• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.256-256
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• 2000

In this parer, we present a real-time path planning algorithm which is integrated the artificial potential field(APF) and simulated annealing(SA) methods for mobile robot. The APF method in path planning has gained popularity since 1990's. It doesn't need the modeling of the complex configuration space of robot, and is easy to apply the path planning with simple computation. However, there is a major problem with APF method. It is the formation of local minima that can trap the robot before reaching its goal. So, to provide local minima recovery, we apply the SA method. The effectiveness of the proposed algorithm is verified through simulation.

• 한국소음진동공학회논문집
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• 제20권11호
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• pp.1071-1077
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• 2010

The reduction of the vehicle interior noise has been the main interest of noise and vibration harshness(NVH) engineers. A passenger vehicle has various and complicated transmission paths of sound and vibration. In order to identify the mechanism of transfer path, estimation of excitation force and exact modeling of transfer path are required. This paper presents method for estimating the noise source contribution on the road noise of the vehicle in a multiple input system where the input sources may be coherent with each other. And vector synthesis technique is employed to identify the characteristics of road noise and its transmission to vehicle compartment through noise and vibration analysis. Vibration reduction efficiency of each transfer path is evaluated by comparing individual vector components obtained virtual simulation.

• 반도체디스플레이기술학회지
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• 제10권4호
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• pp.21-23
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• 2011

Uniformity of plasma etching processes critically depends on the wafer temperature and its distribution. The wafer temperature is affected by plasma, chucking force, He back side pressure and the surface temperature of ESC(electrostatic chuck). In this work, 3D mathematical modeling is used to investigate the influence of the geometry of coolant path and the temperature distribution of the ESC surface. The model that has the coolant path with less change of the cross-sectional area and the curvature shows low standard deviation of the ESC surface temperature distribution than the model with the coolant path of the larger surface area and more geometric change.

• 한국군사과학기술학회지
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• 제11권4호
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• pp.141-148
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• 2008

In this paper, we develop a detailed full dynamic model which includes various rough terrains for 6-wheel skid-steering mobile robot based on the real experimental autonomous vehicle called Dog-Horse Robot. We also design a co-simulation for performance comparison of path tracking algorithms. The control architecture in the co-simulation can be divided into two levels. The high level control is the closed-loop control of path tracking to follow a given path, and the low level is concerned about torque control of wheel motion. The simulation using the mechanical data of the Dog-Horse Robot is performed under the Matlab/Simulink environment. We also simulate and evaluate the performance of the model based adaptive controller.

• International journal of advanced smart convergence
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• 제12권3호
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• pp.13-18
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• 2023

This paper aims to investigate data features for neighbor path selection (NPS) in computer network with regional failures. It is necessary to find an available alternate communication path in advance when regional failures due to earthquakes or forest fires occur simultaneously. We describe previous general heuristics and simulation heuristic to solve the NPS problem in the regional fault network. The data features of general heuristics using proximity and sharing factor and the data features of simulation heuristic using machine learning are explained through examples. Simulation heuristic may be better than general heuristics in terms of communication success. However, additional data features are necessary in order to apply the simulation heuristic to the real environment. We propose novel data features for NPS in computer network with regional failures and Keras modeling for computing the communication success probability of candidate neighbor path.

• 경영정보학연구
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• 제16권3호
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• pp.89-112
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• 2014

본 튜토리얼은 PLS 경로분석 수행을 지원하는 R 패키지인 "plspm"을 이용하여 구조방정식모형을 분석하는 방법을 제시하고 있다. 본 튜토리얼에서는 이를 위해 기존 연구들에서 제시하고 있는 PLS구조방정식모형을 분석하기 위한 기준들을 정의하고, 하나의 예시 연구모형을 제시하여 실질적으로 R을 이용하여 이 예시 모형을 분석하는 것을 보여준다. 본 튜토리얼은 PLS를 처음 접하는 연구자들에게는 연구모형에 대한 실증분석을 위한 유용한 가이드가 될 것이며, 이미 PLS에 익숙한 연구자들에게는 R을 이용한 새로운 PLS 구조방정식모형 분석기법 제시를 통하여 R이라는 통합된 통계 소프트웨어 운영환경에서 심도 있는 분석을 위한 기반 지식을 제공할 것이다.

