• IE interfaces
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• v.17 no.3
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• pp.282-293
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• 2004

Line Balancing is the problem to assign tasks to stations while satisfying some managerial viewpoints. Most researches about the Mixed-Model Line Balancing problems are focused on the minimizing the total processing time or the number of workstations. Independently, some research reports consider the balance issues of the physical workloads on the assembly line. In this paper, we are presenting a new mathematical model to accomplish the line balance considering both the processing time and the workloads at the same time. To this, end, we propose an zero-one integer program problem, and we use the Chebyshev Goal Programming approach as the solution method. Some computational test runs are performed to compare the pay-offs between the processing time and the workloads. And, the test results show us that the reliable balanced work schedules can be obtained through the proposed model.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.08a
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• pp.359-367
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• 2004

In this research on-line model for the prediction of the effective strain distribution in strip on finishing mill process is presented. To describe the effective strain distribution in strip, three guide points and a distribution fitting variable are used. On-line models to get these points and fitting variable non-dimensionalization method and least square method were used with FEM simulation results. The model is developed using strip only FEM simulation as reference sets and compared with roll coupled FEM simulation results as perturbed sets. The on-line model to describe effective strain distribution shows good agreement with coupled FEM analysis results.

• Journal of Institute of Control, Robotics and Systems
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• v.4 no.1
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• pp.76-81
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• 1998

This paper presents an on-line scheme for parameter estimation of continuous-time systems, based on the model adjustment technique and the genetic algorithm technique. To deal with the initialisation and unmeasurable signal problems in on-line parameter estimation of continuous-time systems, a discrete-time model is obtained for the linear differential equation model and approximations of unmeasurable states with the observable output and its time-delayed values are obtained for the nonlinear state space model. Noisy observations may affect these approximation processes and degrade the estimation performance. A digital prefilter is therefore incorporated to avoid direct approximations of system derivatives from possible noisy observations. The parameters of both the model and the designed filter are adjusted on-line by a genetic algorithm, A set of simulation works for linear and nonlinear systems is carried out to demonstrate the effectiveness of the proposed method.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.3
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• pp.105-115
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• 2008

Urbanization results in increased runoff volume and peak flowrate and shortening in time of concentration, which may cause frequent flooding downstream. There are various types of flow retardation methods including detention ponds, retention ponds, and infiltration ponds. In general, hydrologic models to design the detention pond are classified into planning model and design model. This study is comparing and analyzing of planning model to design the detention pond in urban area. Detention ponds data of Disaster Impact Assessment Report on 22 sites were analyzed to investigate proper planning models in this study. From this research, following conclusions are derived, 1) In case of on-line detention pond, Lee model(1991) is the best planning model and similar to real storage volume. 2) In case of off-line detention pond, Abt and Grigg model is much more proper model compared to other models.

• Journal of Information Technology Applications and Management
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• v.10 no.3
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• pp.109-120
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• 2003

This paper proposes an e-business maturity model for small and medium-sized enterprises. The model consists of five maturity levels, which are on-line access, on-line business, matured on-line business, and full on-line business from least matured level to most matured level. The model can be used to assess e-business maturity level of individual enterprises. individual enterprise's maturity level can be assessed by examining sample check lists. Additionally, this paper summarizes the results of an application of the proposed model to a couple of small and medium-sized enterprises. This model can also be used to suggest what individual enterprises need to be upgraded towards higher maturity level.

• Proceedings of the KIEE Conference
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• summer
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• pp.430-432
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• 2004

The standard power system model is needed to test a transmission line protective relay There are two methods to develop a power system model for transmission line protection. First method is based on characteristic power system model, and second method is based on functional power system model. This paper presents a standard power system model for performance test of transmission line protective relay, where the power system model is based on the two methods. And this model is simulated by using RTDS to test a protective relay.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.05a
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• pp.180-183
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• 2003

In this research, on-line model for prediction of effective strain distribution hi strip on finishing mill process is prescribed. It has been developed using several selected non-dimensional parameters and previously made average effective strain model via series of finite element process simulations, $\Delta$$\varepsilon$ was introduced to describe the effective strain distribution in strip. To confirm adequate non-dimensional variables uniqueness test was done. And to decide the order of polynomial in on-line model equation tendency test for each variables was done. The prediction accuracy of the proposed model is examined through comparison with finite element calculation results.

• Journal of the Korea Safety Management & Science
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• v.4 no.2
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• pp.83-101
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• 2002

In this thesis presents line balancing problems of two-sided and mixed model assembly line widely used in practical fields using genetic algorithm for reducing throughput time, cost of tools and fixtures and improving flexibility of assembly lines. Two-sided and mixed model assembly line is a special type of production line where variety of product similar in product characteristics are assembled in both sides. This thesis proposes the genetic algorithm adequate to each step in tow-sided and mixed model assembly line with suitable presentation, individual, evaluation function, selection and genetic parameter. To confirm proposed genetic algorithm, we apply to increase the number of tasks in case study. And for evaluation the performance of proposed genetic algorithm, we compare to existing algorithm of one-sided and mixed model assembly line. The results show that the algorithm is outstanding in the problems with a larger number of stations or larger number of tasks.

• Journal of The Korean Astronomical Society
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• v.31 no.2
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• pp.77-87
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• 1998

The accumulated knowledge of the influence of solar granulation on spectral lines, i.e. their asymmetry, provides a key to analyze stellar spectral line asymmetries. In this paper, a simple line synthesis using a simple 'model' of granulation was calculated. By adjusting the properties of the granule model, the observed imprints of convection on spectral lines can be reproduced. Since we depict convective flows using a continuous function rather than using a few components of flows (cf. Gray and Toner 1985, 1986; dravins 1990), we were able to identify which components of convection are important in line bisector shapes. The results of this study can be summarized as follows: Firstly, the intensity contrast (i.e. temperature fluctuation), and the area coverage of up- and down-flows are the two important factors which determine the line bisector shapes. Secondly, on the contrary to the assumption of other studies, the effect of horizontal flows is non-negligible. This exercise provides a qualitative understanding of the effect of convection on spectral lines. This knowledge serves as a guideline for understanding the characteristic difference in convection for stars on either side of the 'Granulation Boundary' (Gray 1982; Gray and Nagel 1989).

• Transactions of Materials Processing
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• v.28 no.2
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• pp.83-88
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• 2019

This paper introduces a new concept - on-line FE model, as applied to metal rolling. The new technology allows for completion of process simulation within a tiny fraction of a second without loss of high-level prediction accuracy inherent to FEM. The three steps of an on-line FE model design namely, process metamorphosis, mesh design, and process variable design, are described in detail. The procedure is demonstrated step by step through designing actual on-line models for the prediction of the dog-bone profile in edge rolling. The validity and prediction accuracy of the on-line FE models are analyzed and discussed.