• New & Renewable Energy
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• v.1 no.3 s.3
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• pp.35-41
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• 2005

This paper analyses the economics of grid-connected photovoltaic systems. With the 2003 cost of photovoltaic systems, under prevailing capital market conditions, with a system lifetime of 30 years, and under the best climatic conditions, it appears that the cost of production of grid-connected electricity could be of 0.21 US $/kWh, and under medium climatic conditions, European locations, Switzerland, Japan and South Korean could be of 0.28$/kWh. If the lifetime if the system goes up, due to future technological improvements, to a very large value such as 50 years, these costs can be lowered by 10-20%. Competitiveness of grid-connected photovoltaic electricity, while it still cannot be taken for granted, is a possibility, especially if major technological advances further lowers the costs of photo cells and increases their lifetimes.

• International Journal of Automotive Technology
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• v.2 no.3
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• pp.103-107
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• 2001

Many researches on pressure-swirl injectors due to the variety of application have been conducted on the effects of nozzle design, operating conditions, properties of liquid and ambient conditions on the flow and spray characteristics. The breakup length of conical emulsified fuel sheet resulting from pressure-swirl atomizer using in the oil burner was investigated with the digital image processing method with neat light oil and emulsion with water content of lotto% and the surfactant content of 1-3%. The injection pressure ranged from 0.1 to 1.2 MPa was selected. The various regimes for the stage of spray development within the experimental conditions selected in this study is newly suggested in terms of Ohnesorge number and injection pressure. The breakup length for both criteria show the same tendency even though the random nature of perforation and disintegration process of liquid sheet. The stage of spray development is widely different with the physical properties of liquid atomized, mainly viscosity of liquid. The breakup length decreases smoothly with increase in the injection pressure for the lower viscous liquid.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1998.10a
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• pp.224-229
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• 1998

This study was conducted to develop the simple and convenient irrigation control model which can maintain the appropriate rates of irrigation and drainage of nutrient solution according to the environmental conditions and growth stages in soilless culture of cucumber. In order to obtain fundamental data for development of the model, investigation of the actual state of soilless culture practices was carried out. Most irrigation systems of soilless culture were controlled by the time clock. Evapotranspiration of cucumber in soilless culture was investigated and correlations with environmental conditions were analyzed, and its prediction model was developed. A irrigation control model based on the time clock control and there were considered seasons, weather conditions, and growth stages was developed. Applicability of the model was tested by simulation. Drainage rates of irrigation system controlled by conventional time clock, integrated solar radiation, and the developed model were 61%, 20%, and 32%, respectively in cucumber perlite culture.

• Magazine of the Korean Society of Agricultural Engineers
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• v.41 no.2
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• pp.37-43
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• 1999

This study was conducted to develop the simple and convenient irrigation control model which can maintain the appropriate rates of irrigation and drainage of nutrient solution according to the enviornmental conditions and growth stages in soilless culture of cucumber. In order to obtain fundamental data for development of the model, investigation of the actual state of soilless culture practices was carried out. Most irrigatioin systems of soillness culture were controlled by the time colock. Evapotranspiration of cucumber in soilness culture was investigated and correlations with environmental conditions were analyzed , and its estimating model was developed. In order to develop the irrigation system which can control the amount of nutrient solution applied according to seasons, weather conditions, and growth stages, a irrigation clock control was developed. Applicability of the model was tested by simulation. Drainage rates of nutrient solution controlled by conventional time clock, integrated solar radiation, and the developed model were 61% , 20%, and 32% , respectively in cucumber perlite culture.

