• Proceedings of the Korean Institute of Building Construction Conference
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• 2010.05a
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• pp.95-97
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• 2010

This study revealed unusual weather phenomena by comparing and analyzing monthly average temperature and amount of snowfall for the past 10 years, and, based on the weather phenomena, analyzed damage cases of concrete structures in winter. As a result, the temperature for the recent one year became greatly low compared with the monthly average for the past 10 years, and the snowfall increased by 4-5 times compared with the past, so that the frost damage of concrete structures also greatly occurred. Accordingly, in case of concrete construction, because there may occur various variables owing to abnormal weather conditions, it is required that thorough quality control should be performed even from the stage of construction plan, execution and maintenance.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.5B
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• pp.267-272
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• 2012

To reduce the flood risk caused by unexpected heavy rainfall, many prediction methods for flood have been developed. A major constituent of flood prediction is an accurate rainfall estimation which is an input of hydrologic models. In this study, a regional-scale weather model which can provide relatively longer lead time for flood mitigation compared to the Nowcasting based on radar system will be introduced and applied to the Chongmi river basin located in central part of South Korea. The duration of application of a regional weather model is from July 11 to July 23 in 2006. The estimated rainfall amounts were compared with observations from rain gauges (Sangkeuk, Samjook, and Sulsung). For this rainfall event at Chongmi river basin, Thomson and Kain-Frisch Schemes for microphysics and cumulus parameterization, respectively, were selected as optimal physical conditions to present rainfall fall amount in terms of Mean Absolute Relative Errors (MARE>0.45).

• Atmosphere
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• v.27 no.4
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• pp.467-481
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• 2017

A correction method of reflectivity in partial beam blockage (PBB) area is suggested, which is based on the combination of digital terrain information and self-consistency principle between polarimetric observation. First, the reflectivity was corrected by adding the radar energy loss estimated from beam blockage simulation using digital elevation model (DEM) and beam propagation geometry in standard atmosphere. The additional energy loss by unexpected obstacles and non-standard beam propagation was estimated by using the coefficient between accumulated reflectivity ($Z_H$) and differences of differential phase shift (${\Phi}_{DP}$) along radial direction. The proposed method was applied to operational S-band dual-polarization radar at Jindo and its performance was compared with those of simulation method and self-consistency method for six rainfall cases. When the accumulated reflectivity and increment of ${\Phi}_{DP}$ along radial direction are too small, the self-consistency method has failed to correct the reflectivity while the combined method has corrected the reflectivity bias reasonably. The correction based on beam simulation showed the underestimation. For evaluation of rainfall estimation, the FBs (FRMSEs) of simulation method and self-consistency principle were -0.32 (0.59) and -0.30 (0.57), respectively. The proposed method showed the lowest FB (-0.24) and FRMSE (0.50). The FB and FMSE were improved by about 18% and by 19% in comparison to those before correction (-0.42 and 0.70). We can conclude that the proposed method can improve the accuracy of rainfall estimation in PBB area.

• International Journal of Internet, Broadcasting and Communication
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• v.12 no.1
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• pp.130-136
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• 2020

There are many problems that occur currently in agriculture industries. The problems such as unexpected of changing weather condition, lack of labor, dry soil were some of the reasons that may cause the growth of the plants. Condition of the weather in local area is inconsistent due to the global warming effect thus affecting the production of the crops. Furthermore, the loss of farm labor to urban manufacturing jobs is also the problem in this industry. Besides, the condition for the plant like air humidity, air temperature, air quality index, and soil moisture are not being recorded automatically which is more reason for the need of implementation system to monitor the data for future research and development of agriculture industry. As of this, we aim to provide a solution by developing IoT-based platform along with the irrigation for increasing crop quality and productivity in agriculture field. We aim to develop a smart garden system environment which the system is able to auto-monitoring the humidity and temperature of surroundings, air quality and soil moisture. The system also has the capability of automating the irrigation process by analyzing the moisture of soil and the climate condition (like raining). Besides, we aim to develop user-friendly system interface to monitor the data collected from the respective sensor. We adopt an open source hardware to implementation and evaluate this research.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1081-1082
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• 2008

Photovoltaic (PV) power generation system has been widely studied as a clean and renewable power source. The purpose of this study is to keep the output power of photovoltaic cells maximum under any weather conditions. There are so many MPPT (Maximum Power Point Tracking) methods. P&O method has been used as a key MPPT method, both voltage and current coming out from PV array have to be feedback in the method. Thus, the system has a complex structure, and may fail to track MPP of PV array when unexpected weather conditions happen. In order to reduce the feedback components, POS MPPT control method was proposed by the authors. In this paper, the authors apply the POS MPPT control method to three phase PCS system. And the effectiveness of the proposed control scheme is demonstrated through PSCAD/EMTDC simulation.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.12 no.1
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• pp.11-18
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• 2000

On the 25th of November in 1997 winter season, unprecedented high waves were recorded at the southern part of Korea Peninsular. The significant wave heights over 4 m were recorded at Marado, Pusan and Ulrungdo successively with time lags. Seoguipo breakwaters which were under construction were damaged by the unexpected high waves. These unprecedented southerly high waves in winter seem to be caused by unusual development and traveling of low pressure. Weather charts and wave fields calculated by a numerical model were analyzed to examine the unusual development of these waves. Protection against the southerly high waves in winter must be considered in coastal constructions and structures.

