• Journal of the Korean Statistical Society
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• v.20 no.2
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• pp.156-161
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• 1991

Exact $D_{s}$-efficient designs for the precise estimation of all the coefficients of the quadratic terms are studied in a quadratic response surface model. Efficient exact designs are constructed for 2 q 5 w.r.t. $D_{s}$-optimaity criterion based on Pesotchinsky's(1975) and approximate $D_{s}$-optimal design given in Lim & Studden(1988) . Moreover, they seem to have reasonably good D-efficiencies. Similar idea could apply to q$\geq$6 cases.

• Journal of Korean Society for Quality Management
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• v.47 no.3
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• pp.523-535
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• 2019

Purpose: We research on the efficient response surface methodology(RSM) design to develop a design space in Quality by Design(QbD). We propose practical designs for the successful construction of the design space in QbD by allowing different number of replicates at the box points, star points, and the center point in the rotatable central composite design(CCD). Methods: The fraction of design space(FDS) plot is used to compare designs efficiency. The FDS plot shows the fraction of the design space over which the relative standard error of predicted mean response lies below a given value. We search for practical designs whose minimal half-width of the tolerance interval per a standard deviation is less than 4.5 at 0.8 fraction of the design space. Results: The practical designs for the number of factors between two and five are listed. One of the designs in the list could be chosen depending on the experimental budget restriction. Conclusion: The designs with box points replications are more efficient than those with the star points replication. The sequential method to establish a design space is illustrated with the simulated data based on the two examples in RSM.

• Journal of Korean Society for Quality Management
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• v.46 no.1
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• pp.27-38
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• 2018

Purpose: A large number of attributes with mixed levels are often considered in the conjoint analysis. In the cases where attributes have two or three levels, we research on the efficient design of survey questionnaire to estimate all the main effect and two factor interaction effects with a reasonable size of it. Methods: To reduce the number of questions in a questionnaire, the balanced incomplete block mixed level factorial design with minimum aberration was proposed by Lim and Chung (2016). Based on the number of questions and that of the respondents in that design, D-optimality criterion is adopted to find efficient designs where the main effect and two factor interaction effects are estimated. Results: The list of the number of questions and that of the respondents in efficient designs for survey questionnaire are recommended based on the D-efficiency of each design and the proposed selection criteria for the number of both questions and the respondents. By analyzing all the respondents survey data generated by the simulation study, we find the proper model. Conclusion: The proposed methods of designing survey questionnaires seem to perform well in the sense that how often the proper model is found in a simulation study where all the respondents survey data are generated by the simulation model.

• Journal of Korean Society for Quality Management
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• v.48 no.2
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• pp.269-282
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• 2020

Purpose: The practical design for experiments with mixtures of q components is consisted in the four types of design points, vertex, center of edge, axial, and center points in a (q-1)-dimensional simplex space. We propose a sequential method for the successful construction of the design space in Quality by Design (QbD) by allowing the different number of replicates at the four types of design points in the practical design when the quadratic canonical polynomial model is assumed. Methods: To compare the mixture designs efficiency, fraction of design space (FDS) plot is used. We search for the practical mixture designs whose the minimal half-width of the tolerance interval per a standard deviation, which is denoted as d₂, is less than 4.5 at 0.8 fraction of the design space. They are found by adding the different number of replicates at the four types of the design points in the practical design. Results: The practical efficient mixture designs for the number of components between three and five are listed. The sequential method to establish a design space is illustrated with the two examples based on the simulated data. Conclusion: The designs with the center of edge points replications are more efficient than those with the vertex points replication. We propose the sample size of at least 23 for three components, 28 for four components, and 33 for the five components based on the list of efficient mixture designs.

• Journal of the Korean Society of Costume
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• v.65 no.1
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• pp.104-117
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• 2015

Recently, the fashion industry has been integrating with The IT industry in order to develop in various ways. This study looks into ways to utilize the 3D CAD system, which would reduce time and cost while producing samples, and strengthen the communication between the brand and its cooperators by deploying knit designs using Knit CAD system's 3D virtual clothing program. The research method was reference, Internet resources 3D fashion CAD system and 3D Knit CAD system. Based on the data, simulation of the complete design of 4 deployed knit designs was done by using 3D virtual clothing program of the Knit CAD system utilizing knit design elements. One of each design element among the virtual clothing designs was chosen to produce real clothing, and the experts did verification on the appearance assessment of 3D virtual clothing knit designs of the Knit CAD system. As a result, 3D virtual clothing knit design of the Knit CAD system proved itself as an efficient system in terms of time and cost.

