• Journal of the Korea Computer Graphics Society
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• v.5 no.1
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• pp.11-17
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• 1999

This paper proposes example guided inverse kinematics (EGIK) which extends and enhances existing inverse kinematics technique. In conventional inverse kinematics, redundancy in the model produces an infinite number of solutions. The motion could be jerky depending on the choice of solutions at each frame. EGIK exploits the redundancy for imitating an example motion (a premeasured motion data) so that a unique solution is chosen. To minimize the gap between the goal and current end-effector position and imitate the original motion at the same time, nonlinear optimization technique is employed. So, the resulting motion resembles the original one in an optimal sense. Experiments prove that the method is a robust and effective technique to animate high DOF articulated models from an example motion.

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.124-126
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• 1989

Inverse kinematic problem is a crucial point for robot manipulator control. In this paper, to implement the Jacobian control technique we used the Hopfield(Tank)'s neural network. The states of neurons represent joint veocities, and the connection weights are determined from the current value of the Jacobian matrix. The network energy function is constructed so that its minimum corresponds to the minimum least square error. At each sampling time, connection weights and neuron states are updated according to current joint position. Inverse kinematic solution to the planar redundant manipulator is solved by computer simulation.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.655-658
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• 1999

In this paper we design a key-frame editor for 3D sign-language animation using the inverse kinematics. Using the editor, we can calculate the joint angles for two arms automatically. Up to now we have computed the values of the joint angles using the forward kinematics, where we have determined the values heuristically based on our experiences. To overcome the drawbacks, we employ the arm transformation matrix of the inverse kinematics. Experimental results show a possibility that the proposed method could be used for making up the sign-language communication dictionaries.

• Electronics and Telecommunications Trends
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• v.14 no.3 s.57
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• pp.44-53
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• 1999

국내 컴퓨터 그래픽스 시장에서 가장 일반적으로 선택되어지는 애니메이션 소프트웨어인 Maya, Soft-Image, 3D Studio Max를 대상으로 그 기능과 편의성을 위주로 비교한다. 애니메이션 작업에 가장 널리 사용되는 키프레임 애니메이션, 변형, 역운동학 및 동역학 애니메이션 기술 등을 애니메이션 소프트웨어 설계의 관점에서 비교한다

• Proceedings of the Korea Information Processing Society Conference
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• 2004.05a
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• pp.153-156
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• 2004

이 연구에서는 동작 포착 데이터에서 최적의 동작을 얻기 위한 비용과 시간을 줄이고, 캐릭터의 체형 크기에 무관하게 복합 지형에서 적응적인 이동 동작을 빠르고 효율적으로 생성하는 방법을 제안한다. 즉 캐릭터의 신장이나 걷는 속도, 걸음폭 등의 매개변수들을 사용하여 평지면, 경사면, 계단면 그리고 굴곡면 등 다양한 지형에서의 달리기 동작을 생성하며 역운동학(Inverse Kinematics) 개념을 적용하여 관절들의 위치나 각도를 산출하고 관절의 이동 궤적을 계산하기 위해 큐빅 스플라인 곡선을 활용한다.

• The KIPS Transactions:PartB
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• v.12B no.2 s.98
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• pp.157-166
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• 2005

In 3D virtual environment the description of character' s movement that has utilized the conventional key-frame technique is gradually being developed toward the application of motion control method to generate more realistic and natural motion. Even the motion control method, however, has the limitation for expression of character's motion adapted to the ground properties of virtual world. That is, the walking motions of character are not only, for the most part, so uniform simple and repeated often as to feel to be tedious, but also the unnatural motion in which the tips of the toes soak through a plane or float in the air discording with the conditions of terrain lowers the semblance of reality. This paper proposes an adaptive motion control method for human figure locomotion in virtual environments or games, in which the walking motion is dynamiccally adapted to the ground's sliding properties. We compute an optimal parameters for one cycle of walking motion adapted to the ground properties by combining the coefficient of friction and centripetal force, and therefrom we induce a set of nonskid speed corresponding to various sliding properties of the ground.

