• The Transactions of the Korean Institute of Electrical Engineers
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• v.40 no.8
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• pp.799-807
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• 1991

The various degradation phenomena, such as the evolution of gases, tan e, moisture content and total acid number in insulation oils of power transformer have been measured and analyzed as a function of aging temperatures and periods. The insulation oils have been degraded at laboratory in the period of 17, 34, and 72 days. We have also extracted the insulation oils from the working power transformers. The dissolved gases (such as CO, CO2, H2, CH4 C2H2---), tane, moisture content and total acid number in laboratory samples and field samples have been measured and characterized. It has been found that gases increase with degradation temperature and tane increases with total acid number while the moisture content does not increase with tane.

• Korean Journal of Health Education and Promotion
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• v.15 no.1
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• pp.151-163
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• 1998

The purpose of this study is to find options which reduce the job stress and to enhance morale through a variable analysis, and also apply this data in the legal and administration fields. The data for the research was obtained from 217 dental hygienists working in the dental clinics, dental hospitals and university's dental hospitals' in Seoul. The tool used by this study was a Questionnaire measuring on-the-job stress of dental hygienists, was a modified and revised. The Questionnaire version used to measure bank's job stress and used to suggest options by Dae-ha Yoon(1991). Classification of items for measuring job stress was based on Theoretical Study on Job Stress by Dae-hyon Song(1986). The scale used in study was the two points (yes or no in the job stress) scale measuring for variables. The period of data collection was 30 days from December 4, 1995 to January 5, 1996. The methods of data collection were self-writing, direct visit, and postal Questionnaire answering, 224 copies of Questionnaire data were collected, but only 217 copies were used. 7 copies could not be analyzed, were not used for this study. The data analysis was conducted by SPSS after coding the collected raw data. The general characteristics was obtained from real digits and percentages. In order to analyze the difference of sub-variables against the job stress based on general characteristics. Mean, Standard Deviation, and F test (ANDVA) were conducted. The following were the results of job stress variables: 1. Meaningful variable affecting the working organization, is compensation system(p〈0.03). 2. Meaningful variable affecting the working period, is work overload(p〈0.02). 3. Meaningful variable affecting average patients per day, is the career management and payment(p〈0.04, p〈0.01). 4. Meaningful variable affecting number of staff, is the comrade relationship, role conflict among patients, work overload, and job overload(p〈0.000, p〈0.05, p〈0.04, p〈0.01). The comrade relationship is most affected to the number of staffs aides. 5. Meaningful variables affecting job diversion, are the desire and value, the non-role play, and the environment(p〈0.003, p〈0.02, p〈0.005).

• Journal of Preventive Medicine and Public Health
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• v.19 no.2 s.20
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• pp.224-232
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• 1986

This study was conducted to evaluate health consequences of phenol resin workers for 6 weeks from February 21, to March 28, 1986. The subject population was 26 in a factory with phenol resin and control group was 30 non-exposed workers who were working in the other factory. The biological parameters chosen for this study were phenol concentration in working room-air, total phenol level in urine and BUN of phenol resin workers. The phenol concentration in working room-air and total phenol in urine were significantly correlated (r=0.791, p<0.01). The frequency of symptom and sign in phenol resin workers were higher than control group. The frequent symptom and sign were coughing, weight loss, poor appetite, headache, dyspnea, eye irritation and tinnitus, in order. Total phenol in urine was not reversed to normal range in spite of interruption of exposure for 4 days. The BUN value in blood and total phenol in urine were not correlated.

• Korea Journal of Hospital Management
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• v.25 no.3
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• pp.14-28
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• 2020

Purpose: The purpose of this study was to calculate the total daily nursing workload and the optimum number of nurses per intensive care unit (ICU) based on the nursing intensity and the direct nursing time per inpatient using the patient classification. Methods: Two ICUs at one general hospital were investigated. To calculate the nursing intensity, patient classification according to the nursing needs was conducted for 10 days in each unit during September 2018. We performed patient classifications for a total of 167 patient-days in the Medical Intensive Care Unit (MICU) and 86 patient-days in the Surgical Intensive Care Unit (SICU). The total number of person-days for nurses who responded to the Nursing Time survey was 151 for MICU and 85 for SICU. In each unit, direct and non-direct nursing hours, nursing intensity score, and direct nursing hours were analyzed using descriptive statistics such as frequency, percentage, and average calculated using Microsoft Excel. The amount of nursing workload and the optimum number of nurses were calculated according to the formula developed by the authors. Findings: For the MICU, the average direct nursing time per patient was 5.59 hours for Group 1, 6.98 hours for Group 2, and 9.28 hours for Group 3. For the SICU, the average direct nursing time per patient was 5.43 hours for Group 1, 7.21 hours for Group 2, 9.75 hours for Group 3, and 12.82 hours for Group 4. Practical Implications: This study confirmed that the appropriate number of nurses was not secured in the nursing unit of this study, and that leisure time such as meal time during nursing work hours was not properly guaranteed. The findings suggest that to create working environments where nurses can serve for extended periods of time without compromising their professional standards, hospitals should secure an appropriate number of nurses.

