• 대한인간공학회지
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• 제21권2호
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• pp.25-33
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• 2002

The purpose of study is to investigate the relationship between the trunk muscle fatigue and recovery time during repetitive extension by using a surface electromyogram(EMG). Ten healthy subjects particioated in a simulated lifting task with five levels of recovery time and three levels of sub-maximal contraction. EMG signals of the L1(Lumbar 1st Vertebrae) and L3(Lumbar 3rd Vertebrae) level of the erector spinae muscle were recorded. and analyzed in terms of MPF(mean power frequency) parameter to quantify the level of muscle fatigue. It was found that MPF significantly (p<0.05) decreased during repetitive extension task at 50% and 75% sub-maximal contractions. Then it took minutes for the trunk muscle to recover from fatigue during 50% sub-maximal contraction. and it took five minutes during 75% sub-maximal contraction. and it took five minutes during 75% sub-maximal contraction. The recovery time estimated by the maximum force needs to be re-evaluated for the trunk muscle to fully recover from fatigue. In conclusion. the work/rest cycle needs to be studied based upon the information of muscle fatigue in order to prevent workers from musculoskeletal injuries during repetitive lifting task.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권4호
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• pp.1282-1301
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• 2015

Traditional infrastructure has been superseded by cloud computing, due to its cost-effective and ubiquitous computing model. Cloud computing not only brings multitude of opportunities, but it also bears some challenges. One of the key challenges it faces is recovery of computing nodes, when an Information Technology (IT) failure occurs. Since cloud computing mainly depends upon its nodes, physical servers, that makes it very crucial to recover a failed node in time and seamlessly, so that the customer gets an expected level of service. Work has already been done in this regard, but it has still proved to be trivial. In this study, we present a Cost-Time aware Genetic scheduling algorithm, referred to as CTaG, not only to globally optimize the performance of the cloud system, but also perform recovery of failed nodes efficiently. While modeling our work, we have particularly taken into account the factors of network bandwidth and customer's monetary cost. We have implemented our algorithm and justify it through extensive simulations and comparison with similar existing studies. The results show performance gain of our work over the others, in some particular scenarios.

• 대한물리치료과학회지
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• 제11권4호
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• pp.5-10
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• 2004

This study selected 10 university football male players and repeatedly treated them as sports massage group, exercise resumption group, and stability resumption. After maximum exercise, when sport massage, exercise resumption, and stability resumption were applied during recovery, blood lactic acid concentration and $LDH_5$ isozyme concentration were examined. Finally this study obtains the following conclusion 1. There was a significant difference in both lactic acid concentration and time between groups. Besides, the cross-action on group and time was significant. 2. There was a significant difference in both $LDH_5$ concentration and time between groups. Besides, the cross-action on group and time was significant. Based on the above findings, this study suggests that sport massage resumption and exercise resumption remove blood lactic acid more quickly than stability resumption to promote recovery. That means that sport massage and exercise resumption anre very effective for lowering the level of fatigue. Thus sport massage or exercise resumption treatment is considered to have a very positive effect on player's quick recovery and it should be used aggressively in a field.

• 한국산학기술학회논문지
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• 제13권10호
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• pp.4786-4793
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• 2012

최근 모바일 컴퓨팅 환경에서 실시간 트랜잭션 처리에 대한 트랜잭션 모델에 대한 연구가 활발히 진행되고 있다. 그러나 회복모델에 대한 연구는 상대적으로 미흡하다. 이러한 모바일 컴퓨팅 환경에서는 핸드오프가 발생하였을 경우 데이터 손실이 발생하므로 데이터베이스의 안정성을 위한 모바일 회복기법은 매우 중요하다. 그래서 모바일 컴퓨팅 환경에서는 입출력을 줄일 수 있는 효율적인 회복기법에 대한 연구가 절실히 요구된다. SLL기법은 순차파일로 구성되어 있기 때문에 입출력시간이 증가된다. 본 연구에서는 모바일 컴퓨팅 환경에서 효율적인 모바일 회복 기법을 제안하였다. 마지막으로 제한한 회복기법의 성능평가를 수행하여 효율성을 입증하였다.

• 한국자동차공학회논문집
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• 제20권2호
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• pp.78-84
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• 2012

The purpose of this study is to investigate the performance characteristics of new exhaust heat recovery device for the engine's fast warm-up. In this study, two different interior area designed for prototyping and on the exhaust heat recovery device to evaluate the performance compare the performance characteristics were chosen a better product. A company's product and selected prototype-2 were evaluated and compared the performance. This experiment was conducted under the same conditions. The time from starting to warm-up of engine was measured. As a result, the performance characteristics of the prototype-2 was not higher than that of the A company's product. However, in comparison with base system, prototype-2 of the exhaust heat recovery device discover that the warm-up time was shortened.

