• Communications for Statistical Applications and Methods
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• v.25 no.3
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• pp.321-328
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• 2018

In clinical trials with repeated measurements, the time-averaged difference (TAD) may provide a more powerful evaluation of treatment efficacy than the rate of changes over time when the treatment effect has rapid onset and repeated measurements continue across an extended period after a maximum effect is achieved (Overall and Doyle, Controlled Clinical Trials, 15, 100-123, 1994). The sample size formula has been investigated by many researchers for the evaluation of TAD in two treatment groups. For the evaluation of TAD in multi-arm trials, Zhang and Ahn (Computational Statistics & Data Analysis, 58, 283-291, 2013) and Lou et al. (Communications in Statistics-Theory and Methods, 46, 11204-11213, 2017b) developed the sample size formulas for continuous outcomes and count outcomes, respectively. In this paper, we derive a sample size formula to evaluate the TAD of the repeated binary outcomes in multi-arm trials using the generalized estimating equation approach. This proposed sample size formula accounts for various correlation structures and missing patterns (including a mixture of independent missing and monotone missing patterns) that are frequently encountered by practitioners in clinical trials. We conduct simulation studies to assess the performance of the proposed sample size formula under a wide range of design parameters. The results show that the empirical powers and the empirical Type I errors are close to nominal levels. We illustrate our proposed method using a clinical trial example.

• Fashion & Textile Research Journal
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• v.21 no.2
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• pp.189-202
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• 2019

This study develops a bodice pattern for high school girls aged 17 to 19 that use virtual garment simulation. The study developed a bodice pattern based on the fit evaluation result for two selected bodice patterns. The basic formula of the design method based on the result of 3 times of fit evaluation is as follows: waist back $length=stature/8{\times}1.85cm$, waist front length=waist back length+bust/40+0.7cm, front bust girth=bust/2+4cm, back bust girth=Chest/2+3cm, armscye depth=Chest/4+0.5cm, back interscye length=bishoulder length -1.2cm, front interscye length=back interscye length -1.2cm, front neck width=back neck width -0.3cm. The developed bodice pattern used Bishoulder Length as a criteria for the calculation formula of back interscye length, and back interscye length as a criteria for the calculation formula of front interscye length. The fit evaluation showed the relevance of the bishoulder length, front interscye length, and back interscye length based on a comparison of the calculated figure. A bodice pattern with great body suitability and fitness to high school girls was developed through 3D virtual garment simulation that calculated the application of body proportion to width. This study only analyzed the evaluation result of a virtual model only in a representative form; however, a pattern study is also proposed to compare and analyze the design methods of patterns by body type.

• Journal of the Earthquake Engineering Society of Korea
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• v.16 no.6
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• pp.29-36
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• 2012

Involved in a research for the application of seismic isolation to the nuclear industry, this study evaluates firstly the responses of seismic isolation system considering general ranges of structural period and damping ratio by using preliminary design formula. Secondly, coupling effects of input motions were evaluated to find out appropriate conditions of excitations and effect of the iteration for calculating yield displacement of lead core was also assessed in terms of response of a seismically isolated structure. Finally, the results of preliminary design calculation were compared with those of dynamic analysis and the propriety of the formula was evaluated and appropriate ranges of reduction factor were also suggested from the results.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.3 s.174
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• pp.645-652
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• 2000

A method for shape design sensitivity analysis is proposed utilizing commercial software ANSYS for thermal conduction problems. While the sensitivity formula is derived analytically by introduing adjoint variable concept, sensitivity calculation in practice as well as the primal and adjoint solution of thermal conduction is performed using the ANSYS very easily. Since the formula always takes boundary integral form, sensitivity evaluation in ANSYS requires a little more addition of post-processing routine which involves evaluation of boundary variable from the obtained solution. Though the BEM has been used as a better tool for this purpose, the present study shows it can also be calculated using any kind of analysis code such as ANSYS since the formula is based on analytic nature. Therefore the present study provides a new and efficient way of optimization which was not possible before using commercial software. The usefulness of the method is illustrated via a weight minimization problem of thermal diffuser.

• Journal of the Korea Institute of Military Science and Technology
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• v.17 no.4
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• pp.471-478
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• 2014

Navy forces of ROK asked for more than 90% operational availability in the requirement document of combat ship. This study proposes the evaluation methodology of operational availability with the evaluation process, calculation formula, analysis of operational test data. As the case study, the developed methodology is proved to apply for 00 batch-I naval ship using the data to be acquired during the operational test period. The operational availability by test data was 90.03%, and it was satisfied with objective value 90%. The paper will contribute not only to establish the evaluation methodology of operational availability for combat ship but also other general weapon system.

