• Asia pacific journal of information systems
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• v.18 no.2
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• pp.15-40
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• 2008

With the explosive growth of the Internet, Internet shopping malls have become recognized as one of the major purchasing channels for consumers, as well as one of the competitive distribution channels for companies that allow them to contact with customers without intermediaries. It has motivated information systems(IS) researchers to examine the factors influencing consumer behavior and the purchase decision process in the context of Internet shopping malls. Despite the extensive research that has been conducted on the purchase decision process of consumers in online shopping malls, the results have demonstrated a need for further understanding of consumer behavior due to the unique features of virtual space and the characteristics of online consumers. Previous studies from marketing and consumer behavior domains have suggested that the concept of involvement plays an important role in explaining consumers' purchase behavior. Despite the critical role of involvement and the explosive growth of e-commerce, little research has examined the role of involvement in the Internet shopping mall context. With this motivation, this study has two research objectives. First, it introduces and tests an theoretical model capable of better explaining consumers' intention to purchase in the Internet shopping mall context. The proposed model extends and integrates existing models on purchase intention by incorporating purchase experience, innovativeness, and perceived self-control as the consumer factors, along with perceived risk, information provision, and perceived price as the Internet shopping mall factors. Second, this study examines how involvement differences may affect consumers' intention to purchase. For this purpose, two factors from involvement theory, involvement type and involvement level, are introduced into the research model as moderating variables. In order to test the proposed model, the overall approach employed was a field study using the structural equation model. We developed our data collection instrument by adopting existing validated questions wherever possible. All question items were measured with a seven-point, Likert-type scale, with anchors ranging from 'strongly disagree' to 'strongly agree.' Two IS researchers reviewed the instrument and checked its face validity. We collected empirical data for this study over a period of two weeks from subjects who had purchase experiences through Internet shopping malls. A total of 473 complete and valid responses were obtained. We carried out data analysis using a two-step methodology with AMOS 4.0. The first step in the data analysis was to establish the convergent and discriminant validity of the constructs. In the second step, we examined the structural model based on the cleansed measurement model. The empirical results partly support the proposed model and identify the moderating effect of involvement differences. Theoretical and practical implications of the study are discussed, along with its limitations.

• Journal of the Korean Geotechnical Society
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• v.32 no.10
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• pp.17-29
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• 2016

A debris flow analysis model has been developed to simulate the erosion and entrainment of soil layer. Special attention is given to the model which represents strength softening behaviour of soil layer due to velocity of deformation. The 3D FE analysis by Coupled Eulerian-Lagrangian (CEL) model is conducted to simulate the debris flow. The model is validated using published data on laboratory experiment (Mangeny et al., 2010). It has been definitely shown that proposed model is in good agreement with the results of laboratory data. Futhermore, the FE analysis is conducted to ensure capability of simulating the real scale debris flow. The result of Ramian watershed, Korea shows that the debris flow has increased the volume and speed and it is in good agreement with field investigation. Based on this, it is confirmed that proposed model shows good agreement of the behavior of the actual and analytical debris flow.

• Journal of KIBIM
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• v.3 no.1
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• pp.1-10
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• 2013

BIM(Building Information Modeling) ordering manuals and guidelines are diffused with the recent BIM activation. However, it is causing drawbacks such as an increase of work at each design stage and a decline of BIM application level that the standard of making up and managing BIM is vague and it includes comprehensive meaning. Therefore, this study aims to secure BIM work standard by establishing BIM making-out standard based on LOD(Level of Detail) classification considering domestic design process. It compared each definition of LOD by analyzing domestic and foreign BIM guideline examples, and figured out insufficiency of existing domestic and foreign design process and BIM guidelines. Moreover, it drew architects' work articles for promoting the progression of the efficient design process, and analyzed BIM requirements on design process, dividing BIM application scale by field. Through this analyzing process, it finally established BIM making-out standard classified by design process. The effects of establishing BIM making-out standard would include improving a division of labor and cooperation environment by creating integrated BIM model on design stages, advancing work efficiency by preventing a repetition and an increase of work, and upgrading project completeness and design quality. Besides, it can secure BIM work standard by clarifying responsibility for working steps. BIM making-out standard established by this study will contribute to developing the future BIM work standard document and BIM guideline as a data base.

