• Atmosphere
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• v.18 no.2
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• pp.137-146
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• 2008

This study examines one thermal index, perceived temperature (PT), over the Korean Peninsula during 2007 summer. Heat/cold stress has been described using air temperature and humidity for warm seasons and air temperature and wind velocity in the cold conditions, while PT is based on a heat budget model of the human body that considers air temperature, humidity, wind velocity and radiation effect regardless of climates, regions and seasons. PT is higher about $4-5^{\circ}C$ than air temperature in the summer. Humidity increases PT, while wind tends to reduces PT possibly by evaporation of water vapor. The geographical distribution of summer PT indicates that the lowest PT happened in the east central region, with the appearance of the highest PT in the inland of southern region in Korea. Although the latitudinal trend shows that PT decreases northward, inland PT is higher than that of coastal region. Compared to the heat index or the discomfort index that considers air temperature and humidity, PT represents distinctive regional characteristics of thermal comfort. The distribution of PT shows that it may be a useful thermal index for the assessment of thermal comfort or stress region in the Korean Peninsula.

• Atmosphere
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• v.24 no.2
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• pp.265-281
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• 2014

Currently, Korea is developing a Cheollian follow-on satellite program, named as Geostationary Korea Multipurpose Satellite 2 (GK-2), which consists of two satellites. One satellite (GK-2A) is dedicated to the meterological mission, while the second one (GK-2B) hosts two main payloads for the ocean and environmental application. As GK-2A is dedicated to the meteorological mission unlike Cheollian, there have been discussions on the possibility of transferring the responsibilities of the GK-2A program to the Korea Meteorological Administration. To help resolve any consumptive disputes or to find an efficient way for the GK-2A program, the events happened after the successful launch of the first meteorological satellite TIROS-1 in the U.S. in April 1960 are investigated. With the successful demonstration of usefulness of TIROS-1 for the meteorological applications, organizations such as the Weather Bureau and the Department of Defense, responsible for the real time application of the TIROS 1 data, strongly requested for an operational meteorological satellite program which resulted in the plan for the National Operational Meteorological Satellite System (NOMSS). The plan was strongly supported by Kennedy Adminstration and was put forwarded for the new program under the responsibility of Weather Bureau to the Congress. However, the responsible Committee on Science and Aeronautics sided with NASA and requested major revision of the responsibility. Due to many unfavorable conditions, Weather Bureau accepted the requests and signed with NASA on the agreement for the operational meteorological satellite. However, with the delay of Nimbus satellite which is planned to be used for the prototype of the operational satellite and changes of the unfavorable situations, the Weather Bureau could draw a second agreement with NASA. The new agreement reflected most propositions requested by the Weather Bureau for the NOMSS plan. Until now the second agreement is regarded as the basic principles for the operational meteorological satellite program in the U.S. This study investigates the backgrounds and processes of the second agreement and its implications for the GK-2 program.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.11
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• pp.1988-1993
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• 2008

Photovoltaic (PV) modules operate over a large range of conditions but manufacturer's information is not sufficient to determine their overall performance. Designers need a reliable tool to predict energy production from a photovoltaic module under all conditions in order to make a sound decision. The modeling method of photovoltaic (PV) module are useful to perform detailed analysis of PV system performance for changing meteorological conditions, verify actual rated power of PV system sizing and determine the optimal design of PV system and components. This paper indicates a modeling approach of PV module performance in terms of meteorological conditions and identifies validity of PV modules modeling by comparing measured with simulated value.

• Journal of the Korea Institute of Military Science and Technology
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• v.13 no.2
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• pp.320-327
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• 2010

The IR signature data of a ship is mainly affected by location, meteorological conditions(atmosphere temperature, wind direction and velocity, humidity etc.), atmospheric transmittance, solar position and ship surface temperature etc. The IR signatures received by a remote sensor at a given temperature and wavelength region is consisted of the self-emitted component directly from the object surface, the reflected component of the solar irradiation at the object surface, and the scattered component by the atmosphere without ever reaching the object surface. Computer simulations for prediction of the IR signatures of ships are very useful to examine the effects of various sensor positions. In this paper, we have acquired the IR signature for different sensor positions by using computer program for prediction of the IR signatures. The numerical results show that the IR signature contrast as compared to the background sea considering the meteorological conditions, solar and sky irradiations.

• Nuclear Engineering and Technology
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• v.16 no.3
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• pp.136-140
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• 1984

A new medal is presented in order to evaluate the risk from a nuclear facility following accidents directly combining the on-site meteorological data using the Monte Carlo Method. To estimate the radiological detriment to the surrounding population-at-large (collective dose equivalent), in this study the probability distribution of each meteorological element based upon on-site data is analyzed to generate atmospheric dispersion conditions. The random sampling is used to select the dispersion conditions at any given time of effluent releases. In this study it is considered that the meteorological conditions such as wind direction, speed and stability are mutually independent and each condition satisfies the Markov condition. As a sample study, the risk of KNU-1 following the large LOCA was calculated, The calculated collective dose equivalent in the 50 mile region population from the large LOCA with 50 percent confidence level is 2.0$\times$10$^2$ man-sievert.

