• Journal of Preventive Medicine and Public Health
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• v.33 no.3
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• pp.343-348
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• 2000

Objectives : This study was conducted to integrate the results of studies assessing the association between chronic noise exposure and blood pressure. Methods : Using a MEDLINE search with noise exposure, blood pressure and hypertension as key words, we retrieved articles from the literature that were published from 1980 to December 1999. The criteria for quality evaluation were as follows: 1) the study subjects must have been workers employed at a high noise level area 2) The paper should use average and cumulative noise exposure as method for exposure evaluation. 3) Blood pressure in each article should be reported in a continuous scale Among the 77 retrieved articles, six studies were selected for quantitative meta-analysis. Before the integration of the regression coefficients for the association between blood pressure and noise level, homogeneity tests were conducted. Results : All studies were a cross-sectional design and the study subjects were industrial workers. Five papers used a time-weighted average for noise exposure and only one paper calculated the cumulative noise exposure level. The measurement of blood pressure in the majority of studios were accomplished in a resting stale, and used an average of two or more readings. The homogeneity of studies was rejected in a fixed effect model, so we used the results in a random effect model. The results of the quantitative meta-analysis, the weighted regression coefficient of noise associated with systolic blood pressure and diastolic blood pressure were 0.05 (95% confidence interval [CI]: -0.03, 0.13) and 0.06 (95% CI: -0.01, 0.13), respectively. Conclusions : Our results suggested that chronic exposure to industrial noise does not cause elevated blood pressure.

• Journal of Korean Society of Steel Construction
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• v.19 no.6
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• pp.671-680
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• 2007

In this study, we performed a loading test to evaluate the effect of load distribution on continuous two-span plate-girder bridges with or without bottom lateral bracing using one-fifth-scale bridge specimens. From the test results, when specimens with lateral bracing were loaded eccentrically, the load distribution capacity of the concrete deck and cross beam improved and greater loading was distributed to the other side of the girder subjected to loading. The load distribution rate of the specimens with and without lateral bracing system was evaluated from the analytical model that was verified by the test results. From the result of the quantitative evaluation, when specimen without lateral bracing was loaded eccentrically, mostly 21% of loading according to the concrete deck was distributed to the other side of the girder subjected to loading. However, when specimen with lateral bracing was loaded eccentrically, the load distribution rate increased by 1.7 times as all cross beams, bracing and concrete deck participated in load distribution. The reason is that the torsional rigidity increased as the model with lateral bracing behaved like a pseudo-closed box section.

• Journal of Korea Water Resources Association
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• v.32 no.5
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• pp.579-591
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• 1999

The operation of a reservoir system is necessary for establishing the operation rule as well as designing the reservoirs for water resources planning or management. Increasingly complex water resource systems require more advanced operation techniques. As a result, various techniques have been introduced and applied until now. In this study Linear Tracking model based on optimal control theory is applied to the operation of the largest scale multi-reservoir system in the Han river and its applicability proved. This system normally supplies the water resources required downstream for hydro-power and plays a role in satisfying the water demand of the Capital region. For the optimal use of the water resources the Linear Tracking model is designed with the objective to maximize the hydro-power energy subject to the water supply demand. The multi-reservoir system includes the seven main reservoirs in IIan river such as Hwachon, Soyanggang, Chunchon, Uiam, Cheongpyong, Chungju and Paldang. These reservoirs have been monthly operated for the past 21 years. Operation results are analyzed with respect to both hydro"power energy and water supply. Additionally the efficiency of the technique is assessed.sessed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.11
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• pp.19-26
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• 2019

To construct buildings on limited land, the size of the building is important. The development process needs to be minimized because determining the size of a structurally safe building at the planning stage incurs considerable time and cost. This study proposes the Limit Slenderness Ratio Approximation Equation. This study examined an outrigger structure system among several systems proposed for controlling the lateral displacement in tall buildings. This study compared the Limit Slenderness Ratio Approximation Equation with the approximate equation by changing the variables of the building model, and examined the size of the building using the approximate Equation. As an analysis program, the MAIDAS architectural structural analysis program was used to conduct model-specific analysis. The appropriate scale of the building to minimize the error between the approximate value calculated by the Limit Slenderness Ratio Approximation Equation and the analysis result of the structural analysis program is as follows. As the number of outrigger installation increases, the error can be reduced; the ratio of the cores is reasonable, from 20% to 30%, and the arrangement of the column is suitable only for the outer column without an internal column.

• Korean Journal of Agricultural and Forest Meteorology
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• v.8 no.4
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• pp.242-249
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• 2006

Potential impacts of the future climate change on crop production can be inferred by crop simulations at a landscape scale, if the climate data may be provided at appropriate spatial scales. Northern Gyunggi Province is one of the few prospective regions in South Korea for growing quality soybeans. Any geographical shift of production areas under the changing climate may influence the current land planning policy in this region. A soybean growth simulation was performed at 342 land units in northern Gyunggi province to test the potential geographical shift of the current production areas for quality soybeans in the near future (form 2011 to 2100). The land units for soybean cultivation were selected by the land use, the soil characteristics, and the minimum arable land area. Daily maximum and minimum temperature, precipitation, the number of rain days and solar radiation were extracted for each land unit from the future digital climate models (DCM, 2011-2040, 2041-2070, 2071-2100). Daily weather data for 30 years were randomly generated for each land unit for each normal year by using a well-known statistical method. They were used to run CROPGRO-Soybean model to simulate the growth, phonology, and yields of 3 cultivars representing different maturity groups grown at 342 land units. According to the model calculations, the warming trend in this region will accelerate the flowering and physiological maturity of all cultivars, resulting in a 7 to 9 days reduction in overall growing season and a 1 to 15% reduction in grain yield of early to medium maturity cultivars. There was a slight increase in grain yield of the late maturing cultivar under the projected climate by 2070, but a decreasing tend was dominant by the year 2100.

