• 디지털융복합연구
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• 제15권9호
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• pp.231-239
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• 2017

산업의 급격한 발전은 화석에너지의 고갈을 야기하였고, 이러한 이유로 화석연료를 대체하기 위한 에너지로 태양광에너지가 각광받기 시작하였다. 하지만 기술발전에 있어 전체적인 연구방향 및 향후 연구 방향에 대한 논의가 부족하였다. 이에 보다 효과적인 기술개발을 위해 특허 데이터와 논문 데이터를 활용하여 태양광 에너지의 기술 동향을 파악하고 논의를 진행하였다. 분석방법으로는 토픽 모델링과 텍스트 마이닝을 활용하여 1997년도부터 2015년까지의 데이터를 토대로 기술 동향과 연구의 방향성에 대하여 분석한다. LDA알고리즘을 통하여 토픽을 선정하고, 선정된 기술 범주에 포함된 키워드의 증가량을 살펴보고, 태양광 기술의 발전방향에 대하여 분석하였다. 태양광 발전 기술에 대한 연구는 꾸준히 진행될 것으로 예상되며, 특히 고효율화 및 고성능화 기술에 대하여 집중적으로 연구가 이루어질 것으로 분석된다. 향후 연구로는 해외의 특허데이터와 다양한 논문데이터를 추가하여 연구를 진행할 수 있을 것이다.

• 한국태양에너지학회 논문집
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• 제31권1호
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• pp.51-58
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• 2011

The energy makes the basic element which improves the quality of life with motive power of industry and life. However, using the fossil fuel resources was restricted through it's abuse and exhaustion, and that cause a global warming resultingly. According to the reason, the world increased the interest that are stability and use of new and renewable energy which is clean energy with environment. Therefore, the property data of new and renewable is needed for developing and supplying the energy. In other words, the data of new and renewable energy becomes the standards for supply and evaluation of new and renewable energy with development of industry and technology. Also, the necessity came to the fore as the reference and standards of new and renewable energy data. Therefore, in this study, we evaluate and collect the solar radiation data as the new and renewable data and process the collected data through the standards for valuation. We evaluate uncertainty with standards which are NREL, WMO, and GUM. Whereby the data becomes reference standards data and gains the credibility. For the reliability data, we correct the measuring instrument with correction period. Using the DQMS and SERI QC, we efficiently manage and evaluate the solar radiation data. As a result, we evaluate uncertainty as 1,120 case about 16 area. we achieve credibility of data from evaluated solar radiation data and provide an accurate information to user. The annual average of horizontal radiation presents between 1,484 and 4,577, then the uncertainty evaluates from 163 to 453. The error of uncertainty presents smaller than the measurement values. So, we judge a credibility of data by expression of reliability quantitatively. In additional, the reference standards data which is possible to approach anywhere will be used for the supporting related industry and policy making.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2007년도 동계학술발표대회 논문집
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• pp.416-422
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• 2007

The application analysis of bubble pump on the domestic solar water heater system is presented. The system investigated in this study is a passive device, self pumping and self regulating. It was test to use the bubble pump on solar water heater system. The test experiment has been taken on the existed vacuum tube about the efficiency, working fluid temperature and pressure and circulated power. In order to check the working temperature and working pressure effectively, the bubble pump was test separated from the solar water heater. The equipment consists of the bubble pump, heater and heat exchanger. The main structure of bubble pump was design depend on the character of two phase flow. The complete system was instrumented to measure pressures, temperatures and their relationship with the solar radiation intensity. The theory analysis of design bubble pump has been given and the experiment result analysis has been included in the paper.

• 한국산업융합학회 논문집
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• 제26권4_2호
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• pp.715-724
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• 2023

Solar energy forecasting is essential for (1) power system planning, management, and operation, requiring accurate predictions. It is crucial for (2) ensuring a continuous and sustainable power supply to customers and (3) optimizing the operation and control of renewable energy systems and the electricity market. Recently, research has been focusing on developing solar energy forecasting models that can provide daily plans for power usage and production and be verified in the electricity market. In these prediction models, various data, including solar energy generation and climate data, are chosen to be utilized in the forecasting process. The most commonly used climate data (such as temperature, relative humidity, precipitation, solar radiation, and wind speed) significantly influence the fluctuations in solar energy generation based on weather conditions. Therefore, this paper proposes a hybrid forecasting model by combining the strengths of the Prophet model and the GRU model, which exhibits excellent predictive performance. The forecasting periods for solar energy generation are tested in short-term (2 days, 7 days) and medium-term (15 days, 30 days) scenarios. The experimental results demonstrate that the proposed approach outperforms the conventional Prophet model by more than twice in terms of Root Mean Square Error (RMSE) and surpasses the modified GRU model by more than 1.5 times, showcasing superior performance.

