• 품질경영학회지
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• 제49권1호
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• pp.31-45
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• 2021

Purpose: A noncentral composite design method is to be developed to explore farther region for the first factorial design. A general guideline for sequential experimentation is provided. Methods: (1) A non-overlapping noncentral composite design (NNCD) is developed, in which the second factorial design shares one design point that indicates the best response value in the first factorial design. (2) Four composite designs are compared in terms of the four design evaluation criteria, which are D-, A, G, and I-optimality. (3) A follow-up design strategy is suggested based on the interaction effect, direction of improvement, number of factors. Results: (1) NNCD and model building method are presented, which is useful for exploring farther region from first factorial design block. (2) The performances of the four composite designs are compared. (3) A follow-up design strategy is suggested. Conclusion: (1) NNCD will be useful to explore farther region for the first factorial design. (2) A follow-up design strategy can be beneficial to the experimental practitioners for product and process design and improvement.

• International Journal of Reliability and Applications
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• 제2권3호
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• pp.209-240
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• 2001

Computer-based simulation and analysis is used extensively in engineering for a variety of tasks. Despite the steady and continuing growth of computing power and speed, the computational cost of complex high-fidelity engineering analyses and simulations limit their use in important areas like design optimization and reliability analysis. Statistical approximation techniques such as design of experiments and response surface methodology are becoming widely used in engineering to minimize the computational expense of running such computer analyses and circumvent many of these limitations. In this paper, we compare and contrast five experimental design types and four approximation model types in terms of their capability to generate accurate approximations for two engineering applications with typical engineering behaviors and a wide range of nonlinearity. The first example involves the analysis of a two-member frame that has three input variables and three responses of interest. The second example simulates the roll-over potential of a semi-tractor-trailer for different combinations of input variables and braking and steering levels. Detailed error analysis reveals that uniform designs provide good sampling for generating accurate approximations using different sample sizes while kriging models provide accurate approximations that are robust for use with a variety of experimental designs and sample sizes.

• Advanced Composite Materials
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• 제18권4호
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• pp.327-338
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• 2009

In this paper, through an evaluation process conducted on several designs of mini-LIPCA (Lightweight Piezo-Composite curved Actuator), an optimal design of a mini-LIPCA has been proposed. Comparing with the LIPCA-C2, the design of the mini-LIPCA comes with reduced overall size and a thinner active layer. Since a variation in the number and lay-up of fiber composite layers may strongly affect the performance of the device, one is able to configure several designs of mini-LIPCA. The evaluation process is then followed in order to determine a configuration which characterizes the possibly optimal performance. That is, a design of a mini-LIPCA is said to be optimal if it is capable of producing a maximum out-of-plane displacement. The size of the LIPCA to be investigated was selected to be $10\;mm\;{\times}\;20\;mm$ in which the thickness of PZT plate is about 0.1 mm. The thickness of glass/epoxy and carbon/epoxy are about 0.09 mm and 0.1 mm, respectively. The evaluation process has been conducted thoroughly, i.e., analytical estimation, numerical approximation and the experimental measurement are all involved. Firstly, the design equation was used to calculate essential parameters of proposed lay-up configurations. Secondly, ANSYS, a commercial FEA package, was utilized to estimate displacement outputs of the actuators upon being excited. Finally, experimental measurements were able to verify the predicted results.

• 대한통합의학회지
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• 제2권3호
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• pp.23-30
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• 2014

Purpose : The purpose of this study was to grasp the general status and trend of the driving rehabilitation research focusing on interested topics, study subjects, therapeutic approaches, study designs, etc. Methods : It targeted 18 papers published in the RISS (Research Information Service System) from 2000 to 2014, and performed a descriptive statistical analysis by classifying these papers to topics, study subjects, study forms, study designs, study fields, and researchers. Results : As a result of the analysis, for the study form in the driving rehabilitation field, the rate of experimental papers was 61.1%, the highest. Major study subjects turned out to be occupational therapists, the disabled, and the aged, in order. For the study quality and design, the rate of survey and non randomized-single experimental study, which correspond to stage IV, was the highest, and the general study quality was found to be low. For the study field, the rates of the roles and recognition of occupational therapists, evaluation on driving ability of the disabled, and institutional improvement and future measures were the highest, each of which being 16.7%. Conclusion : Through this study, major study subjects and study quality in the driving rehabilitation field could be grasped, and it could be found that for development of the driving rehabilitation field, higher quality researches on more various study subjects would be needed in the future.

• Journal of Pharmaceutical Investigation
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• 제40권1호
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• pp.1-7
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• 2010

K-$BEtest^{(R)}$ is a well known program for bioequivalence test using a $2{\times}2$ design. Lee et al.(1998) and Park et al.(1999) suggested a $3{\times}3$ and $3{\times}2$ design, and also discussed their benefits. We developed a computer program, called BioEquiv, which can analyze some complex experimental designs such as, $3{\times}3$ design and $3{\times}2$ design including a standard $2{\times}2$ design. This program is a user-friendly one and overcomes the disadvantages of K-$BEtest^{(R)}$. The detailed statistical formula and structure of BioEquiv are presented with some examples. The comparison between K-$BEtest^{(R)}$ and BioEquiv are given with actual data analysis. BioEquiv is able to present a table of ANOVA test over some complex experimental designs. Moreover K-$BEtest^{(R)}$ and BioEquiv draw the same result when data consists of $2{\times}2$ design.

