• 대한임상전기생리학회지
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• 제10권1호
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• pp.1-5
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• 2012

Purpose : In this study, stroke patients' limits of stability and functional reach test and tibialis anterior, gastrocnemius muscle of lower extremity muscle activities to evaluate the correlation. Methods : 30 adult stroke patients to participate in this study. Limits of stability were measured using biorescue, tibialis anterior and gastrocnemius muscle of muscles activities were measured with functional reach test when there was movement. Results : Limits of stability and functional reach test (r=0.753, p<0.01), RMS value of the limits of stability and tibialis anterior muscle (r=0.706, p<0.01), RMS value of the limits of stability and gastrocnemius muscle (r=0.766, p<0.01), RMS value of the functional reach test and tibialis anterior muscle (r=0.835, p<0.01), RMS value of the functional reach test and gastrocnemius muscle (r=0.663, p<0.01), RMS value of the tibialis anterior and gastrocnemius muscle (r=0.816, p<0.01) correlations are shown as statistically significant. Conclusion : The balance and lower extremity muscle activities of stroke patients were studied, and were positively correlated with the RMS value of the limits of stability and functional reach test, tibialis anterior muscle, and gastrocnemius muscle. This study has shown that stroke patients' ankle joint muscle activity can greatly.

• Journal of Radiation Protection and Research
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• 제41권2호
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• pp.101-104
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• 2016

Background: To protect the public from natural radioactive materials, the 'Act on safety control of radioactive rays around living environment" was established in Korea. There is an annual effective dose limit of 1 mSv for products, but the activity concentration limit for products is not established yet. Materials and Methods: To suggest the activity concentration limits for consumer goods containing NORM, in this research, we assumed the "small room model" surrounding the ICRP reference phantom to simulate the consumer goods in contact with the human bodies. Using the Monte Carlo code MCNPX, we evaluate the effective dose rate for the ICRP reference phantom in a small room with dimension of phantom size and derived the activity concentration limit for consumer goods. Results and Discussion: The consumer goods have about 1600, 1200 and $19000Bq{\cdot}kg^{-1}$ for $^{226}Ra$, $^{232}Th$ and $^{40}K$, and the activity concentration limits are about six times comparing with the values of building materials. We applied the index to real samples, though we did not consider radioactivity of $^{40}K$, indexes of the some samples are more than 6. However, this index concept using small room model is very conservative, for the consumer goods over than index 6, it is necessary to reevaluate the absorbed dose considering real usage scenario and material characteristics. Conclusion: In this research, we derived activity concentration limits for consumer goods in contact with bodies and the results can be used as preliminary screening tool for consumer goods as index concept.

• 한국안전학회지
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• 제16권4호
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• pp.103-108
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• 2001

Explosive limit is one of the major physical properties used to determine the fire and explosion hazards of the flammable substances. Explosive limits are used to classify flammable liquids according to their relative flammability. Such a classification is important for the safe handling of flammable liquids which constitute the solvent mixtures. Explosive limits of all compounds and solvent mixtures can be calculated with the appropriate use of the fundamental laws of Raoult, Dalton, Le Chatelier and activity coefficient models. In this paper, Raoult,s law and van Laar equation(activity coefficient model) are shown to be applicable for the prediction of the explosive limits in the flammable ethylacetate-toluene system. The values calculated by the proposed equations were a good agreement with literature data within a given percent. From a given results, by the use of the proposed equations, it is possible to predict explosive limits of the other flammable mixtures. It is hoped eventually that this method will permit the estimation of the explosive Properties of flammable mixtures with improved accuracy and the broader application for other flammable stances.

• Journal of Radiation Protection and Research
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• 제24권3호
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• pp.171-184
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• 1999

본 논문에서는 저준위 환경방사능 측정시 이용되는 검출한계에 대한 기본개념 및 수식을 통계학적 이론을 기초로 서술하였다. 방사능을 정확하게 검출할 신뢰도를 95%로 설정하여 알파 베타 및 감마선 측정기에 대한 검출한계치값을 계산하였다. 또한 환경 방사능 계측에 많이 사용되는 방사능 핵종에 대해 최소 검출 방사능 농도값을 검출한계치 개념을 근거로 계산하여 저준위 환경 방사능 분석시 환경방사능 측정결과에 대한 신뢰도 평가에 활용 가능 하도록 하였다.

