• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.05a
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• pp.53-58
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• 2009

Solar photovoltaic power generation system is judging that by the most suitable new refreshing energy in real condition of our country forward continuously interest for solar photovoltaic power generation system and diffusion me enlarged. Output decline problem is item to consider necessarily and should be verified in continuous interest for solar photovoltaic power generation system are diffusion. Present plan that minimize output decline calculating module liver optimum interval that consider recitation of a poem to reduce output decline by module liver shade by incidence angle consideration and this that occupy most parts among factor because do output of solar photovoltaic power generation system well.

• Asian Journal of Business Environment
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• v.11 no.1
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• pp.27-37
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• 2021

Purpose: This article aims to provide a balanced understanding of the structural conditions and social processes involved in the creation and diffusion of innovation. Research design, data and methodology: Drawing on organizational and economic sociology and strategic management literature, this article offers a conceptual framework that highlights the two dimensions of network structures: the vertical dimension focusing on power and legitimacy vs. the horizontal dimension highlighting information value. By organizing the literature on the functions and consequences of network, this paper advances a theoretical perspective in understanding the vast array of empirical studies on innovation involving network analysis. Results: Using the proposed framework, this article explains how the mechanisms of power, legitimacy, and information value work together with social structural factors, thus enriching our understanding of innovation. This study reveals that the information mechanism (horizontal dimension) has been most important in innovation creation and diffusion, and that trust, credibility, and legitimacy are operative in innovation diffusion. Conclusions: This paper contributes to the literature by responding to calls to extend existing frameworks to better account for the dynamics between innovation and network. In addition, this article highlights how conceptualizing innovation within the horizontal-vertical dimensions of network structures, creates new opportunities for future research.

• Publications of The Korean Astronomical Society
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• v.14 no.1
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• pp.23-32
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• 1999

We have developed a Monte Carlo code, which solves the problem of radiative transfer in anisotropically scattering atmosphere. The radiative code is flexible in handlings of the system geometry, the distribution of scattering particles, and the source-particle geometry. This code treats the case of highly forward throwing scattering. As performance tests, we have compared the result of Monte Carlo calculations with that of Quasi-Diffusion method for a spherically symmetric cloud model.

• Membrane Journal
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• v.26 no.4
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• pp.273-280
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• 2016

Pressure assisted forward osmosis (PAFO) is recently introduced because of its improved process efficiency to overcome drawbacks of forward osmosis (FO) such as low water flux and reverse solute diffusion. However, it is known that membrane fouling becomes deteriorated by additional hydraulic pressure applied in PAFO compared to FO. This study was performed to investigate possibility of intermittent pressure-assisted forward osmosis (I-PAFO) operation for fouling mitigation using colloidal silica particles as model foulants. FO, PAFO were operated as well to compare with. Two different solution pH conditions (pH 3, 10) were applied to see the effect of electrostatic interactions between the membrane and silica particles on fouling tendency. In the results, higher water flux was observed during pressurization and pressure relaxation periods in I-PAFO than water flux of PAFO, and FO on both pH conditions. Water flux decreased less in I-PAFO than PAFO after fouling. It resulted in higher water flux recovery in I-PAFO than PAFO after physical cleaning.

• Economic and Environmental Geology
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• v.53 no.1
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• pp.11-21
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• 2020

One-dimensional analytical solutions were used for forward and back diffusion of trichloroethylene (TCE) and tetrachloroethylene (PCE) in a single system with high- and low-permeability layers. Concentration profiles in a low-permeability layer, diffusive fluxes at the interface between the high- and low-permeability layers, and contaminant persistence in the high-permeability layer due to back diffusion were simulated with a comparison of semi-infinite and finite analytical solutions. In order to validate the analytical solutions used in this study, the results of one-dimensional analytical solutions developed by Yang et al. (2015) were compared with Nash-Sutcliffe model efficiency coefficient (NSE). When compared with Yang et al. (2015), the analytical solutions used in this study showed good agreements (NSE = 0.99). When compared with semi-infinite analytical solutions, TCE and PCE concentration profiles in the low-permeability layer, the diffusive fluxes, and the contaminant tailings of the high-permeability layer were underestimated. In order to determine the appropriate analytical solutions based on the effective diffusion coefficient, the thickness of the low-permeability layer, and the diffusion time in the TCE and PCE contaminated site, a term of dimensionless diffusion length (Z_d) was used. If the Z_d is less than 0.7, the semi-infinite solutions can be used to simulate accurate concentration profiles in low-permeability layers. If the Z_d is greater than 0.7, the reliability of simulations may be improved by using the finite solutions.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.27 no.7
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• pp.883-892
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• 2003

The experiment using three-dimensional laser Dopperr velocimetery (LDV) measurements and the computation using the Reynolds stress model of the commercial code, FLUENT, were conducted to give a clear understanding on the structure of tip leakage flow in a forward-swept axial-flow fan operating at the maximum efficiency condition. The tip leakage vortex was generated near the position of the minimum wall static pressure, which was located at approximately 12% chord downstream from the leading edge of blade suction side, and developed along the centerline of the pressure trough within the blade passages. A reverse flow between the blade tip region and the casing, induced by tip leakage vortex, acted as a blockage on the through-flow. As a result, high momentum flux was observed below the tip leakage vortex. As the tip leakage vortex proceeded to the aft part of the blade passage, the strength of tip leakage vortex decreased due to the strong interaction with the through-flow and casing boundary layer, and the diffusion of tip leakage vortex caused by high turbulence. In comparison with LDV measurement data, the computed results predicted the complex viscous flow patterns inside the tip region, including the locus of tip leakage vortex center, in a reliable level.

