• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.4
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• pp.685-694
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• 2001

In this study, a transfemoral prosthesis system of which both stance phase and swing phase are controllable has been developed for the recovery of the biomechanical function of the amputated leg. It consists of a 5 bar link mechanism, a hydraulic-rubber knee damper for stance phase control and a pneumatic cylinder controlled via a microprocessor for stance phase control. The mechanical characteristics of the knee damper which absorbs the impact energy generated at the heel contact were investigated. The characteristics of the pneumatic cylinder essential for the speed adaptation of the prosthesis during swing phase were also studied for its mechanical characteristics. The prosthesis was subject to the clinical tests, and the gait characteristics obtained were very close to those of normal subjects. The stance and swing controlled prosthesis that were developed in this study showed good stability during the stance phase and showed good controllability during the swing phase.

• Proceedings of the KSME Conference
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• 2000.11a
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• pp.504-509
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• 2000

In this study, a transfemoral prosthesis system of which stance phase and swing phase are controlled during walking has been developed for the recovery of the biomechanical function of the amputated leg. It consists of a 5 bar link mechanism, a hydraulic-rubber knee damper for stance phase control and a pneumatic cylinder controlled via a microprocessor for stance phase control. The mechanical characteristics and behaviour of the knee damper which absorbs the impact energy generated at the heel contact was investigated. The characteristics of the pneumatic cylinder essential for the speed adaptation of the prosthesis during swing phase was also studied for its mechanical characteristics. The prosthesis was subject to the clinical test ant the gait characteristics obtained were very close to those of normal. The stance and swing controlled prosthesis that were developed in this study showed good stability during the stance phase and showed good controllability during the swing phase.

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.5
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• pp.407-412
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• 2015

This paper presents the design of a lab-built powered knee prosthesis based on a BLDC motor, a sensored impedance control using a force sensor, and a sensorless impedance control through torque estimation. Firstly, we describe the structure of the lab-built powered knee prosthesis and its limitations. Secondly, we decompose the gait cycle into five stages and apply the position-based impedance control for the powered knee prosthesis. Thirdly, we perform an experiment for the torque estimation and the sensorless impedance control of the prosthesis. The experimental results show that we can use the torque estimation to control the low impedance during the swing phase, although the estimated torque data has a delay compared with the measured torque by a load cell.

• Microbiology and Biotechnology Letters
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• v.20 no.6
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• pp.668-676
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• 1992

For the purpose of optimizing poly-l3-hydroxybutyrate (PHB) production from Alcaligenes eutrophus, two-stage fed-batch culture was adopted. In this system, specifk growth rate was maximized during the first stage whereas specific production rate was maximized during the second stage. The optimal concentrations of glucose and ammonium chloride were 16.6 and 0.54 g/I in the growth stage and 20.0 and 0.07 g/l in the production stage, respectively. Proportional feedback control considering time lag was suggested for PHB production process and a simulator was developed for real-time control purpose.

• Proceedings of the Korean Information Science Society Conference
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• 2003.10b
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• pp.451-453
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• 2003

인터넷과 네트워크의 발달로 유.무선네트워크를 통해 댁내의 가전기기가 연결되고 외부접속을 통한 원격제어가 가능해지는 홈네트워크[5]가 여러 가전기기들의 제품특성에 맞게 각기 적용되고 있다. 하지만 이들 가전기기의 사용을 위해 제공되는 홈네트워크의 사용자를 위한 인터페이스[1]를 살펴보면 몇 가지 사용상의 제한을 가지고있다. 첫째, 댁내에 동일제품이지만 여러 대의 제품이 설치된 환경에서 특정제품 이용시 검색의 단계를 거처야 한다. 둘째, 다수사용자 환경에서 개인별 차별기능을 제공하지 못한다. 셋째, 실제제품과 화면상의 제품간 차이로 인해 현실감이 부족하다. 본 논문에서는 Object를 인식하고 위치를 파악하며 실제Object에 가상효과를 더할 수 있는 증강현실[2]을 적용하여 개선안을 제시한다.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.7 no.2
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• pp.75-84
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• 2013

