• 한국산업보건학회지
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• 제22권4호
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• pp.316-328
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• 2012

Objectives: This study was designed to provide the information regarding chemicals classification and health hazard by evaluating the toxicological effect through repeated inhalation exposure of methyl acrylate(MA) in Sprague-Dawley(SD) rat for 13 weeks. Methods: According to the notification with Ministry of Labor(No. 2009-68) and OECD Test Guideline 413, the rats were exposed to MA at concentration of 0, 56, 168, 280 ppm via whole body inhalation for 6 hours per day, 5 days per week, for 13 weeks. All animals were observed for mortality, morbidity and the change of body weight and food consumption were determined during the exposure period. Necropsy finding, organ weight, hematology, clinical biochemistry and histopathological examination following exposure were also performed. Results: There were no death and abnormal clinical signs relate to exposure MA. However, At 160 ppm and 280 ppm exposure groups, body weight and food consumption showed statistically significant decrease and histopathological changes in lung, trachea, nasal cavity, larynx were observed. Conclusions: MA was mainly affected respiratory tract. It is consequently provided to be classified as category 2(0.2 mg/L/6h < category 2 ${\leq}$ 1.0 mg/L/6h) for specific target organ toxicity following repeated exposure according to Standard for Classification and Labeling of Chemical Substance and Material Safety Data Sheet. The NOAEL(no observable adverse effect level) of MA was also determined to be lower than 56 ppm.

• 대한안전경영과학회지
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• 제24권2호
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• pp.11-16
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• 2022

When picking up cargo, workers manually load and unload the cargo. Workers have different intensity of work depending on the amount and weight of cargo. In particular, as the intensity of manual work increases, workers are exposed to cumulative traumatic diseases. A manual for picking safety work for workers cargo handling in the distribution center is required. In this study, the worker's picking safety work based on the cargo volume and weight was presented as an experimental design model. Like the research results, the disease begins when the worker feels the number of pains presented by the model.

• 한국산업보건학회지
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• 제15권3호
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• pp.153-159
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• 2005

The purpose of this study was to assess the ergonomic risks of lifting tasks in a marine diesel engine manufacturing industry using the National Institute for Occupational Safety and Health(NIOSH) Revised Lifting Equation(NLE). Average Lifting Index(LI=Weight of Load/Recommended Weight Limit) of a total number of 45 lifting tasks was $1.6{\pm}0.7$. The LIs were above 1 at 34 tasks(75.6%), and above 2 at 11 tasks(24.4%). Parts management showed the highest average LI value (LI=2.3) in all departments, which resulted from high frequency and heave load of lifting. The common and significant ergonomic risk factors in the processes were the heavy weight of diesel engine parts and the long horizontal distance. In addition, some lifting tasks had such potential risk factors as the long vertical distance, the high frequency of lifts or the long work duration.

• 한국식품위생안전성학회지
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• 제17권1호
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• pp.15-19
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• 2002

The objectives of this study were to investigate the change of silicon, cations and anions dissolved in water before and after thawing, and analyzed what the white-colored precipitate (WP) farmed after thawing was composed of. The silicon concentration that has been changed might have been compared with the weight of WP under water-free state. The major component of WP has been approved to be a silicon, while calsium was only a little contained. As the weight of WP has been nearly equal to the reduced silicon concentration, the weight of its could be changeable calculated by silica (SiO$_2$) molecular weight. Therefore, WP could have been presumed to be a silica. The more silicon concentration was increased, the more weight of silicon was increased. Except for the sample "C", the amounts of cations and anions could be found to be unchangeable nearly. As a result of that, WP has been apparent to be silica itself while most of ions (excluded with Si) of any others were not changed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 D
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• pp.1639-1641
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• 1999

This paper deals with the seasonal variation of soil resistivity and the special characteristic for ground rods by lapse of time. The ground resistance was changed by humidity, temperature of earth and earth resistance. In this experiment, we studied the resistivity during the period from June 1995 to May 1996 by the soil and the corrosion of the ground rods. As a result, the soil resistivity during the period are appeared minimum in summer and maximum in winter. The loss in weight of Fe rod appeared higher than Cu, Al, Cu-Zn, and St. In the lapse of time, Fe rod was reduced 1.2 % later two years and 1.95 % later three years in weight. Cu rod was defected oxygens of 14.7 % later two years and 30.3 % later three years by EDX.

• 한국농공학회논문집
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• 제55권3호
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• pp.85-89
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• 2013

In the current domestic, many industrial accidents have happened. And these are analyzed according to several factors. But it is difficult that they evaluate their business safety. Thus, we conducted a study on business specific safety assessment techniques in order that business know their safety level and perform appropriative safety activities. Study methods are survey and AHP (Analytic Hierarchy Process). Each specific weighting factors to calculate the survey was conducted for safety and consulting experts (20 persons). Weight factor was used to AHP decision support as one of the ways through a number of alternatives to the ratings for the Minesota Multiphasic. Factors are each type of industry, specific industrial scale, disaster type and strength, worker age and tenure period, and region. First, survey was conducted with 20 professionals to estimate the weighting factors. Weights between factors using the AHP analysis tool based on the mean values were calculated. Second, last 3 years between the industrial accidents statistics were used to calculate the weights for each of the rating factors in the Occupational Safety and Health Agency. Grade weights between each factor which was based on the rating of each factor was calculated as the average of three years. Finally, the weights between each factor and the grade weights for each factor using the safety level of the enterprise were calculated so that you can evaluate the weighting.

