• Journal of the Korea Institute of Military Science and Technology
• /
• v.17 no.4
• /
• pp.404-412
• /
• 2014

We proposed a design method for squib current supply & interlock circuits in guided-missile fire control systems. In order to design squib current supply circuits, various missile squib loads including line resistance and squib devices have to be considered in advance minimizing probability of redesign of circuits and reducing the development cost by implementing the most proper squib current supply circuit. Also, we presented a hardware interlock logic instead of the commonly used software safety logic to improve the safety of guided-missile fire control systems. The proposed squib interlock circuit enhances safety requirements of guided-missile fire control systems. We confirmed that simulation and measurement results of the proposed design method are the same as theoretical analysis results.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.7 no.2
• /
• pp.158-164
• /
• 2002

This paper presents a proper parallel control method using a conventional control and a repetitive control for improving the output voltage waveform of uninterruptable power supply. Although first-order prediction control method shows a good characteristics to rectifier load, it is not sufficient to reduce steady state errors generated in nonlinear loads such as rectifier loads and phase controled loads. So we also employed a repetitive control method. A repetitive control method can eliminate steady state errors in the distorted output voltage caused by cyclic loads. The presented control scheme is verified through simulation and experiment. Experimental results Implemented on a single phase PWM inverter equipped with a LC output filter with 3 kVA, 60 Hz are shown.

• Journal of Korea Water Resources Association
• /
• v.47 no.4
• /
• pp.331-342
• /
• 2014

In water resources planning, to decide proper water supply capacity is a very important task. Once water supply system such as a dam is decided, it will affect whole range of water resources circumstances for a long time. Even though systematic approaches have been implemented since 1980, many problems are still prevail in reality. Especially some issues related to the reliability analysis method used in planning dams in Korea have been persistently brought up. This study is to diagnose problems on the reliability criterion in water supply capacity assessment of water resources systems and discuss a valid method. As a result, the estimates by the different analysis time intervals, in case of the temporal reliability, show no large difference, but there is a large difference when assessment time intervals are differently applied. The volumetric reliability accounts for 2~3% higher than that of the temporal reliability, and resiliency and vulnerability also show large differences by the analysis time intervals.

• Journal of Mechanical Science and Technology
• /
• v.16 no.12
• /
• pp.1687-1692
• /
• 2002

The problem analyzed here is a sheet metal forming process which requires a drawbead. The drawbead provides the sheet metal enough tension to be deformed plastically along the punch face and consequently, ensures a proper shape of final products by fixing the sheet to the die. Therefore, the optimum design of drawbead is indispensable in obtaining the desired formability. A static-explicit finite element analysis is carried out to provide a perspective tool for designing the drawbead. The finite element formulation is constructed from static equilibrium equation and takes into account the boundary condition that involves a proper contact condition. The deformation behavior of sheet material is formulated by the elastic-plastic constitutive equation. The finite element formulation has been solved based on an existing method that is called the static-explicit method. The main features of the static-explicit method are first that there is no convergence problem. Second, the problem of contact and friction is easily solved by application of very small time interval. During the analysis of drawbead processes, the strain distribution and the drawing force on drawbead can be analyzed. And the effects of bead shape and number of beads on sheet forming processes were investigated. The results of the static explicit analysis of drawbead processes show no convergence problem and comparatively accurate results even though severe high geometric and contact-friction nonlinearity. Moreover, the computational results of a static-explicit finite element analysis can supply very valuable information for designing the drawbead process in which the defects of final sheet product can be removed.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.38 no.1
• /
• pp.83-89
• /
• 2015

Selection of efficient supplier is a very important process as risk or uncertainty of a supply chain and its environment are increasing. Previous deterministic DEA and probabilistic DEAs are very limited to handle various types of risk and uncertainty. In this paper, I propose an improved probabilistic DEA which consists of two steps; Monte Carlo simulation and statistical decision making. The simulation results show that the proposed method is proper to distinguish supplier's performance and provide statistical decision background.