• International Journal of Aeronautical and Space Sciences
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• v.18 no.1
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• pp.108-117
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• 2017

This paper presents a distribution simulation model for dual purpose improved conventional munitions based on flight test data. A systematic procedure for designing a dispersion simulation model is proposed. A new accumulated broken line graph was suggested for designing the distribution shape. In the process of verification and simulation for the distribution simulation model, verification was performed by first comparing data with firing test results, and an application simulation was then conducted. The Monte Carlo method was used in the simulations, which reflected the relationship between ejection conditions and real distribution data. Before establishing the simulation algorithm, the dominant ejection parameter of the submunitions was examined. The relationships between ejection conditions and distribution results were investigated. Five key distribution parameters were analyzed with respect to the ejection conditions. They reflect the characteristics of clustered particle dynamics and aerodynamics.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.42
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• pp.211-245
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• 2009

In this paper we firstly review the developmental stages of the Chinese civil aviation industry since 1949 and the background history of the Chinese Civil Aviation Law of 1996. We secondly analyzed the main terms and conditions about the Chinese civil aviation law and pointed out several problematic issues in view of the development of the Chinese aviation industry. Current civil aviation law in China has been in effect for the last 12 years. In these periods, Chinese civil aviation industry has developed in a high speed and great changes have occurred in its market environments. Thus, some of the terms and conditions in current civil aviation law in China have become outdated and unsuitable for the current developmental stage of the Chinese civil aviation industry. Therefore, we proposed some directions of the future amending of the Chinese Civil Aviation Law.

• Journal of Plant Biotechnology
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• v.5 no.4
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• pp.209-214
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• 2003

Expression of 43 flowering-related genes was examined in two inbred lines of Chinese cabbage, Chiifu and Kenshin, under different photoperiod, vernalization and flower development stages. The floral genes cloned by RT-PCR with degenerated primers showed high homology with Arabidopsis counterparts. Genes in two inbred lines, TOC, CRY1, CO, RGAL and GAl, were highly expressed under all tested conditions. However, expression of three genes was regulated by particular experimental conditions. The expression of LHY gene was predominant in Chiifu under the short-day conditions, whereas the expression of RGAL gene was influenced by vernalization in both inbred lines. Besides, the expression of NAP gene was induced by vernalization only in Chiifu. Most of the flower identity-related genes were expressed during flower development. The transcript level for several genes was not detected in this experiment.

• Journal of the Korean Institute of Educational Facilities
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• v.9 no.4
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• pp.5-13
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• 2002

This paper aims to analyse design conditions and propose schematic design for Jangsung High School in Pohang. As for site conditions, it has the size of $14,900m^2$ and a rather flat condition near to the ocean East Sea. And the area is under development with land subdivision method expecting high density housing around it. As a program, Education Facilities Bureau required to provide 36 classes and supporting facilities. To design the schemes, we followed the 7th education policy guidelines. During the design development stage, 3 alternatives are suggested as in the paper. However, staffs of Education Bureau and teachers favoured and selected our scheme, which gives symbolic image, as a new high school education environment.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.2
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• pp.187-192
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• 2003

To evaluate the oceanographic conditions for the artificial upwelling we measured vertical stratification coefficients, current speed distribution and grain size distribution of bottom sediment in the vicinity of Gukdo and Somaemuldo near Geojedo. There were a strong stratification between surface and bottom layers in summer, the stratification was weak from autumn to winter, and the water was well mixed during winter. In summer nutrient concentration of the bottom layer was 4 times higher than that of the surface layer. Underwater currents were strong in the bottom layer. We conclude that the oceanographic conditions in the area will meet the basic requirement for the construction of artificial upwelling.

• Journal of Biosystems Engineering
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• v.30 no.3 s.110
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• pp.166-171
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• 2005

A prototype peeling device with rotating cutter blades was designed to peel altari radish skin. With the designed blades, the maximum peeling depth increased as the cutter clearance increased but the effect of the peeling speed was not significant. The optimal operating conditions for peeling was; the peeling speed was at 0.19m/s when peeled 2.5 blades/sec and the maximum peeling depth was 1.5mm, the minimum peeling depth was 0.5mm, and the leaf rotating speed was 12 rpm, respectively. In the peeling test fur the optimum operation conditions, with a auxiliary rolling device could adjust the rotational speed of the root uniformly, the altari radishes under 70mm diameter were peeled perfectly.