• Proceedings of the KIEE Conference
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• 2000.11b
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• pp.352-354
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• 2000

The induction motor is a high-efficiency machine when working close to its rated operation point. This paper uses a simple induction motor model that includes iron losses. The model, which only requires the knowledge of conventional induction motor parameters, is referred to a field-oriented frame. At steady-state light-load condition the minimum point of the input power can be found with the condition that it is possible to obtain the same torque with different combinations of flux and current values. Using the minimum point. the drive system with the proposed efficiency optimization controller can be controlled easily. Simulation and experimental results show the effectiveness of the control strategy proposed for an induction motor drive.

• Journal of the Mineralogical Society of Korea
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• v.10 no.1
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• pp.1-17
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• 1997

Pneumoconiosis is the result of the long-continued inhalation of dusts and it depends on the interaction between the man and the cloud to which he is exposed. The health effects of dusts, especially silica dust exposure have been since Egyptians had constructed the pyramids in ancient times. Subsequently, many works, including miners, milers, quarry workers, sandblasters, tunnel drivers, are occupationally exposed to mineral dusts. These workers may develop pneumoconiosis and in some instances, malignant neoplasms, particularly lung cancer, as a result of such exposures.Both quantity and quality of mineral dusts in the lungs show significant correlation with the degree of damage from pneumoconiosis. So mineralogical techniques require in pathological studies and in estimation of the airborne dusts in working places.Mineralogy has played an important role in both branches of the protective procedure. This lecture presents the knowledge on lung dust, cytotoxicity and fibrogenetic activity of minerals and control procedures for pneumoconiosis from pont of mineralogist.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.6 s.171
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• pp.61-69
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• 2005

This paper presents the experimental results to analyze the atomization characteristics and environmental impact of cutting fluid in grinding process. Grinding is a major machining process to improve surface quality with different machining mechanism which is compared with turning or milling process. The environmental impact due to aerosol generation via grinding process is a major concern associated with environmental consciousness. Experimental results show that the generated fine aerosol which particle size less than 10 micron appears near working zone under given operational conditions. The aerosol concentration is much higher enough to affect human health risk with its generated aerosol quantities. This study can be provided a basic knowledge fur further research of environmental consciousness machining development.

• Journal of Korean Clinical Nursing Research
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• v.26 no.3
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• pp.305-313
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• 2020

Purpose: The purpose of this study was to identify factors influencing the Radiation Protection(RP) behaviors of endoscopy nurses during endoscopic interventional radiology. Methods: A total of 188 endoscopy nurses working at 30 tertiary or general hospitals participated in this questionnaire-based study. The questionnaire included items on general and job related characteristics, RP knowledge, RP attitude, RP behavior, self-efficacy, and safety climate. Data were collected through online surveys from March 22 to April 10, 2019. Results: Multivariate analysis revealed that RP attitude (β=.65, p<.001), safety climate (β=.12, p=.035), self-efficacy (β=.14, p=.009), and existence of RP protocols (β=.11, p=.038) were significant predictors of better RP behavior. Conclusion: The findings showed that the RP behavior of endoscopy nurses was at high levels and the continuing education for endoscopy nurses and development of a radiation safety management education program were important to improve RP behavior.

• Journal of Information Science Theory and Practice
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• v.10 no.3
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• pp.15-23
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• 2022

Participants in real-time online sessions, be it (business) meetings, virtual school lessons, or social live streams, all engage in cyber social interactions. Unlike parasocial interactions, cyber social interactions are characterized by reciprocity and temporal proximity. In contrast to social interactions, they lack spatial proximity and bodily contact. This is a fairly new concept in information science that rose from technological advances and unprecedented circumstances (e.g., the rise of digital economy and knowledge workers being able to work remotely or, more recently, global lockdowns and contact restrictions). As a result, the past ways of working and socializing were transformed by making them, in some cases predominantly, virtual. Regarding the example of social live streaming we exhibit the importance of cyber social interactions for information behavior research. This conceptual article is a plea for information science to engage more in human-human online relations and interactions.

• Anatomy and Cell Biology
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• v.55 no.2
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• pp.251-254
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• 2022

Variations of the ovarian veins can impact imaging diagnosis, surgical procedures of the region, and can be related to clinical findings such as compression of the ureter. Therefore, a good working knowledge of such variants is important to the clinician who interprets imaging of the posterior abdominopelvic region of women and surgeons who operate in this region. Herein, we present a comprehensive review of duplicated ovarian veins and provide a case illustration.

• Journal of Korean Public Health Nursing
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• v.7 no.1
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• pp.67-79
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• 1993