• Journal of the Society of Naval Architects of Korea
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• v.49 no.2
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• pp.203-211
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• 2012

The main object of this experiment is to estimate the hydrodynamic forces acting on a submerged streamlined body placed in a one-end-opened cylindrical tube moving with certain translational velocity. The best experimental design for this object is mimicking real situation, however sizes of model body and cylinder tube are just the same as those of real, for avoiding scale effects, mimicking real situation is not realizable. Hence, in this experiment, target body and cylindrical tube were designed to be towed with varying body position relative to cylindrical tube. For measuring hydrodynamic forces and flow velocity in the cylindrical tube, six one-component load cells and several one-hole Pitot tubes were used. Several conditions were checked with various end-plates those had different opening areas. Experiment results show that forces and flow velocity had different tendency with those expected, and the presence of a end-plate slows down the flow velocity in the cylindrical tube and affects pressure field in the tube to push the model submerged body forward of the tube. This tendency grows with decreasing opened area.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.3
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• pp.242-253
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• 2020

This study examined the ef ects of freshwater discharge by artificial dikes from the Kanwol and Bunam lakes on the dynamics in the Chunsu Bay, Yellow Sea, Korea, during the summer season based on three-dimensional numerical modeling experiments. Model performances were evaluated in terms of skill scores for tidal elevation, velocity, temperature, and salinity and these scores mostly exceeded 90 %. The variability in residual currents before and after the freshwater discharge was examined. The large amount of lake water discharge through artificial dikes may result in a dramatically changed density field in the Chunsu Bay, leading to an estuarine circulation system. The density-driven current formed as a result of the freshwater inflow through the artificial dikes (Kanwol/Bunam) caused a partial change in the tidal circulation and a change in the scale and location of paired residual eddies. The stratification formed by strengthened static stability following the freshwater discharge led to a dramatic increase in the Richardson number and lasted for a few weeks. The strong stratification suppressed the vertical flux and inhibited surface aerated water mixing with bottom water. This phenomenon would have direct and indirect impacts on the marine environment such as hypoxia/anoxia formation at the bottom.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.22 no.1
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• pp.61-69
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• 1998

Vapor Axial Deposition (VAD), one of optical fiber preform fabrication processes, is performed by deposition of submicron-size silica particles that are synthesized by combustion of raw chemical materials. In this study, flow field is assumed to be a forced uniform flow perpendicularly impinging on a rotating disk. Similarity solutions obtained in our previous study are utilized to solve the particle transport equation. The particles are approximated to be in a polydisperse state that satisfies a lognormal size distribution. A moment model is used in order to predict distributions of particle number density and size simultaneously. Deposition of the particles on the disk is examined considering convection, Brownian diffusion, thermophoresis, and coagulation with variations of the forced flow velocity and the disk rotating velocity. The deposition rate and the efficiency directly increase as the flow velocity increases, resulting from that the increase of the forced flow velocity causes thinner thermal and diffusion boundary layer thicknesses and thus causes the increase of thermophoretic drift and Brownian diffusion of the particles toward the disk. However, the increase of the disk rotating speed does not result in the direct increase of the deposition rate and the deposition efficiency. Slower flow velocity causes extension of the time scale for coagulation and thus yields larger mean particle size and its geometric standard deviation at the deposition surface. In the case of coagulation starting farther from the deposition surface, coagulation effects increases, resulting in the increase of the particle size and the decrease of the deposition rate at the surface.

