• 기술혁신연구
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• 제11권2호
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• pp.71-89
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• 2003

Since technological innovation, adoption, and diffusion is a fundamental engine for a company's competitiveness and in turn a nation's industrial development, diffusion of technological innovation has been one of popular research themes to many researchers and scholars for decades. Especially, in today's knowledge-based economy, the IT technology became a fundamental infrastructure for a nation and thus their impact on a nation's economy has grown to be tremendous. This paper investigates the patterns of technological diffusion of 16 telecommunications services. Firstly, we identify the optimal diffusion model which represents the 15 IT innovation best in terms of goodness-of-fit. Secondly, based on the best model identified we cluster the 16 IT innovations according to their diffusion characteristics such as penetration rate and diffusion speed. Lastly, we categorize the innovations in terms of technology (voice-based innovation and data-based innovation) and demand (household-use and business-use) attributes, and compare their diffusion patterns and found some meaningful difference in diffusion patterns. We hope the result helpful to corporate managers as well as policy makers in relevant areas.

• 한국환경과학회지
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• 제11권7호
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• pp.679-686
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• 2002

Turbulence greatly influence on atmospheric flow field. In the atmosphere, turbulence is represented as turbulent diffusion coefficients. To estimate turbulent diffusion coefficients in previous studies, it has been used constants or 2-level method which divides surface layer and Ekman layer. In this study, it was introduced Smagorinsky method which estimates turbulent diffusion coefficient not to divide the layer but to continue in vertical direction. We simulated 3-D flow model and TKE equation applied turbulent diffusion coefficients using two methods, respectively. Then we showed the values of TKE and the condition of each term to TKE. The results of Smagorinsky method were reasonable. But the results of 2-level method were not reasonable. Therefor, it had better use Smagorinsky method to estimate turbulent diffusion coefficients. We are expected that if it is developed better TKE equation and model with study of computational method in several turbulent diffusion coefficients for reasonably turbulent diffusion, we will able to predict precise wind field and movements of air pollutants.

• 산업공학
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• 제23권4호
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• pp.337-348
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• 2010

The Bass model is the most widely used model in research of new product diffusion because it presents a nice explanation on the diffusion process of new products. However, it has a limitation that its performance of fitness is lower as the available data become less and also, the diffusion curve is bell-shape and so, it can not represent the various diffusion patterns. Recently, a two-pieces Bass model is developed and applied to analyze diffusion of 10 products. The results are encouraging in terms of fitness. However, diffusion pattern is not dealt with in the paper. In this paper, analysis of diffusion pattern is in depth addressed in two-pieces Bass model. It is shown that the diffusion curves are divided into 3 types with respect to the peak adoption rate and each type is divided into 2 types further. Takeoff time of a diffusion process is analyzed by using the inflection point and regime-change time where it represents the point that imitation and innovation parameters change. Empirical studies for 68 products(28 domestic products and 40 USA products) are performed to analyze the diffusion pattern. Findings are that diffusion patterns of all products except 1 USA product show type I and regime-change time becomes shorter as the introduction time of the product is later in domestic products and regime-change time can be regarded as a takeoff time in 47% of total 68 products.

• Journal of Information Technology Applications and Management
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• 제17권2호
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• pp.187-205
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• 2010

This study takes a holistic approach to understand the diffusion of IPTV services by combining the adoption-diffusion model and the use-diffusion model of innovation. IPTV service, a leading digital converged application coupling media content with telecommunications, has been recently launched commercially in Korea. We created a structural model of adoption-diffusion, using the perceived easeof-use and usefulness of TAM(Technology Acceptance Model) as mediating variables, and a structural model of use-diffusion, with the rate of use and the variety of use as mediating variables. To empirically analyze these models, non-users of IPTV were surveyed using the adoption-diffusion model to identify factors influencing their intention to subscribe to the service. Meanwhile, users of IPTV were surveyed using the use-diffusion model to determine the factors that influence their satisfaction with the service and their intention to re-use it. Under the adoption-diffusion model, we found that trialability, household innovativeness and perceived risk were the determinants of user satisfaction with IPTV, and perceived ease-of-use, the mediating factors. Under the use-diffusion model, complementarity and communication were shown to be the determinants of users' satisfaction with IPTV, and variety of use, the mediating factor. We also found that consumers' intention to re-use IPTV was strongly influenced by its relative advantage and perceived risk.

• 한국농공학회논문집
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• 제50권4호
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• pp.27-37
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• 2008

It is most serious problem which is various occurs from the agricultural concrete structure and off shore concrete structure the problem which it comes to think is deterioration of the concrete which is caused with the corrosion of the reinforcing steel which is caused by with permeation of the water and the sea water. Specially the off shore concrete structure has been deteriorated by the steel reinforcement corrosion. The latex modified concrete(LMC) was adds latex in the plain concrete as the latex has increase the durability of concrete. This study were accomplished to the estimate the diffusion coefficient of LMC, and the time dependent constants of diffusion. The average chloride diffusion coefficient was estimated. Also, the average chloride diffusion coefficient was compared with diffusion coefficient test results of 28 curing days. The test results indicated that the average chloride diffusion coefficient could closely estimate the test results of the diffusion coefficient test results of 28 curing days.

