• Geomechanics and Engineering
• /
• 제35권5호
• /
• pp.475-486
• /
• 2023

Ballast particles have an irregular shape and are discrete in nature. Due to the discrete nature of ballast, it exhibits complex mechanical behaviour under loading conditions. The discrete element method (DEM) can model the behaviour of discrete particles under a multitude of loading conditions. DEM is used in this paper to simulate a series of three-dimensional direct shear tests in order to investigate the shear behaviour of railway ballast and its interaction at the microscopic level. Particle flow code in three dimension (PFC3D) models the irregular shape of ballast particles as clump particles. To investigate the influence of particle size distribution (PSD), real PSD of Indian railway ballast specification IRS:GE:1:2004, China high-speed rail (HSR) and French rail specifications are generated. PFC3D built-in linear contact model is used to simulate the interaction of ballast particles under various normal stresses, shearing rate and shear box sizes. The results indicate how shear resistance and volumetric changes in ballast assembly are affected by normal stress, shearing rate, PSD and shear box size. In addition to macroscopic behaviour, DEM represents the microscopic behaviour of ballast particles in the form of particle displacement at different stages of the shearing process.

• 한국의상디자인학회지
• /
• 제8권3호
• /
• pp.1-15
• /
• 2006

The purpose of this research is to find out the effect of clothing style and mixtures of stripe pattern direction, width, and coloration of an upper garment. The experimental materials made for this study are a set of stimuli and response scale(The 7-Point semantic). The subjects were 480 female undergraduate students in Seoul, Busan, Gyung-nam. The 80 stimuli which were variously incorporated with clothing styles and stipe patterns were assessed by the students. The following contents summarizes the results of the research. Impression factors of the stimuli consists of the 5 dimensions(Attractiveness, Show, Activity, Clearness, mildness). Amon these, the Attractiveness and Show dimensions proved to be more important. The clothing style and pattern direction indicated main effect in attractiveness and activity dimension. The pattern coloration showed a significant effect in dimensions except attractiveness and clearness. The pattern width had a significant effect only in the activity. Significant interaction effects of each clothing clause were found in the attractiveness, activity and clearness, but Show and mildness had no significant interaction effect. This research, as the 06 S/S, F/W trend, is a meaningful study in that it handled in the form of expression the stripe pattern used unrestrictedly in the casual wear or the formal wear by a fashion keyword.

• 대한조선학회논문집
• /
• 제55권2호
• /
• pp.161-168
• /
• 2018

This paper presents the design procedure of the suction bucket used to support a subsea manifold. The soil-suction bucket interaction numerical analysis technique was verified by comparing the present results with a reference data. In order to simulate the soil-bucket interaction analyses of a subsea manifold structure, various material data such as undrained shear strength, elastic modulus, and poisson ratio of soft clay in Gulf of Mexico were collected from reference survey. We proposed vertical and horizontal design loads based on system weights and current-induced drag forces. Under the assumption that diameter of the suction bucket was 3.0 m considering real dimension of the subsea manifold frame structures, aspect ratio was decided to be 3.0 based on reference survey. The ultimate bearing load components were determined using tangent intersection method. It was proved that the two design load components were less than ultimate bearing loads.

• 한국의류산업학회지
• /
• 제10권5호
• /
• pp.625-635
• /
• 2008

The purpose of this study was to investigate the mediating roles of the relationship quality and the switching cost during the processing of effects of service quality on the service loyalty in the beauty industry. Service quality factors were defined as the interaction quality, the outcome quality and the physical environment quality. The relationship quality were defined as the satisfaction and the trust of customer. Amos was used to analyze the research hypotheses and the proposed model. All research hypotheses were adopted. The empirical results were as follows; Service quality influenced positively on the relationship quality, and then the relationship quality yielded the service loyalty. Also the relationship quality influenced positively on the switching cost and then the switching cost influenced positively on the service loyalty. Each service quality dimension had a significant effect on the satisfaction, the trust and the relative importance of service quality dimensions on the satisfaction, the trust followed the order of the interaction quality, the outcome quality and the physical environment quality.

• Structural Engineering and Mechanics
• /
• 제75권1호
• /
• pp.109-122
• /
• 2020

An asymptotic local plane strain elasticity theory is reformulated for the static analysis of a simply-supported, multiple graphene sheet system (MGSS) in cylindrical bending and resting on an elastic medium. The dimension of the MGSS in the y direction is considered to be much greater than those in the x and z directions, such that all the field variables are considered to be independent of the y coordinate. Eringen's nonlocal constitutive relations are used to account for the small length scale effects in the formulation examining the static behavior of the MGSS. The interaction between the MGSS and its surrounding foundation is modelled as a Winkler foundation with the parameter k_w, and the interaction between adjacent graphene sheets (GSs) is considered using another Winkler model with the parameter c_w. A parametric study with regard to some effects on the static behavior of the MGSS resting on an elastic medium is undertaken, such as the aspect ratio, the number of the GSs, the stiffness of the medium between the adjacent layers and that of the surrounding medium of the MGSS, and the nonlocal parameter.