• Journal of Energy Engineering
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• v.13 no.1
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• pp.12-19
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• 2004

A Molded Case Circuit Breaker (MCCB) is an electric control device to interrupt the abnormal currents which result from the over-loads or short-circuits. Its malfunction will result in severe accidents. In the development of the MCCB, higher current-rating and improved thermal performance become more and more important in providing the safe function and reliability for the modern devices requiring small scale and high performance. It is also very important to consider the factors of temperature rise in the design of MCCB. The major reasons of temperature rise in the MCCB result from the resistances, which are come from the connection and contact surfaces. These resistances are influenced by current, time, configuration of contact surfaces and applied voltage. In order to predict the temperature distribution inside MCCB, we have simulated the model with some assumptions and simplifications, using commercial code ICEPAK. To verify the results of temperature field analysis, the numerical results are compared with experimental ones for the same model. The results show a good agreement with actual temperature rise obtained by experiments.

• International Journal of Highway Engineering
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• v.8 no.1 s.27
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• pp.139-152
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• 2006

Many experimental and numerical approaches have been developed to evaluate paving materials and to predict pavement response and distress. Micromechanical simulation modeling is a technology that can reduce the number of physical tests required in material formulation and design and that can provide more details, e.g., the internal stress and strain state, and energy evolution and dissipation in simulated specimens with realistic microstructural features. A clustered distinct element modeling (DEM) approach was implemented In the two-dimensional particle flow software package (PFC-2D) to study the complex behavior observed in asphalt mixture fracturing. The relationship between continuous and discontinuous material properties was defined based on the potential energy approach. The theoretical relationship was validated with the uniform axial compression and cantilever beam model using two-dimensional plane strain and plane stress models. A bilinear cohesive displacement-softening model was implemented as an intrinsic interface and applied for both homogeneous and heterogeneous fracture modeling in order to simulate behavior in the fracture process zone and to simulate crack propagation. A disk-shaped compact tension test (DC(T)) with heterogeneous microstructure was simulated and compared with the experimental fracture test results to study Mode I fracture. The realistic arbitrary crack propagation including crack deflection, microcracking, crack face sliding, crack branching, and crack tip blunting could be represented in the fracture models. This micromechanical modeling approach represents the early developmental stages towards a 'virtual asphalt laboratory,' where simulations of laboratory tests and eventually field response and distress predictions can be made to enhance our understanding of pavement distress mechanisms, such its thermal fracture, reflective cracking, and fatigue crack growth.

• Journal of computational fluids engineering
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• v.17 no.4
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• pp.81-86
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• 2012

The objective of the present study is to investigate the effects of various turbulence models on the aerodynamic noise of an air-conditioner (AC) indoor unit. The results from URANS (unsteady Reynolds-averaged Navier-Stokes) simulations with the standard k-$\varepsilon$, k-$\omega$ shear stress transport (SST) and Spalart-Allmaras (S-A) turbulence models were analyzed and compared with the noise data from the experiments. The frequency spectra of the far-field acoustic pressure were computed using the Farrasat equation derived from the Ffowcs Williams-Hawkings (FW-H) equation based on the acoustic analogy model. Two fixed fan casings and the rotating cross-flow fan were used as the source surfaces of the dipole noise in the Farrasat equation. The result with the standard k-$\epsilon$ model showed a much better agreement with the experimental data compared to the k-w SST and S-A models. The differences in the pressure spectra from the different turbulence models were discussed based on the instantaneous vorticity fields. It was found that the over-estimated power spectra with the k-w SST and S-A models are related to the emphasized small-scale vortices produced with these models.

• Journal of Korean Society of Steel Construction
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• v.18 no.4
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• pp.491-502
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• 2006

This paper summarizes full-scale test results on CFT column-to- flat plate connections has gained wide acceptance subjected to gravity loading. CFT construction has gained wide acceptance in a relatively short time in domestic building construction practice due to its various structural and construction advantages. However, efficient details for CFT column to flat plate connections have not been proposed yet. Based on the strategies that maximize economical field construction, several connecting schemes were proposed and tested. Test results showed strength and connection stiffness exceeding those of R/C flat p late counterparts. A semi-analytical procedure is presented to model the behavior of CFT column-to-flat plate connections. The five parameters to model elastic to post-punching catenary action range are calibrated based on the limited test data of t to progressive collapse prevention design is also illustrated.