• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1997년도 추계학술대회
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• pp.39-43
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• 1997

Posturography stands or quantitative assessment of body postural stability analysis. The present study developed a balance plate system to monitor patient's center of pressure (COP) movement and to analyze its stability. An equilateral triangular shaped plate was made of duralumin and forces were measured on the three vertices of the plate using industrial load cells. Specially designed electronic circuit picked up force signals ed into data acquisition system to calculate the cartesian coordinates of COP. COP calculation error was less than 2%. The force signals enabled to compute stability measures, which consisted of a variety of clinical parameters related to postural stability. Clinical experiments were carefully designed and performed on 40 normal subjects. The results were that 1) postural stability decreased with age and 2) the best parameters were those of posture deviation measures. A customized PC-based software package was developed to apply the present technique with a great convenience to monitoring and analyzing postural stability in an accurate and quantitative way.

• 대한의용생체공학회:의공학회지
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• 제30권6호
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• pp.521-528
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• 2009

This study is about to evaluation of postural stability according to characteristics of electrical stimulation on the ankle muscles. We measured body sway(center of pressure, COP) when various parameters of electrical stimulation was applied to ankle muscles in stable and unstable posture. Subjects consisted of 10 young adults, and electrical stimulation was delivered on right and left of tibialis anterior and Achilles tendon. The body sway was measured during electrical stimulation of three duty cycle and frequencies in stable posture and three amplitudes of sensory threshold in unstable posture. Consequently, the COP Shift is higher during electrical stimulation of 1/30(duty ratio) and 100Hz(frequency) in stable posture. In unstable posture, 100% amplitude of sensory threshold induced postural stability. These findings are important for the rehabilitation system of postural stability and the use of electrical stimulation as somatosensory information.

• 동력기계공학회지
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• 제20권2호
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• pp.85-90
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• 2016

Coefficient of performance (COP) for two-stage compression system is investigated in this paper to develop seawater ice machine. The system performance is analyzed with respect to degrees of superheating and subcooling, condensing and evaporating temperatures, compression and mechanical efficiencies and mass flow ratio in an inter-cooler. The main results are summarized as follows : The COP of the system grows when the mass flow ratio, subcooling degree and evaporating temperature edge up. Contrariwise, the system performance descends in case that superheating degree and condensing temperature increase. The most effective factor for the COP is the mass flow rate ratio. Each refrigerant has different limitation for a value of the mass flow ratio in the inter-cooler because of difference in material property.

• 감성과학
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• 제6권4호
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• pp.25-32
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• 2003

본 논문은 "풋 스캐너"와 "족압분석 시스템"을 이용하여 획득한 측정 데이터에서 새로운 보행분석 평가 방법을 제안하였다. 기존의 많은 연구자들에 의해서 보행시 발바닥의 육안적 검사와 압력분포의 분석 방법이 많이 논의되었다. 또한 연구자들은 압력곡선, 압력중심 궤적과 압력중심에서의 속도에 관해서 관심을 가져왔다. 그러나 이런 실험결과들은 실험환경과 피험자의 조건에 의해 의존된다. 결론적으로 우리는 이런 문제를 해결하기 위해 특별한 에너지 변수 등을 고려해야만 한다. 운동 에너지와 충격량 변수는 보행 분석에 활용될 수 있으며, 본 논문의 결과는 8명의 피험자들의 실험을 통하여 새로운 변수의 유용성을 확인하였다. 새로운 변수의 유용성을 확인하였다.

• 대한물리의학회지
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• 제10권3호
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• pp.39-45
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• 2015

PURPOSE: The purpose of this study was to investigate the effect of weight shift training with electrical sensory simulation feedback on quiet standing balance in hemiplegic stroke patients. METHODS: 30 stroke patients were equally allocated at random to an experimental group or a control group. Patients in both two groups underwent comprehensive rehabilitation physical therapy for 30 minutes per day for 5 days per week for 4 weeks. Members of the experimental group received additional weight shift training with electrical sensory simulation feedback was conducted for 15 minutes after 30 minute sessions, whereas members of the control group underwent additional leftward/rightward weight shift training by themselves after 30 minutes per day for four weeks. COP (center of pressure) path lengths, COP velocities, and foot forces were measured before and immediately after the 4-week training period in both groups and results were compared. RESULTS: COP path lengths significantly decreased by 3% after training in the experimental group and this was significantly greater than that observed in the control group (p<0.05). In both groups, foot forces of affected sides showed significant increases after intervention, whereas foot forces of unaffected sides showed significant decreases (p<0.05). No significant difference was observed between the two groups with respect to these changes. CONCLUSION: Weight shift training using electrical sensory simulation feedback has a positive effect on quiet standing balance in hemiplegic stroke.

