• Title/Summary/Keyword: Diffusion study

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The Relationship among Fashion Social Media, Information Usage Behavior, and Purchase Intention (패션 소셜미디어 품질, 정보 이용행동, 구매의도 간 관계 연구)

  • Kim, Naeeun;Kim, Mi-Sook
    • The Journal of Industrial Distribution & Business
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    • v.9 no.11
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    • pp.25-38
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    • 2018
  • Purpose - This study aimed to identify the sub-dimensions of fashion social media quality (information quality, social quality, service quality, system quality) and investigate how they affect purchase intention through fashion information use behavior (information acceptance, information diffusion). Research design, data, and methodology - Data collection was carried out twice for systematic verification of the research model. In the first data collection, the reliability and validity of research variables were verified through 238 respondents and questionnaires were revised and supplemented based on their responses. In March 2018, the final survey was conducted from 755 respondents the age of 20 to 49. Using SPSS 23.0, descriptive statistics, exploratory factor analysis, correlation analysis were performed. In order to test hypotheses, structural equational modeling technique was employed using AMOS 23.0. Results - First of all, fashion Social media quality consists of four factors including information quality, social quality, service quality and system quality. Second, fashion Social media information quality, social quality, and system quality were shown to have a positive(+) effect on information acceptance behavior, and social quality, service quality and system quality were shown to have a positive(+) effect on information diffusion behavior. It was also determined that the acceptance and diffusion behaviors of fashion information through fashion Social media had positive(+) influence on purchase intention. Conclusions - This study holds academic significance in its identification of the components of fashion Social media quality and for conducting an empirical analysis on the causal relationship between fashion information acceptance and diffusion behaviors, and purchase intention. The results of this study indicate that fashion involvement is the key factors in determining the quality of Social media, the acceptance of information through Social media, and, by extension, the purchase of fashion products. Practitioners in the fashion industry may use the findings of this study in order to build more effective Social media strategy.

Nscreen Service User Typology Based on Use-Diffusion and Lifestyle (사용확산 및 라이프스타일에 따른 N스크린 서비스 이용자 유형화)

  • Park, Hyun Jung
    • The Journal of the Korea Contents Association
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    • v.15 no.2
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    • pp.444-454
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    • 2015
  • The purpose of this study is to investigate factors related to use-diffusion of Nscreen service as well as consumers' lifestyle and media usage of Nscreen service, which is fundamentally changing both the competitive landscape for business and the daily lives of consumers. The data of 1,524 consumers used in this study were drawn from the first Korea Media Panel Study in 2012 of Korea Information Society Development Institute. This study categorized adopters depending on the usage rate of contents and the variety of media platforms they used. Consumers using various media platforms enjoyed more categories of contents provided by Nscreen services. The variety of media platforms was useful in grouping users to explain the difference between the groups in terms of lifestyle activities. Based on the factor analysis and cluster analysis based on the consumers' lifestyle to find out different characteristics of each clusters, the result elicited some implications.

A Study on the Delay Effect of Smoke Diffusion by the Installation Intervals and the Blockage Ratio of the Fire Smoke Diffusion Delay Device in a Great Depth Underground Double-Deck Tunnel (대심도 복층터널 화재연기 확산지연장치 설치간격 및 차폐율에 따른 화재연기 지연효과 연구)

  • Yang, Yongwon;Han, Jaehee;Lee, Yuntaek;Moon, Jungjoo;Shin, Taegyun
    • Journal of the Korean Society of Mineral and Energy Resources Engineers
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    • v.55 no.6
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    • pp.596-603
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    • 2018
  • The traffic congestion is frequently occurring due to increasing demand for vehicles and development of subcenter in roads of domestic-downtown. The design of a Great depth underground double-deck tunnel planned for construction as a solution however it's mainly for a compact-car. Its low height and small section cause causalities when fire occurs. From this study, the delay system for fire smoke diffusion is developed to minimize the occurrence of casualties when fire occurs in the Great depth underground double-deck tunnel and the CFD(Computational Fluid Dynamics) is used to find the optimal installation interval and the blockage ratio to maximize the system effects. The study analyzed the shorter the installation interval of the system, the higher the smoke delay effect but the efficiency-change tends to be slight above a certain distance and the larger the blockage ratio, the higher the effect but the efficiency-difference is slight according to installation interval.