• 한국의류학회지
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• 제17권3호
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• pp.475-490
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• 1993

Even though modem ideal body type is rather tall and slim one, most of women don't coincide with it exactly. The objective of this research was to study the optical illusion effect of clothing design line so that average Korean women can approach the modern ideal body type. This research also tried to show the more scientific method to make stimulus by computer simulation and to present quantitative data. For the experiment, 9 design variables were selected from design principal book as follows : waistline level, skirt length, horizontal line emphasis, vertical line emphasis. princess line, vertical stripe, horizontal stripe, diagonal stripe. Each variable was divided into 4 levels so that 36 experimental designs were made. Visual stimuli which same model was wearing each design were recreated by the CAD system. These were given to evaluating panels through slide projecter. Then panels compared experimental design with basic design by 'tall effect' and 'slim effect', All the data from the experiment were analyszed by ANOVA and DUNCAN test for multiple comparison to study significance, direction(positive or negative), degree, proper extent of optical illusion effect. The result showed that some designs have optical illusion effect to make better look. In addition, it proved that the stronger design variable does not mean the more optical illusion effect and there was proper extent which produce the best illusion effect in each design variable.

• Nuclear Engineering and Technology
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• 제40권2호
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• pp.133-138
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• 2008

The use of Supercritical Fluids(SCF) has been proposed for numerous power cycle designs as part of the Generation IV advanced reactor designs, and can provide for higher thermal efficiency. One particular area of interest involves the behavior of SCF during a blowdown or depressurization process. Currently, no data are available in the open literature at supercritical conditions to characterize this phenomenon. A preliminary computational analysis, using a homogeneous equilibrium model when a second phase appears in the process, has shown the complexity of behavior that can occur. Depending on the initial thermodynamic state of the SCF, critical flow phenomena can be characterized in three different ways; the flow can remain in single phase(high temperature), a second phase can appear through vaporization(high pressure low temperature) or condensation(high pressure, intermediate temperature). An experimental facility has been built at the University of Wisconsin to study SCF depressurization through several diameter breaks. The preliminary results obtained show that the experimental data can be predicted with good agreement by the model for all the different initial conditions.

• 한국국방경영분석학회지
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• 제33권1호
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• pp.59-74
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• 2007

컴퓨터 시뮬레이션 모델은 일반적으로 복잡할 뿐더러 운용 시 많은 시간이 소요된다. 따라서 분석의 편의를 위해 좀 더 간단한 메타모델을 수립할 필요가 있다. 본 논문에서는 워게임 모델 JANUS를 사용하여 전차 전투 상황을 묘사하고 이에 대한 메타모델을 수립하였다. 메타모델을 수립하기 위해, 데이터 수집방법으로는 8가지의 실험계획법을, 모델링 방법으로는 2차 반응표면분석과 인공신경망을 고려하였다. 수립된 메타모델의 상대적 성능은 예측치의 평균제곱오차를 기준으로 비교하였다. 본 논문에서 고려한 전투상황에 대해서는 대체적으로 2차 반응표면 모형이 인공신경망 모형보다 더 높은 정확도를 보였으며, 실험계획법으로는 직교배열이나 최대최소거리 기준을 적용한 라틴 하이퍼큐브 계획법이 우수한 성능을 보였다.

• Smart Structures and Systems
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• 제24권1호
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• pp.15-26
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• 2019

Over the past decades, a great variety of dampers have been developed and applied to mechanical, aerospace, and civil structures to control structural vibrations. This study is focused on two emerging damper types, namely, eddy current dampers (ECDs) and electromagnetic damper (EMDs), both of which are regarded as promising alternatives to commonly-applied viscous fluid dampers (VFDs) because of their similar mechanical behavior. This study aims to enhance the damping densities of ECDs and EMDs, which are typically lower than those of VFDs, by proposing new designs with multiple improvement measures. The design configurations, mechanisms, and experimental results of the new ECDs and EMDs are presented in this paper. The further comparison based on the experimental results revealed that the damping densities of the proposed ECD and EMD designs are comparable to those of market-available VFDs. Considering ECDs and EMDs are solid-state dampers without fluid leakage problems, the results obtained in this study demonstrate a great prospect of replacing conventional VFDs with the improved ECDs and EMDs in future large-scale applications.

• 사상체질의학회지
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• 제26권1호
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• pp.98-109
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• 2014

Objectives This paper was aimed to review experimantal and clinical articles on Yeoldahanso-tang(YDHS), figuring out the recent tendency and suggesting the future prospects of YDHS-related studies. Methods The articles published in Korean or English since 2000 were searched, screened, and classified into experimental or clinical studies. And we structured designs, methods and results of the included studies into each table for the experimental studies or the clinical studies. Especially tools to diagnose constitutions and patterns identified in clinical researches were also summarized in the tables. Results 28 articles are finally included. 14 experimental studies are mostly in vitro designs to show efficacy of YDHS. There are only 2 studies for the safety. Among 14 clinical studies, 12 case studies target disorders of central nervous system, viral infection, skin ulcer and so on. 2 studies are before and after studies on cerebral infarction and effects on liver function. Conclusions Based on the efficacy of YDHS on central nervous system, it acquires higher level of evidence such as randomized controlled trials in the future. In addition other diseases such as skin ulcer and so on, it needs to be done more specific experimental or clinical studies so that we can get statistically significant results.