In this study, the patterns and characteristics according to gait cycle were analyzed using to EMG signals during walking, and analyzed in the time domain and frequency domain. The experiments was performed divide to level-ground walking and stair walking, and gait cycle was analysis by stance and swing. In the sagittal plane by using the tilt sensor measures the angle of the lower leg, and EMG was measured from the quadriceps and biceps femoris. The tilt of the lower leg was showed the biggest tilt at HS, and showed lowest value at TO. All in walking according to the gait cycle IEMG showed a specific pattern, and is expected useful to determine the gait cycle and kind. In the frequency domain analysis was using STFT on able to frequency analysis according to time, and using the tilt sensor was identify gait cycle. We analyzed also spectrum of the results of the STFT in all gait types, and recognized that stance had broad bandwidth than that of swing. Through this study, it was confirmed the possibility of judgment and analysis of the gait cycle using EMG and the tilt in the sagittal plane of the lower leg. When used it, can improve the quality of life of amputation patients

• The Journal of the Korea Contents Association
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• v.11 no.12
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• pp.317-325
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• 2011

This study aims to develop the stance-control typed 4-bar linkage orthotic knee joint that replace the locked orthotic knee joint for the disabled with poliomyelitis and muscle weakness of lower limb. Unlike the existing stance-control orthotic knee joint, there are no needs of electric power, connecting circuit, bulky compomnets, etc, because this 4-bar linkage orthotic knee joint is controled by geometric locking. To evaluate the 4-bar linkage orthotic knee joint, a subject participated in this study who has been diagnosed with lower limb poliomyelitis and have used locked type orthotic knee joint. In the results of analysis of subject's gait using 3-dimentional motion analysis system, this 4-bar linkage orthotic knee joint provide the stability during stance phase and knee flexion during swing phase.

• Journal of IKEEE
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• v.23 no.3
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• pp.883-892
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• 2019

This study is the method which is adapted to control ankle joint movement for resolving the problem of gait imbalance in intervals where gait environments are changed and slope walking, as applying terrain-adaptive technique to intelligent above-knee prosthesis. In this development of above-knee prosthesis, to classify the gait modes is essential. For distinguishing the stance phases and the swing phase depending on roads, a machine learning which combines decision tree and random forest from knee angle data and inertial sensor data, is proposed and adapted. By using this method, the ankle movement state of the prosthesis is controlled. This study verifies whether the problem is resolved through butterfly diagram.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.1
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• pp.199-205
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• 2013

The purpose of this study was to analyze the changes in gait according to four style of bag's carryied method and three different bag's weights. Twenty healthy adults participated in four conditions. The first condition, they wearing a bag on one side shoulder and walked. The second condition, they carried a bag sling across on shoulder and walked. The third condition, they carried a bag on a back using both shoulders and walked. The fourth condition, they hold a bag in their right hand and walked. During all four conditions participants wore a SmartStep insole in their right shoe and had a pressure control device strapped to their right ankle. Each participant walked 10 meters carrying a 2.5 kg, 5 kg and 7.5 kg bag under all four conditions. There were significantly differents in stance phase rate; swing phase rate and walking speed according to bag weight of 2.5 kg, 5 kg, 7.5 kg.

• Journal of Animal Environmental Science
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• v.18 no.2
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• pp.99-110
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• 2012

The purpose of the study is to collect basis data for to establish standard administrative processes of liquid fertilizer treatment. From this survey we could make out the key point of each step through a case of effective liquid manure treatment system in pig house. It is divided into six step; 1. piggery slurry management step, 2. Solid-liquid separation step, 3. liquid fertilizer treatment (aeration) step, 4. liquid fertilizer treatment (microorganism, recirculation and internal return) step, 5. liquid fertilizer treatment (completion) step, 6. land application step. From now on, standardization process of liquid manure treatment technologies need to be develop based on the six steps process.