• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.4
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• pp.623-631
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• 2003

It is considered that the application of advanced composite materials to the prostheses for the disables is important to improve their bio-mechanical performance. Particularly, energy storing foot prosthesis is mostly important to restore gait ability of the disables with low-extremity amputation since it could provide propulsion at terminal stance enhancing the disables ability to walk long distance even run and jump. Therefore, the energy storing spring of Prosthetic foot keel under cyclic bending moment use mainly of high strength glass fiber reinforced plastic. The main objective of this study was to evaluate the stacking sequence effect using the delamination growth rate(dA$_{D}$/dN) of energy storing spring in glass fiber reinforced plastic under cyclic bending moment. The test results indicated that the shape of delamination zone depends on stacking sequence in GFRP laminates. Delamination area(A$_{D}$) turns out that variable types with the contour increased non-linearly toward the damage zones.nes.

• Journal of Plant Biotechnology
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• v.34 no.3
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• pp.229-235
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• 2007

Artificial seeds were produced by encapsulation of somatic embryos of Kalopanax septemlobus and investigated the effects of alginic acid concentration, size of somatic embryos, additives in capsules and nursery seedbeds for germination. The most suitable concentration of alginic acid was 3% for germination of encapsulated seeds. Germination was suppressed at higher concentration more than 3% alginic acid. For germination of artificial seeds, 1/2 MS medium with 0.02% activated charcoal was effective. There was no significant differences on the germination among the different size of somatic embryos. Additives in hydrated capsule was very important for germination and post-germinative growth of artificial seeds. Germination was severly inhibited in hydrated capsule containing only distilled water. Both sucrose and MS medium addition in hydrate capsule was effective for germination of artificial seeds. When artificial seeds were transferred to soilbed, germination rate was high in perlite containing 3% sucrose but very low in perlite with only water. These results indicate that nursery additives in both hydrate capsules and soilbeds was important for germination of artificial seeds in Kalopanax septemlobus.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.7
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• pp.769-776
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• 2013

The dynamic compliance characteristics of a prosthetic foot midgait are very important for natural performance in an amputee's gait and should be in a range that provides natural, stable walking. In this study, finite element analysis (FEA) and classical laminate theory were used to examine the mechanical characteristics of a carbon-epoxy composite laminate prosthetic foot as a function of variation in the lamination composition. From this analysis, an FEM model of a prosthetic keel, made from the composite material, was developed. The lamination composition of the keel was designed for improved stiffness. The prototype product was fabricated using an autoclave. Vertical loading response tests were performed to verify the simulation model. The results of the experiments were similar to those from simulations below the loading level of the gait, suggesting use of the proposed simulation model for prosthetic keel design.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2004.10a
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• pp.391-395
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• 2004

본 논문은 맞춤형 신발제작을 위하여 맞춤형 신발에 필요한 화형제작용 데이터를 위한 3차원 측정 장치를 통해 획득한 발의 형상을 인공지능 기법을 기반으로 하는 최적화된 형상을 복원하는 방법을 제시하고자 한다. 본 연구를 위해 개발된 시스템은 PC를 기반으로 하는 기존의 3차원측정 방식을 이용하여 상, 하, 좌, 우로 각각 장착된 8대의 CCD 카메라와 4대의 레이져를 통해 화형 및 발의 형상 데이터를 획득한다 획득된 데이터들은 인공지능 기법을 이용한 영상처리 알고리즘으로 처리되며, 처리 결과는 기존의 지능 기법을 도입하지 않은 시스템에 비해 노이즈제거 특성이 향상되었고, 후처리과정을 간소화 할 수 있다. 따라서 본 논문에서는 3차원 측정을 위해 기구적인 부분과 하드웨어적인 부분의 시스템을 구성하고, 데이터 처리용 소프트웨어에서 입력영상의 전처리 과정 중 영상의 이진화 단계에서 임계값을 결정하기 위하여 간단한 신경망을 사용하였으며, 이에 대한 결과를 제시하고자 한다.

• Proceedings of the KSLP Conference
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• 1998.11a
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• pp.196-196
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• 1998

후두전적출술후 음성재활방법은 식도발성, 기관식도발성, 전기후두발성, 기체역학형 인공후두 발성등이 있다. 본 연구에서는 각각의 음향학적 특성과 어떤 방법이 음성의 발성에 효과적이고, 음의 고저를 잘 나타낼 수 있는 지를 연구하였고 식도발성과 기관식도발성이 동시에 가능한 환자에서도 위와 같이 어떤 것이 음의 고저를 잘 나타낼 수 있는 지를 보고자 본 연구를 시행하였다. 식도발성자 5명, 기관식도발성자 7명(2가지가 다 가능한 발성자 2명을 포함하여), 전기후두발성자 3명과 공기를 이용한 인공후두(Pneumatic speech aid) 발성자 3명을 대상으로 하여 Maximal phonation time(sec), Sound intensity (dB SPL), Fundemental frequency (F0), Jitter(%), Shimmer(%)를 Matlab V5.1을 기초로 저자들이 고안한 프로그램인 Laryngeal analyser Vl.0 으로 측정하였다. 각각의 발성법에 따라 특징적인 변수의 차이가 있었으며 그중 공기를 이용한 인공후두 발성자에서 음의 고저를 가장 잘 표현하였다. (p<0.01). 그리고 식도발성과 기관식도발성을 같이 사용할 수 있는 2명에서 식도발성이 기관식도발성보다 더 효과적으로 음의 고저를 잘 나타냈다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.1173-1174
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• 2012

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.1433-1434
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• 2013

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.10a
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• pp.641-642
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• 2009

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.11a
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• pp.1005-1006
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• 2010

• Journal of Biomedical Engineering Research
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• v.10 no.2
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• pp.117-124
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• 1989

The intelligent trajectory control method that controls moving direction and average velocity for a prosthetic arm is proposed by pattern recognition and force estimations using EMG signals. Also, we propose the real time trajectory planning method which generates continuous accelleration paths using 3 stage linear filters to minimize the impact to human body induced by arm motions and to reduce the muscle fatigue. We use combination of MLP and fuzzy filter for pattern recognition to estimate the direction of a muscle and Hogan`s method for the force estimation. EMG signals are acquired by using a amputation simulator and 2 dimensional joystick motion. The simulation results of proposed prosthetic arm control system using the EMf signals show that the arm is effectively followed the desired trajectory depended on estimated force and direction of muscle movements.