• The Journal of Asian Finance, Economics and Business
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• 제7권1호
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• pp.111-121
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• 2020

The study measures the resource use efficiency of diesel based power generation in the Maldives and analyses factors which influence efficiency levels. Stochastic frontier analysis (SFA) technique is applied to data on 30 plants over two year period from 2016 to 2017. The study finds that technical efficiency scores varies from 0.44 to 0.98 across power plants. About 33 percent of the plants have scores below the mean technical efficiency score of 0.87. Empirical results indicate ownership and use of solar photovoltaic (PV) have an influence on improving efficiency levels. Privately owned power plants in resort islands obtained higher technical efficiency scores compared to public and community owned power plants. This is a significant finding as the first study that used power plants in tourist sector in a comparative study. Size of the power plants was not found significant, but relatively small installed capacities can also be efficient. This finding is important because in many inhabited islands installed capacities remain oversized compared to the load. The benchmarking exercise offers model power plants that are relatively efficient, for other power plants and policy makers in small islands to learn from.

• 대한간호학회지
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• 제16권3호
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• pp.78-96
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• 1986

The sympathico-adrenergic system and the hypophyseal-adrenocortical system mediates the regulation of the internal milieu. And the kidneys regulate both water and electrolyte balance of the body fluid. The kidneys are the sites of production of renin which participate indirectly in maintaining renin. angiotensin-aldosterone system. These system de-serve special attention in the context of adjustment the effects on the body function. And so, maximal exercise and work load are associated with home-osthetic function. The nurses working in the hospital have been complained of fatigue and stress by frequent duty changes and overload. In order to define this, the possible changes of hormonal excretion during three-shift nursing practice were investigated. Urine samples were collected at pre-duty and post-duty, and were measured with chemical assay and radioimmunoassay in 30 nursing students, in nursing practice and 43 nursing students, in studying. The results obtained were as follows. 1. In nursing practice, urinary norepinephrine concentration showed a marked increase during day duty, urinary cortisol concentration showed a marked increase during evening duty, and urinary renin concentration was increased in night duty, 2. Corrected ratio of urinary sodium excreted by the urinary excretion of creatinin (UNa/UCr) and UCl/UCr showed a marked decrease during night duty. Nursing practice did not affect on the UK/UCr and urinary concentrating ability. From these results, it is suggested that further studies the define the effects on some physiological function of the three-shift nursing practice against circadian rhythm are needed for better working condition of nurses.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1997년도 추계학술대회
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• pp.276-279
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• 1997

A simple bio-feedback system was developed to monitor and to analyze patient's postural balance. Two load celIs were used to measure the weight of each side. A specially designed electronic circuit was made to pick up the weight signals and to feed into the data acquisition system. Clinical trials were also made on 20-30 year-old normal subjects and nine hemiplegia patients who had the potential instability in weight bearing. A Microsoft window-based software collected and analyzed the postural balance data. Normal subjects showed only 5% deviations of their body weight. However, hemipegic patients had significant weight shifts toward the healthy limb. With the present system, patients can also exercise their balance and weight bearing. The present system should be of convenience to monitor in real-time and analyze the postural balance control of hemiplegic patients.

• 한국의류산업학회지
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• 제3권3호
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• pp.271-276
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• 2001

In this study, We endeavored to revaluate the effects of different types of clothing and colors on clothing microclimate in the subjects wearing sports wear at sunlight environment. This study was conducted 4 different kinds (cotton 100%) of clothing ensembles, that was W-1(long trousers and shirt of white color), B-1 (long trousers and shirt of black color), W-s (short trousers and shirt white color), B-s (short trousers and shirt black color) and were done in a climate chamber under sunlight ambient temperature ($33.67{\pm}1.8^{\circ}C$, $46.0{\pm}8.5%RH$) by three males subject who are in good healthy. Start a 20-min rest period, 20-min bouts of exercise and final 20-min recovery period were performed. The kinetic load was given for 20 minutes under the condition of 6.0 km/hr walking speed on the treadmill. The results is as followed In case of same type of garment, temperature within clothing which is based on difference of color the white ensemble keeps higher temperature than black one. According to distribution chart of temperature within clothing in case of chest, white one shows higher temperature than black one, in case of back, black one shows higher temperature than white one. Difference of heart rate was so clear and sequence is W-1>B-1>W-s>B-s, so we could find same tendency with temperature within clothing.

