• Journal of the Korean Society of Safety
• /
• v.23 no.2
• /
• pp.57-64
• /
• 2008

The Semiconductor industry in Korea has achieved a great contribution to the growth of its economy for the last 20 years with its product export ranked to #1 nowadays. However, the working environment in semiconductor industry is always exposed to a potential risk of critical safety issue for workers with many kinds of utilities used such as toxic chemicals, gases, high vacuum and high voltages of electricity. This study is focused on empirical research to find out the factors on safety climate and to examine the relationships of safety climate and safe work behaviour in the work site of Korea semiconductor industry. As a result of simulation, a strong positive relationships and safe work behaviour have been identified in this study. Its result and implications has been discussed and suggested further studies on its limitation from this study.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.59 no.6
• /
• pp.1011-1016
• /
• 2010

It is an important issue to electric power system operations that it can reliably supply large-capacity power to consumption area as due to increasing power demand growth. For this purpose, The FACTS equipment based on Power IT technology with the existing mechanical compensators has been applied to power system. Therefore we suggest on this paper that a plan for coordination control of multiple power compensation equipment in order to increase the utilization of each facility and secure operation margin capacity. As the result of simulation, it is possible to cope actively with a suddenly changed power system. This helps greatly for the voltage stability and supply reliability in a suddenly changed power system.

• Journal of Mechanical Science and Technology
• /
• v.18 no.11
• /
• pp.2042-2048
• /
• 2004

A molecular dynamics study has been conducted on an external-force-field-induced isothermal crystallization process of amorphous structures as a new low-temperature athermal crystallization process. An external cyclic-force field with a dc bias is imposed on molecules selected randomly in an amorphous-phase of argon. Multiple peaks smoothed out in the radial distribution functions for amorphous states appear very clearly during the crystallization process that cannot be achieved otherwise. When the amorphous material is locally exposed to an external force field, crystallization starts and propagates from the interfacial region and crystallization growth rates can be estimated.

• Proceedings of the Korean Operations and Management Science Society Conference
• /
• 2000.04a
• /
• pp.330-336
• /
• 2000

This paper discusses the potential of system dynamics modelling to support balanced scorecard. The balanced scorecard is a conceptual framework for translating an organisation's strategy into a set of performance indicators. These performance indicators are distributed across the 'classic'model's four perspective: Customers, Internal Business Processes, Financial, and Learning and Growth. This balanced scorecard, whilst having significant strength, suffers from the limitation of all performance indicator systems, namely that the interrelationships between indicators are overlooked and there is no way of taking into account the impact of delayed feedback which flows from introduction of new policy and legislative changes. System Dynamics is a methodology for understanding complex problems where there is dynamic behaviour and where feedback impacts significantly on system outcomes. System dynamics provides a rigorous basis for qualitative testing of the effects of performance indicators in complex environments such as health or social security. This can be supplemented with quantitative system dynamics simulation tools that further test the validity of indicators and the business rules implicit in them. System dynamics modelling has an important role to play in extending feedback cycle in performance measurements to a full systems approach.

• Journal of Microbiology and Biotechnology
• /
• v.14 no.6
• /
• pp.1163-1169
• /
• 2004

An unstructured mathematical model is presented for lactic acid fermentation based on the energy balance. The proposed model reflects the energy metabolic state and then predicts the cell growth, lactic acid production, and glucose consumption rates by relating the above rates with the energy metabolic rate. Fermentation experiments were conducted under various initial lactic acid concentrations of 0, 30, 50, 70, and 90 g/l. Also, a genetic algorithm was used for further optimization of the model parameters and included the operations of coding, initialization, hybridization, mutation, decoding, fitness calculation, selection, and reproduction exerted on individuals (or chromosomes) in a population. The simulation results showed a good fit between the model prediction and the experimental data. The genetic algorithm proved to be useful for model parameter optimization, suggesting wider applications in the field of biological engineering.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.28 no.2
• /
• pp.47-52
• /
• 2020

Air transport demand is on a sharp rise due to growth in the aviation market. To prepare for this rapidly growing demand for aviation, airport operators are interested in the processing airport capacity. Airport throughput is determined to be the smallest of the facility capacities that make up the airport, but it is customary to determine the cost and time consuming runway capacity as airport capacity. Previous studies have shown that while recent studies have been conducted on airport capacity, there is little research on the criteria for determining capacity. In this study, we would like to determine the extent to which airport capacity is affected by the airport's operating hours and the resulting delays.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.44 no.5
• /
• pp.67-78
• /
• 2002

The purpose of this study is to apply land use planning model (LUPM) to a test village. The LUPM was tested to Uhang village, Ucheon-myeon, Gangwon-do, and its parameters calibrated by land use data from 1973 to 1980. When two test cases were considered of its extended built areas of 10,600㎡ from 1980 to 1985 and 51,300㎡ from 1985 to 1992, there was good similarities between simulated and observed results with R$^2$ being more than 0.95. Land use transfer patterns to residential use could be very similarly simulated from LUPM when comparing the observed patterns, so, LUPM can be applied to the comprehensive simulation of land use change due to the village growth.

• Proceedings of the KIEE Conference
• /
• 2005.07a
• /
• pp.429-431
• /
• 2005

According to the second plan of the Korean Government about technology development, utilization and popularization of new renewable energy, the continuous growth of distributed resources are expected. Various studies about impact of distributed resource on distribution system have been already accomplished. Rut there is a few paper about recloser and sectionalizer coordination and protection scheme in distribution system interconnected a number of distributed resources. In this paper, it is dealt with that recloser and sectionalizer coordination at the cases concerned with fault position. The problems of these cases are investigated through simulation.

• Proceedings of the KIEE Conference
• /
• 2006.10c
• /
• pp.357-359
• /
• 2006

The electric power system of Kwangyang steel works needs to keep the parallel operation with the system of KOPEC(Korea Electric Power Corporation) for supplying the power with safety. Once it is separated from KOPEC due to an accident, it operates the automatic Mill trip system to prevent huge fluctuating loads from the serious frequency drop. In spite of that, it is recent situations that the continuous growth of electric loads facilitates the frequency drop. Therefore, this paper proposes a model of generator control system so as to quantitatively analyze the response characteristics to the frequency change under the single operation, and also suggests the strategy for minimizing the frequency changes. The simulation results show it is desirable to operate the generators by 3% speed droop and 10% load limiter.

• Water Engineering Research
• /
• v.5 no.2
• /
• pp.81-99
• /
• 2004

Long term streamflow regime under virtual climate change scenario was examined. Rainfall forecast simulation of the Canadian Global Coupled Model (CGCM2) of the Canadian Climate Center for modeling and analysis for the IPCC SRES B2 scenario was used for analysis. The B2 scenario envisions slower population growth (10.4 billion by 2010) with a more rapidly evolving economy and more emphasis on environmental protection. The relatively large scale of GCM hinders the accurate computation of the important streamflow characteristics such as the peak flow rate and lag time, etc. The GCM rainfall with more than 100km scale was downscaled to 2km-scale using the space-time stochastic random cascade model. The HEC-HMS was used for distributed hydrologic model which can take the grid rainfall as input data. The result illustrates that the annual variation of the total runoff and the peak flow can be much greater than rainfall variation, which means actual impact of rainfall variation for the available water resources can be much greater than the extent of the rainfall variation.