• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.1184-1186
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• 2002

Recently, according to the industrial development relative to multimedia, demand of display system is radically increase, thus development for power supply of back-lighting is advanced lively. Fluorescent lamp operated at high frequency by the electronic ballast provide benefits like unnoticeable flicker effect and higher luminous efficiency. This paper presents analysis of Push-Pull type resonant inverter for CCFL drive for stable characteristic and life improvement of fluorescent lamp operated at high frequency. Also it has proposed design procedure of Current-Fed type resonant inverter. On the basis of equivalent circuit, component characteristic and suitable region of operation frequency from simulation using Matlab and Pspice is predicted. Suitability of applied equivalent model and validity of design process from the experimental results with CCFL inverter.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.17 no.32
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• pp.155-162
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• 1994

The Japanese "Just-In-Time" technique reduces inventory and unnecessary factors. This technique makes the success of Japanese firms, therefore many Korean firms try to apply it to their situation. But the technique doesn't bare the same success in Korean firms. This paper, therefore, considers the different situations between Korean rim and Japanese firm, then simulates the Pull system and Push system for a multiline, multistage production system. This paper drives the different results of simulation according to variable processing times, variable demand, set-up time and shortages in Pull system and Push system using GPSS. The results show that the performance of Pull system is lower than Push system's in variable master production scheduling and variable processing times.ing times.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.4
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• pp.16-25
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• 2019

Recently, due to labor shortages in rural areas within South Korea, the demand for upland-field machinery is growing. In addition, there is a lack of development of systematic performance testing of upland-field machinery. Thus, this study examined structural safety and drawbar pull based on soil properties, as a first step for systematic performance testing on the test bed. First, the properties of soil samples from 10 spots within the experimental site were examined. Second, the strain was measured and converted into stress on 8 points of an onion harvester that are likely to fail. More specifically, the chosen parts are linked to the power, along with the drawbar pull, using a 6-component load cell equipped between the tractor and the onion harvester. The water content of the soil ranged between 5.7%-7.5%, and the strength between 250-1171 kPa. The test soil was subsequently classified into loam soil based on the size distribution ratio of the sieved soil. The onion harvester can be considered as structurally safe based on the derived safety factor and the drawbar pull of 115-1194 kgf, according to the working speed based on agricultural fieldwork.

• Health Policy and Management
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• v.2 no.2
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• pp.221-237
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• 1992

The reasons for cost inflation in medical insurance expenditure are classified into demand pull inflation and cost push inflation. The former includes increase in the number of beneficiaries and utilization rate, while the latter includes increase in medical insurance fee and the charges per case. This study was conducted to analyze sources of increases of expenditure in medical insurance demonstration area by the period of 1982-1987 which was earlier than national health insurance and the period of national health insurance(1988-1990). The major findings were as follows: Medical expenditure in these areas increased by 9.4%(15.1%) annually between 1982 and 1990 on the basis of costant price(current price) and for this period, the yearly average increasing rate of expenses for outpatient care[10.5%(15.8%)] was higher than that of inpatient care [7.3%(12.6%)]. Medical expenditure increased by 6.3%(8.9%) annually between 1982 and 1987, the period of medical insurance demonstration, while it increased by 10.7%(18.9%) after implementing national health insurance(1988-1990). Medical expenditure increased by 35.9%(45.9%) between 1982 and 1987. Of this increase, 115.2%(92.1%) was attributable to the increase in the frequencies of utilization per beneficiary and 61.0%(68.1%) was due to the increase in the charges per case, but the expenditure decreased by 76.2%(60.2%) due to the reduction in the number of beneficiaries. Beteen 1988 and 1990, the period of national health insurance, medical expenditure increased by 21.2%(41.4%). Of this increase, 87.5%(46.4%) was attributable to the increase in the frequencies of utilization per beneficiary and 52.4%(73.4%) was due to the increase in the charges per case, and of the increase in the charges per case, 69.6%(40.8%) was attributable to the increase in the days of visit per case. Medical expenses per person in these areas increased by 78.2%(89.0%) between 1982 and 1987. Of this increase, 76.6%(69.1%) was attributable to the increase in the frequencies of utilization per beneficiary and 23.4%(30.9%) was due to the increase in the charges per case. For this period, demand-pull factor was the major cause of the increase in medical expenses and the expenses per treatment day was the major attributable factor in cost-push inflation. Betwee 1988 and 1990, medical expenditure per person increased by 31.2%(53.1%). Of this increase, 60.8%(37.2%) was attributable to the demand-pull factor and 39.2%(62.8%) was due to the increase in the charges per case which was one of cost-push factors. In current price, the attributalbe rate of the charges per case which was one of cost-push factors was higher than that of utilization rate in the period of national health insurance as compared to the period of medical insurance demonstration. In consideration of above findings, demand-pull factor led the increase in medical expenditure between 1982 and 1987, the period of medical insurance medel trial, but after implementing national health insurance, the attributable rate of cost-push factor was increasing gradually. Thus we may conclude that for medical cost containment, it is requested to examine the new reimbursement method to control cost-push factor and service-intensity factor.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.36 no.2
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• pp.81-90
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• 2013