• 한국가스학회지
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• 제13권5호
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• pp.20-25
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• 2009

혼합물의 폭발하한계는 Raoult의 법칙, Dalton의 법칙, Le Chatelier 법칙 그리고 활동도계수 모델식을 이용하여 예측될 수 있다. 본 연구에서는 ethylacetate-ethanol 계와 ethanol+toluene 계의 폭발하한계를 예측하기 위해 Raoult의 법칙 그리고 활동도계수 모델식인 van Laar 식과 Wilson 식을 이용하였다. 계산값과 문헌값을 비교한 결과, Raoult의 법칙에 의한 계산값이 활동도 모델식에 의한 계산값 보다 모사성이 뛰어남을 확인하였다.

• 한국산업경영시스템학회:학술대회논문집
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• 한국산업경영시스템학회 2002년도 춘계학술대회
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• pp.69-78
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• 2002

This paper examines the effects on mental fatigue of changes in the intensity of physical activity. A treadmill-equipped instrument and perception tester were used to attain several levels of physical activity In this paper, In order to determine the individual levels of physical activity of subjects, Borg-RPE scale, Heart Rate(HR) and Respiratory Quotient(RQ) were used. Also, an addition test in whole-body activity on treadmill-equipped instrument as an indicator of mental fatigue were performed. In the above experiments, the scores obtained in addition test administered before and after physical activity at each intensity level used. Restricted within the limits of this paper, the results of these tests showed that mental fatigue decreased after physical activity.

• 산업경영시스템학회지
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• 제25권6호
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• pp.42-47
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• 2002

This paper examines the effects on mental task of changes in the intensity of physical activity. A treadmill-equipped instrument and perception tester were used to attain several levels of physical activity. In this paper, in order to determine the individual levels of physical activity of subjects, Borg-RPE scale, heart rate(HR) and respiratory quotient(RQ) were used. Also, an arithmetic addition test in whole-body activity on treadmill-equipped instrument as an indicator of mental task were performed. In the above experiments, the scores obtained in arithmetic addition test administered before and after physical activity at each intensity level used. Restricted within the limits of this paper, the results of these tests showed that the performance of mental task was Increased after physical activity.

• 한국안전학회지
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• 제16권4호
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• pp.182-187
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• 2001

This paper examines the effects on human reaction time and mental fatigue of changes in the intensity of physical activity. A treadmill-equipped instrument and perception tester were used to attain several levels of physical activity. In this paper, in order to determine the individual levels of physical activity of subjects, Borg-RPE scale, Heart Rate(HR) and Respiratory Quotient(RQ) were used. Also, a reaction test in whole-body activity on treadmill-equipped instrument and an addition test as an indicator of mental fatigue were performed. In the above experiments, the scores obtained in addition test administered before and after Physical activity at each intensity level used. Restricted within the limits of this paper, the results of these tests showed that mental fatigue decreased after physical activity.

• Journal of Korean Society for Atmospheric Environment
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• 제10권E호
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• pp.299-302
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• 1994

At a nuclear power plant, environmental radioactivity monitoring is routine work for the radiation safety management For the environmental monitoring of tritium($^3$H) activity in water sampled liquid scintillation counting( LSC) method is applied to measure low- energy beta activity from tritium in the samples. The $^3$H activity is measured using the BECKMAN 5801 system at the KRISS( Korea Research Institute of Standards and Science) for evaluating the lower limits of detection( LLD) of $^3$H measurement and the measuring capability of low-level $^3$H activity at four nuclear Power Plant sites. The LSC systems used for low-level $^3$H activity measurements at the nuclear Power Plants are confirmed to satisfy throughout an intercomparison study under the experimental arrangements by the KRISS.

• Ocean and Polar Research
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• 제25권2호
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• pp.133-145
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• 2003

Deep-sea surface sediments were collected using a multiple corer at 20 stations of Clarion-Clipperton fracture zone in the northeast equatorial Pacific to understand latitudinal and longitudinal variations of geotechnical properties. There was a distinct latitudinal variation of geotechnical properties in the study area. The northern sediments showed finer grain size, lower water content and porosity, higher bulk density and specific grain density, lower liquid limits and plastic limits than their southern counterparts. The northern sediments are classified into inorganic clays of low plasticity (fat clays) on plasticity charts and normal to active clay on activity chart, whereas, the southern sediments are classified into fine-grained, highly-plastic, inorganic and biogenic silt or organic clays on plasticity chart and normal to very active clay on activity chart. When shear strength are considered, the northern sediments were found to be in unconsolidated states, while the southern ones to be normal to over-consolidated states. These latitudinal variations in sediment characteristics are likely caused by differences in productivity of surface water that controls sediment compositions, sedimentation rates, and grain solubility.