• Journal of KIISE:Computing Practices and Letters
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• v.11 no.1
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• pp.15-25
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• 2005

Embedded systems have a set of tasks to execute. These tasks can be implemented either on application specific hardware or as software running on a specific processor. The design of an embedded system involves the selection of hardware software resources, Partition of tasks into hardware and software, and performance evaluation. An accurate estimation of execution time for extreme cases (best and worst case) is important for hardware/software codesign. A tighter estimation of the execution time bound nay allow the use of a slower processor to execute the code and may help lower the system cost. In this paper, we consider an ARM-based embedded system and developed a tool to estimate the tight boundary of execution time of a task with loop bounds and any additional program path information. The tool we developed is based on an exiting timing analysis tool named 'Cinderella' which currently supports i960 and m68k architectures. We add a module to handle ARM ELF object file, which extracts control flow and debugging information, and a module to handle ARM instruction set so that the new tool can support ARM processor. We validate the tool by comparing the estimated bound of execution time with the run-time execution time measured by ARMulator for a selected bechmark programs.

• Therapeutic Science for Rehabilitation
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• v.2 no.1
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• pp.36-47
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• 2013

Objective : To identify the effect of bilateral arm training for activities of daily living(ADL) of the chronic phase after stroke. Methods : 20 patients with stroke, randomized to an experimental group(n=10) and a control group(n=10). Both groups received the usual occupational therapy. In addition, an experimental group received an bilateral arm training, 30-min sessions per a day for 6 weeks. The Functional Independence Measure(FIM) was used to evaluate ADL for both groups. Results : First, there is a significant difference before and after receiving the bilateral arm training(p <.05). Second, there are significant differences in all ADL areas of Self-care, Transfer, Social cognition after bilateral arm training(p<.05). Third, there are significant differences in all sub-areas of Self-care, only stairs of Locomotion, and only Problem solving of Social cognition by comparing sub-areas as bilateral arm activity(before and after) and occupational therapy intervention(before and after). Conclusion : Using bilateral arm training for the chronic phase after stroke improved their abilities of ADL. Therefore, there are an expectation to use bilateral activity training for the chronic after stroke clinically and a need of further study about bilateral arm training related to ADL in the future.

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.138-143
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• 1989

In considering the singularities of robot, singularity avoidance control of robot wrist is very important. Because it is more difficult structurally to exclude the wrist singularity than the arm singularity. Since control policies with Jacobian may bring about mathematical singularities, control policies with Euler parameters that never cause mathematical singularities are necessary. In this research, singular status of robot wrist was analyzed and control algorithms for 3 and 4 axes robot wrist were proposed. Application results of the proposed control algorithms to the path including singularity showed us usefulness and validity.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.3
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• pp.240-247
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• 2013

This paper proposes an optimal three-dimensional coordinate implementation of the vision sensor using two CCD cameras. The PBVS (Position based visual servoing) is implemented using the positional information obtained from images. Stereo vision by PBVS method that has enhanced every frame using calibration parameters is effective in the distance calculation. The IBVS (Image based visual servoing) is also implemented using the difference between reference and obtained images. Stereo vision by IBVS method calculates the distance using rotation angle of motors that correspond eyes and neck without enhanced images. The PBVS method is compared with the IBVS method in terms of advantages, disadvantages, computing time, and performances. Finally, the IBVS method is applied for the dual arm manipulator on the mobile inverted pendulum. The autonomous mobile inverted pendulum is successfully demonstrated using the center of the manipulator's mass.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.5
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• pp.837-844
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• 2013

This study performs erection of a pendulum hanging at a free end of an arm by rotating the arm to the upright position. A mathematical model of a rotary inverted pendulum system (RIPS) is derived. A brain emotional learning based intelligent controller (BELBIC) is designed and used as a controller for swinging up and balancing the pendulum of the RIPS. In simulations performed in the study, a pendulum is initially inclined at $45^{\circ}$ with respect to the upright position. A simulation is also performed for evaluating the adaptiveness of the designed BELBIC in the case of system variation. In addition, a simulation is performed for evaluating the robustness of the designed BELBIC against a disturbance in the control input.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.4
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• pp.364-370
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• 2006

Optical coherence tomography (OCT) is high resolution medical imaging system which is obtaining image inside biological objects with non-destructive method. OCT system is based on Michelson interferometer with a reciprocating mirror in the reference arm and a biological object in the sample arm. The obtained OCT image suffers from a granular or mottled image, called speckle. Speckle is caused by random interferences between reflected coherence waves. In this paper, we propose effective speckle reduction method that uses wavelet transform. With wavelet domain image, sub-windowing and thresholding are performed. Finally, speckle reduction experiments for Misgurnus mizolepis skin and rat eye images are shown.

• Journal of Industrial Technology
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• v.28 no.A
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• pp.75-80
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• 2008

This paper describes the mechanical and control design of a robotic device for providing therapeutic assistance to arm movement following stroke. This is a new robot for arm therapy applicable to the training of activities of daily living in homes and clinics. This instrument has one degrees of freedom, and is equipped with position and force sensors. Repetitive movement can improve movement performance in patients with neurological or orthopaedic lesions. The application of robotics can serve to assist, enhance, evaluate, and document neurological and orthopaedic rehabilitation of movements. The new robot, the mechanical structure, the control circuit, the sensors and actuators and some safety aspects.

• Proceedings of the KIEE Conference
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• 1992.07a
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• pp.468-472
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• 1992

In this paper, we classified electromyographic(EMG) signal for prothesis control using neural network. For this study fast Fourier transform(FFT) with ensemble averaged spectrum is applied to two-channeI EMG signal for biceps and triceps. We used the three layer network. And a cumulative back-propagation algorithm is used for classification of six arm functions, flexion and extension of elbow and pronation and supination of the forearm and abduction and adduction of wrist.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.04a
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• pp.234-238
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• 2001

A lot of researches have been done in teleoperation field. For accurate and reliable teleoperation, force reflection is required so that the master can feel the same force, which is measured at reflection have been applied to most of the master device. Therefore the master can not control the force exerted by the slave robot to the environment. But some tasks such as an insertion with very small tolerance, skewing bolt and so forth, require the force command from the master.

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.6
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• pp.477-483
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• 2002

This paper deals with a workspace analysis of multi-legged walking robots in velocity domain(velocity workspace analysis). Noting that when robots are holding the same object in multiple cooperating robotic arm system the kinematic structure of the system is basically the same with that of a multi-legged walking robot standing on the ground, we invented a way ot applying the technique for multiple arm system to multi-legged walking robot. An important definition of reaction velocity is made and the bounds of velocities achievable by the moving body with multi-legs is derived from the given bounds on the capabilities of actuators of each legs through Jacobian matrix for given robot configuration. After some assumption of hard-foot-condition is adopted as a contact model between feet of robot and the ground, visualization process for the velocity workspace is proposed. Also, a series of application examples will be presented including continuous walking gaits as well as several different stationary posture of legged walking robots, which validate the usefulness of the proposed technique.