Material flow control (MFC) is a kind of operational policy to control of the movement of raw materials, components, and products through the manufacturing lines. It is very important because it varies throughput, line cycle time, and work-in-process (WIP) under the same manufacturing environments. MFC can be largely categorized into three types such as Push, Pull, and Hybrid. In this paper, we set various manufacturing environments to compare five existing MFC mechanisms: Push, Pull, and Hybrid (CONWIP, Gated MaxWIP, Critical WIP Loops, etc). Three manufacturing environments, manufacturing policies (make to stock and make to order), demand (low, medium, high), and line balancing (balanced, unbalanced, and highly unbalanced) are considered. The MFCs are compared in the point of the five functional efficiencies and the proposed compounded efficiency. The simulation results shows that the Push is superior in the functional efficiency and GMWIP is superior in the compounded efficiency.

• Journal of Korean Institute of Industrial Engineers
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• v.39 no.1
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• pp.78-81
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• 2013

In Build-to-Order manufacturing systems, products are usually manufactured by a pull system. The manufacturers order only what they need when it is needed. The suppliers are expected to deliver parts as much as needed. When the part demand fluctuates significantly, this places lots of challenges on the suppliers. In this letter, we explore the decision issues regarding part supplies for Build-to-Order manufacturing systems, especially in the auto industry, and suggest how to address them in order to make the manufacturing systems work more efficiently.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.35 no.1
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• pp.115-123
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• 2012

Material flow control mechanism is a kind of operational policy in manufacturing. It is very important because it varies throughput, throughput time, and work-in-process (WIP) under the same manufacturing resources. Many Researchers have developed various material flow control mechanisms and insisted that their mechanism is superior to others. However the experimental environment used in the performance comparison are different and impractical. In this paper, we set various manufacturing environments to fairly compare five previous material flow control mechanism : Push, Pull, CONWIP, Gated MaxWIP, and Critical WIP Loops. The simulation results show that the Push is superior to others in both of throughput and WIP if required demand is less than 80% of capacity. In addition, the performance of CONWIP and its variants are not different statistically.

• Journal of the Society of Disaster Information
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• v.14 no.3
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• pp.288-295
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• 2018

Purpose: The paper aims to compare the effectiveness of the two types of transport demand management measures, namely pull measures and push measures. Method: Case studies of two metropolitan areas in the developing world assess the extent to which increases in fuel prices can contribute to reducing automobile use and increasing the public transport use and the potential of urban rail transit to cause mode shift from automobiles. Within the case studies, a stated response survey of current car users has been conducted for Cairo and an on-line survey of rail transit users in Algiers. Results: There was a major proportion of car drivers who intend to switch to public transport, depending on the range of fuel prices in Cairo and a considerable proportion of rail users who have switched from automobiles resulting in a measurable reduction in CO2 emissions in Algiers. Conclusion: Investments in urban rail can be highly effective where there are demands for better public transport, but this type of pull measures can be much more effective if combined with push measures which significantly raise driving costs.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.19 no.40
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• pp.301-309
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• 1996

The operation of the traditional pull Kanban system in Domestic is limited because the production circumstance of the Domestic industries have the characteristics of dynamic production circumstance such as high variability of demand, frequent machine breakdown or defect, high absence or separation rates of the employees. The purpose of this study is to find the optimal Kanban system for the production circumstance of the Domestic industry. By using the computer simulation, selected models are tested for the susceptibility to the production factors and with the analysis of the data from the simulations.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 1999.05a
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• pp.268-276
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• 1999

지역정보화는 지역개발을 위한 새로운 패러다임으로서 인간축의 견인력(Demand Pull)을 성숙시켜 기술축 주도(Technology Push)와의 조화 속에 진행되는 일련의 변화과정이다. 그러나 변화는 반드시 저항을 수반하게 된다. 모든 정보화 사업이 그러하듯 지역정보화 역시 그 과정에서 발생하게 될 저항을 어떻게 관리하느냐에 따라 성패가 좌우된다 해도 과언이 아니다. 본 소고에서는 지역정보화를 추진하는 과정에서 우리가 당면하게 될 저항 및 집단간 갈등의 근원과 유형, 그리고 이러한 저항 및 갈등을 최소화하고 나아가 긍정적인 수용환경을 조성하기 위한 대안으로서 변화대리인(Change Agent)의 필요성과 활용방안을 변화관리(Change Management) 차원에서 논의한다.