• Nuclear Engineering and Technology
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• 제48권1호
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• pp.72-86
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• 2016

A steam explosion may occur during a severe accident, when the molten core comes into contact with water. The pressurized water reactor and boiling water reactor ex-vessel steam explosion study, which was carried out with the multicomponent three-dimensional Eulerian fuel-coolant interaction code under the conditions of the Organisation for Economic Co-operation and Development (OECD) Steam Explosion Resolution for Nuclear Applications project reactor exercise, is presented and discussed. In reactor calculations, the largest uncertainties in the prediction of the steam explosion strength are expected to be caused by the large uncertainties related to the jet breakup. To obtain some insight into these uncertainties, premixing simulations were performed with both available jet breakup models, i.e., the global and the local models. The simulations revealed that weaker explosions are predicted by the local model, compared to the global model, due to the predicted smaller melt droplet size, resulting in increased melt solidification and increased void buildup, both reducing the explosion strength. Despite the lower active melt mass predicted for the pressurized water reactor case, pressure loads at the cavity walls are typically higher than that for the boiling water reactor case. This is because of the significantly larger boiling water reactor cavity, where the explosion pressure wave originating from the premixture in the center of the cavity has already been significantly weakened on reaching the distant cavity wall.

• 한국운동역학회지
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• 제23권3호
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• pp.225-233
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• 2013

The purpose of this study was to estimate the potential injury via analyzing ground reaction force components that were resulted from a prolonged-run-induced fatigue. For the present study, passive and active components of the vertical ground reaction force were determined from time and frequency domain. Shear components of GRF also were calculated from time and frequency domain. Twenty subjects with rear foot contact aged 20 to 30, no experience in injuries of the extremities, were requested to run on the instrumented tread-mill for 160 minutes at their preference running speed. GRF signals for 10 strides were collected at 5, 35, 65, 95, 125, and 155 minute during running. In conclusions, there were no significant difference in the magnitude of passive force, impact load rate, frequency of the passive and active components in vertical GRF between running times except the magnitude of active force (p<.05). The magnitude of active force was significantly decreased after 125 minute run. The magnitude of maximum peak and maximum frequency of the mediolateral GRF at heel strike and toe-off have not been changed with increasing running time. The time up to the maximum peak of the anteroposterior at heel-strike moment tend to decrease (p<.05), but the maximum peak and frequency of that at heel and toe-off moment didn't depend significantly on running time.

• PNF and Movement
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• 제16권3호
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• pp.355-363
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• 2018

Purpose: The purpose of this study was to obtain detailed and quantified data concerning the effects of plantarflexor muscle fatigue induced in the non-paretic side on the spatial and temporal gait parameters of the bilateral lower extremities during walking in stroke patients. Methods: This study was conducted on 20 patients with chronic stroke. The load contraction fatigue test was applied to induce muscle fatigue in the non-paretic plantarflexor muscle. Step length, stride length, double support, gait velocity and cadence, and functional ambulatory profile (FAP) score in the bilateral lower extremities were measured using a gait analysis system in order to investigate changes in temporal and spatial gait parameters caused by muscle fatigue on the non-paretic side. The statistical significance of the results was evaluated using a paired t-test. Results: A review of the results for gait parameters revealed a significant increase in double support (p<0.05) and a significant decrease in step length, stride length, gait velocity and cadence, and FAP score (p<0.05). Conclusion: These results indicate that the muscle fatigue in the non-paretic side of the stroke patients also affected the paretic side, which led to a decrease in gait functions. This implies a necessity to perform exercise or training programs in a range of clinical aspects not causing muscle fatigue.

• The Korean Journal of Physiology
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• 제18권1호
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• pp.67-79
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• 1984

고등학교(高等學校) 운동선수(運動選手)의 심폐기능(心肺機能)과 근전도(筋電圖) 혈액성분(血液成分)의 특성(特性)을 구명(究明)하고자 $16{\sim}19$세(歲)의 고등학생(高等學生) 선수군(選手群) 19명(名)과 비선수군(非選手群) 20명(名)을 대상(對象)으로 하여 실시(實施)한 본연구(本硏究)의 결과(結果)를 요약(要約)하면 다음과 같다. 1) 심전도시간간격(心電圖時間間隔)은 선수군(選手群)이 길었으며 특(特)히 R-R, Q-T 및 T-P간격(間隔)이 유의(有意)하게 길었다. 안정시(安靜時) 선수군(選手群)의 심박수(心搏數)는 비선수군(非選手群)에 비(比)해 서맥(徐脈)을 나타내었다. 심전도파고(心電圖波高)도 선수군(選手群)이 $Rv_5$파고(波高)와 $Tv_5$파고(波高)에서 유의(有意)하게 높았다. 2) 폐기능중(肺機能中)에 노력성호기량지수(努力性呼氣量指數)는 선수군(選手群)이 높았으며, 특(特)히 FEV 0.5초치(秒値)가 유의(有意)하게 높았고, 노력성폐류속(努力性肺流速)에서도 선수군(選手群)이 높았으며 특(特)히 PEF, FEF 25%, PIF 및 FEF $200{\sim}1200\;ml$ 치(値)가 유의(有意)하게 높았다. 3) 심변수(心辯數), 혈압(血壓) 및 호흡수(呼吸數)는 운동후(運動後) 유의(有意)하게 증가(增加)하였으며, 이중(中)에 심박수(心博數) 및 호흡수(呼吸數)는 비선수군(非選手群)이 더 증가(增加)하였는데 비(比)해 혈압(血壓)은 선수군(選手群)이 더 증가(增加)하였다. 4) 정귀혈(靜歸血)의 산소분압(酸素分壓)$(Pvo_2)$은 운동후(運動後) 감소(減少)하였고 탄산(炭酸)가스분압(分壓)$(Pvco_2)$는 증가(增加)하였으며, 양군(兩群)사이에는 별(別) 차이(差異)가 없었다. 5) 혈중(血中) glucose농도(濃度) 및 유산농도(乳酸濃度)는 운동후증가(運動後增加)하였고 특(特)히 혈중유산농도(血中乳酸濃度)가 유의(有意)하게 증가(增加)하였으며, 비선수군(非選手群)이 선수군(選手群)에 비(比)해 그 배가(培加)가 더 컸다. 6) 체전도파고(締電圖波高)가 운동부하(運動負荷)의 배(培)에 따라 계속증가(繼續增加)되었으며 이 중(中) 선수군(選手群)의 진폭(振幅)의 증가(增加)가 비선수군(非選手群)에 비(比)해 더 컸다.

