• Title/Summary/Keyword: diffusion

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An Empirical Study of Technology Diffusion on the Internet using Bass Model (Bass 모형을 이용한 인터넷에서의 기술 확산에 대한 실증분석)

  • Nam, Ho-Hun;Yang, Kwang-Min
    • Journal of Digital Convergence
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    • v.6 no.2
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    • pp.55-64
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    • 2008
  • The Internet possesses not only features of mass media but also features of word of mouth communication. Communication channel is considered as one of most important variables in diffusion process. In this paper, we examined functionality of technology diffusion on the Internet through the use of meta tags. We have measured the coefficients of the Bass diffusion model which has been well-established in new product diffusion. This research shows that the Bass model is appropriate for describing technology diffusion on the Internet. The external influence as represented by the coefficient of innovation was found to be much smaller while the internal influence dominates in all meta tag diffusion. In meta tag diffusion, the internal influence as represented by the coefficient of imitation was increased at least twice bigger than that of consumer durables and information technology. Collecting necessary data in social sciences research can be a burden. This research shows that it can be alleviated through the use of software agents over the Internet. The research made use of software agents for collecting longitudinal data from publicly accessible archive such as Archive.org.

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A Technology Diffusion Model Based on Technology Policy: The Case of Solid-State Lighting Technology Diffusion in the U.S. (정책변수를 고려한 확산모형의 연구 - 고체조명(Solid-State Lighting : SSL) 기술을 중심으로)

  • Jin, Mei-Yue
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.6
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    • pp.2522-2527
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    • 2011
  • Technology policy has a substantial impact on the diffusion of a new technology. This paper uses technology policy as a variable in the general epidemic model to quantify the effects of the policy on technology diffusion. The results obtained in this study, using data on solid-state technology diffusion in the U.S. indicate that technology policy plays a positive role in technology diffusion and provide a firm basis for understanding the relationship between technology policy and technology diffusion through the use of quantitative data.

The Factors Affecting Breadth and Depth of Diffusion for Knowledge Management Systems (지식관리시스템의 수직적 확산과 수평적 확산에 관한 실증적 연구)

  • Suh, Chang-Kyo;Seol, Jin-Young
    • Knowledge Management Research
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    • v.9 no.3
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    • pp.77-105
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    • 2008
  • This study primarily aims at identifying what factors significantly affect the diffusion of knowledge management systems(KMS) and finding out how these identified factors can be effectively managed, especially for Korean companies. The research model is derived based on previous researches on innovation diffusion, information systems implementation, and KMS. The model is used to examine the role of determinants in influencing the extent to which KMS is diffused within organizations. Independent variables of this research are composed of technical characteristics, organizational characteristics and environmental characteristics. 'Breadth of diffusion' and 'depth of diffusion' concept are used to measure the extent of KMS diffusion which is the dependent variable of this model. The 101 companies of total 1,000 samples responded to the survey. To analyze tile results of this empirical study, we performed the multiple regression analysis. As a result, it was shown that the relative advantage, complexity, information system maturity, size, top management support, champion, competitive pressure have influences on both the breadth and the depth diffusions. On the other hand, the organizational culture, valuation and compensation, and uncertainty of environmental factors were not verified to be significant. This empirical study will provide Korean companies with insights into effective ways to diffuse the KMS and succeed in business competition.

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The Effect of the Molecular Weight of Poly(ethylene glycol) on Diffusion through Cellulose (폴리에틸렌글리콜의 분자량에 따른 셀룰로스에서의 확산 거동)

  • 윤기종;우종형;서영삼
    • Textile Coloration and Finishing
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    • v.16 no.1
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    • pp.48-52
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    • 2004
  • Diffusion/penetration rates of finishing agents are not a major criterion in the design of low molecular weight finishing agents. However, in the case of polymeric finishing agents, high molecular weights result in large hydrodynamic volumes and diffusion/penetration of the finishing agent into the substrate may become a critical factor in the design of textile finishing agents. Thus the effect of the molecular weight of a model compound, polyethylene glycol, on its diffusion through a cellulose membrane or cotton fabric is studied. Diffusion experiments of polyethylene glycol of molecular weight 400, 1000, 2000, 4600, 8000, and 10000 through cellulose membrane or fabric was carried out in a glass U-tube diffusion apparatus and the half penetration times and the penetration coefficients were determined. Both the half penetration times and the penetration coefficients exhibited a significant change between molecular weight 2000 and 2500 as the molecular weight of polyethylene glycol increased, suggesting that there is a critical molecular weight above which diffusion/penetration becomes difficult. Based on this study on a model compound, it is suggested that polymeric textile finishing agents can be expected to exhibit similar behavior.