• Korean Parent-Child Health Journal
• /
• v.7 no.1
• /
• pp.28-37
• /
• 2004

This study intends to analyse the concept on the child-rearing of parents. Through analysis, several concepts on the child-rearing would be cleared, and therefore the groundwork of the theoretical framework can be constructed. The concepts were analyzed by the method of Walker & Avant(1995). The attribute of child-rearing is as follows; nutrition supply, affectionate mind, caring, growth development supporting, protecting, instructing, pregnancy, delivery etc. The proper child-rearing helps reinforce child development, mother-infant attachment, social disposition, parental-role contentment and family relationship. This study would be helpful to the establishment of child-rearing paradigm. And therethrough this result although helps construct proper child-rearing as well as theoretical groundwork.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.9 no.4
• /
• pp.390-396
• /
• 2004

Recently, there have been Increasing demands for high power factor and low harmonic distortion in the current drawn from utility. The harmonic limits imposed by international standards. It need the PFC techniques in order to reduce line current harmonics and comply with the standards. The average current control method that is the most proper PFC control method in a switching power supply of middle and high power has been used mostly to PFC control method. However, the switching device of PFC circuit has frequently destructed at power return after instantaneous power interrupt. Therefore, this paper have verified the cause of this problems and proposed the solution through simulation and experiment

• Journal of Korean Academy of Nursing Administration
• /
• v.8 no.4
• /
• pp.615-632
• /
• 2002

Purpose : this study was to project demand of home nursing care in Korea for contributing toward the distribution of home nursing care resource. Method : demand of home nursing care is projected according to income level and needed service level of each person. in addition, demand sufficiency of home nursing care is taken by estimating for supply level available. Result : home nursing care service is scarecely provided to people who belong to second area, that is, only $1.6{\sim}2.3%$ out of them are provided and also, supply system comes short of meeting demand of the other people(who belong to one, third area). Conclusion : therefore, for proper provision of home nursing care, different supply system and policy direction for establishment and expansion of home nursing care is to be developed.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.13 no.10
• /
• pp.982-992
• /
• 2001

In this paper, the performance of ventilation equipments in enclosed parking garages were investigated for several air distribution systems by numerical method. Air change effectiveness of the non-mixing system was 0.42. It meant that more supply air as much as the design supply air was needed to maintain good indoor air quality. In the high speed nozzle ventilating system which is most expensive one, air change effectiveness was 0.54. Therefore this system satisfied to ventilation design. In the jet fan ventilating systems, air change effectiveness for jet fan ventilating system-A with 18 jet fans and jet fan ventilating system-B with 6 jet fans in circulation mixing arrangement were 0.565 and 0.42 respectively. Jet fan ventilating system-C with 6 jet fans in transport mixing arrangement was 0.535. Jet fan ventilating system-A and jet fan ventilating system-C met the ventilation design. But velocity in jet fan ventilating system-A was over 2.0m/s which is inappropriate in human comfort. Therefore this system is not proper to ventilation. Jet fan ventilating system-C was the optimum one for enclosed parking garages among 5 systems examined in this paper.

• Proceedings of the Korean Institute Of Construction Engineering and Management
• /
• 2004.11a
• /
• pp.612-615
• /
• 2004

Today, the curtain wall is used in many construction projects because of excellent economical efficiency and constructability. The life-cycle process of curtain wall construction consists of the architectural design, curtain wall design, manufacturing, const겨ction, and maintenance phase which has become one of the most important objects that have to be managed. Since the general management method focused on each separated phase, it has accompanied many problems such as increases of the cost and duration, and loss of productivity. To solve these problems, it is necessa교 to have a new management method based on supply chain management. Thus this research analysed the processes of stick system, semi-unit system, unit system, and panel system classified by the type of the curtain wall, and suggested proper methods of application of SCM concept to each type of curtain wall construction.