• Transactions of the Korean Society of Mechanical Engineers
• /
• v.11 no.6
• /
• pp.971-974
• /
• 1987

Considering heat transfer and heat loss processes for the heat engine operating between two fixed heat reservoirs, it may be qualitatively explained that the maxima of power output and its efficiency depending upon operating conditions are extreme maxima. Furthermore, it is also found that from an economic point of view the above two extremes are related to extreme minima of plant cost per unit power output and operation cost per unit power output respectively, and the condition of minimum cost per unit power output exists between the extreme minimum conditions of plant cost per unit power output and that of operation cost per unit power output.

• Journal of Korean Academy of Nursing Administration
• /
• v.22 no.5
• /
• pp.471-479
• /
• 2016

Purpose: This study was conducted to evaluate the level of safety climate, fatigue, and safety performance and to identify the impact of safety climate and fatigue on the safety performance of operating room nurses. Methods: The study design was a descriptive survey. Participants were 174 operating room nurses from two general hospitals and two university hospitals in S and D cities. Three structurally designed questionnaires were used to evaluate their safety climate, fatigue, and safety performance. Collected data were analyzed using descriptive analysis, t-tests, ANOVAs, Pearson correlation coefficient, and stepwise multiple regression. Results: Safety performance of operating room nurses had a mean of 3.26 on a 5-point scale. 'Current department career'(${\beta}=.17$, p=.006) and 'safety climate (work-unit contribution) (${\beta}=.63$, p<.001) accounted for 39% of the variance in operating room nurses' safety performance. Conclusion: Findings indicate that work-unit contribution towards safety climate is an important factor in increasing operating room nurses' safety performance. Therefore, it is essential to find motivational properties consistent with the characteristics of the operating room environment.

• The Korean Nurse
• /
• v.32 no.5
• /
• pp.66-77
• /
• 1994

The purpose of this study was to develop a new nursing unit which can meet changing health care needs, enhance patients' satisfaction and nurses' job satisfaction, and finally guarantee quality nursing care with present manpower. For this, one medical unit was selected as a unit for quality care. And one medical unit which is similar in staffing and patients' characteristics was selected as a control unit. To assess present problems and identify the remedies to the problems a hospital-wide survey and a workshop were performed. According to the survey results, educational programs and improvement of the facilities and equipment supply system, managereal support for interdepartmental cooperation and intensification of bed-side nursing care were adopted as main principles for operating model unit, This model unit was operated for 3 months from Sep. 1, 1992 to Nov. 30, 1992. To evaluate the effectiveness of the model unit, derect/indirect nursing care hours, patients' satisfaction to nursing care, nurses' job satisfaction, and quality care index were measured. Direct/indirect nursing care hours were compared with that of the control unit, and patients' and nurses' satisfaction and quality care index were measured before and after operating model unit and compared with each other. The results of the study were as follows; 1. In the model unit mean direct nursing care hours per cach shift was 146.88 minutes and indirect nursing care hours was 354.72 minutes. The ratio of the direct nursing care hour to indirect nursing hour was 29.6 ; 70.4 and that of the control unit was 26.9 : 73.1. Direct nursing care hour in model unit was longer than that of the control unit. But, the difference was not significant. In subcategories of direct nursing care, the time spent in mobility and exercise, conservation of body temperature, hygiene, and communication and health education were longer than that of the con" trol unit. 2. Indirect nursing care hour in model unit was shorter than that of the control unit. But, the difference was not significant. In subcategories of indirect nursing care, the time spent in drug management and ward arrangement was shorter than that of the control unit. 3. Patients' satisfaction to nursing care was increased significantly after operating the model unit (T=-3.48, P=-0.002) and satisfaction to subcategories of physical comfort measure, psychological cate, and unit management components were significantly higher than before. 4. In the model unit, nurses' total job satisfaction was increased significantly after operating the model unit(Z=2.1004, P=.0357) and satisfaction to subcategory of satisfaction to administration was significantly higher than before (Z=-2.0732, P=.0382). 5. After operating the model unit, quality care index was increased from 89 to 93. With this results, it can be summarized that all the measures tried for quality care, such as educational programs, managereal support for interdepartmental cooperation, and improvement of the equipment and facility provision resulted in partial increase in direct nursing care hours, nurses satisfaction to their job and patients' satisfaction to nursing care. In can be postulated that managereal support and motivation without proper staff supplementation is not enough for increasing direct nursing care hours. And for the enhancement of the level in clinical nursing, and staff supplement must be considered sincerely and the measures for reducing indirect nursing care hours, such as computerization of nursing care activities, improvement of facilities and equipment and facilities supply system, must be instituted in addition.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.24 no.1
• /
• pp.70-76
• /
• 2012