This study was designed to identify the general health conditions and high risk factors of the male & female environmental workers. Thereby. the results of this study were to provide useful data as a contribution to knowledge for health protection and promotion. The data used for this study were environmental workers' physical examination cards; the male environmental workers were 52 persons. and the female environmental workers 52 persons. The data were analyzed by descriptive statistics, t-test, Pearson correlation, and distinction analysis, using the SPSS program. The results of this study can be summarized as follows; 1. Thers was a significant statistical difference between the two groups as to height. eyesight. serum GPT, hematocrit. The variables having little difference between two groups were weight. systolic blood pressure. total cholesterol. creatinine. 2. The rate of revealed in significant health examination was extra-health discrimination rate $28.8\%$, significant result of illness rate $12.5\%$. injury-inflicting rate $7\%$. second-time urine test $5.7\%$. antigen positive 3.8%. hearing impairment $2.8\%$, urine protein positive $1.9\%$. and urine sugar positive $1.9%$. 3. The workers diagnosed as extra-health discrimination were 30 persons or $28.8\%$. There was a difference between two groups on the prevalence. In the male environmental workers. ten times live problems and six times pulmonary tuberculosis and three times circulatory problems were revealed the higher than thoes of the female environmental workers. 4. In the male environmental workers, the relationship between age and systolic blood pressure revealed a significant correlation (r=0.22. p<0.05). In the female environmental workers. there was a negative correlation between age and weight (r= 0.25, p<0.05). the relationship between age and total cholesterol correlated positively (r=0.30, p<'0.05). 5. In the male environmental workers, there was a negative correlation between working career and creatinine(r=-0. 22, p<0.05) In the female environmental workers, there was a positive correlation between working career and total cholesterol (r= 0.58, p<0.01). 6. There were significant differences on working career and creatinine accdording to the male and female environmental workers who had any problems through x-ray inspection. 7. There were significant differences on height. eyesight. serum GPT according to the male and female environmental workers who were diagnosed as extra-health discrimination. 8. The female environmental workers who were diagnosed as 'care' were positively correlated with weight (r= 0.26. p<0.05)' and systolic blood pressure (r= 0.30. p<0. 05). on the other hand. the left and right eyesight correlated nagatively(r=-0.15. r=-0.33. p<0.01). 9. The most influential variables on the male and female environmental workers' health condition were working career, height. and weight. And these three variables could help determine the two groups at the level of 81. 8 percentage.

• Journal of the Korean Dietetic Association
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• v.21 no.2
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• pp.123-139
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• 2015

The objective of this study was to document how clinical dietitians working at tertiary hospitals spend their time based on several categories of activities using a time measurement study. The questionnaires were distributed to 14 tertiary hospitals, and dietitians answered by classifying their work activities into several categories such as general care, indirect care, direct care, outpatient care, and food service management. A total of 129 clinical dietitians replied and their answers were analyzed according to the categories of activities. The times spent on the categories are as follows: general care (76.7 mins/day, 14%), indirect care (228.4 mins/day, 35%), direct care (120.1 mins/day, 22%), outpatient care (61.5 mins/day, 11%), and food service management (99.0 mins/day, 18%). The total working hours for dietitians was 590.0 mins, which exceeds the standard working hours of 540.0 mins (9 hrs) a day. From this study, we found that clinical dietitians spent very limited time on direct care. Times spent on activities were different according to type of employment and food service. Internship dietitians spent their more time on general care (P<0.001) while irregular dietitians spent more time on outpatient care (P<0.05). In contracted managed food service hospitals, clinical dietitians spent significantly less time on food service management (P<0.001). Regardless of doctors' order and consultation fees, clinical dietitians performed more than 95 percent of free consultation to patients. Entry-level knowledge and skills of dietitians working at hospitals are very important for quality service, but it is equally important to create an administrative and social environment that encourages clinical dietitian to spend more time on direct patient care.

• Journal of the Korean Institute of Gas
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• v.4 no.4 s.12
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• pp.20-24
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• 2000

The electrostatic safety consciousness of safety manager were investigated through questionnaires sent to liquid petroleum gas stations in Korea. In addition, hazards of fire and explosion due to electrostatic on synthetic-polymer-wears and cotton-wears were estimated experimentally. The results of questionnaires indicate most workers wear their working clothes indiscreetly owing to lack of knowledge of preventing electrostatic hazards. The amounts of electrostatic charge generated in synthetic-polymer-wears were 1.79, 1.44 and 1.02 $\mu$C in winter, spring and autumn and summer, respectively. All these values exceed the limit of working wears of 0.60$\mu$C requested by Korea Standard(KS K-7807) for preventing electrostatic hazards, which means hazards may occur. While, the charge in cotton-wears were in the range of 0.42 to 0.52$\mu$C, which suggests that the cotton-wears investigated in this study have no problem of hazards. Therefore workers, visual and experiential education are necessary for elevating the standard of on electrostatics. It is also necessary to establish standards of wearing for preventing electrostatic hazards.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.26 no.1
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• pp.64-74
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• 2016

Objectives: The purpose of this study was to investigate whether chemical exposure among workers has relevance to dyspnea using data from the $3^{rd}$ Korea Working Conditions Survey. Methods: The research subjects were 29,711 wage workers. Chemical exposures consist of four factors, (1) breathing in vapors, fumes, dust and dirt, (2) breathing in organic solvent vapors, (3) handling or touching chemicals, and (4) secondhand smoke. Multiple logistic regression analysis was performed to examine the association between chemical exposure and dyspnea in the last 12months using proc surveylogistic in SAS 9.3 statistical software excluding people who had received a diagnosis of hypertension or obesity that can affect the respiratory distress symptoms(n=27,842). Results: Chemical exposure among workers was associated with dyspnea after adjustment for demographics and job characteristics. Prevalence of dyspnea was 4.9 per 1,000 among men and 5.8 per 1,000. Compared to a total score of 0 points of chemical exposure among workers, a total score of 1, 2-3, and 4 points tended to have increased risk of dyspnea in a dose-response manner for both men (OR=1.43, 1.93, and 4.26; P-for trend=0.002) and women(OR=1.10, 2.81, and 7.70; P-for trend=0.002). Stratified analysis by duration of current job showed that the association between chemical exposure and dyspnea tended to get stronger until 15 years and then disappeared afterwards, which reflects healthy worker survivor effect. Conclusions: We observed significant association between chemical exposure and dyspnea using the data of the $3^{rd}$ Korea Working Conditions Survey. Our results warrants providing knowledge related to chemical exposure, performing prevention activities, and creating various health policies to protect workers.