• 조명전기설비학회논문지
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• 제24권9호
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• pp.159-164
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• 2010

We experiment to analyze on current limiting and recovery characteristics of trigger type SFCL as the composition of the contact. Generally, some superconductor of SFCL is relatively largely loaded due to limit the fault current by oneself and recovery time is affected until the fault cleared. However, in the fault, the proposal trigger type SFCL transfer the fault current to current limiting reactor(CLR) using power switch so it could reduce the recovery time and load of the superconductor. However, because of applying the additional power switches, that could generate some power loss. Therefore, to solve this problem, we proposed the composition method of the double contact for a trigger type SFCL and analyzed on current limiting and recovery characteristics for ones.

• PNF and Movement
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• 제6권3호
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• pp.1-9
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• 2008

Purpose : The purpose of this study was to analyze the reaction of recovery for the fatigue by sports massage treatment after Taekwondo training and then to verify the effectiveness. Subject : The subjects of this study were all the 20 high school Taekwondo players divided into two groups (rest recovery group and sports massage group) selected by systematic random assignment sampling. Method : The variables were the level of hemoglobin, lactic acid and glucose, and measured at rest, immediately-after exercise and 30-minute recovery. The data from this study were analyzed by using one-way ANOVA, independent sample t-test. Results : The results are as follows ; 1. The measurement of the hemoglobin, there was not the significant differences between experiment group and control group. 2. The lactate showed lower in the experiment group than in the control group in 30-minute recovery (p<.001). 3. The glucose showed lower in the experiment group than in the control group in 30-minute recovery (p<.01). So I think the sports massage treatment is more effective in the relief of fatigue than static rest method during the recovery after sports. However the massage treatment influence on the activation of metabolism according to the intensity and the duration of sports, and vary the effect of treatment according to the method and execution time. Therefore the longitudinal investigation of the variation by the long time massage through the more detailed program must be requisite for us.

• Membrane and Water Treatment
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• 제12권1호
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• pp.1-9
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• 2021

This study optimized the chemical cleaning process of discarded RO membranes for reuse in less demanding separation processes. The effect of physicochemical parameters, including the temperature, cleaning time, pH of the cleaning solution, and addition of additives, on the cleaning process was investigated. The membrane performance was evaluated by testing the flux recovery rate and salt rejection before and after the cleaning process. High temperatures (45-50 ℃) resulted in a better flux recovery rate of 71% with more than 80% salt rejection. Equal time for acid and base cleaning 3-3 h presented a 72.43% flux recovery rate with salt rejection above 85%. During acid and base cleaning, the best results were achieved at pH values of 3.0 and 12.0, respectively. Moreover, 0.05% concentration of ethylenediaminetetraacetic acid presented 72.3% flux recovery, while 69.2% flux was achieved using sodium dodecyl sulfate with a concentration of 0.5%; both showed >80% salt rejection, indicating no damage to the active layer of the membrane. Conversely, 0.5% concentration of sodium percarbonate showed 83.1% flux recovery and 0.005% concentration of sodium hypochlorite presented 85.2% flux recovery, while a high concentration of these chemicals resulted in oxidation of the membrane that caused a reduction in salt rejection.

• 한국주거학회논문집
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• 제16권5호
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• pp.67-74
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• 2005

The performance of building should be deteriorated with time while the building would maintain and manage the function and performance to get a living condition. For the efficient maintenance of the building, the repair cycle would be provided and applied during the service-life time. The service-life time of the building components would be needed to determine the repair time and the repair scope. The service-life time of the building components would be calculated with the 1st repair time and the recovery rate of the performance, considering the recovery rate after repaired. In this paper, the 1st repair time would be estimated with the normal probability distribution, choice probability and 3rd quadratic function. The recovery rate of the building components assumes various level according to the research target and utility area. The results of this study are as follows ; first, most of the components of the building work would range about 30 years in the service-life time and the components of the mechanical works range from 28 years to 37 years, those of the electrical works would be about 31 years.

• 전기전자학회논문지
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• 제19권1호
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• pp.94-100
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• 2015

본 논문에서는 U-MOSFET 내부의 기생 body 다이오드(PN diode)를 쇼트키 body 다이오드(Schottky body diode)로 대체한 50V급 전력 U-MOSFET을 제안하였다. 쇼트키 다이오드는 PN 다이오드와 비교 시, 역 회복 손실(reverse recovery loss)을 감소시킬 수 있는 장점을 가지고 있다. 따라서 전력 MOSFET의 기생 body 다이오드를 쇼트키 body 다이오드를 대신함으로써 역 회복 손실을 최소화 할 수 있다. 제안된 쇼트키 body 다이오드(Schottky body diode) U-MOSFET(SU-MOS)를 conventional U-MOSFET(CU-MOS)와 전기적 특성을 비교한 결과, 전달(transfer) 및 출력(output)특성, 항복(breakdown)전압 등 정적(static) 특성의 변화 없이 감소된 역 회복 손실을 얻을 수 있었다. 즉, 쇼트키 다이오드의 폭(width)이 $0.2{\mu}m$, 쇼트키 장벽 높이(Schottky barrier height)가 0.8eV일 때 첨두 역전류(peak reverse current)는 21.09%, 역 회복 시간(reverse recovery time)은 7.68% 감소하였고, 성능지수(figure of merit(FOM))는 35% 향상되었다. 제안된 소자의 특성은 Synopsys사의 Sentaurus TCAD를 사용하여 분석되었다.