• Journal of Ocean Engineering and Technology
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• v.26 no.6
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• pp.59-65
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• 2012

In this research, a novel mater arm was studied as a teaching device for an underwater revolute robot arm used as a slave arm. The master arm was designed to be a seven-degree-of-freedom (DOF) structure, with a structure similar to that of the slave arm, and to be desktop size to allow it to be worn on a human arm. The master arm with encoders on the joints was used as an input device for teaching a slave robot arm. In addition, small electric magnets were installed at the joints of the master arm to generate the haptic force. A control system was designed to sense excessive force and torque in the joints of the master arm and protect it by controlling the position and velocity of the slave arm through the encoder signal of the master arm.

• Journal of Biomedical Engineering Research
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• v.29 no.3
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• pp.179-186
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• 2008

This paper presents a portable tele-assessment system designed for remote evaluation of the hypertonic elbow joint of neurologically impaired patients. A patient's upper limb was securely strapped to a portable limb-stretching device which is connected through Internet to a portable haptic device by which a clinician remotely moved the patient's elbow joint and felt the resistance from the patient. Elbow flexion angle and joint torques were measured from both master and slave devices and bilaterally fed back to their counterparts. In order to overcome problems associated with the network latency, two different tele-operation schemes were proposed depending on relative speed of tasks compared to the amount of time delay. For slow movement tasks, the bilateral tele-operation was achieved in real-time by designing control architectures after causality analysis. For fast movement tasks, we used a semi-real-time tele-operation scheme which provided the clinicians with stable and transparent feeling. The tele-assessment system was verified experimentally on patients with stroke. The devices were made portable and low cost, which makes it potentially more accessible to patients in remote areas.

• Korean Journal of Computational Design and Engineering
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• v.17 no.5
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• pp.303-311
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• 2012

Laparoscopic surgery is a surgical procedure which uses long laparoscopic instruments through tiny holes in abdomen while watching images from a laparoscopic camera through umbilicus. Laparoscopic surgeries have many advantages rather than open surgeries, however it is hard to learn the surgical skills for laparoscopic surgery. Recently, some virtual simulation systems for laparoscopic surgery are developed to train novice surgeons or resident surgeons. In this study, we introduce the techniques that we developed for laparoscopic surgical training simulator for cholecystectomy (gallbladder removal), which is one of the most frequently performed by laparoscopic surgery. The techniques for cholecystectomy simulation include modeling of human organs (liver, gallbladder, bile ducts, etc.), real-time deformable body calculation, realistic 3D visualization of surgical scene, high-fidelity haptic rendering and haptic device technology, and so on. We propose each simulation technique for the laparoscopic cholecystectomy procedures such as identifying cystic duct and cystic artery to clamp and cut, dissecting connective tissues between the gallbladder and liver. In this paper, we describe the techniques and discuss about the results of the proposed cholecystectomy simulation for laparoscopic surgical training.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.30 no.3
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• pp.231-238
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• 2017

Using 3D based BIM(Building Information Modeling) enables a variety of construction simulations. The is no case to simulate BIM demonstration experiment on deeply immersed virtual reality environment in korea. This paper develops a multi screen based simulation system to enable 3D based immersed environment to diverse decision making and virtual construction simulation. In a developed simulation laboratory, we can carry out BIM drawing review, disaster evacuation simulation, constructability review on wild land and design urban planning using haptic device on 3-side space with 4K resolution . Also, It can review large amount of drawings without data conversion because of compatibility with BIM software.

• Journal of the Korea Society of Computer and Information
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• v.17 no.12
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• pp.209-217
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• 2012

In this paper, I proposed new system that a user makes modeling 3D symmetric pottery using mouse and can confirm the result immediately in internet browser. The main advantage of proposed system is that users who have no specialized knowledge about 3D graphic can easily create 3D objects. And a user can use it that has only PC connected network and mouse without additional devices as like expensive haptic and camera device. For developing proposed system, VRML/X3D that is International Standard language for virtual reality and 3D graphics was used. Because it was born based on internet that is different from other 3D graphic languages, it was able to interact and navigate with users. With those features and high completeness of 3D pottery realization using mouse considered, the system may be useful and is superior in performance to other pottery modeling system.

