• 대한산업공학회지
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• 제22권2호
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• pp.231-245
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• 1996

Semiconductor manufacturing line includes several batch processes which are to be controlled effectively to enhance the productivity of the line. The key problem in batch processes is a dynamic batch sizing problem which determines number of lots processed simultaneously in a single botch. The batch sizing problem in semiconductor manufacturing has to consider delay of lots, setup cost of the process, machine utilization and so on. However, an optimal solution cannot be attainable due to dynamic arrival pattern of lots, and difficulties in forecasting future arrival times of lots of the process. This paper proposes an efficient batch sizing heuristic, which considers delay cost, setup cost, and effect of the forecast errors in determining the botch size dynamically. Extensive numerical experiments through simulation are carried out to investigate the effectiveness of the proposed heuristic in four key performance criteria: average delay, variance of delay, overage lot size and total cost. The results show that the proposed heuristic works effectively and efficiently.

• Journal of Biosystems Engineering
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• 제29권2호
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• pp.175-186
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• 2004

The study was designed to forecast and derive future core technologies using Delphi method in Korea agriculture. The technologies will make agriculture for core and strategic industry that has high value-added in 21 century. Questions were given to specialists by each technology in order to survey importance, realization time, level of R＆D in Korea and foremost country, leading group of R＆D, effective policy, etc. for each technology. The target of the survey for Delphi is confined specialists in the area of Bioystems Engineering. 55 core technologies were derived and 31 specialists answered the survey.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2003년도 추계학술대회 논문집(II)
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• pp.40-45
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• 2003

Korea selected to introduce high-speed railway system from advanced countries in order to accumulate railway technologies and develop exiting domestic logistics system. After many twists and turns, we adopted to introduce France's high-speed railway called 'TGV'. Despite many difficulties along with trials and errors, it is expected that Korean high-speed railway will be brilliantly launched in April 2004, although it has been commissioned for multi-discipline tests. It is forecast that the opening of high-speed railway will bring us the epoch-making development of logistics system. However, what if there are really some problems in the operation of high-speed railway? We cannot consider and highlight only the positive aspects of our own high-speed railway. In terms of many challenging aspects we would face in the future, there would be some matters we must consider and point out in this opportunity. In this regard, the direction for developing high-speed railway stations requires the harmony between profitability and public benefits, which must involve compatibility with other traffice systems and practical policies to secure competitive edges.

• Communications for Statistical Applications and Methods
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• 제17권1호
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• pp.27-37
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• 2010

This article concerns the forecasting in binomial AR(p) models which is proposed by Wei$\ss$ (2009b) for time series of binomial counts. Our method extends to binomial AR(p) models a recent result by Jung and Tremayne (2006) for integer-valued autoregressive model of second order, INAR(2), with simple Poisson innovations. Forecasts are produced by conditional median which gives 'coherent' forecasts, and we estimate the forecast distributions of future values of binomial AR(p) models by means of a Monte Carlo method allowing for parameter uncertainty. Model parameters are estimated by the method of moments and estimated standard errors are calculated by means of block of block bootstrap. The method is fitted to log data set used in Wei$\ss$ (2009b).

• 한국국방경영분석학회지
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• 제17권1호
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• pp.1-24
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• 1991

This report concerns the study of deciding replacement requirements for 1/4ton truck in Korea. Two causes of replacement, accidental loss and wearout are considered in the replacement requirements model which was developed in Defence Logistics Agency. The model represents the state of 1/4 ton truck inventory over time as a finite Markov chain process. An accidental loss rate, yearly usage rates. wearout rates are used in conjuction with the current mileage distribution of the inventory to forecast replacement requirements in future time periods.

• Journal of information and communication convergence engineering
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• 제7권4호
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• pp.465-468
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• 2009

There is to solution the environmental data which the importance is seriously taken into consideration in the the 21st century that is set up whether or not be a welfare society advanced country according to quality of life elevations through environments in question to a preferential assignment for an environmental control will decrease of measures, and be proceeded so as to be urgent. However, shall get measurement of a correct environmental pollution duty and reduction measures stopped on bases of the data which there is reliability, and decrease excessive pollution than what, and may overcome efficiency of waste of cost environmental pollution management. Environmental pollution data collected are regarded as important, and, specially, a collection of environmental data forecast a pollution circle, or to analyze future development is important very at an environmental policy decision or decision making step to be national besides pollution reductions.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1992년도 하계학술대회 논문집 A
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• pp.495-497
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• 1992

Hourly load forecasting has become indispensable for practical simulation of electric power system as the system become larger and more complicated. To forecast the future hourly load the cyclic behavior of electric load which follows seasonal weather, day or week and office hours is to be analyzed so that the trend of the recent behavioral change can be extrapolated for the short term. For the long term, on the other hand, the changes in the infra-structure of each electricity consumer groups should be assessed. In this paper the concept and process of hourly load forecasting for hourly load is introduced.

• 기술경영경제학회:학술대회논문집
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• 기술경영경제학회 1999년도 제16회 동계학술발표회 논문집
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• pp.328-347
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• 1999

The substitution of Electronic Commerce(EC) for the traditional transactions triggers the changes of the industry structures and promotes the cost reductions of the firms in the areas of distributions and other administrative operations associated with purchase via EC. Our study clarifies the changes of the environments attributable to EC which are faced inter-and-externally by firms and try to exhibit the trend of EC market growth through such descriptions. Regardless of the rapid spread of EC, recent studies do not show appropriately its impact on the relevant industries and our domestic economy. Therefore, our study focuses on the forecasting of the impacts of EC on the domestic productions and imports. To this end, we develop an analytic framework using the existing data in Input/Output Analysis and the estimations of the EC market growth in the future. We, finally, identify the industrial sectors whose productions and imports are estimated to be accelerated by the extension of EC and forecast the whole effects of EC on domestic productions and imports.

• 한국환경과학회:학술대회논문집
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• 한국환경과학회 2003년도 International Symposium on Clean Environment
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• pp.212-215
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• 2003

The aim of this study was to test the air quality modelling system (HIRES-AIRCHEM) of The University of New South Wales particularly with regard to forecast ozone distribution. This was achieved by assimilating the New South Wales State EPA emissions inventory consisting of road and non-road sources and running the system over the Sydney metropolitan area for the four day period 25-28 February 1998. During this period ozone readings exceeded the EPA＇s goal of 80ppb on several occasions. The model forecasts of ozone distribution verified well with the EPA＇s ozone readings. This result has important implications for possible future use of the system as a tool for routinely assessing air quality.

• 한국시스템다이내믹스연구
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• 제10권1호
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• pp.61-76
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• 2009

We try to use system dynamics to forecast the demand/supply and price, also transportation fare for iron ore. Iron ore is very important mineral resource for industrial production. The structure for this system dynamics shows non-linear pattern and we anticipated the system dynamic method will catch this non-linear reality better than the regression analysis. Our model is calibrated and tested for the past 6 year monthly data (2003-2008) and used for next 6 year monthly data(2008-2013) forecasting. The test results show that our system dynamics approach fits the real data with higher accuracy than the regression one. And we have run the simulations for scenarios made by possible future changes in demand or supply and fare related variables. This simulations imply some meaningful price and fare change patterns.