• 한국항해학회지
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• 제22권2호
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• pp.53-63
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• 1998

This study aims at suggesting a concepturla model of personnel elitism, and at evaluating the model based on a shipping company case. Specifically, it asks whether the company has met the conditions nessary for the attainment of personnel litism prescribed by the conceptural model. In order to evalutate the model, questionnaire and interview methods were adopted. The area of survey includes the quality of personnel , the efficiency level of work processes. and the level of work load. This study concludes that the rationalization of work processes and training and development of personnel are necessary for a company to realize personnel elitism.

• 대한가정학회지
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• 제43권2호
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• pp.203-229
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• 2005

The purpose of this study was to explore the perceived quality of life of Korean university students'. The perceived quality of life was composed of three dimensions: emotion, cognitive efficiency, and satisfaction. The study results were as follow: 1. Korean university students felt more positive emotions when they spent time for social activities. 2. In the cognitive efficiency, social activities also scored highly of 5 questions, but in the item of "awareness of another person's eye", productive activities were higher. 3. Korean university students were more satisfied with themselves when they spent time for productive activities. However, they were more satisfied with their work itself when the work was social activities. 4. Korean university students' emotions, cognitive efficiencies, and satisfaction were significantly different by socio-graphic variables and context.

• 한국수소및신에너지학회논문집
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• 제21권6호
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• pp.570-579
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• 2010

Since the temperature of waste heat source is relatively low, it is difficult to maintain high level of efficiency in power generation when the waste heat recovery is employed in the system. In an effort to improve the thermal efficiency and power output, use of ammonia-water mixture as a working fluid in the power cycle becomes a viable option. In this work, the performance of ammonia-water mixture based Rankine cycle is thoroughly investigated in order to maximize the power generation from the low temperature waste heat. In analyzing the power cycle, several key system parameters such as mass fraction of ammonia in the mixture and turbine inlet pressure are studied to examine their effects on the system performance. The results of the cycle analysis find a substantial increase both in power output and thermal efficiency if the fraction of ammonia increases in the working fluid.

• 한국자동차공학회논문집
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• 제20권6호
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• pp.61-66
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• 2012

Conventional method to transform vehicle driving condition to engine operation mode is to use vehicle road load under neutral gear and mechanical efficiency of drivetrain. But this method requires additional measurement of efficiency of drivetrain on a test rig. And this measurement is normally done at fixed speed and thus estimated accuracy of engine operation mode is not considered to be high enough. This study suggests new method to calculate engine operation mode for prescribed driving mode such as NEDC using vehicle coastdown test under gear engaged condition without measurement of mechanical efficiency of drivetrain. Coastdown test was done under neutral and gear engaged condition for comparison and also trial to extract mechanical loss of drivetrain was carried out. Calculated engine torque by conventional and newly suggested method was compared with actually measured torque of a vehicle on a chassis dynamometer during NEDC. Newly suggested method showed slightly higher accuracy of accumulated brake work during NEDC.

• Journal of Mechanical Science and Technology
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• 제18권6호
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• pp.979-989
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• 2004

Numerical simulations have been performed to investigate tip clearance effect on through-flow and performance of a centrifugal compressor which has the same configuration of impeller with six different tip clearances. Secondary flow and loss distribution have been surveyed to understand the flow mechanism due to the tip clearance. Tip leakage flow strongly interacts with mainstream flow and considerably changes the secondary flow and the loss distribution inside the impeller passage. A method has been described to quantitatively estimate the tip clearance effect on the performance drop and the efficiency drop. The tip clearance has caused specific work reduction and additional entropy generation. The former, which is called inviscid loss, is independent of any internal loss and the latter, which is called viscous loss, is dependent on every loss in the flow passage. Two components equally affected the performance drop as the tip clearances were small, while the efficiency drop was influenced by the viscous component alone. The additional entropy generation was modeled with all the kinetic energy of the tip leakage flow. Therefore, the present paper can provide how to quantitatively estimate the tip clearance effect on the performance and efficiency.

• 간호행정학회지
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• 제17권4호
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• pp.474-483
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• 2011

Purpose: This study was conducted to identify factors affecting nurses' burnout in secondary general hospitals. Methods: Data were collected through structured questionnaires from 241 nurses working at the secondary general hospitals with below 400 beds in the P, C, and S city between April and May, 2009. Data analysis was done with independent t test, ANOVA, Pearson correlation coefficient, and multiple stepwise multiple regression with SPSS WIN v 17.0. Results: Burnout was significantly different according to religion, age, clinical experiences, and shift work. Burnout score of the subjects was 58/100. Burnout of the subjects were positively correlated with job stress and negatively correlated with hardness, self efficiency, self esteem, spiritual wellbeing, social support, and job satisfaction. The explained variances for burnout was 51.8% and factors affecting nurses' burnout in secondary general hospitals were job stress, hardness, self efficiency, job satisfaction and shift work. Conclusion: These results showed the significant factors fo nurses' burnout in secondary general hospitals. These findings can be utilized to development of strategies for reducing job stress and enhancing hardness, self efficiency and job satisfaction.