• Agribusiness and Information Management
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• v.4 no.1
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• pp.13-23
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• 2012

Understanding climate change is not only complex but also extensive. Humanity has never embarked on such a huge challenge of trans-national scope: a problem that began in the past continues now and will be continuing for a long time in the future. Nepalese have also significantly felt the impact of global climate change. The scenarios of climate change indicate that the increased temperatures will cause snow-melt which will result in floods, droughts, and uneven weather patterns. The impact of such unexpected climate hazards and weather patterns have already been felt and will continue to be felt in Nepal. These climate change-induced hazards and risks particularly threaten the agriculture sector, which results in food insecurity and makes poor and vulnerable people face increasingly unanticipated impacts to their lives and wellbeing. This paper explores the climate vulnerability of the Nepalese in terms of their physical, social, economic and primarily agricultural losses due to the increasing impact of climate change. The paper argues the need for a timely adaptation of measures to maintain an environment suitable for agriculture and for the well-being of the population residing in the area.

• Nuclear Engineering and Technology
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• v.53 no.1
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• pp.244-252
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• 2021

Wind plays an important role in cases of unexpected radioactive pollutant dispersion, deciding distribution and concentration of the leaked substance. The accurate prediction of wind has been challenging in numerical weather prediction models, especially near the surface because of the complex interaction between turbulent flow and topographic effect. In this study, we investigated the characteristics of atmospheric dispersion of radioactive material (i.e. ¹³⁷Cs) according to the simulated boundary layer around the HANARO research nuclear reactor in Korea using the Weather Research and Forecasting (WRF)-Mesoscale Model Interface (MMIF)-California Puff (CALPUFF) model system. We examined the impacts of orographic drag on wind field, stability calculation methods, and planetary boundary layer parameterizations on the dispersion of radioactive material under a radioactive leaking scenario. We found that inclusion of the orographic drag effect in the WRF model improved the wind prediction most significantly over the complex terrain area, leading the model system to estimate the radioactive concentration near the reactor more conservatively. We also emphasized the importance of the stability calculation method and employing the skillful boundary layer parameterization to ensure more accurate low atmospheric conditions, in order to simulate more feasible spatial distribution of the radioactive dispersion in leaking scenarios.

• Publications of The Korean Astronomical Society
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• v.38 no.3
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• pp.111-123
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• 2023

In this study, quantitative analysis is attempted on data collected from Chilgapsan Observatory Star Park in Cheongyang-gun, Chungcheongnam-do. The aim of this experimental study in which quantitative analysis of the Astronomical Science Museum in Korea is conducted is to investigate its current situation and secure basic data. As of July 31, 2023, it has had 283,931 cumulative visitors in total. It had the largest number of visitors when it opened (2009 year), after which their number reduced steadily until the pandemic (COVID-19, 2020-2022). Recently, however, the number of visitors has increased. Generally, the number of visitors is highest in August (20.8%) and least in April (4.1%). The visit rate is higher on weekends (Saturday and Sunday) than on weekdays (Monday-Friday), and groups comprise only about 5.3% of the total number of visitors. Moreover, it can be confirmed that the number of visitors increases sharply during events. Finally, it was confirmed that the visit rate was unaffected by weather conditions. Considering these results, we propose the following strategies: 1) Establish a special program that reflects "the weekend effect." 2) Prepare a plan to attract group visitors during the weekdays using "the event effect." 3) Arrange alternative programs (e.g., experiential activities) that can be conducted indoors regardless of weather conditions. We think that our findings will help establish a roadmap for the direction the Astronomical Science Museum should take and aid in preparing a strategic foundation to preemptively respond to unexpected situations (e.g., pandemics).

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.567-570
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• 2007

Recent changes of the climate, which caused by global warming, have much effect world-widely. Korea also has struggled with these kinds of weather problems, and construction industry couldn't get away with them, either. However, the research, regarding to these problems, has not been quite settled, yet. Therefore, this study is to find out how the global warming can affect construction periods. As a result, we could recognize that changes of climate, which caused by global warming, also affects non-working days, too. This study is expected to be used as the data to find out the relationship between weather changes and domestic construction industry in the future.