• The Research Journal of the Costume Culture
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• v.30 no.1
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• pp.66-87
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• 2022

This study explores the possibility of creating new experimental hanbok designs by accommodating the latest world fashion trends and the changing needs of consumers, in order to attempt to overcome the limitations of traditional Korean fashion design. To do so, We analyze works by contemporary Korean fashion designers to investigate current developments in Korean fashion design and to identify areas of improvement within hanbok design. The results show that most contemporary hanbok designs repeat stereotypes of traditional hanbok with minor modifications. So there arises a need to create new hanbok designs that are clearly distinct from traditional hanbok but also maintain its core features. To develop such designs, I apply the techniques of deconstruction fashion, which allow making experiments with form, composition, and materials use to realize new aesthetics. The use of CLO 3D fashion design software also proves to be very efficient for developing experimental designs. The study results make meaningful contributions to the development of virtual clothing and 3D fashion for hanbok, particularly as metaBUS, a cloud-based research synthesis platform, is rapidly gaining ground, and reality and virtual reality are increasingly mixed in everyday life. This attempt at 3D design of hanbok is expected to trigger more creative experimentation in hanbok design.

• Journal of Korean Society for Quality Management
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• v.39 no.3
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• pp.400-411
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• 2011

Process variables are factors in an experiment that are not mixture components but could affect the blending properties of the mixture ingredients. For example, the effectiveness of an etching solution which is measured as an etch rate is not only a function of the proportions of the three acids that are combined to form the mixture, but also depends on the temperature of the solution and the agitation rate. Efficient designs for the mixture components-process variables experiments depend on the mixture components-process variables model which is called a combined model. We often use the product model between the canonical polynomial model for the mixture and process variables model as a combined model. In this paper we propose three starting models for the mixture components-process variables experiments. One of the starting model we are considering is the model which includes product terms up to cubic order interactions between mixture effects and the linear & pure quadratic effect of the process variables from the product model. In this paper, we propose a method for finding robust designs and practical designs with respect to D-, G-, and I-optimality for the various starting combined models and then, we find practically efficient and robust designs for estimating the regression coefficients for those models. We find the prediction capability of those recommended designs in the case of three components and three process variables to be good by checking FDS(Fraction of Design Space) plots.

• Communications for Statistical Applications and Methods
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• v.4 no.3
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• pp.707-714
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• 1997

The littice designs have prove efficient but they are not alwasy available. This article proposes an alternative, an almost lattice design, of the triple lattice design (v=36, k=6, r=4) which is not available. Here, we compare the almost lattice design to the .alpha.-design (v=36, k=6, r=4) which is another alternative of the triple lattice design (v=36, k=6, r=4). Consequently, we show the almost lattice design is a more efficient alternative than the $\alpha$-design through A-, D-, and E-optimality.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.31B no.5
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• pp.42-49
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• 1994

In this paper we consider efficient 1-D and 2-D linear-phased half-band filter designs. We first introduce a new derivation of the existing Vaidynathan-Nguyen 's half-band filter design method, which verifies that the design provides optimal half-band filters. We then propose an approximately-linear-phased IIR half-band filter design method, which is based on the all-pass equalizer design with the linear phase -$\omega$/2. Finally, we propose an efficient method to design optimal 2-D half-band filters, for which we utilize a 2-D all pass prototype filter of half the order of the desired 2-D half-band filters.

• JSTS:Journal of Semiconductor Technology and Science
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• v.15 no.5
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• pp.445-454
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• 2015

As the feature sizes and the operating charges continue to be scaled down, multi-bit soft errors are becoming more critical in SRAM designs of a few nanometers. In this paper, we propose an efficient error detection technique to reduce the size of parity bits by applying a 2D bit-interleaving technique to 3D bit-partitioned SRAM devices. Our proposed bit-interleaving technique uses only 1/K (where K is the number of dies) parity bits, compared with conventional bit-interleaving structures. Our simulation results show that 1/K parity bits are needed with only a 0.024-0.036% detection error increased over that of the existing bit-interleaving method. It is also possible for our technique to improve the burst error coverage, by adding more parity bits.