• Journal of the Korean Society of Safety
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• v.18 no.1
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• pp.81-88
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• 2003

Recently, pile foundations were constructed in rough or soft ground than ground of well condition thus it is important that prediction of ultimate bearing capacity and calculation of proper safety factor applied pile foundation design. This study were performed to dynamic loading tests for the thirty two piles at four different construction sites and selected pile at three site were performed to static loading tests and then compare with measured value and value of static and dynamic loading tests. The load-settlement curve form the dynamic loading tests by CAPWAP was very similar to the results obtained from the static load tests. Based on dynamic and static loading tests, the reliability of pile-driving formula were analyzed and then suggested with proper safety factor for prediction of allowable bearing capacity in this paper.

• Journal of Korea Society of Digital Industry and Information Management
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• v.12 no.4
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• pp.59-69
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• 2016

We proposed a specialized model of performance measurement to measure the training performance of the trainees in cyber practical training. Cyber security professionals are cultivating their expertise, skills, and competencies through cyber practical training in specialized education and training institutions. The our proposed process of trainee evaluation is consisted of an evaluation component discovery, evaluation item selection, evaluation index catalog, ratings and criteria decision, and calculation formula. The trainee evaluation is consisted of a formative evaluation during the training and an overall evaluation after finished training. Formative evaluation includes progress evaluation and participation evaluation, and overall evaluation includes practice evaluation and learning evaluation. The evaluation is weighted according to the importance of evaluation type. Because it is evaluated actual skills and abilities, competencies are assigned a high weight, while knowledge and attitudes are assigned a low weight. If cyber security trainees are evaluated by the proposed evaluation model, cyber security professionals can be cultivated by each skill and knowledge level and can be deployed by importance of security task.

• Journal of Korean Society of Steel Construction
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• v.27 no.5
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• pp.455-470
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• 2015

This research suggest method to calculate more accurate shearing and bending force on corrugated steel plate that it is produced domestically. This research analyze limitation of former formula on domestic design standard and existing research. In addition The strength calculation formula on corrugated steel plate was proposed according to result of the experiment and FEM analysis. In this study, the result that compare experiment with analysis using the proposed shear buckling coefficient and limit width to thickness ratio indicate similar behavior. As the result of the research, It is judged that the structural member design and performance evaluation of the corrugated steel plate was conveniently applied.

• Journal of the Korean Solar Energy Society
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• v.22 no.4
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• pp.26-34
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• 2002

Daylighting in building is very important as it has an effect on work performance as well as on their visual health. It is also regarded as a good energy conservation measure in saving energy used for lighting. There are many daylighting evaluation tools such as empirical equations, tables, nomograms, diagrams, protractors, computer simulation, scale models. This study conducted initial daylight measurements to analyze luminous environment in classrooms of elementary school and comparative analysis on three daylighting evaluation tools, such as daylight factor calculation formula, the graphic method with BRE Protractor and computer simulation with Adeline 3.0. It is found that the computer simulation tool produced the closest result to actual measurements of luminous environment in elementary school classroom, and the other simplified tools made appropriate results so that they can be used in the early stage of daylighting design process.

• Smart Structures and Systems
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• v.20 no.4
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• pp.473-481
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• 2017

This study suggests a simple, convenient and non-destructive method for investigation of the Young's modulus detection in stepped shafts which only utilizes the first-order resonant frequency in flexural mode and dimensions of structures. The method is based on the impulse excitation technique (IET) to pick up the fundamental resonant frequencies. The standard Young's modulus detection formulas for rectangular and circular cross-sections are well investigated in literatures. However, the Young's modulus of stepped shafts can not be directly detected using the formula for a beam with rectangular or circular cross-section. A response surface method (RSM) is introduced to design numerical simulation experiments to build up experimental formula to detect Young's modulus of stepped shafts. The numerical simulation performed by finite element method (FEM) to obtain enough simulation data for RSM analysis. After analysis and calculation, the relationship of flexural resonant frequencies, dimensions of stepped shafts and Young's modulus is obtained. Numerical simulations and experimental investigations show that the IET method can be used to investigate Young's modulus in stepped shafts, and the FEM simulation and RSM based IET formula proposed in this paper is applicable to calculate the Young's modulus in stepped shaft. The method can be further developed to detect mechanical parameters of more complicated structures using the combination of FEM simulation and RSM.