• Resources Recycling
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• v.1 no.1
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• pp.14-22
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• 1992

As a basic study to recover the copper from the copper converter slag, the characterisitcs of converter slag was studied. The results obtained in this work are as follows. 1. The copper converter slag is composed of Cu, $Cu_2$S, $Fe_3$$O_4$, Fayalite and silicate. 2. It is supposed that magnetite in converter slag is oxidized to hematite at $720^{\circ}C$ and this phase is soluted to fayalite. 3. As the converter slag is added in the water solution, pH increased and the heavy metal ions in the water are adsorbed on the slag. 4. Work index of the converter slag cooled for the 10 hour and the 2 hour are 25~27 kWh/ton and 35 kWh/ton, respectively. 5. In the case of grinding test of converter slag, fayalite in converter slag is easily grinded than magnetite in converter slag.

• Journal of Family Resource Management and Policy Review
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• v.10 no.3
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• pp.131-148
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• 2006

The purpose of this study is to examine the allocation of time between work and leisure by the rural elderly in Korea. The data used for this study are collected from fm households during the peak ($17^{th}\;to\;30^{th}$ June) and off-peak ($28^{th}$ November to $10^{th}$ December) farming seasons of 2005 using time diary. The sample for this study consists of 120 elderly over 65 years old living in rural area in eight provinces. The major findings are as follows. (1) The time spent of farm work by rural elderly in much longer than average work hours of elderly in general regardless of farming season. The indicates that the elderly farmers are the sustaining forces of agriculture as the urban industrial sector absorbs the younger labor force rural area. (2) There are significant differences in the work time(including form work, housework, and farm work plus house work) by gender, age, education, marital status, living arrangements. (3) The rural elderly spends less time in leisure compared to the elderly in general even during the off-peak season. (4) Especially during the peak season, time allocation between work and leisure by the rural elderly is heavily skewed, resulting in an inadequate amount of time for reproduction of labor. (5) There is only significant age difference in the amount leisure time regardless of farming season. (6) Male elderly farmers work approximately 30 minutes to 1 hour longer on farm than the females do, but the total work time (farm work plus housework) of female elderly is longer than that of the male elderly. There is no significant gender difference in the amount of leisure time during the peak season, whereas the men have more leisure than the women during the off-peak season. To conclude, the gender differences in time allocation among the rural elderly are minimal. However, the rural elderly of both genders suffers from excessive work hours and heavy workload compared to the urban counterpart.

• Journal of Nutrition and Health
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• v.35 no.7
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• pp.800-817
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• 2002

It is not stipulated concretely in the Food Sanitation Act what the standardized school food service dieticians indices and the dietician's duties and task elements should be. Therefore, this study was required. The specific purposes of this study were : a) to define the school food service dietician's duties and task elements, b) to estimate the performance frequency and work hours of the dietician's duties and task elements c) to investigate the job specification of the dietician over school food services, d) to develop the standardized indices of the dietician needed in school food service operation. For this study, school food service dietician's work functions were defined in 10 duties and 60 task elements based on the studies precedented and literature review and pilot test process. This study was conducted in school food service systems nationwide using written questionnaire and interview with the official in charge and delphi technique. The questionnaires were mailed to the dieticians of three types of school food service systems. Of the 660 schools that participated in this study, the 624 responses were selected for analysis. Statistical analyses were performed with SAS/Win 6.12 program so as to provide a descriptive statistics, T-test, ANOVA. The main results of this study could be summarized as follows: A characteristic common to all the school food service systems was that 'cooking and distribution management' took the longest hours of work, while 'nutrition education' took the shortest hours of work. The standardized index of dietician over school food service was one person in conventional system independently of the number of meals per day. In the commissary system, according to the numbers of meals served per day, it was 0.95-1.38 persons and 1.27-1.55 persons and 1.40-1.91 persons. In joint management system, the standardized index was 1.03-1.42 persons in case of serving less than 700 meals per day.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.15 no.5
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• pp.83-94
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• 2016

Providing a voice alarm to drivers approaching a work zone could be an effective alternative to mitigate the potential safety problems of the work zone. This study conceived a voice alarm with a direction sound speaker and a field test was conducted that evaluated the feasibility of the voice alarm at a highway work zone. During the field study, we carried out on-site driver surveys to obtain drivers' perception and preference, collected approaching speeds, and measured sound level during the off-peak 2-hour for two days, respectively. The results showed that while the voice alarm has the potential to be an effective tool in improving safety, the alternative appeared to have the negative effect of noise. Further refinement to a voice alarm with a directional speaker is required to improve feasibility, and the results are expected to be utilized as basic data useful for the refinement.