• 한국항공운항학회지
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• 제24권1호
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• pp.1-9
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• 2016

In this paper, we integrate three degree of freedom(3DOF) point-mass model for aircraft and three-dimensional path generation algorithms using dubins curve and nonlinear path tracking law. Through this integration, we apply the path generation algorithm to the path planning, and verify tracking performance and feasibility of using the aircraft 3DOF point-mass model for air traffic management. The accuracy of modeling 6DOF aircraft is more accurate than that of 3DOF model, but the complexity of the calculation would be raised, in turn the rate of computation is more likely to be slow due to the increase of degree of freedom. These obstacles make the 6DOF model difficult to be applied to simulation requiring real-time path planning. Therefore, the 3DOF point-mass model is also sufficient for simulation, and real-time path planning is possible because complexity can be reduced, compared to those of the 6DOF. Dubins curve used for generating the optimal path has advantage of being directly available to apply path planning. However, we use the algorithm which extends 2D path to 3D path since dubins curve handles the two dimensional path problems. Control law for the path tracking uses the nonlinear path tracking laws. Then we present these concomitant simulation results.

• 한국컴퓨터정보학회논문지
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• 제13권5호
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• pp.179-186
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• 2008

무선 센서 네트워크의 응용범위가 늘어남에 따라 정확한 무선 채널의 정보를 필요로 한다. 실내 또는 실외의 무선 센서 네트워크의 경우 페이딩에 의한 다중 경로 전파가 문제를 일으키고 있다. 본 논문에서는 실내 2.4 GHz 채널에 대한 log-normal path loss 모델링을 살펴본다. 송신기와 수신기 사이의 거리를 1에서 30m까지 변화시키면서 수신 신호 강도 변화를 측정하고, 채널의 감쇄지수와 표준편차를 계산하였다. 계산한 모델의 패킷 수신율을 이용하여 무선 센서 채널을 연결 영역과 차단 영역으로 정의하고, 시뮬레이션과 실험 결과를 통해서 무선 채널의 특징을 비교하였다. 실험결과 실내에서의 연결 영역은 24m, 실외에서의 연결 영역은 14m로 측정되었다.

• 제어로봇시스템학회논문지
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• 제17권6호
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• pp.531-538
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• 2011

This paper describes a novel sensor system for 3D world modeling of an autonomous vehicle in large-scale outdoor environments. When an autonomous vehicle performs path planning and path following, well-constructed 3D world model of target environment is very important for analyze the environment and track the determined path. To generate well-construct 3D world model, we develop a novel sensor system. The proposed novel sensor system consists of two 2D laser scanners, two single cameras, a DGPS (Differential Global Positioning System) and an IMU (Inertial Measurement System). We verify the effectiveness of the proposed sensor system through experiment in large-scale outdoor environment.

• 디지털융복합연구
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• 제13권7호
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• pp.99-107
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• 2015

새로운 정보기술이 등장할 때마다 연구자와 실무자는 이 기술을 어떻게 보급할 것인가에 대해서 탐구하고 있다. e-커머스 분야에서 소셜 커머스는 최근에 나타나 현상으로, 소셜 커머스 현상을 이해하려는 많은 연구가 다양한 연구모형을 제시하고 있다. 이 연구는 기술준비도(TR), 기술수용모형(TAM), 계획된 행동 이론(TPB)를 통합한 연구모형을 제시하였다. PLS 경로모형분석을 통한 분석결과, TPB의 주관적 규범-의도 경로를 제외한 모든 가설적 경로가 유의한 것으로 밝혀졌다. 이러한 결과는 소셜 커머스 뿐만 아니라 새로운 정보기술의 수용을 이해하는데 통합모형이 유용하다는 사실을 말해준다. 마지막으로 이 연구는 미래 연구를 위한 함의와 제안을 제시하였다.