The purpose of this study is to analyze of the operating characteristics of the Gas engine driven Heat Pump(GHP) and to reduce maintenance costs through the most Economical plan. As the zoning modifications that have economic effects were confirmed. Applications should be made with a similar purpose of the space. The combination of a modified space has led to reduced operating hours of the outdoor unit. The reduction of the outdoor unit operating hours, reducing maintenance costs accordingly. When analyzed at six years have elapsed, the amount of savings through zoning modifications is more than an additional construction cost. During the design phase, cost-effective operation of the GHP is required for the proper zoning plan.

• Korean Management Science Review
• /
• v.28 no.2
• /
• pp.17-29
• /
• 2011

The purpose of this paper is to schedule elective surgery patients using a stochastic programming approach and to illustrate how operating room utilization behaves when a decision-maker varies costs associated with utilization. Because of the uncertainty in surgery durations, the underage and overage costs that a decision-maker considers plays an important role in allocating surgery cases into available operating room capacity. We formulate the problem as a stochastic mixed integer programming and propose a sampling-based approximation method for a computational purpose. Newsvendor model is employed to explain the results from numerical experiments that are conducted with the actual data from a hospital. The results show that the operating room utilization is more sensitive when the unit overtime cost is relatively larger than the unit cost for underutilized time.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2006.11a
• /
• pp.111-118
• /
• 2006

The Emergency Diesel Generator(EDG) is a very important piece of equipment for the safety of a Nuclear Power Plant(NPP). In this study, the operating vibration or three kinds or EDG system was measured. The target EDG systems art Yonggwang 5 unit, Ulchin 2 unit and Ulchin 3 unit. The Yonggwang 5 and Ulchin 3 unit EDG system is the same type but the foundation systems are different. One is an anchor bolt type and the other is a spring and viscous-damper type. The purpose of this measurement is for a verification of the vibration isolation effect according to the foundation system. As a result. it can he said that the spring and viscous damper system of the EDG performed well for the vibration isolation.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.10 no.2
• /
• pp.38-46
• /
• 2007

This paper proposes a design method of a CDU(Control Display Unit) for commercial INS(Inertial Navigation Systems). In order to guarantee reusability and extendability, the design method is based on the class programming of the Windows operating system. Since the CDU has abstracted functions and variables, it can be interfaced with any INS. It is also easy to extend the designed functions using inheritance and polymorphism of the class. In order to show usefulness of the CDU, it has been implemented for the H-726 INS.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.19 no.39
• /
• pp.89-98
• /
• 1996

This paper is concerned with cost analysis model in free -replacement policy under the periodic maintenance policy The free-replacement policy with minimal repairable item is considered as follows; in a manufacturer's view point operating unit is periodically replaced, if a failure occurs between minimal repair and periodic maintenance time, unit is remained in a failure condition. Also unit undergoes minimal repair at failures in minimal-repair interval. Then total expected cost per unit time is calculated according to maintenance period Tin a viewpoint of consumer's. The expected costs are included repair cost and usage cost: operating, fixed, minimal repair and loss cost. Numerical example is shown in which failure time of item has beta distribution.

• Journal of the Ergonomics Society of Korea
• /
• v.8 no.1
• /
• pp.41-46
• /
• 1989

The purpose of this study is to improve robot motion control in teaching and operating the expert system/world coordinate system (TOES/WCS) constructed in the previous study. The major contribution of this study is reduction of the inaccuracy in coordinated reading and the movement time of robots in macro motion control. This study also reduces undesirable time of micro motion control by using an unit control (UC) and a micro unit control (MUC) in micro motion control.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.24 no.6
• /
• pp.649-659
• /
• 2016

This paper describes control algorithm and control structure of vehicle control unit for range-extended electric vehicle equipped with engine-generator system, and specially presents methods which determine optimal operating points and decreases a vibration or a shock for operating the engine-generating system. The vehicle control algorithm is consisted of several parts which are sequence control, calculation of wheel demand torque, determination of operating points, and management of operating points and so vehicle controller has be made possible to efficiently manage calibration parameters. The control algorithm is evaluated by driving test modes, launching performance and operating engine-generator system and so on. In conclusion, this paper present methods for extending a mileage, improving a launching performance and reducing vibration or shock when the engine-generating system is starting or is stopping.