• 신재생에너지
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• 제3권2호
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• pp.40-46
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• 2007

Effluent ground water overflow in deep and broad ground space building. Temperature of effluent ground water is in $12{\sim}20^{\circ}...$ annually and the quality of that water is as good as well water. Therefore if the flow rate of effluent ground water is sufficient as source of heat pump, that is good heat source and heat sink of heat pump. Effuent ground water contain the thermal energy of surrounding ground. So this is a new application of ground source heat pump. In this study open type and close type heat pump system using effluent ground water was installed and tested for a church building with large and deep ground space. The effluent flow rate of this building is $800{\sim}1000\;ton/day$. The heat pump capacity is 5RT. The heat pump heating COP was $3.85{\sim}4.68$ for the open type and $3.82{\sim}4.69$ for the close type system. The system heating COP including pump power is $3.0{\sim}3.32$ for the open type and $3.32{\sim}3.84$ for close type system. This performance is up to that of BHE type ground source heat pump.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 추계학술대회 초록집
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• pp.143.2-143.2
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• 2011

Energy foundations and other thermo-active ground structure, energy wells, energy slab, and pavement heating and cooling represent an innovative technology that contributes to environmental protection and provides substantial long-term cost savings and minimized maintenance. This paper focuses on earth-contact concrete elements that are already required for structural reasons, but which simultaneously work as heat exchangers. Pipes, energy slabs, filled with a heat carrier fluid are installed under conventional structural elements, forming the primary circuit of a geothermal energy system. The natural ground temperature is used as a heat source in winter and heat sink in summer season. The system represented very high heating and cooling performance due to the stability of EWT from energy slab. Maximum heat pump unit COP and system COP were 4.9 and 4.3.

• 한국농공학회지
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• 제40권3호
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• pp.94-102
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• 1998

This experiment was carried out to study on the effect of greenhouse heating by water-to-water heat pump system employing heating water tank(ground water) as the heat source. Followings are the results obtained from this study ; 1. The heat amount absorbed from evaporator and the heat amount rejected from condenser were approximately 9, 000~ 12, 000kcal/h and 13, 000~ 17, OOOkcal/h, respectively. 2. The heat efficiencies of evaporator and condenser used in this experiment were approximately 79% and 83%, respectively. 3. The maximum heating load estimated for the experimental greenhouse was about 18, 000 ~ 25, OOOkcal/h, which was found to be about 28 ~ 32% higher than the heating capacity of the heat pump system adopted for this experiment. 4. The coefficients of performance(COP) for the heat pump and the total heat pump system were approximately 2.9~3.5 and 1.5~2.4, respectively. 5. The coefficient of performance(COP) calculated from the Mollier Diagram was about 3.2 ~ 3.4, which was reasonably close to the COP estimated on the basis of measured values. 6. The temperature of experimental greenhouse heated by the heat pump system could be maintained about 12~15 。C higher than that of a control greenhouse.

• 대한물리치료과학회지
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• 제27권2호
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• pp.88-95
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• 2020

Background: In the present study to investigate the immediate effects of standing position of the trunk stabilization exercise on Guillain-Barre syndrome patient's balance and gait abilities were examined. Design: Case report and conducted as a single-blind. Methods: Standing position of trunk stabilization exercise was conducted for five Guillain-Barre syndrome patient's who met the selection criteria were recruited. The subjects were conducted conservative exercise and trunk stabilization exercise. Conservative exercise was implemented for thirty min, five times for 8 weeks, and trunk stabilization exercise was implemented for 15 min. The participants' balance was measured via force plate (COP), functional reach test (FRT), timed up and go test (TUG), gait was measured using the 10 m walk test, and 6 minute walk test. Results: After training, the change values of the balance and gait ability in the subjects were significantly greater than pre-test. participants showed significant improvements in COP, FRT, TUG, 10 m walk test and 6 minute walk test pre and post the training (p<0.05). Conclusions: standing position of the trunk stabilization exercise was effective on Guillain-Barre syndrome patient's balance (COP, FRT, TUG) and gait (10 m walk test and 6 minute walk test) abilities were examined.

• 생명과학회지
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• 제20권11호
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• pp.1704-1710
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• 2010

본 연구는 뇌졸중 발병 후 재활운동에 참가하는 환자들을 대상으로 재활운동 3개월이 지난 시점에서 1차 실험을 하였고, 6개월이 지난 시점에서 2차 실험을 하여 운동역학적 비교분석을 하였다. 실험에 사용된 장비는 영상분석기, 족저압분석기, 근전도분석기를 사용하였다. 대상자는 7명으로 하였으며 통계방법은 t-test분석 이용하였다. 결과는 엉덩관절의 최대신전 피크 값과 최대신전 피크 모멘트 값에서 통계적으로 유의한 차이를 나타내었다(p<0.05). 족저압의 비교에서는 환측 다리의 족저압에서 일반적인 걷기 동작시에 족저압의 중심이동거리에서 통계적으로 유의한 차이를 나타내었다(p<0.05). 근전도 분석에서는 대퇴사두근 중의 대퇴직근과 외측광근의 근력에서 통계적으로 유의한 차이를 나타내었다(p<0.05).