• Journal of Electrical Engineering and Technology
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• v.13 no.1
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• pp.387-392
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• 2018

Static characteristics of SiC (silicon carbide) lateral p-i-n diodes implemented on semi-insulating substrate without an epitaxial layer are inVestigated. On-axis SiC HPSI (high purity semi-insulating) and VDSI (Vanadium doped semi-insulating) substrates are used to fabricate the lateral p-i-n diode. The space between anode and cathode ($L_{AC}$) is Varied from 5 to $20{\mu}m$ to inVestigate the effect of intrinsic-region length on static characteristics. Maximum breakdown Voltages of HPSI and VDSI are 1117 and 841 V at $L_{AC}=20{\mu}m$, respectiVely. Due to the doped Vanadium ions in VDSI substrate, diffusion length of carriers in the VDSI substrate is less than that of the HPSI substrate. A forward Voltage drop of the diode implemented on VDSI substrate is 12 V at the forward current of $1{\mu}A$, which is higher than 2.5 V of the diode implemented on HPSI substrate.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.11
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• pp.908-913
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• 2000

CoSi$_2$/p+/n diodes(bilayer diodes) were fabricated by using epitaxial CoSi$_2$grown from Co/Ti bilayer as a diffusion source. The I-V characteristics of p+/n diodes were measured and compared with those of diode made from Co monolayer (monolayer diode). Monolayer diodes showed typical p+n junction characteristics with the leakage current of as low as 10$^{-12}$ A and forward current 6-orders higher than the leakage current, when drive-in annealed at 90$0^{\circ}C$ for 20 sec.. On the other hand, bilayer diodes showed the Schottky-like behaviors with forward currents rather higher than those of monolyer diodes, but with too high leakage currents, when drive-in annealed at $700^{\circ}C$ or higher. However, when the annealing temperature was lowered to $700^{\circ}C$ and annealing time was increased to 60 sec., the leakage current was reduced to 10$^{-11}$ A and thus sho3wed typical diode characteristics. The high leakage currents for diodes annealed at $700^{\circ}C$ or higher was attributed to Shannon contacts formed due to unremoved Co-Ti-Si precipitates. But when annealed at 50$0^{\circ}C$, B ions diffused in the direction of the surface layer, and thus the leakage currents were reduced by removing Shannon contacts.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.9
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• pp.3712-3729
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• 2020

Smoke detection is helpful for early fire detection. With its large coverage area and low cost, vision-based smoke detection technology is the main research direction of outdoor smoke detection. We propose a two-stage smoke detection method combined with block Deep Normalization and Convolutional Neural Network (DNCNN) and visual change image. In the first stage, each suspected smoke region is detected from each frame of the images by using block DNCNN. According to the physical characteristics of smoke diffusion, a concept of visual change image is put forward in this paper, which is constructed by the video motion change state of the suspected smoke regions, and can describe the physical diffusion characteristics of smoke in the time and space domains. In the second stage, the Support Vector Machine (SVM) classifier is used to classify the Histogram of Oriented Gradients (HOG) features of visual change images of the suspected smoke regions, in this way to reduce the false alarm caused by the smoke-like objects such as cloud and fog. Simulation experiments are carried out on two public datasets of smoke. Results show that the accuracy and recall rate of smoke detection are high, and the false alarm rate is much lower than that of other comparison methods.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.191-195
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• 2007

In this study, we estimated the performance of PEMFC's unit cell as changing operating temperature in different inlet humidity condition at cathode side but anode dry, and tried to match experimental results with 1-dimensional simulation. We used $Nafion^{\circledR}112$ membrane and a self-manufactured PEMFC with active area of $25cm^{2}$ was used in this study. The range of operating temperature was $40{\sim}70^{\circ}C$ and oxygen through bubbled humidity chamber was supplied $0{\sim}80$% humidity condition as changing water temperature in humidity chamber. For figuring out governing equations, represent water contents in electrolyte membrane, the linear forward difference method was applied about time progress and quadratic central difference method was used about space progress. It was assumed that pressure terms were linearly changed due to thin electrolyte membrane. In low operating temperature condition, $40{\sim}60^{\circ}C$, increasing temperature rarely effected cell performance but we can see performance drop at $70^{\circ}C$. By modifying Henrry's constant and/or diffusion coefficient, the modified one-dimensional model was accomplished for calculation.