• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.3
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• pp.81-88
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• 2014

These days the researches using IT technologies have been done to decrease the traffic accident. Especially, the optimal safety speed considering the weather conditions have to be calculated in real time to protect the traffic accident on the high way in the case of the rain and snow. In this paper, we have simulated the automatic warning broadcasting system for the freezing and foggy regions based on Web to protect the traffic accident. Also, we have developed the simulator that can provide the drivers with the optimal safety speed in real time to protect the traffic accident even under the worst weather conditions using the Fuzzy Reasoning rules.

• International Journal of Air-Conditioning and Refrigeration
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• v.9 no.3
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• pp.18-26
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• 2001

Environmental chamber (EC) is an experimental facility used to analyze the characteristics of thermal response of testing objects by the artificial control of weather conditions. The EC in KIFR can simulate the weather conditions by the control of temperature, humidity, and solar radiation. A two-storied testing building is located inside EC. For the exact thermal response analysis of testing building, monthly or yearly scheduled operations are necessary. Although this long term operation gives the exact experimental data, it requires a high operational cost, long duration, and lots of manpower. Therefore it is necessary to perform the shortened experiments without sacrificing the validity of the obtained results. Since the characteristics of thermal response from the shortened experiments are different from the full time results, the analytical method to analyze the thermal response from the shortened experiments to estimate a full times results is developed in this study The thermal response of testing building is performed using commercial software TRNSYS.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.8
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• pp.131-137
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• 2004

The aim of this paper is to find the weather conditions which make the abnormal propagation of a radar bear In order to analyze the weather conditions which cause superrefraction or ducting, the meteorological data of the west sea and the south sea of Korea are classified which are observed during three years from 2000. Atmospheric indexes of refraction with increasing altitude are calculated and the rate of variation of temperature and hmidity at the altitude where the index is very low are observed. It is found that unwanted radar echoes by anomalous propagation are showed up only when the atmospheric indexes of refraction at a altitude is less than -150/km and the reverse layer of temperature appears with a sudden drop of humidity at the altitude.

• 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.

• Architectural research
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• v.17 no.2
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• pp.65-74
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• 2015

The habitual rooms and other structures related to everyday life are almost always grouped around the courtyard and together make up a house. There are many kinds of variety in types of courtyard houses depending on location, composition, allocation and relationship with inner space of the house. Every type of courtyard house accumulates many factors, which are social and economic circumstances, weather and geographical conditions. They are still well harmonized with life style and weather conditions in each area and basic unit of city organization. A courtyard can be shown as a place for everyday conversation like a community. Everyday space is the connective tissue that binds daily lives together, amorphous and so persuasive that it is difficult even to perceive. In spite of its ubiquity, everyday space is nearly invisible in the professional discourses of the city, like everyday life. Therefore Courtyards are special places that are outside yet almost inside, open to the sky, - a microcosm which gives relief to the inner rooms, gives the inhabitants a sense of ease and calm, and the feeling that they have their own piece of sky to use and protect them. This research will explore a variety of space use and dwelling types through courtyards based on field research and design projects.

• Journal of Satellite, Information and Communications
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• v.11 no.2
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• pp.65-68
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• 2016

In this paper, visible light wireless communication system according to the climate is studied in the marine environment. The light visibility can be determined by the different weather conditions (clear air, rain, storm, fog) in Kim's atmospheric channel model. By simulating the OOK-NRZ modulation technique, the BER performances are compared in the different weather conditions. In the field test, the error bit is measured in the visible-light communication. The effectiveness of visible light communication in the marine environment is confirmed by comparing the analysis of simulations and field experiments.

• Journal of the Korean Solar Energy Society
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• v.34 no.6
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• pp.57-65
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• 2014

Solar energy has attracted wide attention as a promising renewable energy source. The goal of this paper is to estimate the dynamic performance of solar flat plate collector system according to the weather conditions and the capacity of heat storage tank. This study provides a detailed description of the modeling methods and materials of the system. The effects of the daily clearness index and the volume of the heat storage tank on the hourly and daily performances of the system are numerically investigated. Special attention is focused on the important system variables including the solar insolation on the collector surface, useful energy, heat loss at the collector, and collector efficiency.

• Journal of the Optical Society of Korea
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• v.19 no.5
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• pp.437-443
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• 2015

In this paper, we analyze the performance of the all-optical multihop radio over a free space optical (RoFSO) communication system with amplify-and-forward (AF) relays under varying weather conditions. The proposed channel model considers the propagation loss, attenuation and atmospheric fading modeled by the Gamma-Gamma (GG) distribution. Both the amplified spontaneous emission (ASE) noise in the all-optical relays and the background noise projected onto receiver apertures have been considered in the analysis. The lower bound analytical expressions for the end-to-end bit error rate (BER) and outage probability are derived for the multihop system employing the all-optical relays with the full channel state information (CSI). Meanwhile, the exact results for BER and outage probability are obtained via Monte Carlo simulation. Results indicate the performance of the proposed system will be improved by the multihop transmission technology. For a fixed number of relays, the BER and outage probability will be increased with the deterioration of the weather conditions.

• Journal of the Korean Solar Energy Society
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• v.37 no.5
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• pp.1-11
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• 2017

A study on Nacelle Lidar (Light detection and ranging) measurement error and the data reliability verification was carried out at Haengwon wind farm on Jeju Island. For measurement data error processing, the characteristics of Nacelle Lidar measurements were analyzed by dividing into three parts, which are weather conditions (temperature, humidity, atmosphere, amount of precipitation), mechanical movement (rotation of wind turbine blades, tilt variation of Nacelle Lidar) and Nacelle Lidar data availability. After processing the measurement error, the reliability of Nacelle Lidar data was assessed by comparing with wind data by an anemometer on a met mast, which is located at a distance of 200m from the wind turbine with Nacelle Lidar. As a result, various weather conditions and mechanical movement did not disturb reliable data measurement. Nacelle Lidar data with availability of 95% or more could be used for checking Nacelle Lidar wind data reliability. The reliability of Nacelle Lidar data was very high with regression coefficient of 98% and coefficient of determination of 97%.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.11
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• pp.1647-1654
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• 2013

Detection performance of the vehicle on the road depends on weather conditions, the shadow by the movement of the sun, or illumination changes, etc. In this paper, a vehicle detection system in conjunction with a robust background estimate algorithm to environment change on the road in daytime is proposed. Gaussian Mixture Model is applied as background estimation algorithm, and also, Adaboost algorithm is applied to detect the vehicle for candidate region. Through the experiments with input videos obtained from a various weather conditions at the same actual road, the proposed algorithm were useful to detect vehicles in the road.