• Korean Journal of Construction Engineering and Management
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• v.18 no.2
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• pp.58-70
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• 2017

The planning for material lifting operations is one of the key processes in high-rise building construction. Several previous studies have used rough calculations by referring to existing practices or establishing a target value for lifting cycle time or operating rate. Therefore, the purpose of this study is to propose a material lifting process optimization method for reducing the lifting cycle time and increasing the operating rate. In this study, we improve the cyclic operation network (CYCLONE) modeling method that considers the duration and zone information of each work task. This method can be used to hand over work tasks to another crew group in the work process. According to this methodology, this study optimizes the material lifting process, performs a sensitivity analysis, and evaluates the field applicability of the proposed material lifting process optimization method. Therefore, the optimized process was then applied to a high-rise building construction site. The lifting work process time and operating rate for the simulated as - is lifting process data, optimized process data, and field application result data were compared for each lifting height. From this comparison, the effectiveness of the optimization methodology was confirmed.

• Journal of Korean Society of Forest Science
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• v.66 no.1
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• pp.74-78
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• 1984

The highest cutting ratio and the best growth performance of the P. alba, P. alba ${\times}$ P. glandulosa and P. glandulosa were at -0.05 bars of soil water potential (${\Psi}_s$). Their growth and rooting ability of cuttings were better in suitable soil moisture contents, 19.650, but were worse in low soil moisture contents, 11.41% and 16.66%, respectively. Specially, P. alba ${\times}$ P. glandulosa appeared hybrid vigor in high soil water potential (${\Psi}_s$= -0.05 bars) but not appeared it below ${\Psi}_s$ = -0.5 bars. It is believed that P. glandulosa is a natural hybrid between P. davidiana and P. alba in view of morphological characteristics. Aspen, normally, does not have the rooting ability of cuttings, however, P. glandulosa showed the rooting ability, though the ratio was low, 23%. It is estimated that this rooting ability was originated from P. alba. In addition, its growth rate was between P. alba and P. davidiana, and the sensitivity of water requirement for the growth was also really equal to P. alba. This facts prove P. glandulosa to be natural hybrid between P. alba and P. davidiana.

• Journal of Preventive Medicine and Public Health
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• v.27 no.4 s.48
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• pp.747-761
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• 1994

Workers' periodic health examination is the main tools used to manage the health problems of most workers in Korea. The most common health problem found in workers' periodic health examination is liver disorder. Liver disorder is also one of the most common health problems in general population and one of the leading causes of mortality in adult population. Regulation proposed by government (No. 207, Ministry of Labor, 1992) defines the criteria for selection of workers with the liver dysfunction for further evaluative examination and the examination items used for diagnosis of the workers with liver dysfunction. This study was designed to evaluate the proficiency of each examination items presently defined in Regulation and propose the optimal examination items for detection of the liver disorders found by workers' periodic health examination. Study subjects are 186 workers with abnormal liver function tests in screening examination of workers' periodic health examination. Questionnaire survey including past history of liver disorder, drinking history, height and weight was done. Physical examination by physician, routine test items defined by Regulation (SGOT, SGPT, $\gamma$-GTP, protein, albumin, total and direct bilirubin, alkaline phosphatase, $\alpha$-feto protein, HBsAg and anti-HBs), anti-HCV antibody test and liver ultrasonography were done. Results are as follows; 1. Result of evaluative examination utilizing only the items defined in Regulation was; There were 75 workers with suspected live. disorder(40.3%), 63 with no liver dysfunction (33.9%), 13 with suspected hepatitis B(7.0%), 10 workers with hepatitis B(5.4%), 10 workers with hepatitis B carrier state(5.4%), 10 with alcoholic liver disorders(5.4%), 5 with fatty liver(2.7%). When alternative diagnostic criteria applying additional examination items (drinking history, body mass index, anti-HCV antibody and ultrasonography) diagnosability of liver disorder was increased. When all four items were included, final results were; 23 workers (17.8%) with hepatitis B (10 carriers, 13 suspects and 10 hepatitis B), 10 (5.4%) with hepatitis C(4 carriers, 5 suspects and 1 hepatitis C), 13(7.0%) with alcoholic liver disorder, 45(24.2%) with fatty liver (40 suspects, 5 fatty liver), 410%) with suspected liver disorders and 44 (23.7%) with normal liver. 2. Of examination items defined by Regulation, only SGOT, SGPT, $\gamma$-GTP and HBsAg were significantly different in abnormal rate and mean value, and all other laboratory findings did not showed significant difference between two groups. Drinking history, body mass index and anti-HCV antibody test which are the items that authors included in this study, also showed significant difference between two groups. Utilization of body mass index (BMI) for abnormal liver function group in diagnosis of fatty liver had high specificity (97.6%) but sensitivity (22.3%) was low. Therefore we suggest that SGOT, SGPT, $\gamma$-GTP, HBsAg, alcohol drinking history, BMI and anti-HCV Ab were useful for diagnosis of liver disorders among worker's periodic health examination.

