• KOREAN JOURNAL OF CROP SCIENCE
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• v.68 no.4
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• pp.313-326
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• 2023

Owing to adverse weather conditions, there is a heightened focus on actively researching the regulation of the sowing date in field crop cultivation. Soybean, a prominent field crop with extensive acreage and production, is a photophilic and thermophilic crop characterized by short-day photoperiodism. Identifying the optimal sowing time is crucial for mitigating the effects of severe weather conditions on soybean yield. Precise control over the timing of soybean sowing is the key to minimizing yield reduction due to unfavorable weather conditions. Temperature, photoperiod, and their interplay are the most significant factors influencing soybean cultivation among various weather factors. We conducted an experiment using three Korean soybean cultivars with varied maturities (Hwangkeumol: early maturing and Daewonkong and Pungsannamulkong: late maturing) in 2013 and 2014. Our investigation covered aspects of soybean growth, development, yield components, isoflavones, and visual seed quality. Across all three varieties, isoflavone levels increased with later sowing dates, while other measured components exhibited significant variations based on the sowing date. This study also provides valuable insights for the selection of suitable cultivars that perform well in soybean cultivation at various durations of maturity.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.1364-1366
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• 2002

The Photovoltaic(PV) generation system is a promising source of energy for the future. Since the need for renewable energy has been increased, the research of PV generation system has also been progressed. Recently, cost down of PV generation system has been accomplished and practical technologies of the solar energy developed, Moreover, grid connected PV generation system are becoming actual and general. Operational technology of the grid connected PV generation system is being a hot issue. Power output of PV system is directly affected by wether conditions. When AC power supply is needed, power conversion by an inverter and a MPPT control are necessary. In this paper, for stability improvement of PV generation system. Active filter(AF) function is added to PV generation system, and simulations of PV-AF system under various weather conditions are performed.

• Proceedings of the KIEE Conference
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• 2000.11a
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• pp.52-54
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• 2000

In PV power generation system study, huge system apparatuses are needed in order to verify the effect of system efficiency and stability considering the size of solar panels, the sort of converter types, and the load conditions and so on. And also, under the same weather and load conditions it is impossible to compare a certain MPPT control scheme to others. In this paper, in order to obtain effective solutions for the above mentioned topics, the solar cell array is simulated with it's VI characteristic equations, and the real field data of weather conditions is interfaced to EMTDC using Fortran program interface method. Consequently the simulation of PV power generation system using field data is realized in this paper, and acceptable results, which show close match between the real data of PV panel and the simulated data, were obtained.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.11a
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• pp.153-154
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• 2023

In this study, analyzed the difference in compressive strength of concrete under cold conditions, using the 28-day standard curing compressive strength as a reference and examining variations based on cement types and curing temperatures. The results showed that the strength difference based on curing temperatures reached up to 9MPa at 0℃. However, as the curing period progressed, the difference in strength due to curing temperature gradually diminished. These findings are anticipated to be valuable for concrete mixing and quality control in cold weather conditions.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.05a
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• pp.220-221
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• 2014

The various type of polymer such as silicone, modified silicone, polyurethane, etc are being used in domestic construction sealant market. Once sealant is installed in building, it should maintain their specific performances such as preventing moisture, rain, air, etc against environment conditions for several decades. In this study, weather resistance as per polymer type of sealant has been evaluated using QUV accelerated weathering tester. As a result, weather resistance of silicone is highest and modified silicone is lowest in the comparison of other type of polymer.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2003.05a
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• pp.13.2-17
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• 2003

When fresh concrete is exposed to low temperature, the concrete may suffer frost damage due to freezing at early ages and strength development may be delayed. One of the solution methods to resolve these problems is to lower freezing temperature of concrete by the use of chemical admixture called Accelerators for Freeze Protection. In this study, it was the results of appling cold weather concrete using Accelerator for Freeze Protection in the Daewoo Trump world field. Before the application of the cold weather concrete using accelerator for freeze protection, we executed the some test in the laboratory and mock-up test in the field. We examined the manifestation of compressive strength complying with the amount of Accelerators for Freeze Protection and curing conditions, and then made a selection of most suitable amount of Accelerators for Freeze Protection.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.14 no.11
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• pp.897-906
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• 2002

Standard temperature and absolute humidity weather correlations of Seoul for dynamic energy simulation have been developed regressing the measured data compiled by the Korea Meteorological Adminstration during a 10-year period from 1991 to 2000. The mathematical equations can generate the daily and yearly variations of outdoor weather data with consistency unlike the measured data which may show abnormal behavior, Considering that each hour of the day follows a certain yearly pattern, the correlations are developed for each hour. The derived 24 simple mathematical equations can be used for estimating outdoor temperature and humidity conditions for any arbitrary time of the year.

• KIEAE Journal
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• v.9 no.5
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• pp.39-46
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• 2009

Most Plastic Green Houses in Korea are made according the European weather condition, which lead to have very low solar energy efficiency. Moreover, the function of green houses, as well as the structure of them, has not changed for Korean weather condition. Therefore, the structure and function of them should adopt the regional weather condition in order to improve the energy efficiency. This paper investigates the current plastic green housesin Korea, and presents an alternative for improving the energy efficiency. The elements of green houses were investigated. When using a partial opaque insulation with a thermal storage body, the difference of indoor air temperature became 20C during daytime, and 5C during night, which will save massive fossil fuels.

• International Journal of Air-Conditioning and Refrigeration
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• v.11 no.4
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• pp.199-208
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• 2003

Standard temperature and absolute humidity weather data correlations of Seoul for dynamic energy simulation have been developed regressing the measured data compiled by the Korea Meteorological Adminstration during a l0-year period from 1991 to 2000. The mathematical equations can generate consistent daily and yearly variations of outdoor weather data unlike the measured data which may show abnormal behavior. Considering that each hour of the day follows a certain yearly pattern, 24 correlations are developed for each hour of the day. The derived simple mathematical equations can be used for estimating outdoor temperature and humidity conditions for any arbitrary time of the year.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.55 no.7
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• pp.273-280
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• 2006

This paper suggests the method that forecasts Dynamic Line Rating (DLR). Thermal Overload Risk Probability (TORP) of the next time is forecasted based on the present weather conditions and DLR value by Monte Carlo Simulation (MCS). To model weather elements of transmission line for MCS process, this paper will propose the use of statistical weather models that time series is applied. Also, through the case study, it is confirmed that the forecasted TORP can be utilized as a criterion that decides DLR of next time. In short, proposed method may be used usefully to keep security and reliability of transmission line by forecasting transmission capacity of the next time.