• The Korean Journal of Physiology
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• 제20권2호
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• pp.279-288
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• 1986

줄넘기 운동의 신체 단련 효과를 측정하기 위하여 사병 9명에게 9주동안 규칙적으로 줄넘기 운동을 시킨 후 체격, 심폐기능, 혈액화학적인 변화를 관찰, 단련전과 비교하여 다음과 같은 결과를 얻었다. 효과를 검사하기 위해 부하한 운동은 트레드밀 달리기 운동이었다. 1) 단련에 의해 몸무게, 체표넓이, 피부두겹두께 및 총지방량이 유의하게 감소하였다. 2) 안정시 폐기능검사 값 중 최대환기능과 노력성 호기유속 25%가 단련후에 유의하게 증가하였다. 3) 심장박동수는 단련에 의해 안정시와 운동시, 회복기 전 시간대를 통해 매우 유의하게 증가하였다. 4) 단련으로 수축기 동맥혈압은 안정시와 회복기 전 시간대에서 거의 유의하게 감소한 반면, 이완기 동맥혈압은 회복기 전체를 통해 유의하게 증가하였다. 5) 안정시와회복기의 호흡회수는 단련에 의해 변화가 없었다. 6) 안정시와 회복 초기의 혈중 총 콜레스테롤 농도는 단련 후에 유의하게 감소하였지만 혈당, HDL-콜레스테롤 농도는 약간의감소에 그쳤다. 7) 단련전에 비해 단련후의 혈중 젖산 농도는 회복기에 대체로 감소하엿고 20분과 60분 값의 감소는 뚜렷하였다. 이상의 결과로 보아 9주 동안의 규칙적인 줄넘기 운동으로 체내 지방이 감소하고 순환기계 기능에 뚜렷한 향상을 가져오며 혈액화학적인 변화가 생긴다고 할 수 있겠다.

• 한국전문물리치료학회지
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• 제19권4호
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• pp.24-31
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• 2012

The aim of this study was to investigate the effectiveness of self-stretching exercises for iliotibial band (ITB) (Side-lying; right hip and knee were flexed to support the pelvis while left hip was extended and adducted, Standing A; side-bending of the trunk on standing with crossed leg, Standing B; same as Standing A, except the hands were clasped overhead and shifted right side, and Standing C; same as Standing B, except moving the arms diagonally downward) to help determine the most effective self-stretching method to stretch ITB. Twenty-one healthy subjects who do not have ITB shortness from Yonsei University (14 men and 7 women) between the ages of 18 to 28 years voluntarily participated. Ultrasound was performed to measure the thickness of the ITB between the long axis of the ITB and the level parallel to the lateral femoral epicondyle during four self-stretching exercises. All data were found to approximate a normal distribution. We used a one-way repeated-measures analysis of variance (ANOVA) to compare the thickness of the ITB among all self-stretching exercises. The level of significance was set at ${\alpha}$=.05. The ANOVA was followed by Bonferroni's correction. The overall mean of ITB thickness was $1.14{\pm}.4$ mm (${\pm}$ standard deviation) in resting status. The change in the ITB thickness in percentages between the tested position of each self-stretching exercises and resting status was significant (p<.05) (Side-lying $26.62{\pm}10.18%$ with 95% confidence interval [CI]=21.99~31.25%; Standing A $29.46{\pm}16.19%$ with 95% CI=22.09~36.84%; Standing B $44.06{\pm}14.82%$ with 95% CI=37.31~50.81%; Standing C $53.76{\pm}12.1%$ with 95% CI=48.25~59.29%). Results indicated significant differences among four self-stretching exercises except Side-lying versus Standing A (p<.01). Based on these findings, the Standing C self-stretching exercise was the most effective in stretching the ITB thickness among four types of ITB self-stretching exercises. Additionally, the Side-lying self-stretching exercise using gravity to stretch the ITB is recommended as a low-load (low-intensity), long-duration stretch.