• The Transactions of the Korean Institute of Electrical Engineers
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• v.32 no.2
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• pp.43-49
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• 1983

In this study, model simplification problem using singular perturbation technique is considered. The correctness and errors of simplified model which is obtained by the use of this technique, depends upon the order and the time scaling factor of the simplified model But, unfortunately, there is no explicit criteria for selections of these parameters. In this paper, error equations are derived and expanded by using the useful properties of $L_2$-norm. Then, new criteria for selecting the order of the simplified model and time scaling factor with respect to error bound are suggested. Since these criteria, newly proposed in this study, have strong concern about error bound, it can be used to choose the minimum order of the simplified model and time scaling factor with respect to given error bound. Conversely, if the order of the simplified model and time scaling factor are given, the error induced by the simplification can also be computed easily.

• The Korean Journal of Applied Statistics
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• v.1 no.1
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• pp.75-90
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• 1987

Statistical data analysis using the statisticaal packages can be performed on the personal computers. But it is not easy to select a personal computer in which statisticians could run statistical packages. The paper discusses some of the minimum requirements of the personal computers to use statistical packages and how to choose good statistical packages with better numerical results and introduces the statistical packages which are available in the personal computers.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.35 no.4
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• pp.98-109
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• 2012

Recently, the optimisation of end-of-life (EOL) product remanufacturing processes has been highlighted. In particular, computer remanufacturing becomes important as the amount of disposed of computers is rapidly increasing. At the computer remanufacturing, depending on the selections of used computer parts, the value of remanufactured computers will be different. Hence, it is important to select appropriate computer parts at the reassembly. To this end, this study deals with a decision making problem to select the best combination of computer parts for minimising the total remanufacturing computer cost. This problem is formulated with an integer nonlinear programming model and heuristic search algorithms are proposed to resolve it.

• Journal of the East Asian Society of Dietary Life
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• v.19 no.6
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• pp.1039-1048
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• 2009

The purpose of this study was to establish a model of the use-utility of cooking equipments and kitchen centers using survey data and to compare U.S.A. with Korea. The survey was conducted to identify attributes that were related to the efficiency of kitchen centers as well as equipments. Indices for the most important attributes were developed and used to compare different selections of equipment. The impact of adding an equipment item was found to vary with the attributes of the item, the degree of importance ascribed to the attributes of the work center and specific functions performed there. Similarities and differences between the U.S.A. and Korea are discussed, and implications for those who have interest in the use-utility model of cooking equipment and kitchen centers are provided.

• Proceedings of the Acoustical Society of Korea Conference
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• 1994.06a
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• pp.949-956
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• 1994

In this paper, we introduce a new speech synthesis method for Japanese and Korean arbitrary sentences using the natural speech data-base. Also, application of this method to a CAI system is discussed. In our synthesis method, a basic sentence and basic accent-phrases are selected from the data-base against a target sentence. Factors for those selections are phrase dependency structure (separation degree), number of morae, type of accent and phonemic labels. The target pitch pattern and phonemic parameter series are generated using those selected basic units. As the pitch pattern is generated using patterns which are directly extracted form real speech, it is expected to be more natural than any other pattern which is estimated by any model. Until now, we have examined this method on Japanese sentence speech and affirmed that the synthetic sound preserves human-like features fairly well. Now we extend this method to Korean sentence speech synthesis. Further more, we are trying to apply this synthesis unit to a CAI system.

• Transactions of Materials Processing
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• v.9 no.1
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• pp.17-26
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• 2000

A series of parametric study was performed for the investigation on the influence of analysis parameters to the solution behavior in the elastic-plastic-static analysis of several sheet metal forming processes, such as deflection by a point force under plane strain and axisymmetric conditions, plane strain bending by a punch, axisymmetric stretching by a punch, axisymmetric bulging by hydraulic pressure, and axisymmetric deep drawing by a punch. The parameters considered are kind of element, number of elements, integration scheme for elemental equation and friction coefficient. Results obtained for different selections of those parameters were compared with each other, experimental measurements and analytical solution.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.430-434
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• 2004

The geometric parameters between wheel and rail change wheel/rail contact geometry characteristics, and this influence dynamic behavior of rolling stock. So, the selections of optimum geometric parameters between wheel and rail is important for planning of railway system. In this study, we have analyzed the influence of geometric parameters like wheel flange-back distance, gage, and rail inclination to the equivalent conicity relating dynamic behavior. The analyses show the following results. The widening of wheel flange-back distance increase the equivalent conicity, the widening of gage, rail inclination 1/20 compared with rail inclination 1/40 decrease the equivalent conicity.

• Journal of electromagnetic engineering and science
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• v.13 no.4
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• pp.251-258
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• 2013

A procedure for antenna parameter selections is proposed that considers the relationships between synthetic aperture radar performance and the antenna parameters of a parabola-type reflector antenna with a central flat dish. The effects of a central dish designed for weight reduction on the antenna beam pattern are also quantitatively analyzed using commercially available software based on the physical optics algorithm. The results of the theoretical analysis and simulation predict that a larger size of the central dish results in an increase in the sidelobe level, which is the reason for the increase in two important ambiguities, such as range ambiguity ratio (RAR) and azimuth ambiguity ratio (AAR). The dependence of RAR and AAR on Pulse repetition frequency is also analyzed and discussed.

• Culinary science and hospitality research
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• v.10 no.1
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• pp.46-63
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• 2004

The service quality factors which causes an effect in restaurant selections appeared with gain and loss factors of essence and the customers. The restaurant recommendation factor was appeared with shedding of blood characteristics. The research which sees Korean-style food party's decision making is difficult with the plan of the security and loyalty of customers presented. The marketing strategy for the customer loyalty of Korean-style food party will be able to be overcome. The critical point of the research which sees for the security of the loyalty customer selects a target market, and the strategy which invades intensively is necessary. The Korean-style food party decision may cause the customer fractionation anger which follows in market fractionation anger. It does not become accomplished from the research which sees but with the critical point of research to appear, the research of creation of the loyalty customer who applies a market fractionation anger necessity will be becomes feed with hereafter research subject.

• Journal of Power Electronics
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• v.11 no.6
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• pp.811-818
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• 2011

Modulation strategies for multilevel inverters have typically focused on synthesizing a desired set of sinusoidal voltage waveforms using a fixed number of dc voltage sources. This makes the average power drawn from different dc voltage sources unequal and time varying. Therefore, the dc voltage sources are unregulated and require that corrective control action be incorporated. In this paper, first two new selections are proposed for determining the dc voltage sources values for asymmetric cascaded multilevel inverters. Then two modulation strategies are proposed for the dc power balancing of these types of multilevel inverters. Using the charge balance control methods, the power drawn from all of the dc sources are balanced except for the dc source used in the first H-bridge. The proposed control methods are validated by simulation and experimental results on a single-phase 21-level inverter.