• Industrial Engineering and Management Systems
• /
• v.3 no.1
• /
• pp.38-51
• /
• 2004

Over the years, most or many companies have focused their attention to the effectiveness and efficiency of their business units. As a new way of doing business, these companies have begun to realize the strategic importance of planning, controlling, and designing their own supply chain system. This paper analyzes the coordination issues in supply chains that consist of one manufacturer and multiple retailers operating under uncertain end customer demand and delivery lead-time. We use the Genetic Algorithm (GA) to determine the appropriate ordering and inventory level at which the manufacturer and multiple retailers can maximize the profit of the chain. This is performed under three controlling policies: the traditionally centralized controlling policy under the manufacturer's perspective, the entire chain’s perspective, and lastly the coordinating controlling policy with an incentive scheme. The outcome from the study reveals that the coordinating controlling policy with an incentive scheme can outperform the traditional centralized controlling policies by creating a win-win situation in which all members of the chain benefit from higher profit, thus resulting in more willingness from all members to join the chain.

• Proceeding of Spring/Autumn Annual Conference of KHA
• /
• 1994.05a
• /
• pp.37-44
• /
• 1994

The purpose of this research is to present necessity of manament system establishment and policy direction for fundmental data, understanding management reality and problem, comparing resident's management attitude to related variables in apartment and raw houses multi-family houses. The major finding were as follows : 1) The management attitude of Apartment inhabitant is very highm especially the attitude of maintenance management is the higest. But they disagree with the raise of management cost necessary to maintenance management. 2) The management attitude of Raw multi-family houses inhbitant is especially high, the maintenance management demand for safety and community-life contol attitude, resident's mutual cooperation is especially high, they think much of autonomy management, desire to achieve under more sysemnatic plan.

• Health Policy and Management
• /
• v.18 no.4
• /
• pp.85-110
• /
• 2008

In this study, we explore the long-term demand forecasting of high-price medical equipments based on logistic and Bass diffusion model. We analyze the specific pattern of each equipment's diffusion curve by interpreting the parameter estimates of Bass diffusion model. Our findings are as follows. First, ultrasonic imaging system, CT are in the stage of maturity and so, the future demands of them are not too large. Second, medical image processing unit is between growth stage and maturity stage and so, the demand is expected to increase considerably for two or three years. Third, MRI is in the stage of take-off and Mammmography X-ray system is in the stage of maturity but, estimates of the potential number of adopters based on logistic model is considerably different to that based on Bass diffusion model. It means that additional data for these two equipments should be collected and analyzed to obtain the reliable estimates of their demands. Fourth, medical image processing unit have the largest q value. It means that the word-of-mouth effect is important in the diffusion of this equipment. Fifth, for MRI and Ultrasonic system, q/p values have the relatively large value. It means that collective power has an important role in adopting these two equipments.

• Journal of the Korean Society for Railway
• /
• v.17 no.6
• /
• pp.457-465
• /
• 2014

This study proposes a policy for urban railway travel demand management system in order to decrease the load factor of the Seoul metro Circle line, particularly for the segment between Sadang and Samsung stations, through analyzing the transit smart card data. We propose mixed train operations of the existing Circle line and a line that goes toward Samsung station in order to transport passengers that have two distinct groups: those with the destination of Samsung station and those with destinations after Samsung station. The introduction of a mixed train operation that encourages passengers passing through Samsung station to take a Circle line train will decrease the congested load factor by 11.3% during the morning peak hours using the mixed train operation of the Circle and Samsung lines. This policy could be an effective method to decrease the load factor and improve the comfort of rail passengers without extra investment in the railway facilities.

• Korean Journal of Construction Engineering and Management
• /
• v.6 no.3 s.25
• /
• pp.178-187
• /
• 2005

In order to respond the opening of technology market by the agreement with WTO, the mutual authentication of professional engineers (PEs) by nh, and the promotion and encouragement of education in technology, the preparation of robustic regulation and regal system to secure the authority of PEs and to enhance their quality is required. And a scheme to train PEs with the advanced country level of quality and secure the practical use of PE's expertise should be developed to cope with current issues after the survey of supply and demand for PEs. In this paper, the problem of supply and demand of construction PEs is surveyed under the current regal system and the idea to regulate the supply and demand with the improvement of the regal system is suggested. The result of this research is used for building the supply and demand system of quality PEs and the efficient training and practical arrangement system. Furthermore, the result would be used for the fundamental data to establish the government policy about PEs.

