• Journal of the Korean Vacuum Society
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• v.8 no.3A
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• pp.181-186
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• 1999

The diffusion of oxygen atoms on tungsten (110) surface is studied by comparison of experiment results and recent calculations. It has been suggested that the thermodynamic factor which is inversely proportional to be compressibility has strong temperature dependence which may cause non-Arrhenius behavior of diffusion coefficient. Recent experiments, however, indicate effectively no temperature dependence of this factor and support the view that non-Arrhenius behavior originates from the dynamic factor rather than the thermodynamic factor. Discrepancies in coverage dependence of physical quantities between theory and experiment are discussed.

• Journal of The Korean Society of Agricultural Engineers
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• v.50 no.6
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• pp.49-60
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• 2008

This study were predicted the corrosion threshold reached at steel reinforcement in latex modified concrete(LMC) which were applied the agricultural hydraulic concrete structures. Accelerated testing was accomplished to the evaluate the diffusion coefficient of LMC mix, and the time dependent constants of diffusion. Also, the average chloride diffusion coefficient was estimated. From the average chloride ion diffusion coefficient, the time which critical chloride contents at depth of reinforcement steel was estimated. Test results indicated that the corrosion threshold reached at reinforcement in LMC were effected on the mix proportion factor including cement contents, latex content, and water-cement ratio. Especially, the average chloride diffusion coefficient, the corrosion threshold reached at reinforcement in LMC were affected by the all mix proportion factor.

• Journal of Distribution Science
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• v.14 no.5
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• pp.71-80
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• 2016

Purpose - In case of automobile parts, there has been a lot of progress in the study on supplier development plans and SCM in industrial progress study as well as on the relationship between ERP and SCM. But supplier development program providers have researched on SCM performance in accordance with the interests of the supplier development program most, thus, buyers were knowledgeable about the earlier program performance. Therefore, the purpose of this study is to prove correlation factor, supplier factor, purchaser factor affecting SCM performance and ERP activating diffusion through the process of supplier development. Supplier development maturity formation model is considered important variables as mediators related to the procedure. Finally, the performance formation model of the supplier development maturity through supplier development factor would be presented as the outcome of this study. Research design, data, and methodology - Data gathering was as follows: questionnaires were delivered to 87 companies that have business connection with H Company. The empirical research to test our hypothesis was grounded on statistical analysis (adapting SPSS 19.0 & AMOS 19.0). The hypothesis is that the supplier development factor variables consist of correlation factor, supplier factor, purchaser factor, and have non-negative effects on the next variables: mediators such as supplier development maturity; and the supplier development maturity variables have a positive effect on the next variables: ERP activating diffusion, ERP activating diffusion has a non-negative effect on supply chain performance. We experimented the hypothesized model using path analysis with latent variables. Results - First, it was known that cooperation

, reliability

, comprehension on the purpose of SDP

, adaptation of change

, knowledge transfer program

, have significant positive effects on supplier development maturity. Second, supplier development maturity has positive effects significantly on ERP activating diffusion

. Finally, the causal relationships from ERP activating diffusion to SCM performance were significantly accepted. Its significance, as through the hypotheses, presented a structural model for the elaboration, suppliers develop maturity, and ultimately SCM performance that affect ERP leveraging spread beyond the concept of maturity of information system. Therefore, it was a mainstay of research on the existing ERP has they believed. Conclusion - First, with the fast changes in business circumstances, company should get the right information to implement SCM appropriately. For successful SCM, firms should understand the supplier development maturity formation and ERP activating diffusion. Second, supplier development factor has significant effects on supplier development maturity. Third, mediator such as supplier development maturity significantly affects ERP activating diffusion. Finally, ERP activating diffusion has significant impacts on SCM performance. This study makes a meaningful contribution to further appreciation on how supplier development maturity formation affects SCM performance. This study shows implications. First, there would not have been dealt with introducing the concept of supplier development maturity. Second, through empirical analysis and provider factors, the providers will develop the maturity that affect interactive factors between purchaser and supplier.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.30 no.3
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• pp.46-56
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• 1998

The objective of this study was to investigate the relationship between water vapor diffusion properties and the pore structure of paper. Gas-phase molecular diffusivity of water vapor through pores was determined based on the kinetic theory of gas. A mathematical model was derived to characterize the dimensional changes of the pore caused by the fiber-swelling mechanism. A modified-Fickean diffusion model was designed to simulate the water-vapor diffusion phenomena in porous paper web. Structural characterisocs of paper pores including the tortuosity and the shape factor was studied on a theoretical basis of Knudsen flow diffusion. Results are summarized as follows: 1. The theoretical water vapor diffusivity in gas-phase was 0.092$cm^2$ /min, 2. Porosity was inversely proportional to the degree of wet-swelling of paper, 3. Solid-phase water-diffusivity of fiber was 1.2 $ \times 10^{-5}cm^2/min$, 4. Modified diffusion model was fairly consistent to the experimental data (from part I), and 5. The Fickean pore tortuosity, ranging from 1,000 to 2,500, was in inverse proportion to the porosity of paper, and the Knudsen shape factor and length-angle factor for micro-pores in paper were 0.5~3.5 and about 340, respectively.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.3073-3078
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• 2008

