• International Journal of Naval Architecture and Ocean Engineering
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• v.13 no.1
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• pp.450-465
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• 2021

In this study, an attempt has been made to investigate the water-entry characteristics of the high-speed parallel projectile numerically. The shear stress transport k-𝜔 turbulence model and the Zwart-Gerber-Belamri cavitation model based on the Reynolds-Averaged Navier-Stokes method were used. The grid independent inspection and grid convergence index is carried out and verified. The influences of the parallel water-entry on flow filed characteristics, trajectory stability and drag reduction performance for different values of initial water-entry speed (𝜈₀ = 280 m/s, 340 m/s, 400 m/s) and clearance between the parallel projectiles (L_p = 0.5D, 1.0D, 2.0D, 3.0D) are presented and analyzed in detail. Under the condition of the parallel water-entry, it can be found that due to the intense interference between the parallel projectiles, the distribution of cavity is non-uniform and part of the projectile is exposed to water, resulting in the destruction of the cavity structure and the decline of trajectory stability. In addition, the parallel projectile suffers more severe lateral force that separates the two projectiles. The drag reduction performance is impacted and the velocity attenuation is accelerated as the clearance between the parallel projectiles reduces.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.3
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• pp.872-881
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• 1996

The concept of homology design has been devised for the application to large telescope structure by S.v.Hoerner. It is defined that the deformation of a structure shall be called homologous, if a given geometrical relation holds, for a given number of structural points, before, during, and after the deformation. Recently, the need of homology design in the structural design has been increase due to the required precision in the structure. Some researchers have utilized the theory on the structural design with finite element method in the late 1980s In the present investigation, a simple method using geometrical equality constraints is suggested to gain homologous deformation. The previous method is improved in that the decomposition of FEM eqation, which is very expensive, is not necessary. The basic formulations of the homology design with the optimization concept are described and several practical examples are solved to verify the usefulness and validity. Especially, a back-up structure of a satellite antenna is designed by the suggested method. The results are compared with those of existing researches.

• Progress in Medical Physics
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• v.18 no.1
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• pp.20-26
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• 2007

It is expected that synaptic construction and electrical characteristics In degenerate retina might be different from those In normal retina. Therefore, we analyzed the retinal waveform recorded with multielectrode array in normal and degenerate retina using principal component analysis (PCA) and Independent component analysis (ICA) and compared the results. PCA Is a well established method for retinal waveform while ICA has not tried for retinal waveform analysis. We programmed ICA toolbox for spatiotemporal analysis of retinal waveform. In normal mouse, the MEA spatial map shows a single hot spot perfectly matched with PCA-derived ON or OFF ganglion cell response. However In rd/rd mouse, the MEA spatial map shows numerous hot and cold spots whose underlying interactions and mechanisms need further Investigation for better understanding.

• Earthquakes and Structures
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• v.6 no.3
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• pp.317-334
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• 2014

The work is concerned with an investigation of the advantages stemming from the use of lightweight aggregate concrete in earthquake-resistant reinforced concrete construction. As the aseismic clauses of current codes make no reference to lightweight aggregate concrete beams made of lightweight aggregate concrete but designed in accordance with the code specifications for normal weight aggregate concrete, together with beams made from the latter material, are tested under load mimicking seismic action. The results obtained show that beam behaviour is essentially independent of the design method adopted, with the use of lightweight aggregate concrete being found to slightly improve the post-peak structural behaviour. When considering the significant reduction in deadweight resulting from the use of lightweight aggregate concrete, the results demonstrate that the use of this material will lead to significant savings without compromising the structural performance requirements of current codes.

• Journal of Pharmaceutical Investigation
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• v.40 no.5
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• pp.297-304
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• 2010

The present work focuses on preparation of olanzapine, orally dispersing tablets by direct compression method. Effect of super disintegrant crospovidone, disintegration time, drug content on in vitro release has been studied. A factorial design was employed in formulating a prompt dispersible tablet. The selected independent variables crospovidone and fmelt showed significant effect on dependent variables i.e. disintegration time and percent drug dissolved. Disintegration time and percent drug dissolved decreased with increase in the level of crospovidone. The similarity factor $f_2$ was found to be 97.48 for the developed formulation indicating the release was similar to that of the marketed formulation. Pharmacokinetics of olanzapine after single-dose oral administration of orally disintegrating tablet in normal volunteers were evaluated and the results showed that PK parameters (Cmax, Tmax, AUC) of the designed ODT matrix were similar to those of commercial product, Zyprexa Zydis$^{(R)}$ as a reference.