• The KIPS Transactions:PartB
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• v.13B no.2 s.105
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• pp.187-196
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• 2006

In 3D animation most people adjust the moving motion of their characters on various terrains by using motion data acquired with the motion capture equipment. The motion data can be used to present real human motions naturally, but the data must be captured again to apply to the different terrains from those given at acquiring mode. In addition, there would be a difficulty when applying the data to other characters, in that case the motion data must be captured newly or the existing motion data must be heavily edited manually. In this paper we propose a unified method to generate human motions of walking and running for various terrains such as flat plane, inclined plane, stairway and irregular face. With these methods we are able to generate human motions controlled by the parameters : body height, moving speed, stride, etc. In the proposed methods, the positions and angles of joint can be calculated by using inverse kinematics, and we calculate the trajectory of the swing leg and pelvis according to the cubic spline. With these methods we were presented moving motions using a model of a human body.

• Journal of KIISE:Software and Applications
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• v.30 no.11
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• pp.1092-1101
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• 2003

Most of 3D character animation adjusts the gait of their characters for various terrains, using motion capture data through the motion capture equipments. This motion capture data can be naturally presented as real human motions, which are to be adjusted according to the various types of terrain. In addition, there would be a difficulty applying motion capture data for other characters in which the motion data will be captured again or edited for the existing motion data. Therefore, this paper proposes a method that is to generate walking motion for various terrains, such as flat, inclined plane, stair, and irregular face, and a method that is to calculate the trajectory of the swing leg and pelvis. These methods are able to generate various gaits controlled by the parameters of body height, walking speed, stride, etc. In addition, the positions and angles of joint can be calculated by using inverse kinematics, and the cubic spline will be used to calculate the trajectory of the joint.

• Broadcasting and Media Magazine
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• v.3 no.2
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• pp.31-43
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• 1998

가상 인물은 컴퓨터에 의해 합성된 가상적인 연기자로 최근 많은 영상물에 사용되어 대중에게 큰 호응을 얻고 있고 점차 그 활용 범위가 확대될 전망이다. 가상인물의 동작은 가상 인물의 사실성을 좌우하기 때문에 자연스러운 동작을 보다 적은 노력으로 빠르게 만들기 위해 다양한 방법들이 연구되었다. 가상 인물의 동작의 기본이 되는 자세를 제어하기 위해 다관절체와 인체변형 기법들이 제안되었다. 키프레임 보간법은 소수의 자세로 동작을 생성하고 역운동학을 이용하여 편리하게 동작을 제어할 수 있지만 사용자의 많은 노력과 시간을 요구한다. 대안으로 제시된 동력학 기반 동작 생성은 자연스러운 동작을 자동으로 생성할 수 있는 반면 사용자의 제어가 어렵다. 최근에 각광 받고 있는 연기 기반 방법은 실제 연기자의 동작을 가상 인물에 대입하여 빠르고 자연스러운 동작 생성을 가능하게 한다. 생성된 동작은 동작 혼합이나 전이의 방법으로 재 사용된다. 가상 인물 스스로가 충돌을 검사하여 충돌을 피할 수 있는 경로를 계획하여 동작을 생성하게 하는 연구, 더 나아가서 가상 인물이 주변 상황을 파악하고 능동적으로 대처할 수 있게 하는 연구를 통해 가상 인물은 보다 실제 인간에 가까운 모습으로 발전하고 있다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.15 no.4
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• pp.295-300
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• 1990

Inverse kinematic problem is a crucial point for robot manipulator control. In this paper, to implement the Jacobian control technique we used the Hopfield, Tank's neural network. The states of neurons represent joint velocities, and the connection weights are determined from the current value of the Jacobian matirx. The network energy function is constructed so that its minimum corresponds to the minimum least square error. At each sampling time, connection weights and neuron states are updated according to current joint positon. Inverse kinematic solution to the planar redundant manipulator is solved by computer simulation.