• Atmosphere
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• v.25 no.4
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• pp.611-622
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• 2015

Heavy rainfall ($>30mm\;hr^{-1}$) over the Korean Peninsula is examined in order to understand thermo-dynamic characteristics of the atmosphere, using radiosonde observational data from seven upper-air observation stations during the last 17 years (1997~2013). A total of 82 heavy rainfall cases during the summer season (June-August) were selected for this study. The average values of thermo-dynamic indices of heavy rainfall events are Total Precipitable Water (TPW) = 60 mm, Convective Available Potential Energy (CAPE) = $850J\;kg^{-1}$, Convective Inhibition (CIN) = $15J\;kg^{-1}$, Storm Relative Helicity (SRH) = $160m^2s^{-2}$, and 0~3 km bulk wind shear = $5s^{-1}$. About 34% of the cases were associated with a Changma front; this pattern is more significant than other synoptic pressure patterns such as troughs (22%), migratory cyclones (15%), edges of high-pressure (12%), typhoons (11%), and low-pressure originating from Changma fronts (6%). The spatial distribution of thermo-dynamic conditions (CAPE and SRH) is similar to the range of thunderstorms over the United States, but extreme conditions (supercell thunderstorms and tornadoes) did not appear in the Korean Peninsula. Synoptic conditions, vertical buoyancy (CAPE, CIN), and wind parameters (SRH, shear) are shown to discriminate among the environments of the three types. The first type occurred with high CAPE and low wind shear by the edge of the high pressure pattern, but Second type is related to Changma front and typhoon, exhibiting low CAPE and high wind shear. The last type exhibited characteristics intermediate between the first and second types, such as moderate CAPE and wind shear near the migratory cyclone and trough.

• Journal of the Society of Naval Architects of Korea
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• v.42 no.6 s.144
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• pp.679-685
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• 2005

Until now, the stealth design to reduce the infrared signature of ship haven't been carried out using the proper design criteria. The study on the maritime meteorological environment in the Korean seas hasn't been accomplished yet, so the design criteria of the maritime meteorological environment was just given by the engineering sense without experience of the Navy and/or of the shipyard. Even in rather good conditions(summer condition), the estimated IR signature of a ship showed larger values and couldn't predict the worst condition during the operation of a ship at sea. In this study, domestic maritime meteorological data were collected and variables affecting the IR signature of a ship had been derived through the sensitivity study of IR signature according to the maritime meteorological environment in Korean seas. The basic study on the criteria of the stealth design of IR signature has been carried out.

• Wind and Structures
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• v.13 no.6
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• pp.519-528
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• 2010

A meteorological model, RAMS, and a commercial computational fluid dynamics (CFD) model, FLUENT are combined as a one-way off-line nested modeling system, namely, RAMS/FLUENT system. The system is experimentally applied in the wind simulation over a complex terrain, with which numerical simulations of wind field over Foyeding weather station located in the northwest mountainous area of Beijing metropolis are performed. The results show that the method of combining a meteorological model and a CFD model as a modeling system is reasonable. In RAMS/FLUENT system, more realistic boundary conditions are provided for FLUENT rather than idealized vertical wind profiles, and the finite volume method (FVM) of FLUENT ensures the capability of the modeling system on describing complex terrain in the simulation. Thus, RAMS/FLUENT can provide fine-scale realistic wind data over complex terrains.

• Smart Structures and Systems
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• v.32 no.2
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• pp.83-99
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• 2023

The temperature prediction approaches of three important locations in an operational longitudinal slab track-bridge structure by using three typical neural network methods based on the field measuring platform of four meteorological factors and internal temperature. The measurement experiment of four meteorological factors (e.g., ambient temperature, solar radiation, wind speed, and humidity) temperature in the three locations of the longitudinal slab and base plate of three important locations (e.g., mid-span, beam end, and Wide-Narrow Joint) were conducted, and then their characteristics were analyzed, respectively. Furthermore, temperature prediction effects of three locations under five various meteorological conditions are tested by using three neural network methods, respectively, including the Artificial Neural Network (ANN), the Long Short-Term Memory (LSTM), and the Convolutional Neural Network (CNN). More importantly, the predicted effects of solar radiation in four meteorological factors could be identified with three indicators (e.g., Root Means Square Error, Mean Absolute Error, Correlation Coefficient of R2). In addition, the LSTM method shows the best performance, while the CNN method has the best prediction effect by only considering a single meteorological factor.

• Atmosphere
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• v.20 no.1
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• pp.1-12
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• 2010

Temporal distributions and characteristics of PWV (Precipitable Water Vapor) and LWP (Liquid Water Path) are investigated by using the microwave radiometric profiler at Haenam NCIO from 1 August 2007 to 31 July 2008. Temporal variations of PWV are closely connected with the thermal response of water vapor in atmosphere. The variations of LWP are characterized by the rainfall variation being basically attributable to the heavy rain-bearing clouds. The frequency distributions of PWV and LWP according to the four sky conditions ('clear', 'lightly cloudy', 'cloudy', and 'deeply cloudy') by total cloud amount at Wando Observatory corresponds with a change of slope in cumulative distribution function for PWV and LWP. There results implies that the classification of sky condition can be applied by using the distribution of PWV and LWP from microwave radiometric profiler.