• Journal of Korean Society for Geospatial Information Science
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• v.21 no.4
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• pp.73-81
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• 2013

Ordinary least squares (OLS) regression is the primary statistical method in previous studies for vegetation distribution patterns in relation to landform. However, this global regression lacks the ability to uncover some local-specific relationships and spatial autocorrelation in model residuals. This study employed geographically weighted regression (GWR) to examine the spatially varying relationships between NDVI (Normalized Difference Vegetation Index) patterns and changing trends of landform (elevation, slope) and solar intensity (insolation and duration of sunshine) in Mt Geum-gang of North-Korea. Results denoted that GWR was more powerful than OLS in interpreting relationships between NDVI patterns and landform/solar intensity, since GWR was characterized by higher adjusted R2, and reduced spatial autocorrelations in model residuals. Unlike OLS regression, GWR allowed the coefficients of explanatory variables to differ by locality by giving relatively more weight to NDVI patterns which are affected by local landform and solar factors. The strength of the regression relationships in the GWR increased significantly, by showing regression coefficient of higher than 70% (0.744) in the southern ridge of the experimental area. It is anticipated that this research output will serve to increase the scientific and objective vegetation monitoring in relation to landform and solar intensity by overcoming serious constraints suffered from the past non-GWR-based approach.

• 한국태양에너지학회:학술대회논문집
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• 2008.04a
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• pp.49-54
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• 2008

This study is to investigate an optimal size and position of PV system for apartment complex enough the electrical load matching analysis. The 4 types of arrangements of apartment buildings are considered as follows; ㅡtype, alternative ㅡtype, ㄱtype and ㅁtype. We assume that the studied site is composed of 9 buildings. Firstly, solar access evaluation of roof and facade in apartment buildings was performing with the hourly simulations of total received insolation on each surface considering the hading effect of buildings. Electrical load profile of typical Korean apartments was investigated for the lad matching analysis. To calculate an annual total PV output, we used MERIT program which is a sourly based load matching tool developed by ESRU. TRY weather data of Daejeon are applied for this analysis. Result shows that approximately 11% of total electric load of the site can be supplied by the PV system in the case of full installation of PV system at the whole south-face roof area of 9 buildings in this stuided apartment complex. Depending of a various installation option of roof and facade area, the possible ratio of PV supply in total electrical load varies from 9% to 42%. Among the 4 arrangement types, the ㅡ type revealed the best option for the maximum output of PV system.

• Solar Energy
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• v.18 no.3
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• pp.31-39
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• 1998

Selection of a right weather data set has been considered as one of important factors for a successful building energy audit process. A set of 30 year raw weather data base for six major cities has been developed to provide the weather data file for building energy audit and retrofit analysis in Korea. The program named as KWDP(KIER Weather Data Processor) uses the DB to produce a right data set for a specific building energy performance simulation program like DOE2.1E. A program called WMAKE has been developed to generate the right set of input parameters for DOE2.1E weather utility program. The set of the programs could provide the right weather data for specific building energy audit and retrofit analysis.

• Land and Housing Review
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• v.13 no.1
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• pp.113-129
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• 2022

A building's eco-friendliness is directly related to various values including the life cycle cost of a building. However, the conventional architectural design method has a limitation in that it cannot create an optimized case according to the surrounding environmental conditions. Therefore, the purpose of this research is to present a design assistance tool that can review planning cases optimized for the environmental conditions of the building site in the planning stage of architectural production. To achieve the purpose of the study, an algorithm for realizing 3D modeling of the region and analysis of the solar environment was produced based on the site contours, building, and road information from the digital topographic map provided by the National Geographic Information Institute. To examine the validity of the developed algorithm, a comparative experiment was conducted targeting the elevation direction of the existing building. As a result, it was found that the optimal elevation direction selected by the algorithm can receive higher insolation compared to the front facade of the main building.

• Korean Journal of Agricultural Science
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• v.49 no.4
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• pp.697-706
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• 2022

The effect of varied light intensities on the growth of daughter plants during propagation and after transplant to raised beds were examined in 'Sulhyang' strawberry. To this end, four treatments in controlling solar radiation inside a plastic house were made: 55% retractable shading and 35, 55, and 75% fixed shading. The plastic house was shaded only from 11:00 to 16:00 in June and 10:00 to 16:00 in July to September for the treatment of 55% retractable shading. The mean solar radiation inside the plastic house in the retractable 55% shading treatment was 317 W·m^-2 and those in the 35, 55, and 75% fixed shading treatments were 183, 165, and 116 W·m^-2, respectively, at 10 o'clock in the morning. The 55% and 75% fixed shading resulted in taller daughter plants with wider leaf areas than 55% retractable shading. The retractable shading also showed higher leaf numbers, crown diameters, root weights, and fresh weights compared to fixed shading treatments. Regarding the inorganic element contents, daughter plants grown under 75% fixed shading had 1.35% total nitrogen content followed by 1.19% in 35% fixed shading, 1.14% in 55% fixed shading, 1.14% in open culture, and 1.10% in 55% fixed shading. After 54 days following the transplant of daughter plants to a raised bed, the fresh weight of the aboveground part was the heaviest in the 55% retractable shading and non-shading treatments. The 75% fixed shading treatment had the lowest fresh weight of the aboveground plant parts. The results of this study could be used for the production of high-quality daughter strawberry plants.

