• 융합신호처리학회 학술대회논문집
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• 한국신호처리시스템학회 2001년도 하계 학술대회 논문집(KISPS SUMMER CONFERENCE 2001
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• pp.33-36
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• 2001

MC-CDMA시스템에서는 송신 데이터열을 병렬 서브캐리어로 전송하기 때문에 DS-CDMA에 비하여 심볼 길이가 길다. 이러한 긴 길이의 심볼은 무선채널의 지연확산의 효과를 감소시킬 수 있지만, 시간선택적 페이딩의 영향을 더 많이 받게 한다. 즉, 주파수선택적 페이딩에 대하여는 강인하게 되지만, 단말기가 이동하는 경우 도플러 확산의 영향을 더 받기 쉬워 진다는 문제점이 있다. 본 논문에서는 MC-CDMA 시스템에서 단말기가 이동하는 경우 채널이 보이는 시간선택적 페이딩의 효과를 MC-CDMA 수신기의 결합기 출력에서 원하는 신호전력대 서브캐리어간 간섭전력의 비 관점에서 분석한다.

• 한국산업융합학회 논문집
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• 제19권2호
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• pp.75-80
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• 2016

This study proposes a efficient technology to control the optimal trajectory planning and real-time implementation method which can perform autonomous travelling for unmaned factory automation. Online path planning should plan and execute alternately in a short time, and hence it enables the robot avoid unknown dynamic obstacles which suddenly appear on robot's path. Based on Route planning and control algorithm, we suggested representation of edge cost, heuristic function, and priority queue management, to make a modified Route planning algorithm. Performance of the proposed algorithm is verified by simulation test.

• International journal of advanced smart convergence
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• 제7권3호
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• pp.8-14
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• 2018

In the field of surveillance cameras, it is possible to increase the people detection accuracy by using depth information indicating the distance between the camera and the object. In general, depth information is obtained by calculating the parallax information of the stereo camera. However, this method is difficult to operate in real time in the embedded environment due to the large amount of computation. Jetson TX2, released by NVIDIA in March 2017, is a high-performance embedded board with a GPU that enables parallel processing using the GPU. In this paper, a stereo camera is installed in Jetson TX2 to acquire depth information in real time, and we proposed a people counting method using acquired depth information. Experimental results show that the proposed method had a counting accuracy of 98.6% and operating in real time.

• Journal of electromagnetic engineering and science
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• 제11권1호
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• pp.11-15
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• 2011

Preserving high-order accuracy in high-order FDTD solutions across dielectric interfaces is very important for practical time-domain electromagnetic simulations. This paper presents a fourth-order accurate numerical boundary scheme for the planar dielectric interface to be used in the fourth-order FDTD method proposed earlier by the author. The interface scheme for the two-dimensional (2-D) transverse magnetic (TM) polarization case is derived and validated by monitoring the $L_2$ norm errors in the numerical solutions of a partially-filled cavity demonstrating its fourth-order convergence and long-time numerical stability in the presence of the planar dielectric interface.

• 융합보안논문지
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• 제13권1호
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• pp.3-10
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• 2013

본 연구에서는 소프트웨어 제품 테스팅 과정에서 관측고장시간에 근거한 결함 발생률을 고려한 소프트웨어 신뢰성 모형에 대하여 연구 하였다. 신뢰성 분야에서 많이 사용되는 S-분포모형을 이용한 새로운 결함 확률을 추가한 문제를 제시하였다. 수명분포는 유한고장 비동질적인 포아송과정을 이용하였다 본 논문의 결함 발생률을 고려한 소프트웨어 고장 자료 분석에서는 고장 시간 자료를 적용하였으며 모수추정 방법은 최우추정법을 이용하여 결함 발생 확률에 대한 관계와 신뢰도를 추정 하였다.

• 한국게임학회 논문지
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• 제18권5호
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• pp.15-22
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• 2018

현재 많은 증강현실 콘텐츠가 존재하지만 두 개 이상의 단말기가 실시간으로 통신하며 동시에 이용하는 증강현실 콘텐츠는 거의 상용화되지 않았다. 본 논문에서는 블루투스 통신을 이용하여 네트워크 증강현실 콘텐츠의 가능성에 대해 연구하려 한다. 이 연구를 통해 네트워크 증강현실 개발과 콘텐츠의 종류를 한층 더 넓힐 수 있을 것이다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1993년도 하계학술대회 논문집 A
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• pp.348-351
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• 1993

The simulated annealing(SA) algorithm is a stochastic strategy for search of the ground state and a powerful tool for optimization. based on the anneal ins process used for the crystallization in physical systems. It's main disadvantage is the long convergence time. Therefore, this paper shows that the new algorithm using SA can be applied to reduce the computation time. This idea has been used to solve the estimation problem of the nonlinear parameter.

• 한국군사과학기술학회지
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• 제9권2호
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• pp.152-160
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• 2006

Time marching methods are well-suited for high speed compressible flow computations. However, it is well known that the time marching methods suffer a slow down in convergence due to disparity in Eigenvalues. A local preconditioning method is one of numerical methods to enhance convergence characteristics of low mach number flows by modifying Eigenvalues of the governing equations. In this paper, the local preconditioning method of Weiss is applied to a 2 dimensional Navier-Stokes code and the efficiency of the preconditioning method is shown through a number of computational examples.

• 융합신호처리학회논문지
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• 제12권1호
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• pp.44-49
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• 2011

The need of data transmission in oceans and other underwater mediums are increasing day by day, so as the research. The underwater medium is very different from that of air. Propagation of electromagnetic wave in water or underground is very difficult because of the conductivity of the propagation materials. In this case, we usually use acoustic signals as ultrasonic but, they are not easy to transfer long distance with coherent method because of time varying multipaths, Doppler effects and attenuations. So, we use non-coherent methods such as FSK or ASK to communicate between long distances. But, as the propagation speed of acoustic wave is very slow, BW of the channel is narrow. It is very hard to guaranty the enough speed for the transmission of digital image data. In previous studies, we proposed this data communication protocol theoretically. In this paper, an underwater channel is modeled and this protocol is tested in this channel condition. The results show that the protocol is 4-6 times faster than ASK. Some relations and results are shown depending on the data length, channel length, bit rate etc.

• 한국산업융합학회 논문집
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• 제23권2_1호
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• pp.149-161
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• 2020

We describe a new approach to implement of trajectory control and track record of articulated manipulator based on monitoring simulator for smart factory. The learning control algorithm was applied in implementation real-time control to provide enhanced motion control performance for robotic manipulators. The proposed control scheme is simple in structure, fast in computation, and suitable for real-time control. Moreover, this scheme does not require any accurate dynamic modeling, or values of manipulator parameters and payload. Performance of the proposed controller is illustrated by simulation and experimental results for robot manipulator consisting of six joints at the joint space and Cartesian space.by monitoring simulator.