http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
방향성 정수 변환을 이용한 비디오 압축 효율 개선 알고리즘
김동형(Donghyung Kim),정세윤(Seyoon Jeong),정원식(Won-Sik Cheong),최진수(Jin-Soo Choi),문경애(Kyung-Ae Moon),홍진우(Jinwoo Hong) 대한전자공학회 2007 대한전자공학회 학술대회 Vol.2007 No.11
H.264 standard adapts new coding tools such as 1/4-pel accuracy motion estimation, 4×4 integer transform, and intra prediction in spatial domain. In this paper, the directional reordering method for integer transform is proposed. Simulation results show that the proposed method is potentially able to improve coding efficiency.
로봇형 차량의 경로 추종 및 장애물 회피를 위한 운동 계획에 관한 연구
김동형(Donghyung Kim),김창준(Changjun Kim),김상호(Sangho Kim),최주영(Jooyoung Choi),한창수(Changsoo Han) 한국자동차공학회 2010 한국자동차공학회 학술대회 및 전시회 Vol.2010 No.11
This paper presents the motion planning of robotic vehicles for the path tracking and the obstacle avoidance. To follow the given path, the vehicle moves through the turning radius obtained through the pure pursuit method, which is a geometric path tracking method. In this paper, we assume that the vehicle is equipped with a range scanner, allowing it to avoid obstacles within its sensing range. The turning radius for avoiding the obstacle, which is inversely proportional to the virtual force, is then calculated. Therefore, these two kinds of the turning radius are used to generate the steering angle for the front wheel of the vehicle. And the vehicle reduces the velocity when it meets the obstlace or the large steering angle using the potentials of obstacle points and the steering angle. Thus the motion planning of the vehicle is done by planning the steering angle for the front wheels and the velocity. Finally, the performance of the proposed method is tested through simulation.
자율주행 차량의 경유점 추종을 위한 통합된 궤적 계획기 및 제어기에 관한 연구
김동형(Donghyung Kim),김창준(Changjun Kim),김상호(Sangho Kim),최주영(Jooyoung Choi),최민석,한창수(Changsoo Han) 한국자동차공학회 2011 한국자동차공학회 부문종합 학술대회 Vol.2011 No.5
This paper presents the integrated trajectory planner and controller for the waypoint tracking of autonomous vehicles. In the case of that there are no driving lanes, the trajectory should be planned for the vehicle. However, because of the nonholonomic constraint which renders the motion orthogonal to the vehicle’s forward direction is impossible, the trajectory planning and the control problems are becoming complicated. To solve these problems, the trajectory planning and control are integrated using the flatness property of the kinematic model of the vehicle. And with the given waypoints, the waypoint tracking algorithm is proposed to plan the trajectory for the next waypoint. Therefore the vehicle follows the waypoints in order. Finally, the performance of the proposed method is tested through simulation.
PIV 기법을 이용한 손톱건조기 내부 이온풍 주변 유동 가시화 및 열원의 열전달에 대한 연구
김동형(Dong Hyeong Kim),오승민(Seung Min Oh),유환민(Hwan Min Yoo),추지훈(Ji Hoon Choo),고한서(Han Seo Ko) 대한기계학회 2018 대한기계학회 춘추학술대회 Vol.2018 No.12
In this study, the heat transfer efficiency was improved inside a nail dryer by utilizing the ionic wind generated by the release of corona discharge. First, the flow field of the ionic wind according to various conditions was obtained by the flow visualization using a PIV (Particle image velocimetry) method. With these results, the boundary conditions of a CFD(Computational fluid dynamics) could be imported and velocity profiles induced by the boundary layer were identified. The heat transfer experiments were also carried out, and the reliability was validated by comparing the results of the experiment with the numerical analysis. As a results, the high voltage could induce the high flow rate of the ionic wind and the great heat transfer efficiency which could be expressed by the Nusselt number.
축소 모델 차량을 통한 자율 주행 차량의 경로 추종 및 장애물 회피 기법에 관한 연구
김동형(Donghyung Kim),김창준(Changjun Kim),김영렬(Youngryul Kim),한창수(Changsoo Han) 한국자동차공학회 2010 한국자동차공학회 부문종합 학술대회 Vol.2010 No.5
This paper presents a method that integrates the geometric path tracking and the obstacle avoidance for autonomous ground vehicle (AGV). AGV follows the path by moving through the turning radius given from the pure pursuit method which is the one of the geometric path tracking methods. As the AGV equipped with 2D laser scanner, the obstacle within the sensing range of 2D laser scanner, the virtual force is obtained. Therefore, the turning radius for avoiding the obstacle is calculated by inversely proportional to the virtual force. By integrating the turning radius for avoiding the obstacle and the turning radius for following the path, AGV follows the path and avoids the obstacle simultaneously. The effectiveness of the proposed method is verified through the real experiments using a scale-down vehicle.