• The Journal of Engineering Geology
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• v.33 no.3
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• pp.389-401
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• 2023

Climate, weather, insolation (solar radiation), and solar energy in major cities of Tajikistan were investigated prior to construction of infrastructure for the Dushanbe Solar Station. In Dushanbe city there was a 70% probability of sunny days from May 16 to October 23, a period of 5.2 months. August had the most sunny days of in the year, with 99% probability of a sunny, the cloudiest month was February with a 41% chance of being sunny. In major cities of the Sughd and Gorno-Badakhshan states, the average number of cloudy days per month was ~3.3, with Dzhauz having 53 day and Fedchnko Glacier 79 days. For the 18 major cities of Tajikistan, the average annual total solar radiation was 2,429 W/m², and the average monthly solar radiation was 202 W/m². The city with the lowest annual total and monthly average solar radiation was Shartuz in Sughd state, with values ~2.7% less than the national average. The cities with the highest annual total and monthly average solar radiation were Khorog and Jirgatol in Gorno-Badakhshan state, with values ~10% above the national average. The daily average incident shortwave solar energy in the cities Dushanbe, Karakul, and Jirgatol was ~7.8 kWh per 2.4 m² during summer (May-August), and 2.7 kWh during winter (November-February), or ~35% that of summer.

• Ocean Science Journal
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• v.42 no.4
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• pp.241-246
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• 2007

Northern Arabian Sea (NAS) between $17^{\circ}N-20.5^{\circ}N$ and $59^{\circ}E-69^{\circ}E$ was observed by using Argo float daily data fur about 9 months, from April 2002 through December 2002. Results showed that during April - May mixed layer shoaled due to light winds, clear sky and intense solar insolation. Sea surface temperature (SST) rose by $2.3^{\circ}C$ and ocean gained an average of 99.8 $Wm^{-2}$. Mixed layer reached maximum depth of about 71 m during June - September owing to strong winds and cloudy skies. Ocean gained abnormally low $\sim18Wm^{-2}$ and SST dropped by $3.4^{\circ}C$. During the inter monsoon period, October, mixed layer shoaled and maintained a depth of 20 to 30 m. November - December was accompanied by moderate winds, dropping of SST by $1.5^{\circ}C$ and ocean lost an average of 52.5 $Wm^{-2}$. Mixed layer deepened gradually reaching a maximum of 62 m in December. Analysis of surface fluxes and winds suggested that winds and fluxes are the dominating factors causing deepening of mixed layer during summer and winter monsoon periods respectively. Relatively big]h correlation between MLD, net heat flux and wind speed revealed that short term variability of MLD coincided well with short term variability of surface forcing.

• 한국신재생에너지학회:학술대회논문집
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• 2005.11a
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• pp.479-491
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• 2005

지구환경문제와 에너지 수급관계를 감안할 때, 청정 및 대체에너지 연구개발은 불가피하며, 그 중에서도 태양에너지는 대표적인 대안의 하나로 인식된다. 따라서 태양에너지의 적극적인 활용에 필요한 기초자료의 마련은 필수적이다. 태양에너지의 이용 및 관련 절약 기술에 필요한 태양에너지 자원(기상)에 대한 기술자료는 최소한 30년간의 측정 자료를 필요로 한다. 이들 자료에는 시간별 수평면전 일사량, 법선면 직달일사량 및 수평면 산란일사량은 물론 시간별 평균치로 운량, 기온, 습도 등이 포함된다. 이들 자료로부터 자료의 분포, 평균 및 최고, 최저값 등과 같은 기초자료들을 선별하여 관련 시스템 설계에서 요구하는 기준을 충족하여야 하는 것이다. 그러나 우리나라의 경우, 태양에너지 자원에 대한 정밀한 측정은 1982년 이후 수평면 전일사량, 1990년 이후에서나 법선면 직달일사량에 대하여 본격적으로 이루어진 실정으로, 자료의 표준화 및 신뢰성 확보에는 여전히 상당한 시간과 노력이 요구되는 실정이다. 지속적인 측정과 더불어 요구되는 것으로 측정자료의 가공기술을 들 수 있다. 즉, 측정자료의 품질평가 및 관리 기술, 미측정 또는 불량자료의 복원 기술 및 측정 지역외 자료의 추정을 위한 보간기술 등이다. 이와 같은 기초자료 및 기술에 관한 연구개발은 보다 구체적인 적용에 앞서 필수적으로 이루어져야 할 과제이다.

• Proceedings of the KIPE Conference
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• 2004.07a
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• pp.117-120
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• 2004

As the maximum power operating point (MPOP) of photovoltaic (PV) power generation systems changes with varying atmospheric conditions such as solar radiation and temperature, an important consideration in the design of efficient PV system is to track the MPOP correctly. Although the efficiency of these Maximum Power Point Tracking algorithms is usually high, it drops noticeably in case of rapidly changing atmospheric conditions. This paper describes common MPPT control algorithm: Constant Voltage Control, Perturbation and Observation(P&O), Incremental Conductance (IncCnd) and proposes a new MPPT algorithm based on P&O algorithm. The conception and control principles of the proposed MPPT method are explained in detail and its validity of the proposed method is verified through several simulated results. As it doesn't use digital signal processor, this MPPT method has the merits of both a cost efficiency and a simple control circuit design. Therefore, it is considered that the proposed MPPT method is proper to low power, low cost PV applications.

• Proceedings of the KIPE Conference
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• 2003.11a
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• pp.271-274
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• 2003

In this paper, compare and analyze existent MPPT algorithms. Existent algorithms have defects which don't generate it in a partial shade or low insolation. Therefore, to supplement it, we design improved IncCond algorithm consisted of a Aux. switch and capacitor with Generation Control circuit which can always obtain maximum generation power at the factor which is reduced generational efficiency by partial shade. Generation Control circuit is method which can always get maximum output power as it regularly controls each voltage of serial connected solar cell. Accordingly, it can improve efficiency and confidence of utility interaction inverter. Construction of system use a low price PIC16F87X. We analyze special character according to system operation through simulation and prove the validity through experiments.