The Effect of Diffusion Starters' Centralities on Diffusion Extent in Diffusion of Competing Innovations on a Social Network (사회 네트워크 상의 기술 확산 경쟁에서 확산 시작 지점의 중심성에 따른 확산 경쟁의 결과)

  • Hur, Wonchang
    • Journal of the Korean Operations Research and Management Science Society
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    • v.40 no.4
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    • pp.107-121
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    • 2015
  • Diffusion of innovation is the process in which an innovation is communicated through certain channels over time among the members of a social system. The literatures have emphasized the importance of interpersonal network influences on individuals in convincing them to adopt innovations and thereby promoting its diffusion. In particular, the behavior of opinion leaders who lead in influencing others' opinion is important in determining the rate of adoption of innovation in a system. Centrality has been recognized as a good indicator that quantifies a node's influences on others in a given network. However, recent studies have questioned its relevance on various different types of diffusion processes. In this regard, this study aims at examining the effect of a node exhibiting high centrality on expediting diffusion of innovations. In particular, we considered the situation where two innovations compete with each other to be adopted by potential adopters who are personally connected with each other. In order to analyze this competitive diffusion process, we developed a simulation model and conducted regression analyses on the outcomes of the simulations performed. The results suggest that the effect of a node with high centrality can be substantially reduced depending upon the type of a network structure or the adoption thresholds of potential adopters in a network.

A Study on Forecasting the Diffusion of Certified Testing Service Institutions and Direction of Policy Making in Defense Industry (방산분야 공인시험기관의 수요확산 예측 및 정책 방향 연구)

  • Lee, Yong-Hak;Cho, Hyun-Ki;Kim, Woo-Je;Kang, Cho-Rong
    • IE interfaces
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    • v.25 no.2
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    • pp.255-263
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    • 2012
  • In order to ensure the reliability and specialty of weapon system test results, a policy of extending certified testing service institutions has been driven by applying accreditation system of the ones in defense industry. Bass and Logistic models are used to apply the policy effectively and forecast the diffusion pattern of certified testing service institutions. The parameters for diffusion forecast are estimated using the diffusion pattern of certified testing service institutions in non-defense industry, and these are applied to forecast the diffusion of certified ones in defense industry. Coefficients of innovation and imitation of Bass model are analyzed to derive the factors influencing the early adoption and diffusion patterns. The more increasing the coefficients, the earlier adoption occurred. Diffusion pattern due to coefficient of imitation, internal factor, has larger effect on sensitivity of diffusion pattern. This means that the self recognition of necessity is more effectively worked than the policy or regulations driven by government.

An Analysis of Hall field in the Base Region of Magnetotransistors Using the Diffusion Model (확산모델을 이용한 자기트랜지스터의 베이스 영역에서의 홀 전계 해석)

  • 이승기;강욱성;한민구
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.43 no.7
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    • pp.1127-1134
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    • 1994
  • The analytical model for the induced Hall field in the magnetotransistor considering the diffusion of carriers has been proposed and verified by experiment and simulation. Previous models for the induced Hall field in the magnetotransistor do not consider the influence of the diffusion carrier transport. However, the carrier diffusion in the base region of magnetotransistors cannot be neglected and should be considered to evaluated the Hall field in the magnetotransistors accurately. We have measured the Hall voltage in the base region of the fabricated magnetotransistors. The measured values have been compared with the numerical results evaluated from our diffusion model as well as the calculated results from the conventional model. The evaluated Hall voltage from the diffusion model agrees well with the measured values while the sign of the Hall voltage calculated by the conventional model is opposite to that of the measured values in the saturation region. This discrepancy is due to the fact that the diffusion model considers the carrier diffusion while the conventional one does not. The Hall field model including the influence of carrier diffusion may be an important tool to optimize the device structure and to understand the operating principle of the magnetotransistor.