• Geomechanics and Engineering
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• 제6권2호
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• pp.99-115
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• 2014

Uncertainties in design variables and design equations have a significant impact on the safety of geotechnical structures like retaining walls and slopes. This paper presents a possible framework for obtaining the partial safety factors based on reliability approach for different random variables affecting the stability of a reinforced concrete cantilever retaining wall and a slope under static loading conditions. Reliability analysis is carried out by Mean First Order Second Moment Method, Point Estimate Method, Monte Carlo Simulation and Response Surface Methodology. A target reliability index ${\beta}$ = 3 is set and partial safety factors for each random variable are calculated based on different coefficient of variations of the random variables. The study shows that although deterministic analysis reveals a safety factor greater than 1.5 which is considered to be safe in conventional approach, reliability analysis indicates quite high failure probability due to variation of soil properties. The results also reveal that a higher factor of safety is required for internal friction angle ${\varphi}$, while almost negligible values of safety factors are required for soil unit weight ${\gamma}$ in case of cantilever retaining wall and soil unit weight ${\gamma}$ and cohesion c in case of slope. Importance of partial safety factors is shown by analyzing two simple geotechnical structures. However, it can be applied for any complex system to achieve economization.

• 대한안전경영과학회지
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• 제25권2호
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• pp.17-28
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• 2023

This study aimed to verify the validity of the evaluation items and weight determination of the indoor environmental safety area, which has the most frequent accidents, among the safety certification evaluations of educational facilities by the Ministry of Education of the Republic of Korea, which has been conducted since May 2021. As a preceding study, the evaluation items of the school safety evaluation checklist being implemented in the US state of Vermont were compared, and the causes of accidents judged by teachers in the accident experiences written by 200 Korean teachers were compared with the safety certification evaluation items belonged to the Ministry of Education. In addition, research literature using the AHP analysis technique on safety risks of elementary and secondary schools in China and safety evaluation index study cases of 539 elementary school children in Indonesia were analyzed. Through these preceding studies, measures to add and adjust evaluation items were derived and the validity and importance rankings of evaluation items were calculated through AHP questionnaires to teachers and safety experts. In addition, a survey was conducted on 104 ordinary people to verify the results of expert analysis. As a result of expert AHP analysis, 'safety education and disaster response training (.396)' was the highest priority for the relative importance of the first layer, followed by 'safety measures (.387)' and 'building materials'. Safety (.216)' was found to be the highest priority. In the overall importance ranking of the 13 second-tier screening items, safety accident prevention education had the highest priority and disaster preparedness training ranked second, proving that the Ministry of Education's review weight was underestimated. In addition, slip and collision accident countermeasures, which were not in the existing Ministry of Education review items, ranked 4th, laboratory practice room safety measures ranked 6th, and sanitation, cleanliness, hazardous substance management, and cafeteria/cooking room safety measures ranked 9th, indicating a significant level of importance. Referring to the importance ranking, which is the result of this study, it is suggested that it is necessary to review the weight of each review item again.

• 한국운동역학회지
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• 제14권3호
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• pp.67-82
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• 2004

The purpose of this study was to evaluate the function and the safety of an additional weight shoe developed for the improvement of aerobic capacity, and to improve some problems found by subject's test for an additional weight shoe. The subjects employed for this study were 10 college students. 4 video cameras, AMTI force platform and Pedar insole pressure distribution measurement device were used to analyze foot motions. The results of the study were as follows: 1 The initial achilles tendon angle and initial rearfoot pronation angle of an additional weight shoe during walking were 183.7 deg and 2.33 deg, respectively, and smaller than a barefoot condition. Maximum achilles tendon angle and the angular displacement of achilles tendon angle were 185.35 deg and 4.21 deg respectively, and smaller than barefoot condition. Thus rearfoot stability variables were within the permission value for safety. 2. Maximal anterior posterior ground reaction force of additional weight shoe was appeared to be 1.01-1.2 B.W., and was bigger than a barefoot condition. The time to MAPGRF of an additional weight shoe was longer than a barefoot condition. Maximal vertical ground reaction force of additional weight shoe was appeared to be 2.3-2.7 B.W., and was bigger than a barefoot condition in propulsive force region. But A barefoot condition was bigger in braking force region. The time to MVGRF of an additional weight shoe was longer than a barefoot condition. 3. Regional peak pressure was bigger in medial region than in lateral region in contrast to conventional running shoes. The instant of regional peak pressure was M1-M2-M7-M4-M6-M5 -M3, and differed form conventional running shoes. Regional Impulse was shown to be abnormal patterns. There were no evidences that an additional weight shoe would have function and safety problems through the analysis of rearfoot control and ground reaction force during walking. However, There appeared to have small problem in pressure distribution. It was considered that it would be possible to redesign the inner geometry. This study could not find out safety on human body and exercise effects because of short term research period. Therefore long term study on subject's test would be necessary in the future study.

• 한국식품위생안전성학회지
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• 제5권3호
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• pp.111-120
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• 1990

정상 마우스와 Cyclophosphamide(CY)로 처리된 마우스에 Royal Jell(RJ)를 투여하여 면역계에 미치는 영향을 실험한 결과 다음과 같은 결론을 얻었다. 1. 정상 마우스에 RJ를 투여하였을 때는 대조군에 비하여 마우스의 체중, 비장, 흉선 , WBC 수 , DNFB에 대한 접촉성 과민 반응으로 측정된 세포성 면역반응 및 면양 적혈구에 대한 응집가와 용혈가로 측정된 체액성 면역 반응이 투여일에 따라 증가 또는 감소되었고, RBC수와 간 중량은 영향을 받지 않았다. 2. 증가 작용을 보여준 투여일에 RJ를 병용 투여함으로써, CY 처리로 인한 마우스의 생존율, 비장의 중량 , WBC수 및 세포성 면역 반응의 감소가 약간 억제되었으나, CY를 감소된 흉선의 중량 및 체액성 면역반응에는 영향을 나타내지 않았다.