• 한국시뮬레이션학회논문지
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• 제23권4호
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• pp.229-235
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• 2014

생산시스템의 시간과 비용 효율성을 개선하는 것은 경쟁 우위를 구축하고 경쟁적인 비즈니스 환경에서 수익성을 향상하는 중요한 수단 중 하나이다. 그 중에서도 CONWIP(constant work-in-process)과 DBR(drum-buffer-rope)방법은 생산 공정의 효율을 개선하는 데 널리 사용된다. 이 연구에서는 실제 단추 공장 생산 시스템의 시뮬레이션 모델을 개발했다. 연구 결과에 의하면, CONWIP과 DBR 생산시스템 모두 병목 공정의 대기 시간을 감소시키는 등 실제 생산시스템보다 나은 결과를 나타냈다. 시뮬레이션 모델 결과를 바탕으로 제안된 생산시스템을 적용함으로써, 실제의 제조 공정의 효율을 크게 향상시킬 수 있을 것으로 기대된다.

• 한국태양에너지학회 논문집
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• 제31권1호
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• pp.15-22
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• 2011

It is a great interest to convert more energy in the heat source into the power and to improve the efficiency of power generating processes. Since the efficiency of power generating processes becomes poorer as the temperature of the source decreases, to use an ammonia-water mixture instead of water as working fluid is a possible way to improve the efficiency of the system. In this work performance of ammonia-water regenerative Rankine cycle is investigated for the purpose of extracting maximum power from low-temperature waste heat in the form of sensible energy. Special attention is paid to the effect of system parameters such as mass fraction of ammonia and turbine inlet pressure on the characteristics of system. Results show that the power output increases with the mass fraction of ammonia in the mixture, however workable range of the mass fraction becomes narrower as turbine inlet pressure increases and is able to reach 16.5kW per unit mass flow rate of source air at $180^{\circ}C$.

• 한국사회복지학
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• 제46권
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• pp.236-262
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• 2001

This discovery-oriented study explored 31 social workers' perceptions of discrepancies between explicit and implicit rules in their work places that are supposed to affect the quality of social work services, and identified eight categories of dilemmas: (a) confused accountability or purpose, (b) ambiguous principle, (c) improper authority, (d) confused role of social workers, (e) conflict between ideal and reality, (f) confused work ethics, (g) confused boundary of workers' rights, and (h) binds. These eight categories revealed the real philosophy and purposes of social work agencies, work ethics and values prevalent among social work agencies, agencies' orientation toward clients, and the conditions of social support from the society in large. Instead of searching for discrete variables as separately responsible for inefficient social work services, this approach probed malfunctioning implicit rules in a holistic context to see if inefficient or ineffective provision of social work services is a logical response to a much larger and deeper nexus. Insight into discrepant rules does not solely ensure the improvement of social work practice in the field, particularly if their identification is simply used as another opportunity to blame and avoid self-responsibility. However, such discrepancies between implicit and explicit rules are real enough to the staff workers and agency administrators that they may want to begin the dialogue of contradictory rules as a way of sanctioning discussion of previously forbidden topics. This study provided the ground-work for the dialogue.

• 근관절건강학회지
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• 제27권3호
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• pp.247-254
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• 2020

Purpose: This was a descriptive observational study examining the reasons for, frequency of, and factors affecting work interruption among intensive care unit (ICU) nurses. Methods: Convenience sampling was used to recruit 46 regular nurses who had been working in an ICU at D tertiary hospital in B metropolitan city for at least six months. To measure the degree of work interruption, this study revised a tool used by Brixey et al. (2007) for analyzing the type of work interruption. Results: A total of 1,787 work interruptions occurred during 368 hours of observation, i.e., at an average of 4.85 times per hour. Communication-related factors caused work interruption most frequently, followed by environmental, work-related, and personal factors. As for the work-related characteristics of nurses, participants experienced work interruption more frequently while working on weekdays, when the medical staff were stationed, than on weekends. Conclusion: ICU nurses experienced work interruption frequently. With the health care system expected to become more complicated in the future, efforts should be made to reduce unnecessary work interruptions to improve the operation efficiency of ICUs.