• Journal of Advanced Navigation Technology
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• v.22 no.3
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• pp.233-239
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• 2018

Since solar power generation is intermittent depending on weather conditions, it is necessary to predict the accurate generation amount of solar power to improve the efficiency and economical efficiency of solar power generation. This study proposes a short - term deep learning prediction model of solar power generation using meteorological data from Mokpo meteorological agency and generation data of Yeongam solar power plant. The meteorological agency forecasts weather factors such as temperature, precipitation, wind direction, wind speed, humidity, and cloudiness for three days. However, sunshine and solar radiation, the most important meteorological factors for forecasting solar power generation, are not predicted. The proposed model predicts solar radiation and solar radiation using forecast meteorological factors. The power generation was also forecasted by adding the forecasted solar and solar factors to the meteorological factors. The forecasted power generation of the proposed model is that the average RMSE and MAE of DNN are 0.177 and 0.095, and RNN is 0.116 and 0.067. Also, LSTM is the best result of 0.100 and 0.054. It is expected that this study will lead to better prediction results by combining various input.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.11
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• pp.792-798
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• 2012

A general concept on the definition of the second law efficiencies of thermodynamic cycles is introduced. The efficiency is defined to be proportional to the entropy generation divided by the maximum possible entropy generation. This way of definition of the cycle efficiency is clear and concise and, moreover, follows faithfully the concept of the second law of thermodynamics. This definition is applied to heat engine, refrigerator and heat pump. The second law efficiencies of heat engine and refrigeration cycles are derived, which are the same as the existing ones, respectively. The second law efficiency of heat pump, however, finds to be different from the existing one. Discussion is given about the difference and its cause.

• Journal of the Korean Graphic Arts Communication Society
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• v.11 no.1
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• pp.103-122
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• 1993

A cause and counterplan of the increase in dark decay rate of$\varepsilon$-CuPc/PVCz photoreceptor which is consist of the carrier generation layer (CGL) of$\varepsilon$type copper phthalocyanine ($\varepsilon$-CuPc) thin film by an aqueous coating method and the carrier transport layer (CTL) of polyvinylcarbazol (PVCz) by spin coating, are studied in this paper. Electrochemical deposition of CGL was accompanied by an increase in work function of the aluminium substrate during the processes and the enhanced work function 5.3 eV rose above the ionization potential 5.16 eV of $\varepsilon$-CuPc. This resulted in the increased injection of holes from substrate into CGL and a fast dark decay rate. Improved photoreceptor, an electron-transport $\varepsilon$-CuPc/TNF photoreceptor, led to lowing of dark decay rate and increasing of photosensitivity. The carrier generation efficiency (ηg), carrier injection efficiency (ηi) and xerographic gain (G) of the $\varepsilon$-CuPc/TNF photoreceptor were obtained by XTOF method and PIDC.

• Journal of Power Electronics
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• v.16 no.2
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• pp.666-674
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• 2016

In this paper, a high efficiency satellite electrical power supply system is proposed. The increased efficiency of the power supply system allows for downscaling of the solar array and battery weight, which are among the most important satellite design considerations. The satellite power supply system comprises two units, namely a generation unit and a storage unit. To increase the efficiency of the solar array, a maximum power point tracker (MPPT) is used in the power generation unit. In order to improve the MPPT performance, a novel algorithm is proposed on the basis of the hill climbing method. This method can track the main peak of the array power curve in satellites with long duration missions under unpredicted circumstances such as a part of the array being damaged or the presence of a shadow. A lithium-ion battery is utilized in the storage unit. An algorithm for calculating the optimal rate of battery charging is proposed where the battery is charged with the maximum possible efficiency considering the situation of the satellite. The proposed system is designed and manufactured. In addition, it is compared to the conventional power supply systems in similar satellites. Results show a 12% increase in the overall efficiency of the power supply system when compared to the conventional method.

• Journal of the Korean institute of surface engineering
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• v.48 no.3
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• pp.105-109
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• 2015

We studied emission characteristics of blue fluorescent multi-tandem OLEDs using $Al/MoO_x$ as charge generation layer(CGL). Threshold voltage for 2, 3, 4, and 5 units tandem OLEDs was 8, 11, 14 and 18 V, respectively. The threshold voltage in multi-tandem OLEDs was lower than multiple of 4 V for the single OLED. Maximum current efficiency and maximum quantum efficiency of single OLED were 7.6 cd/A and 5.5%. Maximum current efficiency for 2, 3, 4, and 5 units tandem OLEDs was 22.6, 31.4, 41.2, and 46.6 cd/A, respectively. Maximum quantum efficiency for 2, 3, 4, and 5 units tandem OLEDs was 11.8, 15.8, 21.8, and 25.6%, respectively. The maximum current efficiency and maximum quantum efficiency in multi-tandem OLEDs were higher than multiple of those for the single OLED. The intensity for 508 nm peak was changed and the peak wavelength was red shift by increase of tandem unit in electroluminescent emission spectra. These phenomena can be caused by micro-cavity effect with increasing of organic layer thickness.