• Journal of Biosystems Engineering
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• 제38권1호
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• pp.41-47
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• 2013

Purpose: The objectives of this study were to construct the solar drying system with evacuated tubular solar collector and to investigate its performance in comparison with indoor and outdoor dryings. Methods: Solar drying system was constructed with using CPC (compound parabolic concentrator) evacuated tubular solar collector. Solar drying system is mainly composed of evacuated tubular solar collector with CPC reflector, storage tank, water-to-air heat exchanger, auxiliary heater, and drying chamber. Performance test of solar drying system was conducted with drying of agricultural products such as sliced radish, potato, carrot, and oyster mushroom. Drying characteristics of agricultural products in solar drying system were compared with those of indoor and outdoor ones. Results: Solar drying system showed considerable effect on reducing the half drying time for all drying samples. However, outdoor drying was more effective than indoor drying on shortening the half drying time for all of drying samples. Solar drying system and outdoor drying for oyster mushroom showed the same half drying time. Conclusions: Oyster mushroom could be dried easily under outdoor drying until MR (Moisture Ratio) was reached to about 0.2. However, solar drying system showed great effect on drying for most samples compared with indoor and outdoor dryings, when MR was less than 0.5.

• 반도체디스플레이기술학회지
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• 제10권2호
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• pp.1-5
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• 2011

In recent years, worldwide production of solar wafers increased rapidly. Therefore, the solar wafer technology in the developed countries already has become an industry, and related industries such as solar wafer manufacturing equipment have developed rapidly. In this paper we propose the color classification method of the polycrystalline solar wafer that needed in manufacturing equipment. The solar wafer produced in the manufacturing process does not have a uniform color. Therefore, the solar wafer panels made with insensitive color uniformity will fall off the aesthetics. Gaussian mixture models (GMM) are among the most statistically mature methods for clustering and we use the Gaussian mixture models for the classification of the polycrystalline solar wafers. In addition, we compare the performance of the color feature vector from various color space for color classification. Experimental results show that the feature vector from YCbCr color space has the most efficient performance and the correct classification rate is 97.4%.

• 한국산업융합학회 논문집
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• 제26권6_1호
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• pp.1001-1010
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• 2023

To solve the problem that photovoltaic panels can not harvest electrical energy at a cloudy day and night, a floating solar thermoelectric generator (FSTEG, hereafter) is studied. The FSTEG is consisted of a dome shaped Fresnel lens to condense solar energy, a thermoelectric module connected with a heat sink to keep temperature difference, a floating system simulating a wavy ocean and an electrical circuit for energy storage. The dome shaped Fresnel lens was designed to have 29 prisms and its optical performance was evaluated outdoors under natural sunlight. Four thermoelectric modules were electrically connected and its performance was evaluated. The generated energy w as stored in a Li-ion battery by using a DC-DC step-up converter. For the application of ocean environment, the FSTEG was covered by the dome shaped Fresnel lens and sealed to float in a water-filled reservoir. The harvested energy shows a potential and a method that the FSTEG is suitable for the energy generation in the ocean environment.

• 무역학회지
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• 제41권2호
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• pp.185-202
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• 2016

온실가스 감축 의무와 방사능 유출 우려 등으로 각국의 신·재생에너지에 대한 관심이 높아지고 있다. 그 중에서도 태양광은 가장 현실적인 에너지로 주목받고 있으며, 세계 시장의 수요가 증가함에 따라 한국 태양광 산업의 해외진출 및 무역요인에 관한 체계적 분석이 필요하다. 본 연구에서는 한국과 태양광 제품을 거래하는 11개국을 대상으로 1990년부터 2014년까지 총 25년간의 패널데이터를 연구하여 보았다. 중력모형을 중심으로 분석을 시행하였으며, 분석결과 한국의 태양광 제품은 일반적으로 중력모형과 일치하는 것으로 나타났다. 그러나 경제규모와 거리 이외의 요인에서는 각각 다른 결과가 도출되었다.

• 디지털산업정보학회논문지
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• 제12권3호
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• pp.231-257
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• 2016

Several efforts to replace the use of existing fossil energy resources have already been made around the world. As a result, a new industry of renewable energy has been created, and efficient energy distribution and storage has been promoted intensively. Among the newly explored renewable energy sources, the most widely used one is solar energy generation, which has a high market potential. An energy storage system (ESS) is a system as required. In this paper, the design and implementation of an ESS for the efficient use of power in stand-alone street lights is presented. In current ESS applied to stand-alone street lights, either 12V~24V DC (from solar power) or 110V~220V AC (from commercial power) is used to recharge power in systems with lithium batteries. In this study, an ESS that can support both solar power and commercial power was designed and implemented; it can also perform emergency recharge of portable devices from solar powered street lights. This system can maximize the scalability of ESSes using lithium batteries with efficient energy conversion, with the advantage of being an eco-friendly technology. In a ripple effect, it can also be applied to smart grids, electric vehicles, and new, renewable storage markets where energy storage technology is required.

• 태양에너지
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• 제11권3호
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• pp.84-88
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• 1991

본 내용에서는 대체에너지 이용기술개발 및 실용화를 위해 국책 사업으로 추진하는 정부의 의지와 함께 국내에 보급되고 있는 태양열 이용 시스템의 가장 중요한 구성요소인 집열기와 온수기에 대한 취급업체 현황 및 종류를 분류 정리하여 에너지 자원을 거의 수입에 의존하고 있는 국내 실정을 감안 민간 업체에서도 태양에너지 분야에 대한 다각적인 검토와 적용이 이루어져 국가에너지 절약을 꾀함을 물론 국산화 개발과 실용화에 관련하여 기본적인 참고가 되도록 정리하는데 의의를 두었다.