should reflect the real labor cost. Several methods have been proposed in the study in terms of unit labor cost, service time, material cost, and the weight of the labor cost. All variables, including the service time surveyed in this study, can easily be translated into numerical values and it would not difficult to estmate the cost of hospice care. Hence by letting the hospice care be insured, hospice care can be expected to function as a good alternative to the present medical system.

• Journal of Communications and Networks
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• 제18권3호
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• pp.411-419
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• 2016

This article investigates the problem of distributed channel selection in opportunistic spectrum access networks from a perspective of interference minimization. The traditional physical (PHY)-layer interference model is for information theoretic analysis. When practical multiple access mechanisms are considered, the recently developed binary medium access control (MAC)-layer interference model in the previous work is more useful, in which the experienced interference of a user is defined as the number of competing users. However, the binary model is not accurate in mathematics analysis with poor achievable performance. Therefore, we propose a real-valued one called stochastic MAC-layer interference model, where the utility of a player is defined as a function of the aggregate weight of the stochastic interference of competing neighbors. Then, the distributed channel selection problem in the stochastic MAC-layer interference model is formulated as a weighted stochastic MAC-layer interference minimization game and we proved that the game is an exact potential game which exists one pure strategy Nash equilibrium point at least. By using the proposed stochastic learning-automata based uncoupled algorithm with heterogeneous learning parameter (SLA-H), we can achieve suboptimal convergence averagely and this result can be verified in the simulation. Moreover, the simulated results also prove that the proposed stochastic model can achieve higher throughput performance and faster convergence behavior than the binary one.