• Korean Journal of Agricultural and Forest Meteorology
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• v.17 no.4
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• pp.399-410
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• 2015

The objective of our study was to predict future cultivation areas for walnut trees (Juglans sinensis), using the cultivation suitability map provided from Korea Forest Service and MaxEnt modelling under future climate conditions. The climate conditions in 2050s and 2070s were computed using the Regional Climate Prediction (RCP) 4.5 and 8.5 scenarios with the HadGEM2-AO model. As a result, compared to the present area, the cultivation area of the western Korea including Chungcheongnamdo, Jeollabuk-do, Jeollanam-do decreased on a national scale under RCP 4.5, and those of Gyeongsangbukdo and part of Gyeongsangnam-do decreased under RCP 8.5. However, Gangwon-do which is located in higher altitude over 600 meters than other regions showed increases in cultivation areas of 18.3% under RCP 4.5 and of 56.6% under RCP 8.5 by 2070s. The predicted map showed large regional variations in the cultivation areas with climate change. From the analysis of current top ranking areas, the cultivation areas in Gimcheon-si and Yeongdong-gun dramatically decreased by 2070s under RCP 4.5 and 8.5; that of Gongju-si decreased more under RCP 4.5; and those of Muju-gun and Cheonan-si sustained the areas by 2070s under both scenarios. The results from this study can be helpful for providing a guide for minimizing the loss of walnut production and proactively improving productivity and quality of walnuts with regard to unavoidable climate change in South Korea.

• Science of Emotion and Sensibility
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• v.12 no.4
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• pp.501-510
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• 2009

This study is to establish GUI (graphic user interface) in mobile touch phone for grooming user by using two dimensional emotion model determined by multi-dimensional scale method. The processes conducted in the research were as the followings: First of all, visceral, behavioral, and reflective factors of emotion (Norman, 2002) was defined from investigating the life styles of the Grooming users. Secondly, factor analysis was performed to extract the representative emotional words. In the third step, they were mapped into the two-dimensional emotion model through multi-dimensional scaling. Finally, the mapped emotional words were tried to be related to GUI factors of touch phones and normalizing their relation degree between 0 and 1. This study determined GUI factors significantly related to representative emotions described as special, self-centered, sophisticated, free, passionate, neat for application to mobile touch phone. This study determined the major emotion factors that should be considered the most important while designing the GUI factors.

• 대한공업교육학회지
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• v.39 no.2
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• pp.122-143
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• 2014

The purpose of this research were to develop program of elementary school technology education using history of technology and to learn about its effect. In order to accomplish the purpose of the research, we developed the program by referring to various records and perform the qualitative experiment study through several questionnaire, pictures and materials, to learn about the program effect. The research took the mixed-model design, consisted of collection of quantitative data by Likert scale and collection of qualitative data including the open-ended questions. And the research results were as below. First, development of elementary school technology education program using history of technology was developed as program for 12 hours, 12 themes, for the elementary levels. Second, seeing the result of program of elementary school technology education using history of technology, the program for history of technology for the primary school students, a majority of answers showed high satisfaction about the program, giving answers such as 'I want to do it again following hands on minds on activity.' Third, according to the analysis on the qualitiative evidence of the program, students were found to take pictures with hands on minds on activity camera obscura with much interest and curiosity. Many students are seen to complete the task on their own with a great a look of self-satisfaction, understanding the principle of camera.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.34 no.3
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• pp.283-290
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• 2016

Even though existing methods for orthophoto production in traditional photogrammetry are effective in large areas, they are inefficient when dealing with change detection of geometric features and image production for short time periods in small areas. In recent years, the UAV (Unmanned Aerial Vehicle), equipped with various sensors, is rapidly developing and has been implemented in various ways throughout the geospatial information field. The data and imagery of specific areas can be quickly acquired by UAVs at low costs and with frequent updates. Furthermore, the redundancy of geospatial information data can be minimized in the UAV-based orthophoto generation. In this paper, the orthophoto and DEM (Digital Elevation Model) are generated using a standard low-end UAV in small sloped areas which have a rather low accuracy compared to flat areas. The RMSE of the check points is σ_H = ±0.12 m on a horizontal plane and σ_V = ±0.09 m on a vertical plane. As a result, the maximum and mean RMSE are in accordance with the working rule agreement for the airborne laser scanning surveying of the NGII (National Geographic Information Institute) on a 1/500 scale digital map. Through this study, we verify the possibilities of the orthophoto generation in small slope areas using general-purpose low specification UAV rather than a high cost surveying UAV.

• Journal of the Korea Organic Resources Recycling Association
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• v.8 no.2
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• pp.154-160
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• 2000

Landfill gas (LFG) utilization in old landfill was estimated using LFG models. The results showed that Scholl Canyon model best described the LFG generation. LFG was extracted more than the amount of natural production which caused air inflow from outside that resulted in dilution of methane concentration and increase of oxygen concentration. It was negative for the LFG utilization. Therefore, to use LFG, the plan of stabilization by LFG extraction should be ineffective. The use of LFG will have no problem if LFG is extracted less than the amount of natural production which was estimated based on modeling. At 8 years elapsed from landfill, now, the amount of natural landfill gas production was decreased sharply. The plan for using LFG from old landfill is feasible if LFG is used for the less than the amount of natural production as a small scale even though for the aspect of efficiency, it was less economic than use of LFG just after closing landfilling and it was helpful for stabilization of landfill by LFG extraction.