• Journal of Korean Academy of Nursing
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• v.24 no.2
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• pp.175-189
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• 1994

This study examined the daily rhythmic patterns of mood in shift workers. Ten rotating shift nurses (shift worker group) were matched with ten non-rotating student nurses (non - shift worker group) working under the same conditions at University Hospital. The subjects completed the Mood Adjective Checkist (MAC) every two or three hours from 6AM to 9-11 PM for six consecutive days. The MAC was constructed by Mansour and conversed the mood factors of Anger - Depression. Happiness, Mental, and Social. These data were analyzed by using Cosinor method. The results are summarized as follows : 1. There was no difference in mean scores for Anger - Depression, Happiness, Mental, and Social mood rhythm between the shift workers and the non - shift workers. 2. There was no difference in the amplitude of Anger - Depression, Happiness and Social mood between the two groups, but the shift workers had a higher amplitude of Mental mood. 3. The acrophases of the Anger - Depression mood were between 1:28 and 2:05, and those of Happiness, Social, and Mental mood were between 12:5 and 15:03 for both groups. There were no differences between the groups. 4. The number of the subjects with statistically significant mean cosinor rhythms for Anger-De-pression and Mental moods were higher in the shift workers than in the non-shift workers, but there were no differences between the shift workers and the non-shift workers in those of Happiness and Mental mood. This study showed that the mod manifested circadian periodicities, and a rapidly rotating shift system did not changed the circadian rhythm of mood. It is expected that this study will facilitate a better understanding of circadian rhythm in mood in the shiftworkers.

• Journal of Preventive Medicine and Public Health
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• v.24 no.3 s.35
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• pp.279-286
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• 1991

Much of the working population in developing countries are engaged in shift work now and the number of shift workers is not expected to decrease in the future mostly because the need for continuity of production is increasing. Therefore, the possible effects of shift work on health are of particular interest, and in fact, there have been many epidemiological studies on shift work since the first world war. However, no studies on health effects of shift work have been reported in Korea, and the existing studies in western world have arrived at quite different conclusions mainly because the conditions of work other than shift work, such as age and selection of workers, work environment, and labor conditions also influence the health of workers. This study was firstly carried out in Korea to investigate the health risks related to shift work with 2,093 female workers randomly selected from three major manufacturing industries in proportion to total number of female workers in those industries. Differences of work conditions other than shift work in this study were adjusted by multivariate analysis. Ma findings obtained from this study are as follows : 1. There were significant differences between shift and day workers in the distribution of age, type of industry, condition of noise and dust, regularity of mealtime, working position, and working duration. Shift workers tended to be younger, to have shorter working duration, to have more irregular mealtime, to work in standing position, and to work under more noisy and dusty environment than day workers. 2. Univariate analysis showed that shift work increased the Todai Health Index (THI) scores of digestive tract, respiratory tract, and mental instability symptom categories. Shift work also increased days of sickness absence and number of industrial accident per 100 workers per month. 3. Multivariate analysis that adjusted the differences of demographic, occupational and non-occupational health-related working conditions showed that digestive tract symptom and mental instability symptom scores were significantly higher in shift workers than those in day workers. Based on these study results, it is concluded that the shift work has significant effects on some psychophysiological conditions of the workers and the effects are also influenced by several other personal and working conditions.

• Journal of Institute of Convergence Technology
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• v.3 no.2
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• pp.11-15
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• 2013

These days, the quality of goods is required to improve in the process of manufacturing the semiconductor through the short working hours and clean transportation. The non-contact transport device using magnetic levitation can be a solution in the manufacturing process. The non-contact transport device, using electromagnetic actuation, is the system that can actually transport them by only using attraction force from the electromagnetic source without authentic contact. Moreover, the system using electromagnetic force has a substantial number of benefits ranging from unrestricted design to unlimited expansion. Especially, the price is competitive. The non-contact transport device, using electromagnetic force, has another merits in controlling by giving the same amount of attraction force to ferromagnetic body. By controlling the currents given to coil, the operator is able to decide the direction of the transportation. In order to design the optimal system, we implemented five different things such as the presence of the links below the electromagnetic, the electromagnet changes due to coupling method, the change according to the thickness of the links below electromagnet, due to changes in between electromagnetic distance direction, and the size of the current. Through simulations and the optimum design, it seems to control easily and figure out the exact size of power. It might definitely be the non-contact transport that can sharply reduce tiny scratches and particles in the process of manufacturing the semiconductor.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.11 no.2
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• pp.12-18
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• 2015