• Journal of the Korean Society of Physical Medicine
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• v.12 no.2
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• pp.113-120
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• 2017

PURPOSE: The purpose of this study was to investigate the effect of a physical therapy-based tailored exercise program on pain, accident incidence rates, the number of work days lost, and economical loss cost for workers in an automobile parts manufacturing company. METHODS: A total of 530 workers with musculoskeletal symptoms were given a physical therapy-based tailored exercise program twice a week, for one hour a day. This exercise program consisted of movement pattern correction, muscle stretching and strengthening, and postural correction exercises, according to principles of movement impairment syndromes and medical training therapy. From 2011 to 2016, the lost days of work, accident incidence rates, and loss cost were examined. The pain measured by VAS (visual analogue scale) and the number of workers participating in the exercise program from 2014 to 2016 were also measured. The single subjects A-B design was applied and analyzed. RESULTS: After applying the exercise program, pain decreased and the number of workers participating in the program increased. Accident incidence rates, number of work days lost, and economical loss cost decreased. There was a significant correlation between the number of workers who received exercise therapy by year and accident incidence rates, lost days of work, and economical loss cost (p<.05). CONCLUSION: It is necessary to expand the physical therapy-based tailored exercise program to prevent musculoskeletal disorders because it has a positive effect on both workers and employers.

• Journal of the Korean Society of Safety
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• v.10 no.3
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• pp.81-95
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• 1995

Now, safety assurance in construction sites should be accomplished by its own organization rather than control of the code or government. It is believed that the safety assurance can be considerably improved by a lecture or an education using the existing theories or literatures up to now, but it is thought that fundamental safety assurance we not able to be accomplished without developing safety devices '||'&'||' equipment or taking fundamental measures, based on the result analyzed from workers behaviors. There are various behaviors of the workers showed in construction site, but only tests for hammerusing works such as form, re-bar, stone workers directly related to the grip strength are mainly performed, investigated and measured here for the study. The above works are similar to power grip, 7th picture on seven items which are categorized for hand grip types(Ammermin 1956 ; Jones ; Kobrick 1958). Measurements of grip strength are commonly taken in anthropometric surveys. They are easy to administer but unfortunately it is rather dubious whether they yield any data that are of interest to the engineer. Very fewer controls of tools are grasped and squeesed studies showed very little overall correlation between grip strength and other measures of bodily strength (Laubach, Kromer, and Thordsen 1972), but hammer-using work which is practically progressed in construction site are mainly influenced with grip strength. According to the investigation on work measurement, it is shown that 77% of form worker are using hammer to be related to grip strength. In this study, it is particularly noticed that wearing safety gloves in construction site is required for workers safety but 20% difference between grip strength with safety gloves and without ones are commonly neglected in the site(Fig. 1). Nevertheless, safety operation with consideration of the above 20% difference is not considered in the construction site. Factors of age, kinds of work, working time, with or without safety gloves are in vestigated '||'&'||' collected at the sites for this study. Test, not at each working hour but at 14 : 00 when the almost all of the workers think the most tired, resulting from the questionaires, also when it is shown on the research report has been performed and compared for main kinds of works : form '||'&'||' re-bar work. Tests were performed with both left SE rightand of the workers simultaneously in construction site using Rand Dynamometer(Model 78010, Lafayette Instrument Co., Indiana, U.S.A) by reading grip strength on the gauge while they are pulling, and then by interviewing on their ages, works, experiences and etc., directly. The above tests have been performed for the dates of 15th march-26th May '95 with consideration of site condition. And even if various factors of ambient temperature on the testing date, working condition, individual worker's habit and worker's condition of the previous ate are concerned with the study. Those are considered as constants in this study. Samples are formwork 53, rebar 62, electrician 5, plumber 4, welding 1 from D construction Co., Ltd, ; formwork 12, re-bar 5, electrician 2, from S construction Co., Ltd, , formwork 78, re-bar 18, plumber 31, electrician 13, labor 48, plumber 31, plasterer 15, concrete placer 6, water proof worker 3, maisony 5 from B construction Co., Ltd. As In the previously mentioned, main aspect to be investigated in this study will be from '||'&'||' re-bar work because grip strength will be directly applied to these two kinds of works ; form '||'&'||' re-bar work, eventhough there are total 405 samples taken. It is thought that a frequency of accident occurrence will be mainly two work postures "looking up '||'&'||' looking down" to be mainly sorted, but this factor is not clarified in this study because It will be needed a lot of work more. Tests has been done at possible large scale of horizontally work-extended sites within one hour in order to prevent or decrease errors '||'&'||' discrepancies from time lag of the test. Additionally, the statistical package computer program SPSS PC＋has been used for the study.