The coupling effect of drying shrinkage and moisture diffusion in concrete

  • Suwito, A.;Ababneh, Ayman;Xi, Yunping;Willam, Kaspar
    • Computers and Concrete
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    • v.3 no.2_3
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    • pp.103-122
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    • 2006
  • Drying shrinkage of concrete occurs due to the loss of moisture and thus, it is controlled by moisture diffusion process. On the other hand, the shrinkage causes cracking of concrete and affects its moisture diffusion properties. Therefore, moisture diffusion and drying shrinkage are two coupled processes and their interactive effect is important for the durability of concrete structures. In this paper, the two material parameters in the moisture diffusion equation, i.e., the moisture capacity and humidity diffusivity, are modified by two different methods to include the effect of drying shrinkage on the moisture diffusion. The effect of drying shrinkage on the humidity diffusivity is introduced by the scalar damage parameter. The effect of drying shrinkage on the moisture capacity is evaluated by an analytical model based on non-equilibrium thermodynamics and minimum potential energy principle for a two-phase composite. The mechanical part of drying shrinkage is modeled as an elastoplastic damage problem. The coupled problem of moisture diffusion and drying shrinkage is solved using a finite element method. The present model can predict that the drying shrinkage accelerates the moisture diffusion in concrete, and in turn, the accelerated drying process increases the shrinkage strain. The coupling effects are demonstrated by a numerical example.

p-type Zn Diffusion using by Solid State Method of $GaAs_{0.60}P_{0.40}$ and the Properties of Electroluminescence (고상 확산 법에 의한 P-type Zn 확산과 $GaAs_{0.60}P_{0.40}$의 전계발광 특성)

  • Pyo, Jin-Goo;Lim, Keun-Young;So, Byung-Moon;Park, Choon-Bae
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.11a
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    • pp.481-485
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    • 2003
  • To diffuse Zn at solid-state, the $SiO_2/ZnO/SiO_2$ wafers was made by PECVD and RF Spotter. Thicknesses of bottom $SiO_2$ and cap $SiO_2$ was about $500{\AA}$ and about $3500{\AA}$. First test was Diffusion temperatures were $760^{\circ}C$, $780^{\circ}C$, and $800^{\circ}C$, and diffusion times were 1, 2, 3, 4, 5, and 6 hr and 2nd test was Diffusion temperatures were $760^{\circ}C$, $720^{\circ}C$, and $680^{\circ}C$, and diffusion times were 1, 2, 3, 4, 5, and 6 hr. LED chips were fabricated by the diffused wafers at Fab. The peak wavelength of all chips showed about $625{\sim}650\;nm$ and red color Main reason for Iv change was by diffusion temperature not diffusion time. The lower temperature was the higher Iv. We thick that these properties is because of the very high diffusion temperature.

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A multilevel in space and energy solver for multigroup diffusion eigenvalue problems

  • Yee, Ben C.;Kochunas, Brendan;Larsen, Edward W.
    • Nuclear Engineering and Technology
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    • v.49 no.6
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    • pp.1125-1134
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    • 2017
  • In this paper, we present a new multilevel in space and energy diffusion (MSED) method for solving multigroup diffusion eigenvalue problems. The MSED method can be described as a PI scheme with three additional features: (1) a grey (one-group) diffusion equation used to efficiently converge the fission source and eigenvalue, (2) a space-dependent Wielandt shift technique used to reduce the number of PIs required, and (3) a multigrid-in-space linear solver for the linear solves required by each PI step. In MSED, the convergence of the solution of the multigroup diffusion eigenvalue problem is accelerated by performing work on lower-order equations with only one group and/or coarser spatial grids. Results from several Fourier analyses and a one-dimensional test code are provided to verify the efficiency of the MSED method and to justify the incorporation of the grey diffusion equation and the multigrid linear solver. These results highlight the potential efficiency of the MSED method as a solver for multidimensional multigroup diffusion eigenvalue problems, and they serve as a proof of principle for future work. Our ultimate goal is to implement the MSED method as an efficient solver for the two-dimensional/three-dimensional coarse mesh finite difference diffusion system in the Michigan parallel characteristics transport code. The work in this paper represents a necessary step towards that goal.