Latex Particles's Behavior in Chemically Cross-Linked Gels (화학겔 안에서의 라텍스 입자의 거동에 관한 연구)

  • Jang, Kyung Ho;Sohn, Dae Won
    • Journal of the Korean Chemical Society
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    • v.42 no.2
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    • pp.156-160
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    • 1998
  • Probe diffusion with latex particles in two different types of chemically cross linked gel has been studied. The diffusion of particles in silica gel is decreased by decreasing the gel correlation length but the particles' diffusion in the acrylamide gel still shows the heterogeneity of the gel. By increasing the contents of the gel network the silica gel makes a more homogeneous and compact structure than that of acrylamide gel which has partial heterodyning. Dynamic light scattering study with the probe particles in two different gels reveals the heterogeneity of the gel network. The latex particles trapping in the gel has been investigated by using non-ergodic concepts.

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Modeling of damage in cement paste subject to external sulfate attack

  • Xiong, Chuansheng;Jiang, Linhua;Zhang, Yan;Chu, Hongqiang
    • Computers and Concrete
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    • v.16 no.6
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    • pp.847-864
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    • 2015
  • This study aimed to develop models of sulfate diffusion and ettringite content profile in cement paste for the predication of the damage behavior in cement paste subject to external sulfate. In the models, multiphase reaction equilibrium between ions in pore solution and solid calcium aluminates phases and the microstructure changes in different positions of cement paste were taken into account. The distributions of expansive volume strain and expansion stress in cement paste were calculated based on the ettringite content profile model. In addition, more sulfate diffusion tests and SEM analyses were determined to verify the reliability and veracity of the models. As the results shown, there was a good correlation between the numerical simulation results and experimental evidences. The results indicated that the water to cement ratio (w/c) had a significant influence on the diffusion of sulfate ions, ettringite concentration profile and expansion properties in cement paste specimens. The cracking points caused by ettringite growth in cement paste specimens were predicted through numerical methods. According to the simulation results, the fracture of cement paste would be accelerated when the specimens were prepared with higher w/c or when they were exposed to sulfate solution with higher concentration.

THE NUMERICAL SIMULATION OF HYDROGEN JET DIFFUSION FOR HYDROGEN LEAKAGE IN THE ENCLOSED GEOMETRY (밀폐공간에서 수소 누설로 인한 수소 제트 확산에 대한 수치해석)

  • Ahn, Hyuk-Jin;Lee, Sang-Hyuk;Hur, Nahm-Keon;Lee, Moon-Kyu;Yong, Gee-Joong
    • 한국전산유체공학회:학술대회논문집
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    • 2009.04a
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    • pp.176-182
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    • 2009
  • In the present study, a numerical simulation for the diffusion of hydrogen jet in a enclosure was performed to aid the leakage test of the hydrogen for the safety of the hydrogen vehicle. The temporal and spatial distributions of the hydrogen concentration in the test chamber are predicted from the present numerical analyses. Flammable region of 4-74% and explosive region of 18-59% hydrogen by volume was identified from the present results. Factors influencing the diffusion of the hydrogen jet were examined to evaluate the effectiveness of forced ventilation for relieving the accumulation of the leaked hydrogen gas in the chamber, which include location of open windows, size of leakage nozzle, and leakage rate among others. The distribution of the concentration of the leaked hydrogen for various cases can be used as a database in various applications for the hydrogen safety.

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Simultaneous Formation of NiSi Contact and Cu Plug/Ti Barrier (NiSi 접촉과 Cu 플러그/Ti 확산방지층의 동시 형성 연구)

  • Bae, Kyoo-Sik
    • Korean Journal of Materials Research
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    • v.20 no.6
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    • pp.338-343
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    • 2010
  • As an alternative to the W plug used in MOSFETs, a Cu plug with a NiSi contact using Ta / TaN as a diffusion barrier is currently being considered. Conventionally, Ni was first deposited and then NiSi was formed, followed by the barrier and Cu deposition. In this study, Ti was employed as a barrier material and simultaneous formation of the NiSi contact and Cu plug / Ti barrier was attempted. Cu(100 nm) / Ti / Ni(20 nm) with varying Ti thicknesses were deposited on a Si substrate and annealed at $4000^{\circ}C$ for 30 min. For comparison, Cu/Ti/NiSi thin films were also formed by the conventional method. Optical Microscopy (OM), Scanning Probe Microscopy (SPM), X-Ray Diffractometry (XRD), and Auger Electron Microscopy (AES) analysis were performed to characterize the inter-diffusion properties. For a Ti interlayer thicker than 50 nm, the NiSi formation was incomplete, although Cu diffusion was inhibited by the Ti barrier. For a Ti thickness of 20 nm and less, an almost stoichiometric NiSi contact along with the Cu plug and Ti barrier layers was formed. The results were comparable to that formed by the conventional method and showed that this alternative process has potential as a formation process for the Cu plug/Ti barrier/NiSi contact system.