• Journal of the Korea Convergence Society
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• v.9 no.11
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• pp.291-297
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• 2018

Due to difficulty in minimally invasive surgery, training simulator is actively researched. A volumetric deformable organ is created by employing a shape-retaining chain-linked (S-chain) model to realize positioning a human organ model in virtual space. Since the main principle of the S-chain algorithm is that the repulsive force is proportional to the number of chain elements, the calculation time can be increased according to the magnitude of deformation. In this work, the advanced S-chain algorithm is used to calculate the repulsive torque according to spin motion. Finally, haptic architecture was constructed using this S-chain model by incorporating the virtual organ with a real master device, which allows the repulsive force and target position to be transferred to each other. The control performance of S-chain algorithm has been evaluated via experiment.

• The Journal of the Korean dental association
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• v.50 no.3
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• pp.140-147
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• 2012

Recently, the digital solution of fabricating removable prosthesis by applying haptic input device, electronic surveying, and rapid prototyping was introduced. This review article covers the concept of electronic surveying, computer-aided denture framework designing procedure, discussions after several digital denture cases, directions of future development, such as digital tooth arrangement and RP flasking.

• IEMEK Journal of Embedded Systems and Applications
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• v.3 no.4
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• pp.244-250
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• 2008

This paper describes the design and implementation of an unmanned ground vehicle (UGV) and also estimates how well autonomous navigation and remote control of UGV can be performed through the optimized arbitration of several sensor data, which are acquired from vision, obstacle detection, positioning system, etc. For the autonomous navigation, lane detection and tracing, global positioning, and obstacle avoidance are necessarily required. In addition, for the remote control, two types of experimental environments are established. One is to use a commercial racing wheel module, and the other is to use a haptic device that is useful for a user application based on virtual reality. Experimental results show that autonomous navigation and remote control of the designed UGV can be achieved with more effectiveness and accuracy using the proper arbitration of sensor data and navigation plan.

• 한국HCI학회:학술대회논문집
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• 2008.02a
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• pp.590-594
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• 2008

근래에 인간과 컴퓨터의 상호작용을 통하여 사용자에게 직관적인 정보를 제공하는 기술들이 발전하고 있으며, 그래픽 기술의 비실사 렌더링을 이용한 미술 기법을 사실감 있게 가상 체험하기 위한 어플리케이션이 제안되고 있다. 본 논문은 미술 기법 중 방망이를 이용한 탁본 기법을 가상의 환경에서 모사하기 위해 탁본의 방망이를 통한 힘 쉐이딩을 새롭게 고안하여 제안한다. 햅틱 커서의 포인트와는 달리 탁본 방망이의 면적이 접촉하는 부분에서 생기는 문제점을 해결하기 위하여 Height map으로 사용된 Canny Edge Detection 이미지를 통해 Height map을 부분적으로 재 정의하고 힘의 계산에 적용하여 충돌된 방망이의 힘 쉐이딩을 가능하게 하는 것이 원리이다. 그래픽 렌더링 효과와 함께 실시간으로 사용자에게 햅틱 장치를 이용하여 촉감 정보를 전달함으로써 다양한 미술 교육적 효과를 체험할 수 있는 방안을 제공할 것으로 기대된다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.768-773
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• 2004

Developed in this paper a mass-spring engine to represent and manipulate deformable objects. The deformable object model is a basic technology in the ‘Tangible Space Initiative’. The mass-spring model consists of structural, shear and bending springs. Various forces like external, friction, gravity, spring, and damping forces are considered and collision with planes and spheres are treated. When a sphere collide mass-spring model, mass-spring engine calculates external force to interface mass-spring model. A prototype system is implemented in C on an MS windows machine.