• Asia pacific journal of information systems
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• 제10권4호
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• pp.1-20
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• 2000

Electronic Data Interchange(EDI) has the potential to improve business operations by expediting the exchange of business documents. It will also provide substantive operational and strategic benefits to the trading firms. However, the successful implementation of EDI systems requires the mutual trust and cooperation between the trading firms. The extent of EDI diffusion and performance depends on inter-organizational, intra-organizational, as well as innovation factors. Researches based on the sociopolitical process framework in the use of IT, organizational theory, resource dependence theory, and innovation diffusion theory have identified 3 inter-organizational variables(transaction climate, dependence, external IS expert support) and 4 intra-organizational variables(strategic IS planning, infrastructure, top management support, education/training,), and 3 innovation variables(compatibility, relative advantage, cost) that affect EDI diffusion. In this study, a multi-dimensional measure on EDI diffusion has been developed to capture the external and internal integration. Then, the influence of these 10 variables on the extent to which the EDI adopting firms pursue diffusion has been examined. Whether more diffusion leads to superior performance has also been studied. International trade managers from 107 firms in the trade industry participated in a field survey. The results based on a structural equation model(SEM), developed using AMOS, provide quite a strong support for the hypothesized relations. Both education/training and IT infrastructure influenced external and internal diffusion of EDI systems. Internal diffusion of EDI enables the adopting firms to improve operational and strategic performance, whereas external diffusion contributes only to operational performance.

• 한국응용과학기술학회지
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• 제24권1호
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• pp.79-85
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• 2007

The diffusion behavior of phenol, toluene and benzoic acid in aqueous SDS solution was examined. It showed a similar experimental results for phenol and toluene. The diffusion coefficients of the solutes were characterized by the presence of two distinct regions: below the cmc and above the cmc. For phenol and toluene, it remained approximately unchanged when the SDS concentration was below the cmc. Above the cmc there was an apparent decrease in the diffusion coefficients of the two solutes with increasing SDS concentration. However, for benzoic acid the diffusion behavior was different from that of phenol and toluene. The diffusion coefficient of benzoic acid decreased slightly with increasing SDS concentration, however the diffusion coefficient was almost constant above the cmc. For benzoic acid the diffusion behavior was dependent on the joint contribution of benzoic acid molecules as well as the benzoate ions.

• 한국데이타베이스학회:학술대회논문집
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• 한국데이타베이스학회 2010년도 춘계국제학술대회
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• pp.165-180
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• 2010

This study takes a holistic approach to understanding the diffusion of IPTV services by combining the adoption-diffusion model and the use-diffusion model of innovation. IPTV service, a leading Digital converged application coupling media content with telecom, has been recently launched commercially in Korea. We created a structural model of adoption-diffusion, using the perceived ease-of-use and usefulness of TAM(Technology Acceptance Model) as mediating variables, and a structural model of use-diffusion, with the rate of use and the variety of use as mediating variables. To empirically analyze these models, non-users of IPTV were surveyed using the adoption-diffusion model to identity factors influencing their intention to subscribe to the service. Meanwhile, users of IPTV were surveyed using the use-diffusion model to determine the factors that influence their satisfaction with the service and their intention to fe-use it. Under the adoption-diffusion model, we found that trialability, household innovativeness and perceived risk were the determinants of user satisfaction with IPTV, and perceived ease-of-use, the mediating factors. Under the use-diffusion model, complementarity and communication were shown to be the determinants of users' satisfaction with IPTV, and variety of use, the mediating factor. We also found that consumers' intention to re-use IPTV was strongly influenced by its relative advantage and perceived risk.

• 한국토양환경학회지
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• 제1권2호
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• pp.83-90
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• 1996

토양내에서의 가스나 증기상의 오염물질의 이동은 여러 가지 현상에 의해서 일어나고 있으나 농도차에 의해서 일어나는 확산이 가장 중요하다. 그런데 토양내에서의 확산은 토양 입자들로 인한 확산 부피의 감소, 또 확산경로의 불규칙성, 확산 경로에 있어서 단면적의 변화 등으로 인해 대기중에서 일어나는 확산과는 다른 면을 보인다. 본 논문에서는 이러한 현상을 설명하기 위하여 흔히 사용되는 굴절계수(toruosity), 유효확산계수(effective diffusion coefficient)의 서로 다른 그러나 같은 이름으로 사용되는 많은 정의들과 다양한 수학적 모델들에 대한 비교 검토가 이루어졌다. 굴절계수나 유효확산계수를 사용할 때는 각각의 경우 정의와 각 식의 특징에 대하여 세밀한 검토와 주의가 행하여져야 한다.

• 한국유통학회지:유통연구
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• 제15권4호
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• pp.61-85
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• 2010

본 연구에서는 국내 대형할인점의 확산을 효과적으로 설명하기 위해 기업의 정보와 구매자의 구전으로 확산을 설명하는 Bass모형에 제3의 요소로 공간적 영향력을 고려하였다. 국내 대형할인점의 확산은 확산중심지인 서울경인지역에서 저차중심지인 4개 지역권역으로 확산되는 형태를 보임에 따라 공간적 영향이 중요하게 작용할 것으로 기대된다. 본 연구에서 공간적으로 구분된 시장 A(확산중심지)가 시장 B(저차중심지)에 미치는 영향이 완전히 통제되지 못하는 상황에서 시장 A가 시장 B에 미치는 공간적 영향을 다국가확산모형(multinational diffusion model)을 확장한 공간확산모형(spatial diffusion model)을 이용하여 정의하였다. Bass모형과 공간확산모형의 모수추정을 통해 두 가지 정보전달경로와 관련된 혁신계수와 모방계수로 확산을 설명하는 Bass모형보다 공간확산모형이 국내 대형할인점 확산을 더욱 효과적으로 설명하는 것으로 나타났다. 또한 혁신중심지인 서울경인과 4개 지역권역의 소매환경을 나타내는 개념적 거리에 따라 공간확산모형에서 공간적요인의 영향력이 달라질 것이 기대되어 공간확산계수와 소매환경변수간의 상관관계를 살펴보았고, 연구결과 확산중심지에서 저차중심지에 대한 공간적 영향력은 저차중심지의 소매환경이 확산중심지의 소매환경과 유사할수록 크다는 것을 밝혀내었다.