• 품질경영학회지
• /
• 제40권4호
• /
• pp.543-558
• /
• 2012

Purpose: The purpose of this study was to propose useful suggestions by analyzing causal effect relationship between port service quality, and customer satisfaction and performance in port industry. Methods: The collected data through the survey were analyzed using multi-regression analysis. The measurement tools used for this study were divided into three dimensions such as internal quality, interaction quality and environmental quality. Results: The results of this study are as follows; regarding the influence of pot service quality dimension on customer satisfaction, it was found that the effects of interaction quality and internal quality were significant and those of environmental quality was not significant on customer satisfaction. It was found that customer satisfaction made statistically significant influence on performance from the investigation of the causal effect relationship between customer satisfaction and performance. Conclusion: Incheon Port needs to act actively paying attention to port facilities, efficient operation, network, cargo recruitment activities, smooth communication and fast handling.

• 한국통계학회:학술대회논문집
• /
• 한국통계학회 2005년도 추계 학술발표회 논문집
• /
• pp.31-36
• /
• 2005

An identification and characterization of susceptibility genes for common complex multifactorial diseases is a challengeable task, in which the effect of single genetic variation will be likely dependent on other genetic variations(gene-gene interaction) and environmental factors (gene-environment interaction). To address is issue, the multifactor dimensionality reduction (MDR) has been proposed and implemented by Ritchie et al. (2001), Moore et al. (2002), Hahn et al.(2003) and Ritchie et al. (2003). With MDR, multilocus genotypes effectively reduce the dimension of genotype predictors from n to one, which improves the identification of polymorphism combinations associated with disease risk. However, MDR cannot handle missing observations appropriately, in which missing observation is treated as an additional genotype category. This approach may suffer from a sparseness problem since when high-order interactions are considered, an additional missing category would make the contingency table cells more sparse. We propose a new MDR approach with minimum loss of sample sizes by considering missing data over all possible multifactor classes. We evaluate the proposed MDR by using the prediction errors and cross validation consistency.

• Communications for Statistical Applications and Methods
• /
• 제29권1호
• /
• pp.65-83
• /
• 2022

Although various statistical methods have been developed to map time-dependent genetic factors, most identified genetic variants can explain only a small portion of the estimated genetic variation in longitudinal traits. Gene-gene and gene-time/environment interactions are known to be important putative sources of the missing heritability. However, mapping epistatic gene-gene interactions is extremely difficult due to the very large parameter spaces for models containing such interactions. In this paper, we develop a Gaussian process (GP) based nonparametric Bayesian variable selection method for longitudinal data. It maps multiple genetic markers without restricting to pairwise interactions. Rather than modeling each main and interaction term explicitly, the GP model measures the importance of each marker, regardless of whether it is mostly due to a main effect or some interaction effect(s), via an unspecified function. To improve the flexibility of the GP model, we propose a novel grid-based method for the within-subject dependence structure. The proposed method can accurately approximate complex covariance structures. The dimension of the covariance matrix depends only on the number of fixed grid points although each subject may have different numbers of measurements at different time points. The deviance information criterion (DIC) and the Bayesian predictive information criterion (BPIC) are proposed for selecting an optimal number of grid points. To efficiently draw posterior samples, we combine a hybrid Monte Carlo method with a partially collapsed Gibbs (PCG) sampler. We apply the proposed GP model to a mouse dataset on age-related body weight.

• 한국의류학회지
• /
• 제47권3호
• /
• pp.560-576
• /
• 2023

Drawing on gamification affordance theory, this study examines the relationships among key affordances of avatar fashion styling, perceived enjoyment, and engagement behavior intentions-defined as the intention to share content on avatars in the metaverse platform-and the moderating role of metaverse familiarity. Based on survey data collected from 198 Korean ZEPETO users with avatar fashion styling experience, the hereby proposed research model was tested with structural equation modeling. The results demonstrated that self-expression and competition positively influenced perceived enjoyment, which subsequently affected customers' engagement behavior intention. Furthermore, metaverse familiarity as a moderating effect intensified the positive association between affordances and perceived enjoyment as well as between perceived enjoyment and engagement behavior intentions. The individual interaction effect of each affordance dimension on perceived enjoyment was different, with self-expression having a greater influence on enjoyment among the high-familiarity group and competition having a greater influence on enjoyment among the low-familiarity group. Considering that users with low metaverse familiarity might have higher needs for social interaction for adaptation, competition, being more socially triggering, might have affected these users more crucially.

• 한국전자통신학회논문지
• /
• 제9권3호
• /
• pp.297-302
• /
• 2014

증강현실이란 실세계의 오브젝트에 가상의 오브젝트를 증강시키는 기술로 현실세계에 디지털 정보를 시각화 해주는 기능을 한다. 또한, 증강현실은 실세계와 가상세계를 실시간으로 결합함과 동시에 사용자와 컴퓨터간 상호작용하도록 함으로써 사용자에게 정보전달은 물론 지각능력에 도움을 주며 사용자의 몰입감을 높여주는 기술이라고 할 수 있다. 본 논문에서는 VRML로 모델링된 3차원 객체를 프로그래밍을 통해 3차원 데이터가 증강되는 컨텐츠를 개발하였다. 또한, 가상물체들의 조합을 통해 3차원 아바타 및 다양한 가상의 의상들을 증강시키는 응용기술을 제안하였다. 게다가, 사용자가 직접 마커를 움직여 컴퓨터와 사용자간의 상호작용이 가능한 인터페이스를 제시하여 사용자의 몰입감을 증대 시킬 수 있었다.