The energy pile, used for both structural foundations and heat exchangers, brings about heat exchange with the ground formation by circulating a working fluid for heating and cooling buildings. As heat exchange occurs in the energy pile, thermal stress and strain is generated in the pile body and surrounding ground formation. In order to investigate the thermo-mechanical behavior of an energy pile, a comprehensive experimental program was conducted, monitoring the thermal stress of a cast-in place energy pile equipped with five pairs of U-type heat exchanger pipes. The heating and cooling simulation both continued for 30 days. The thermal strain in the longitudinal direction of the energy pile was monitored for a 15 operation days and another 15 days monitoring followed, without the application of heat exchange. In addition, a finite element model was developed to simulate the thermo-mechanical behavior of the energy pile. A non-linear contact model was adopted to interpret the interaction at the pile-soil interface, and thermal-induced structure mechanics was considered to handle the thermo-mechanical coupled multi-field problem.

• The Journal of Fisheries Business Administration
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• v.38 no.2
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• pp.79-101
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• 2007

The purpose of this study is to estimate the economic value of the Songieong Beach in Off-season, using a Individual Travel Cost Model(ITCM). Songieong Beach is located in Busan but far away from city. These days, however, the increased rate of traffic inflow to the Songieong beach and the five-day working week are reflected in the trend analysis. Moreover, people have changed psychological value. For that reason, visitors are on the increase on the beach in off-season. The ITCM is applied to estimate non-market value or environmental Good like a Contingent Valuation Method and Hedonic Price Model etc. The ITCM was derived from the Count Data Model(i.e. Poisson and Negative Binomial model). So this paper compares Poisson and negative binomial count data models to measure the tourism demands. The data for the study were collected from the Songjeong Beach on visitors over the a week from November 1 through November 23, 2006. Interviewers were instructed to interview only individuals. So the sample was taken in 113. A dependent variable that is defined on the non-negative integers and subject to sampling truncation is the result of a truncated count data process. This paper analyzes the effects of determinants on visitors' demand for exhibition using a class of maximum-likelihood regression estimators for count data from truncated samples, The count data and truncated models are used primarily to explain non-negative integer and truncation properties of tourist trips as suggested by the economic valuation literature. The results suggest that the truncated negative binomial model is improved overdispersion problem and more preferred than the other models in the study. This paper is not the same as the others. One thing is that Estimating Value of the Beach in off-season. The other thing is this study emphasizes in particular 'travel cost' that is not only monetary cost but also including opportunity cost of 'travel time'. According to the truncated negative binomial model, estimates the Consumer Surplus(CS) values per trip of about 199,754 Korean won and the total economic value was estimated to be 1,288,680 Korean won.

• Journal of Korean Academy of Nursing Administration
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• v.6 no.1
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• pp.31-54
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• 2000

This study was aimed for effective nursing performance of the nurse to be able dedicate to the development of professional nursing work by understanding correlation between the leadership style of head nurse and the nursing performance of the nurse. The materials have been collected through structured questionnaires for 18 days from Feb. 2, 1999 to Feb. 20 from 234 nurses presently working at 4 hospitals Circumstances aptitude theory of Fleishman (1973) were used as the device of measuring leadership style, and staff nurses nursing performance were done by head nurses utilizing questionnaire adopted from Park. Data was analyzed by frequency, mean, ANOVA, ANCOVA, and Pearson's correlation coefficiency by using SPSS program. The results are as follows ; 1. Head nurse leadership was classified in the following manner : duty and human relationships oriented style of head nurse leadership(3.76), human relationship oriented style(3.30), duty leadership oriented style(3.12), and non-interference leadership style(2.77). Duty and human relationships showed highest score in this category. 2. The mean of nursing performance was 3.66, dependent nursing duty was 3.88, interpersonal relationship 3.78, and independent nursing was 3.34. 3. An education course of nursing performance by general characteristics was statistically significant. Job satisfaction, for seen working periods, and motivation for choosing a nursing job of nursing job characteristics was statistically siginficant. 4. As the degree of independence nursing performance increases, the degree and of dependance and interpersonal relationship of nursing performance increases. 5. The relationship between nurse leadership style and nursing performance were statistically different. The degree of duty and human relationship style of the head nurse were highest in dependent and independent nursing performance. Therefore, it is desirable that the head nurse should demonstrate the leadership style high in the duty and human relationships for effective nursing performance.