• The Korean Journal of Ecology
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• v.8 no.2
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• pp.61-68
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• 1985

The modeling of interception and absorption of light was studied in plant canopies at Mt. Kwanak. Followering results were obtained. Light intensity passing through the stacked leaves is attenuated exponentially. This phenomenon seems to be more clearly applied to the plant canopies, if they have large cumulative leaf area and are matured densely. Light interception and absorption are influenced by leaf thickness, shape pigments, and leaf area, and they have great effect on the maturation of canopies. It was confirmed that the light penetrating through the stratified canopies is decreased exponentially in dual pattern. The cumulative leaf area of a definite space in a certain plant canopy is the same as the growth of leaf area of the canopy at that time. A hypothetical model for calculating the light absorption in plant canopies, was established on the bases of phenomena that incident light is captured at the maximum level and light inerception effect is minimized by leaves.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.4
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• pp.718-724
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• 2009

Recently, Increase of energy consumption is continued accordingly because economy is constant growth. so we need long term of energy supply stability and develop new energy source. The effort of environmental improvement is necessary and our country has to educe conservatory gas in these situation, our energy policy is summarized that minimizes energy consumption and uses kinds of energy source. This paper studied some effort of stability that distributed generation put in electric system through line fault, sudden load change. And then this paper calculated penetrated level of distributed generation in system transient stability.

• Journal of Information Processing Systems
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• v.2 no.2
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• pp.124-129
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• 2006

With the explosive increase in the generation and utilization of spatiotemporal data sets, many research efforts have been focused on the efficient handling of the large volume of spatiotemporal sets. With the remarkable growth of ubiquitous computing technology, mining from the huge volume of spatiotemporal data sets is regarded as a core technology which can provide real world applications with intelligence. In this paper, we propose a 3-tier knowledge discovery framework for spatiotemporal data mining. This framework provides a foundation model not only to define the problem of spatiotemporal knowledge discovery but also to represent new knowledge and its relationships. Using the proposed knowledge discovery framework, we can easily formalize spatiotemporal data mining problems. The representation model is very useful in modeling the basic elements and the relationships between the objects in spatiotemporal data sets, information and knowledge.

• Earthquakes and Structures
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• v.14 no.4
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• pp.297-303
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• 2018

Seismic behavior of Osmanli and Senyuva stone bridges was addressed in this study. A combination of FEM and DEM was employed for getting closer to the real behavior of the bridge. One of the unique features of this combinational method is simulation close to reality. Modal numerical analysis was also used to verify the modeling. At the end of earthquake, a part of two lateral walls of Osmanli bridge was broken. The growth of arch cracks also increased during the earthquake. A part of right-hand wall of Senyuva Bridge was destructed during the earthquake. The left-hand side of the bridge wall was damaged during the earthquake but was not destructed.

• Environmental Engineering Research
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• v.21 no.4
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• pp.355-364
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• 2016

Beijing, as a cradle of modern industry and the third largest metropolitan area in China, faces more responsibilities to adjust industrial structure and mitigate carbon emissions. The purpose of this study is aimed at predicting and comparing industrial carbon emissions of Beijing in ten scenarios under different policy focus, and then providing emission-cutting recommendations. In views of various scenarios issues, system dynamics has been applied to predict and simulate. To begin with, the model has been established following the step of causal loop diagram and stock flow diagram. This paper decomposes scenarios factors into energy structure, high energy consumption enterprises and growth rate of industrial output. The prediction and scenario simulation results shows that energy structure, carbon intensity and heavy energy consumption enterprises are key factors, and multiple factors has more significant impact on industrial carbon emissions. Hence, some recommendations about low-carbon mode of Beijing industrial carbon emission have been proposed according to simulation results.

• Knowledge Management Research
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• v.18 no.4
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• pp.137-157
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• 2017

With the rapid growth of the internet, Social Network Services (SNSs) have played an important role. As the use of SNSs increases, users experience a sense of responsibility to respond to other people's messages or requests, and consequently experience an social overload, feeling too much social support for other users. In this study, we examined the effects of social overload on loneliness and SNS discontinuous usage intention. To verify the research model, data were collected from 83 SNS users and analyzed using SmartPLS, a structural equation modeling tool. The results of this study showed that the communal orientation and the degree of use of SNS influenced the social overload, and the social overload had a significant effect on loneliness and SNS discontinuous usage intention. The findings of this study are expected to help understand the social overload and loneliness in the use of SNS, and may also provide a strategic direction for SNS service providers.

• Communications of the Korean Mathematical Society
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• v.23 no.3
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• pp.401-411
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• 2008

In this paper, we characterize Sobolev spaces $H^s(\mathbb{R}^n),\;s{\in}\mathbb{R}$ by the initial value of solutions of heat equation with a growth condition. By using an idea in its proof, we also discuss a stability problem for Cauchy functional equation in the Sobolev spaces.

• Journal of Powder Materials
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• v.18 no.2
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• pp.172-175
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• 2011

We developed a 3D simulation model of microstructure evolution of vertically aligned porous structure due to phase separation during film growth. The model proves its validity by reproducing the results of previous researches which are topological features of the microstructures and effects of varied processing parameters. The model will be extended by including bulk diffusion effect and elastic effect.

• Journal of the Korean Society of Combustion
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• v.15 no.4
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• pp.22-28
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• 2010

The Direct Quadrature Method of Moments (DQMOM) has been presented for the solution of population balance equation in the wide range of the multi-phase flows. This method has the inherently interesting features which can be easily applied to the multi-inner variable equation. In addition, DQMOM is capable of easily coupling the gas phase with the discrete phases while it requires the relatively low computational cost. Soot inception, subsequent aggregation, surface growth and oxidation are described through a population balance model solved with the DQMOM for soot formation. This approach is also able to represent the evolution of the soot particle size distribution. The turbulence-chemistry interaction is represented by the laminar flamelet model together with the presumed PDF approach and the spherical harmonic P-1 approximation is adopted to account for the radiative heat transfer.

• Journal of Information Technology Services
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• v.13 no.2
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• pp.19-34
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• 2014

As the global smartphones market is growing at a brisk pace, their associated mobile applications are becoming increasingly ubiquitous in our daily life. The growth of mobile application business is explosive. Like other digital contents businesses, illegal downloads of copyrighted mobile applications become major obstacle in the future of the industry. In spite of anti-piracy efforts, the phenomenon has been getting worse. It is necessary to change the focus of current deterrence policies and strategies. This study investigates the factors influencing smartphone applications piracy behavior. For better understanding of illegal behavior, a research model of potential determinants for the piracy behavior is developed and empirically tested via path analysis using structural equation modeling. Findings show that social factors, beliefs concerning benefits from piracy, self-efficacy, and habit have significant effects on attitude toward smartphone application piracy. The result also shows perceived risks and facilitating conditions were not significantly related to their attitude. Implications for research and practice are discussed.