Analysis and Measurement of Effective Refractive Indices with Ion-exchanged Slab Waveguide (이온교환 평판도파로의 실효굴절율 측정 및 해석)

  • 천석표;박정일;박태성;정홍배
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1995.05a
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    • pp.73-76
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    • 1995
  • In this study, the slab waveguide was fabricated using potassium-nitride(KNO$_3$) or silver-nitride (AgNO$_3$) molten sources by ion-exchange process. The effective refractive indices of waveguide were measured by Prism-Coupling method. and The characteristics of waveguide(mode dispersion, effective diffusion depth. surface refractive index, diffusion coefficient, and refractive index profile etc,) were investigated by WKB method, In the case of potassium ion-exchange, the computer calculation showed that the refractive index profile of waveguide followed Gaussian function, the surface refractive index increased with ion-exchange time and the effective diffusion depth increased a little as ion-exchange time increased, while the surface refractive index of silver ion-exchanged waveguide decreased with ion-exchange time because of the ion depletion on the surface of waveguide, and the effective diffusion depth seriously with ion-exchange tim. Double ion-exchanged waveguide was fabricated by performing silver ion-exchange after potassium ion-exchange. Double ion-exchanged waveguide had a tight mode binding force since the surface refractive index was larger than single step ion-exchanged waveguide.

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A model for columnar-dendritic solidification of binary alloys accounting for dendrite tip undercooling (선단과냉을 고려한 이원합금의 주상 수지상응고 모델)

  • Yu, Ho-Seon
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.22 no.5
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    • pp.698-707
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    • 1998
  • A simplified model for predicting microsegregation during columnar-dendritic solidification of binary alloys is developed, in which back diffusion, dendrite arm coarsening and dendrite tip undercooling are simultaneously incorporated. The inclusion of tip undercooling is accomplished by modifying the initial conditions of the existing solute diffusion model, in such forms that tip undercooling depresses the beginning of solidification below the liquidus temperature, and that the secondary arm spacing evolves in accordance with the minimum undercooling theory. Sample calculations for the well-known benchmark system show that the present predictions not only consist with the extablished limiting cases, but also agree favorably with the available experimental data within a reasonable tolerance. In particular, a typical decreasing trend in the eutectic fraction at high cooling rates is successfully resolved. Comparison of the individual and combined effects of characteristic parameters in reference with the limiting cases reveals the interactions among parameters. Every parameter plays the role of reducing the eutectic fraction, and the degree of influence depends primarily on the cooling rate. Coarsening enhances the effect of tip undercooling, while suppressing that of back diffusion. A vigorous back diffusion seems to restrain the apperance of the undercooling effect. Overall, each contribution of the three parameters to microsegregation is estimated to be of the same order, which suffices to justify the present study.

THERMAL DIFFUSION AND RADIATION EFFECTS ON UNSTEADY MHD FREE CONVECTION HEAT AND MASS TRANSFER FLOW PAST A LINEARLY ACCELERATED VERTICAL POROUS PLATE WITH VARIABLE TEMPERATURE AND MASS DIFFUSION

  • Venkateswarlu, M.;Ramana Reddy, G.V.;Lakshmi, D.V.
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.18 no.3
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    • pp.257-268
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    • 2014
  • The objective of the present study is to investigate thermal diffusion and radiation effects on unsteady MHD flow past a linearly accelerated vertical porous plate with variable temperature and also with variable mass diffusion in presence of heat source or sink under the influence of applied transverse magnetic field. The fluid considered here is a gray, absorbing/emitting radiation but a non-scattering medium. At time t > 0, the plate is linearly accelerated with a velocity $u=u_0t$ in its own plane. And at the same time, plate temperature and concentration levels near the plate raised linearly with time t. The dimensionless governing equations involved in the present analysis are solved using the closed analytical method. The velocity, temperature, concentration, skin-friction, the rate or heat transfer and the rate of mass transfer are studied through graphs in terms of different physical parameters like magnetic field parameter (M), radiation parameter (R), Schmidt parameter (Sc), Soret number (So), Heat source parameter (S), Prandtl number (Pr), thermal Grashof number (Gr), mass Grashof number (Gm) and time (t).