In this study to find out the amount of soot, LII method, which utilizes a laser, was used in laminar diffusion flame and based upon the temperature and soot measured from the turbulent Diesel diffusion flame in the constant-volume chamber using the two-color method. Through these experiments, we could know that the LII signal is generally proportional to the soot amount in a laminar diffusion flame. And we could acquire the temperature and soot using the two-color method in a turbulent Diesel diffusion flame effectively. In addition to, this experiment revealed that the KL factor was high on parts of the chamber where the temperature dropped. On the other hand, the KL factor was low where the temperature increased rapidly. Also, it was possible to measure the highest temperature of a turbulent Diesel diffusion flame is approximately 2300K.

• Journal of the Korean Electrochemical Society
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• v.12 no.1
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• pp.1-10
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• 2009

This article reviewed transport behaviours of electroactive species in ionic compounds, focusing on chemical diffusion of Li through the transition metal oxide in a current flowing condition. For this purpose, a distinction has been first briefly made between migration and diffusion with respect to current, driving force and charge of electroactive species considered. Then, the equations for chemical diffusion are derived theoretically in open-circuit and current flowing conditions. Finally, the experimental methods such as ac impedance spectroscopy and current (potential) transient techniques are described in details for characterising chemical diffusion. In addition, the role of the thermodynamic enhancement factor in chemical diffusion is discussed.

• Journal of Distribution Research
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• v.15 no.4
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• pp.61-85
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• 2010

Introduction: Diffusion is process by which an innovation is communicated through certain channel overtime among the members of a social system(Rogers 1983). Bass(1969) suggested the Bass model describing diffusion process. The Bass model assumes potential adopters of innovation are influenced by mass-media and word-of-mouth from communication with previous adopters. Various expansions of the Bass model have been conducted. Some of them proposed a third factor affecting diffusion. Others proposed multinational diffusion model and it stressed interactive effect on diffusion among several countries. We add a spatial factor in the Bass model as a third communication factor. Because of situation where we can not control the interaction between markets, we need to consider that diffusion within certain market can be influenced by diffusion in contiguous market. The process that certain type of retail extends is a result that particular market can be described by the retail life cycle. Diffusion of retail has pattern following three phases of spatial diffusion: adoption of innovation happens in near the diffusion center first, spreads to the vicinity of the diffusing center and then adoption of innovation is completed in peripheral areas in saturation stage. So we expect spatial effect to be important to describe diffusion of domestic discount store. We define a spatial diffusion model using multinational diffusion model and apply it to the diffusion of discount store. Modeling: In this paper, we define a spatial diffusion model and apply it to the diffusion of discount store. To define a spatial diffusion model, we expand learning model(Kumar and Krishnan 2002) and separate diffusion process in diffusion center(market A) from diffusion process in the vicinity of the diffusing center(market B). The proposed spatial diffusion model is shown in equation (1a) and (1b). Equation (1a) is the diffusion process in diffusion center and equation (1b) is one in the vicinity of the diffusing center. $$\array{{S_{i,t}=(p_i+q_i{\frac{Y_{i,t-1}}{m_i}})(m_i-Y_{i,t-1})\;i{\in}\{1,{\cdots},I\}\;(1a)}\\{S_{j,t}=(p_j+q_j{\frac{Y_{j,t-1}}{m_i}}+{\sum\limits_{i=1}^I}{\gamma}_{ij}{\frac{Y_{i,t-1}}{m_i}})(m_j-Y_{j,t-1})\;i{\in}\{1,{\cdots},I\},\;j{\in}\{I+1,{\cdots},I+J\}\;(1b)}}$$ We rise two research questions. (1) The proposed spatial diffusion model is more effective than the Bass model to describe the diffusion of discount stores. (2) The more similar retail environment of diffusing center with that of the vicinity of the contiguous market is, the larger spatial effect of diffusing center on diffusion of the vicinity of the contiguous market is. To examine above two questions, we adopt the Bass model to estimate diffusion of discount store first. Next spatial diffusion model where spatial factor is added to the Bass model is used to estimate it. Finally by comparing Bass model with spatial diffusion model, we try to find out which model describes diffusion of discount store better. In addition, we investigate the relationship between similarity of retail environment(conceptual distance) and spatial factor impact with correlation analysis. Result and Implication: We suggest spatial diffusion model to describe diffusion of discount stores. To examine the proposed spatial diffusion model, 347 domestic discount stores are used and we divide nation into 5 districts, Seoul-Gyeongin(SG), Busan-Gyeongnam(BG), Daegu-Gyeongbuk(DG), Gwan- gju-Jeonla(GJ), Daejeon-Chungcheong(DC), and the result is shown