• Korean Journal of Construction Engineering and Management
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• v.5 no.6 s.22
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• pp.80-89
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• 2004

Among the various factors influencing construction productivity, weather conditions or elements become very important factors in planning and executing construction project. It is especially true in Korea where the weather changes dramatically through few seasons. In this study, relationship between construction productivity of the reinforced concrete structure we for the high-rise apartment buildings and 5 weather elements including temperature, humidity, day time, rainfall, and wind velocity have been analyzed The results trough regression analysis showed that weather elements explain $58.8\%$ of productivity in total and temperature and day time were more important factors among them.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.3
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• pp.1111-1116
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• 2011

Heat exchangers have been used for the automotive, HVAC systems, and other various industrial facilities, so the market is very wide. In general, high-efficiency heat exchangers with louver fins are used in the dust-free environment while heat exchangers with wavy fins are used for dusty environment such as construction site, etc. In this study, numerical analysis has been performed for typical heat exchangers, used as oil coolers or fuel coolers, with dual cell model that can handle different grids for the air-side and oil-side of heat exchangers. First wind tunnel tests were conducted to obtain one-dimensional thermal performance data of heat exchangers. Then, heat release rates with varying air flows were numerically predicted using the three-dimensional dual-cell model. The model can greatly enhance the accuracy of thermal design since it includes the effects of nonuniformity of air flows across heat exchangers.

• Journal of the Korean Data and Information Science Society
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• v.26 no.3
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• pp.661-668
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• 2015

Them traffic accidents have been increased every year due to increasing of vehicles numbers as well as the gravitation of the population. The carelessness of drivers, many road weather factors have a great influence on the traffic accidents. Especially, the number of traffic accident is governed by precipitation, visibility, humidity, cloud amounts and temperature. The purpose of this paper is to analyse the effect of road weather factors on traffic accident. We use the data of traffic accident, AWS weather factors (precipitation, existence of rainfall, temperature, wind speed), time zone and day of the week in 2013. We did statistical analysis using logistic regression analysis and decision tree analysis. These prediction models may be used to predict the traffic accident according to the weather condition.

• Journal of the Korean Data and Information Science Society
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• v.27 no.3
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• pp.577-586
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• 2016

Hazardous air pollution caused by heavy metals in the air is at a serious level. Although manganese(Mn), one of the heavy metals, is a non-carcinogenic substance, it has a harmful influence on the human body. It is partially measured because automatic monitoring technologies have not yet be fully established. We introduced a statistical model for the daily concentration of manganese. Incorporating a linkage between Mn and meteorology, the proposed model is formulated in way to identify meteorological effects and to allow for seasonal trends, enabling not only accurate measurement of manganese concentration, but also information about the evaluation on a Hazard Quotient (non-cancer risk).

• Journal of the Korean Solar Energy Society
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• v.37 no.6
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• pp.25-37
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• 2017

A study on factors influencing measurement error of Ground-based LiDAR(Light Detection And Ranging) system was conducted in Kimnyeong wind turbine test site on Jeju Island. Three properties of wind including inclined angle, turbulence intensity and power law exponent were taken into account as factors influencing the measurement error of Ground-based LiDAR. In order to calculate LiDAR measurements error, 2.5-month wind speed data collected from LiDAR (WindCube v2) were compared with concurrent data from the anemometer on a nearby 120m-high meteorological mast. In addition, data filtering was performed and its filtering criteria was based on the findings at previous researches. As a result, at 100m above ground level, absolute LiDAR error rate with absolute inclined angle showed 4.58~13.40% and 0.77 of the coefficients of determination, $R^2$. That with turbulence intensity showed 3.58~23.94% and 0.93 of $R^2$ while that with power law exponent showed 4.71~9.53% and 0.41 of $R^2$. Therefore, it was confirmed that the LiDAR measurement error was highly affected by inclined angle and turbulence intensity, while that did not much depend on power law exponent.

• Journal of the Korean Data and Information Science Society
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• v.28 no.6
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• pp.1437-1445
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• 2017

This paper suggests a temperature guidance which must be addressed in the preparation of specifications for military equipment used in ocean/coastal environment of the Korean peninsula. It would often be costly to design materiel to operate under the most extreme environmental conditions ever recorded. Therefore, military planners usually accept equipments designed to operate under environmental stresses for all the time except a certain small percentage of the time. In this study, an 1-percent frequency of occurrence is recommended. Pohang and Shineiju are chosen to represent the hottest and coldest regions, respectively, based on surface weather observations among 28 costal regions from 1904 to 2015. The 1st and 99th percentile temperatures for Pohang and Shineiju are $37.7^{\circ}C$ and $-23.7^{\circ}C$, respectively. Diurnal cycles, including solar radiation, relative humidity and wind-speed are also provided.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.3
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• pp.156-162
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• 2004

In this paper, a technique that estimate the optimal capacity of the solar-wind hybrid power system for minimizing the total monthly electric power expenses is presented. The hybrid power system is assumed to be operated in connection with the utility power system and electric bill be paid for the power not covered by the hybrid system generation. Monthly generation cost is estimated based on total life-cycle cost analysis. The monthly utility power bill is assumed to be increased quadratically in proportion with the net utility power consumption which is the difference between the total monthly load minus the hybrid system generations. Test results demonstrate applications potential of the proposed technique.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.8
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• pp.905-911
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• 2012

To establish a floating offshore wind turbine simulation model, a tension leg platform is added to an onshore wind turbine. The wind load is calculated by using meteorological administration data and a power law that defines the wind velocity according to the height from the sea surface. The wind load is applied to the blade and wind tower at a regular distance. The relative Morison equation is employed to generate the wave load. The rated rotor speed (18 rpm) is applied to the hub as a motion. The dynamic behavior of a 2-MW floating offshore wind turbine subjected to the wave excitation and wind load is analyzed. The flexible effects of the wind tower and the blade are analyzed. The flexible model of the wind tower and blade is established to examine the natural frequency of the TLP-type offshore wind turbine. To study the effect of the flexible tower and blade on the floating offshore wind turbine, we modeled the flexible tower model and flexible tower-blade model and compared it with a rigid model.

• Journal of the Korean Society of Marine Environment & Safety
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• v.13 no.1 s.28
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• pp.69-73
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• 2007

As the interest in environmental pollution increases, the use of renewable energy is uprising. Among the renewable energy resources, wind and solar energy have no environmental impact and they can be used as unlimited resources. The two power systems are mutual supplementary systems. So the two systems are usually combined for generation. We have measured several data about wind and solar. These data can be used the foundation data for the construction of wind and solar power generation plants. Also we analyzed the possible optimal solar power system for 10[kW] wind power.

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.1
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• pp.59-65
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• 2013

In recent years, the crisis of energy is growing seriously and also the contamination of ecology has been reverberated as international problem. The social concerns on energy crisis have been growing for the last several years and also the interests in new and renewable energy have been increased. Therefore, in order to solving these problems, as solution of one, this paper is investigated using the aeration system at the fish farm, etc from nature energy such as wind power. This study suggests the fundamental data of designing for these similar apparatus and examines the parameters of wind velocity and wind receiving area. Especially, the water outlet position was mainly investigated with optimum outlet angle of wind pump.