• Proceedings of the KIEE Conference
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• 2009.04a
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• pp.46-48
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• 2009

This paper aims to investigate generation conditions necessary for the most efficient generation by measuring electricity power under various irradiation conditions, since the photovoltaic generation system has high costs and low efficiency. In addition, because the irradiation varies hourly, daily, monthly, and yearly, the research on the irradiation necessary for photovoltaic generation was carried out by analyzing the pattern o( Bower under various irradiation conditions. Also, after measuring the daily variations of irradiation and generation power, the monthly accumulated irradiation and monthly accumulate power which had the most generation power were investigated and the pattern of the annual generation power was analyzed. The results of this study are as follows. As for the relationship between the photovoltaic generation system and the irradiation, the generation power increased with the irradiation and when the irradiation was more than 600 $[W/m^2]$ the generation power amounted to more than 100 [Wh] as the resonable result.

• New & Renewable Energy
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• v.2 no.3
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• pp.23-30
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• 2006

Need developments of substitute energy to solve problem of global warming by excess use of fossil energy, excess discharge of carbon dioxide. wind power generation system is all-important energy in next generation as clean energy. Environmental pollution of wind power generation system is not exhausted entirely. And, electric-power generation system cost is cheap than other energy. Wind Generation system that is supplied much present is most horizontality style blade structure. But, Horizontal style structure is serious noise and there is problem in stability of blade. We designed special blade solve to this problem. And, manufactured vertical axis wind power generation system because using blade. Also, developed assistance power generator to increase driving efficiency ago wind power generation. We expect this devices that is such cover shortcoming of wind power generation system.

• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.412-415
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• 2005

Solar thermal power generation is one of promising and well-proven ways to convert solar energy to electricity. Though it requires high initial cost for system construction and continuous efforts for maintainment. it is more positive in terms of efficiency than other solar power generation technologies. Moreover, solar thermal power generation allows additional benefits of cheap thermal storage and easy hybridization with other fossil fuel-driven power generation. Owing to these benefits, large scale solar thermal power generation technology is expected to be competitive to other commercial technologies in the near future. In this paper an overview on the solar thermal hybrid power generation technology and the state of the art in Korea were briefly introduced.

• International journal of advanced smart convergence
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• v.11 no.3
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• pp.187-196
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• 2022

In this paper, we propose an example of designing and constructing a roof-type solar power plant structure equipped with a Pseudo-BIPV (Building-Integrated Photovoltaic) shape suitable for use as a roof of a small warehouse with a sandwich-type panel structure. As the characteristics of the roof-type solar power generation facility to be installed in the small warehouse proposed in this study, the shape of the roof is not a general A type, but a right-angled triangle shape with the slope is designed to face south. We chose a structure in which an inverter for one power plant and a control facility are linked by grouping several roofs of buildings. In addition, the height of the roof structure is less than 20 cm from the floor, and it has a shape similar to that of the BIPV, so it is building-friendly because it is almost in close contact with the roof. At the same time, the roof creates a reflective light source due to the white color. By linking this roof with a double-sided solar panel, we designed it to obtain both the advantage of the roof-friendliness and the advantage of efficiency improvement for the electric power generation based on the double-sided panel. Compared to the existing solar power generation facilities using A-shaped cross-sectional modules, the power generation efficiency of roofs in this case is increased by more than 11%, which we can confirm, through the comparison analysis of monitoring data between power plants in the same area. Therefore, if the roof-type solar structure suitable for the small warehouse we have presented in this paper is used, the facilities of electric power generation is eco-friendly. Further it is easier to obtain facility certification compared to the BIPV, and improved capacity of the power generation can be secured at low material cost. It is believed that the roof-type solar power generation facility we proposed can be usefully used for warehouse or factory-based smart housing. Sensor devices for monitoring, CCTV monitoring, or safety and environment management, operating in connection with the solar power generation facilities, are linked with the Internet of Things (IoT) solution, so they can be monitored and controlled remotely.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.5
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• pp.583-592
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• 2016

IMO (International Maritime Organization) in the UN (United Nations) set up that aim at reducing $CO_2$ emission from ship by up to 30 percent until 2030. The final purpose of this study is the development of marine thermoelectric generation system using waste heat from vessel of internal combustion engines. Before the development of marine thermoelectric generation system, this paper carried out the fundamental heat analysis of marine thermoelectric generation system. It was able to obtain the valuable results about the efficiency improvement of the thermoelectric generation system. The results is as follows : 1) It was confirmed that the efficiency of thermoelectric generation system improves to 8.917 % with increasing the temperature difference of peltier module by reducing the temperature difference between peltier module and heat source at the hot side. 2) System efficiency according to change in the external load resistance was confirmed that the change width of about 6 % which does not significantly occur. 3) System efficiency in the case stainless steel at the same condition is 8.707 %. System efficiency could be confirmed that the stainless steel is higher than duralumin (8.605 %), copper (8.607 %).