• Journal of the Society of Disaster Information
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• v.19 no.4
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• pp.806-814
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• 2023

Purpose: According to the Occupational Safety and Health Act of the Ministry of Employment and Labor, in order to prevent industrial accidents, the right to stop work must be exercised in the event of an imminent danger. This study conducted a fact-finding survey on whether employers fulfilled the right to suspend work in the workplace when an imminent danger, such as a typhoon, was encountered. Method: For two days from August 9 to October, when the impact of Typhoon Khanun No. 6 was significant, it was confirmed by wire whether or not the work suspension was carried out at the workplace, and the subjects of the survey were 1,649 construction sites, 830 manufacturing sites, and 278 other industries, for a total of 2,757 sites. Result: As a result of the fact-finding survey, 56% (1,555 locations) on August 9th and 77% (2,142 locations) on August 10th carried out full or partial work suspension. In particular, on August 10, when the typhoon landed, 40% of all workplaces completely stopped work. Conclusion: Through this study, it was confirmed that the right to suspend work by employers is being used in actual workplaces. In the future, when there is an imminent danger, in addition to the right to suspend work, flexible and telecommuting, working hour adjustments, etc. must be actively used to ensure the safety of workers and protect their lives.

• Journal of Korean Port Research
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• v.5 no.2
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• pp.19-37
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• 1991

This work aims to : establish a model of the container physical distribution system of Pusan port comprising 4 sub-systems of a navigational system, on-dock cargo handling/transfer/storage system, off-dock CY system and an in-land transport system : examine the system regarding the cargo handling capability of the port and analyse the cost of the physical distribution system. The overall findings are as follows : Firstly in the navigational system, average tonnage of the ships visiting the Busan container terminal was 33,055 GRT in 1990. The distribution of the arrival intervals of the ships' arriving at BCTOC was exponential distribution of $Y=e^{-x/5.52}$ with 95% confidence, whereas that of the ships service time was Erlangian distribution(K=4) with 95% confidence, Ships' arrival and service pattern at the terminal, therefore, was Poisson Input Erlangian Service, and ships' average waiting times was 28.55 hours In this case 8berths were required for the arriving ships to wait less than one hour. Secondly an annual container through put that can be handled by the 9cranes at the terminal was found to be 683,000 TEU in case ships waiting time is one hour and 806,000 TEU in case ships waiting is 2 hours in-port transfer capability was 913,000 TEU when berth occupancy rate(9) was 0.5. This means that there was heavy congestion in the port when considering the fact that a total amount of 1,300,000 TEU was handled in the terminal in 1990. Thirdly when the cost of port congestion was not considered optimum cargo volume to be handled by a ship at a time was 235.7 VAN. When the ships' waiting time was set at 1 hour, optimum annual cargo handling capacity at the terminal was calculated to be 386,070 VAN(609,990 TEU), whereas when the ships' waiting time was set at 2 hours, it was calculated to be 467,738 VAN(739,027 TEU). Fourthly, when the cost of port congestion was considered optimum cargo volume to be handled by a ship at a time was 314.5 VAN. When the ships' waiting time was set at I hour optimum annual cargo handling capacity at the terminal was calculated to be 388.416(613.697 TEU), whereas when the ships' waiting time was set 2 hours, it was calculated to be 462,381 VAN(730,562 TEU).