• Journal of Power Electronics
• /
• v.15 no.5
• /
• pp.1227-1234
• /
• 2015

The efficient electric power demand management in electric power supply industry is currently being changed by distributed generation. Meanwhile, small-scale distributed generation systems using renewable energy are being constructed worldwide. Several small-scale renewable distributed generation systems, which can supply electricity to the grid at peak load of the grid as per policy such as demand response programs, could help in the stability of the electric power demand management. In this case, the power quality of the small-scale renewable distributed generation system is more significant. Low prices of power semiconductors and multilevel inverters with high power quality have been recently investigated. However, the conventional multilevel inverter topology is unsuitable for the small-scale renewable distributed generation system, because the number of devices of such topology increases with increasing output voltage level. In this paper, a single-phase multilevel inverter based on H-bridge, with DC_Link divided by bi-directional switches, is proposed. The proposed topology has almost half the number of devices of the conventional multilevel inverter topology when these inverters have the same output voltage level. Double Fourier series solution is mainly used when comparing PWM output harmonic components of various inverter topologies. Harmonic components of the proposed multilevel inverter, which have been analyzed by double Fourier series, are compared with those of the conventional multilevel inverter. An inverter prototype is then developed to verify the validity of the theoretical analysis.

• Journal of Dairy Science and Biotechnology
• /
• v.25 no.2
• /
• pp.33-40
• /
• 2007

The Korean dairy industry has been developed continuously for the past seventy years both in quality and quantity; now the total amount of dairy products accounts for 13 percent of that of livestock production - a remarkable turnover. Korea now stands at the 13th economic power around the world and it is inevitable that we must pursue an open-door policy at a global level; the dairy industry should also strengthen its potentialities in the long term in order to compete with advanced dairy countries. It is predicted that the impact of DDA agreement and FTA negotiations on the domestic dairy industry will be great; so it is urgently needed that we should reconsider the current status of the dairy industry and comprehensive mesures for dairy industry development to improve its international competitiveness. Such measures comprise the three aspects: first, reforming the policy of dairy industry-related systems, second, improving the productivity and third, expanding the consumption of dairy products. In terms of the system reforming, the most important things are, above all, the planned production relevant to market needs, the milk supply and demand management, and the raw milk transaction method. Secondly, the appropriate scale of management is important for the enhancement of productivity together with the modernization of dairy facilities. Thirdly, step-up effort is needed to expand the milk consumption; especially, more milk should be provided to the students by improving the standing milk ration system in middle and senior high schools. The government should make more effort to support and develop new dairy products tuned to consumers' taste, accelerating the publicity of diverse and steady milk consumption together with related organizations.

• Korea Journal of Hospital Management
• /
• v.13 no.1
• /
• pp.1-23
• /
• 2008

In the shortest period of time, we achieved both industrialization and democratization. We also achieved good performance in health care sector. Whole population are covered by health insurance since 1989 and health outcomes, such as infant mortality, life expectance show good level. However, health care system has several problems, rapidly increasing rate of health care expenditure, dissatisfaction of both consumers and suppliers. Current health care system does not reconcile with market competition principle. Causes of these problems originated from 1977 paradigm which was formed to expand health insurance to whole population within short period. Dominant assumption of 1977 paradigm is to assure equitable access of health care by government's command and control. We urgently demand to reform the 1977 paradigm to suitable in 21th century. Our economy entered into a road to advancement. We have concerns how President Lee's administration reform health care system to harmonize with economic development and to achieve advancement in health care sector.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.24 no.3
• /
• pp.109-123
• /
• 1999

Fleet sizing and empty equipment redistribution are two of the most critical problems in managing a fleet of equipment over a transportation network. Where the demand pattern followed the compound Poisson process(CPP) which can be generated one or more at a time under homogeneous Poisson process(HPP), this paper presented a mathematical model to determine control parameters of a decentralized distribution policy and fleet size in case of the pure hub-and-spoke system, a popular form of a logistics system. and validated this model by simulation. That is, where the number of demanded equipments followed geometric and binomial distributions, respectively, cost models on the pure hub-and-spoke logistics system with deterministic trans-portation times, which could be solved analytically, were established and analyzed. We also compared the deterministic case with stochastic one that the transportation time follows some probability distributions.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.12 no.1
• /
• pp.27-33
• /
• 1987

A stochastic model for an inventory system in which depletion of stock takes place due to random demand as well as random loss of items is studied under the assumption that the intervals between cussessive unit demands as well as those between cussessive unit losses, are independently and identically distributed random variables having negative exponential distributions with respective parameters .mu. and .lambda. It is further assumed that leadtime for each order is an outstanding-order-dependent random variable. The steady state probability distribution of the net inventory level is derived under the continuous review (S -1, S) inventory policy, from which the total expected coast expression is formulated.