• Journal of the Korean Home Economics Association
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• v.40 no.1
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• pp.135-146
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• 2002

The Purpose of this study was to identify the sensibility elements and the evaluative dimensions of internet fashion shopping mall to supply optimal experience to the customer. First, association words for internet fashion shopping mall by open-ended method and sensibility-expression-adjective feeling as navigating personally 57 shopping mall dealing with fashion products were collected. Collected adjectives were ranked after making index by frequency and diversity. Then, correlation analysis was executed to extract independent adjective and their opposite words. Semantic differential scale was made for internet-fashion-shopping-mall-evaluation. After preliminary investigation with this scale, factor analysis was implemented. 12 sensibility evaluation words were extracted. Then, 200 subjects evaluated satisfaction degree for 8 selected shopping mall. To explain the hierarchy of internet fashion shopping mall, cluster analysis was applied. The understanding of sensibility element and evaluative dimensions of internet fashion shopping mall can be utilized efficiently as basic materials when marketer plans internet shopping mall design and makes marketing strategy.

• Journal of the Korea Society of Computer and Information
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• v.24 no.6
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• pp.151-158
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• 2019

In this paper, we analyzed the relationship between employment stability, wage level, welfare system, working condition, job satisfaction and organizational commitment in order to find out ways to develop and competitiveness of the nano-convergence industries. Through this study, we conducted the possibility of deriving organizational commitment by job satisfaction which is given through employment stability, wage level, welfare system, and working condition for continuing their work life. In order to find relationships between each concepts, we used a multiple regression analysis with job satisfaction and commitment as dependent variable and employment stability, wage level, welfare system, and working condition as independent variables. Through this study, it was expected to increase the organizational commitment through the job satisfaction of the employees if a changing method of employees management is centered on some tasks suggested for the sound working condition and efficient utilization policies.

• PNF and Movement
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• v.6 no.3
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• pp.1-9
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• 2008

Purpose : The purpose of this study was to analyze the reaction of recovery for the fatigue by sports massage treatment after Taekwondo training and then to verify the effectiveness. Subject : The subjects of this study were all the 20 high school Taekwondo players divided into two groups (rest recovery group and sports massage group) selected by systematic random assignment sampling. Method : The variables were the level of hemoglobin, lactic acid and glucose, and measured at rest, immediately-after exercise and 30-minute recovery. The data from this study were analyzed by using one-way ANOVA, independent sample t-test. Results : The results are as follows ; 1. The measurement of the hemoglobin, there was not the significant differences between experiment group and control group. 2. The lactate showed lower in the experiment group than in the control group in 30-minute recovery (p<.001). 3. The glucose showed lower in the experiment group than in the control group in 30-minute recovery (p<.01). So I think the sports massage treatment is more effective in the relief of fatigue than static rest method during the recovery after sports. However the massage treatment influence on the activation of metabolism according to the intensity and the duration of sports, and vary the effect of treatment according to the method and execution time. Therefore the longitudinal investigation of the variation by the long time massage through the more detailed program must be requisite for us.

• Steel and Composite Structures
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• v.48 no.3
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• pp.321-333
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• 2023

This paper proposes a comprehensive investigation on lateral stiffness of corner-supported steel modular frame using splice connection. A full-scale modular frame with two stacked steel modules under lateral load is tested. Ductile pattern in the transfer of lateral load is found in the final failure mode. Two types of lateral stiffness, including tangent stiffness and secant stiffness, are defined from the load-displacement due to the observed nonlinearity. The difference between these two types of stiffness is found around 20%. The comparisons between the experimental lateral stiffness and the predictions of classical methods are also conducted. The D-value method using hypothesis of independent case is a conservative option for predicting lateral stiffness, which is more recommended than method of contraflexural bending moment. Analyses on two classical short-rod models, including fix-rod model and pin-rod model, are further conducted. Results indicate that fix-rod model is more recommended than pin-rod model to simplify splice connection for simulation on lateral stiffness of modular frame in elastic design stage.

• The Korean Journal of Applied Statistics
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• v.14 no.1
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• pp.161-175
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• 2001

Meta-analysis refers to quantitative methods for combining results from independent studies in order to draw overall conclusions. Hierarchical models including selection models are introduced and shown to be useful in such Bayesian meta-analysis. Semiparametric hierarchical models are proposed using the Dirichlet process prior. These rich class of models combine the information of independent studies, allowing investigation of variability both between and within studies, and weight function. Here we investigate sensitivity of results to unobserved studies by considering a hierachical selection model with including unknown weight function and use Markov chain Monte Carlo methods to develop inference for the parameters of interest. Using Bayesian method, this model is used on a meta-analysis of twelve studies comparing the effectiveness of two different types of flouride, in preventing cavities. Clinical informative prior is assumed. Summaries and plots of model parameters are analyzed to address questions of interest.