• Safety and Health at Work
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• v.6 no.3
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• pp.192-199
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• 2015

Background: Overweight, obesity, and cardiovascular disease risk factors are prevalent among firefighters in some developed countries. It is unclear whether physical activity and cardiopulmonary fitness reduce cardiovascular disease risk and the cardiovascular workload at work in firefighters. The present study investigated the relationship between leisure-time physical activity, cardiopulmonary fitness, cardiovascular disease risk factors, and cardiovascular workload at work in firefighters in Hong Kong. Methods: Male firefighters (n = 387) were randomly selected from serving firefighters in Hong Kong (n = 5,370) for the assessment of cardiovascular disease risk factors (obesity, hypertension, diabetes mellitus, dyslipidemia, smoking, known cardiovascular diseases). One-third (Target Group) were randomly selected for the assessment of off-duty leisure-time physical activity using the short version of the International Physical Activity Questionnaire. Maximal oxygen uptake was assessed, as well as cardiovascular workload using heart rate monitoring for each firefighter for four "normal" 24-hour working shifts and during real-situation simulated scenarios. Results: Overall, 33.9% of the firefighters had at least two cardiovascular disease risk factors. In the Target Group, firefighters who had higher leisure-time physical activity had a lower resting heart rate and a lower average working heart rate, and spent a smaller proportion of time working at a moderate-intensity cardiovascular workload. Firefighters who had moderate aerobic fitness and high leisure-time physical activity had a lower peak working heart rate during the mountain rescue scenario compared with firefighters who had low leisure-time physical activities. Conclusion: Leisure-time physical activity conferred significant benefits during job tasks of moderate cardiovascular workload in firefighters in Hong Kong.

• Safety and Health at Work
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• v.2 no.1
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• pp.39-51
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• 2011

Objectives: This study was designed to evaluate exposure levels of various chemicals used in wafer fabrication product lines in the semiconductor industry where work-related leukemia has occurred. Methods: The research focused on 9 representative wafer fabrication bays among a total of 25 bays in a semiconductor product line. We monitored the chemical substances categorized as human carcinogens with respect to leukemia as well as harmful chemicals used in the bays and substances with hematologic and reproductive toxicities to evaluate the overall health effect for semiconductor industry workers. With respect to monitoring, active and passive sampling techniques were introduced. Eight-hour long-term and 15-minute short-term sampling was conducted for the area as well as on personal samples. Results: The results of the measurements for each substance showed that benzene, toluene, xylene, n-butyl acetate, 2-methoxy-ethanol, 2-heptanone, ethylene glycol, sulfuric acid, and phosphoric acid were non-detectable (ND) in all samples. Arsine was either "ND" or it existed only in trace form in the bay air. The maximum exposure concentration of fluorides was approximately 0.17% of the Korea occupational exposure limits, with hydrofluoric acid at about 0.2%, hydrochloric acid 0.06%, nitric acid 0.05%, isopropyl alcohol 0.4%, and phosphine at about 2%. The maximum exposure concentration of propylene glycol monomethyl ether acetate (PGMEA) was 0.0870 ppm, representing only 0.1% or less than the American Industrial Hygiene Association recommended standard (100 ppm). Conclusion: Benzene, a known human carcinogen for leukemia, and arsine, a hematologic toxin, were not detected in wafer fabrication sites in this study. Among reproductive toxic substances, n-butyl acetate was not detected, but fluorides and PGMEA existed in small amounts in the air. This investigation was focused on the air-borne chemical concentrations only in regular working conditions. Unconditional exposures during spills and/or maintenance tasks and by-product chemicals were not included. Supplementary studies might be required.