최적 타이어 힘 분배 방법을 통한 전기차의 독립 6WD/6WS에 관한 연구
김동형(Dong-Hyung Kim),김창준(Chang-Jun Kim),김영렬(Young-Ryul Kim),한창수(Chang-Soo Han) 제어로봇시스템학회 2010 제어·로봇·시스템학회 논문지 Vol.16 No.7
This paper presents an optimum tire force distribution method for 6WD/6WS(6-Wheel-Drive and 6-Wheel-Steering) electric vehicles. Using an independent steering and driving system, the performance of 6WD/6WS vehicles can be improved, as, for example, with respect to their maneuverability under low speed and their stability at high speed. Therefore, there should be a control strategy for finding the optimum tire forces that satisfy the driver’s command and minimize energy consumption. From the driver’s commands (steering angle and accelerator/brake pedal stroke), the desired yaw moment, the desired lateral force, and the desired longitudinal force were obtained. These three values were distributed to each wheel as the torque and the steering angle, based on the optimum tire force distribution method. The optimum tire force distribution method finds the longitudinal/lateral tire forces of each wheel that minimize the cost function, which is the sum of the normalized tire forces. Next, the longitudinal/lateral tire forces of each wheel are converted into the reference torque inputs and the steering wheel angle inputs. The proposed method was tested through a simulation, and its effectiveness was verified.
로봇형 차량의 자율주행을 위한 센서 기반 운동 계획법 개발
김동형(Dong-Hyung Kim),김창준(Chang-Jun Kim),이지영(Ji-Yeong Lee),한창수(Chang-Soo Han) 제어로봇시스템학회 2011 제어·로봇·시스템학회 논문지 Vol.17 No.6
This paper presents the motion planning of robotic vehicles for the path tracking and the obstacle avoidance. To follow the given path, the vehicle moves through the turning radius obtained through the pure pursuit method, which is a geometric path tracking method. In this paper, we assume that the vehicle is equipped with a 2D laser scanner, allowing it to avoid obstacles within its sensing range. The turning radius for avoiding the obstacle, which is inversely proportional to the virtual force, is then calculated. Therefore, these two kinds of the turning radius are used to generate the steering angle for the front wheel of the vehicle. And the vehicle reduces the velocity when it meets the obstacle or the large steering angle using the potentials of obstacle points and the steering angle. Thus the motion planning of the vehicle is done by planning the steering angle for the front wheels and the velocity. Finally, the performance of the proposed method is tested through simulation.
무선 네트워크 환경에서 H.264 부호화된 영상을 전송하기 위한 시스템 설계 및 구현
김동형(Dong-Hyoung Kim),권순각(Soon-Kak Kwon),이종민(Jong-Min Lee),빈기철(Ki-Cheol Bin) 한국멀티미디어학회 2007 한국멀티미디어학회 학술발표논문집 Vol.2007 No.1
광대역통신망의 급속한 발전과 보급은 고화질 영상의 새로운 컨텐츠 시대를 열어가고 있다. 최신 동영상 압축부호화 기술 국제표준인 H.264기법은 높은 압축률 덕택에 방송, 통신을 비롯해 디지털가전, 게임에 이르기 까지 입계로부터 폭넓은 주목을 받고 있다. 본 논문에서는 H.264 영상 압축기술을 이용하여 PC 카메라로 부터 받은 영상을 실시간으로 압축하여 상대방 PDA기기로 전송하는 실시간 1:1영상전송 기능을 제공한다. 이 시스템을 이용하여 사용자는 PDA익 무선랜을 이용하여 언제 어디서나 원하는 상대방과 영상통신이 가능 해진다.
Adaptive RRT 를 사용한 고 자유도 다물체 로봇 시스템의 효율적인 경로계획
김동형(Dong-Hyung Kim),최윤성(Youn-Sung Choi),염서군(Rui-Jun Yan),라로평(Lu-Ping Luo),이지영(Ji Yeong Lee),한창수(Chang-Soo Han) 제어로봇시스템학회 2015 제어·로봇·시스템학회 논문지 Vol.21 No.3
This paper proposes an adaptive RRT (Rapidly-exploring Random Tree) for path planning of high DOF multibody robotic system. For an efficient path planning in high-dimensional configuration space, the proposed algorithm adaptively selects the robot bodies depending on the complexity of path planning. Then, the RRT grows only using the DOFs corresponding with the selected bodies. Since the RRT is extended in the configuration space with adaptive dimensionality, the RRT can grow in the lower dimensional configuration space. Thus the adaptive RRT method executes a faster path planning and smaller DOF for a robot. We implement our algorithm for path planning of 19 DOF robot, AMIRO. The results from our simulations show that the adaptive RRTbased path planner is more efficient than the basic RRT-based path planner.
조대술 후 구강내 접근술을 통한 거대 법랑모세포종의 치험례 : 증례보고
김동형,조성웅,서동원,강지연,심재환,이동근,김상중,Kim, Dong-Hyung,Cho, Sung-Woong,Seo, Dong-Won,Kang, Ji-Yeon,Sim, Jae-Hwan,Lee, Dong-Keun,Kim, Sang-Jung 대한구강악안면외과학회 2008 대한구강악안면외과학회지 Vol.34 No.2
Ameloblastoma is the most frequently accuring odontogenic tumor in mouth. The biologic behavior of this neoplasm is locally invasive tumor with a high rate of recurrence. But in case of unicystic ameloblastoma, it was known that the neoplasm can be treated by marsupialization and the recurrence rate is lower. In our clinic, we tried to treat one of ameloblastoma cases by marsupialization and finished the treatment by enucleation via intra-oral approach with sagittal ramus osteotomy. This is a report of that case about 29 years old female patient.