• Journal of the Korean earth science society
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• v.31 no.7
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• pp.720-737
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• 2010

This study is to analyze the temporal and spatial distributions of solar radiation in South Korea. Solar radiation data is observed every minute at 22 KMA (Korea Meteorological Administration) stations using pyranometer from January 2000 to August 2007. These data were calibrated using intensive comparative observation and solar radiation model. Intensive comparative observations are accomplished at 22 KMA stations between KNU (Kangnung (Gangneung-Wonju) National University) standard and station instruments during the month of August 2007. The solar radiation of a clear sky mainly is affected by precipitable water, solar altitude and geological height. Also old (raw) data is corrected by the solar radiation model only about clear day and is revised based on the temporal trend of instrument's sensitivity decrease. At all periods and all stations, differences between raw data (13.31 MJ/day) and corrected data (13.75 MJ/day) are 0.44 MJ/ day. So, the spatial distribution of solar radiation is calculated with seasonal and annual mean, and is the relationship with cloud amount is analyzed. The corrected data show a better consistency with the cloud amount than the old data.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.4
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• pp.415-421
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• 2015

This paper describes the study of the design procedure for the step-by-step setup parameters and of the magnetizing method for performance and size reduction in the development of a haptic vibrator. The study of magnetization was accomplished by comparing the electromagnetic force in accordance with the horizontal and the vertical magnetization. The theoretical results indicated that the horizontal magnetization resulted in a better performance. The systematic design of a step-by-step procedure for establishing the design parameters was verified by testing the characteristics of the fabricated prototype product. The vibration response function analysis and electric field analysis were processed by decoupling of the analytical method, and these were determined to be in good agreement with the test results. The design parameters to contributing to the product reliability included the spring height, the welding position, and the coil position. The sensitivity of the electromagnetic field and the performance change were analyzed based on the design parameters. As a result, we proposed a design method to implement a reliability-based, high performance haptic vibrator.

• Journal of Korean Society for Atmospheric Environment
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• v.29 no.3
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• pp.264-274
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• 2013

This study investigates long-term trends and characteristics of aerosol light scattering coefficient at Seoul and Baengnyeongdo in order to understand aerosol optical and radiative properties around Korea. The analysis period is limited to one year of 2011. First, the aerosol scattering coefficients (${\sigma}_{sp}$) of both sites show strong linear dependence on the $PM_{2.5}$ mass concentrations with significant correlations between both. Further, correlations and sensitivity between ${\sigma}_{sp}$ and $PM_{2.5}$ increase with relative humidity, implying both relationships are strongly dependent upon moisture amounts in the atmosphere. This study applied 3-step careful quality control procedures to the analysis of ${\sigma}_{sp}$ for the insurance of data confidence. For the relationship analysis of extinction coefficients (${\sigma}_{ext}$) to visibility and aerosol optical depth, ${\sigma}_{sp}$ observed at 3 p.m. have been used with help of aerosol absorption coefficients (${\sigma}_{ap}$) in order to remove its dependence upon relative humidity, and also those of rainy period have been excluded. As expected, ${\sigma}_{ext}$ estimated are inversely proportional to visibility observation by eye. Finally, aerosol extinction coefficients have been vertically integrated with an assumption of nearly well-mixed within an e-folding height to determine aerosol optical depth, and compared with those retrieved from sunphotometer. The results show a reasonable agreement in spite of an inherent difference of each definition. We expect these findings would help to eventually understand aerosol radiative forcing and its effect on the regional climate change around Korea.

• Journal of Nutrition and Health
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• v.34 no.2
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• pp.188-197
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• 2001

The nutritional status is important for the physical and mental development of children. Children should have sufficient nutrient intake, specially for the developmentally disabled children. In spite of the importance not much research has been done for their food habit and nutritional status. In this study, nutritional status of the disabled children were examined, the number of children studied is 50 children in Seoul between 5 to 6 years old, of whom 11 were austism, 5 were mentally retarded children and 8 were down\\`s syndrome. In order to get the data questionnaires about the food habit and other related factors, and two days food records were used. Their mean height was 108.8$\pm$21.0cm and their average weight was 19.5$\pm$4.6kg. The proportion of study subject with problems of the food habits was 36%, without keeping the regular meal time was 16%, and having snacks 2-4 time daily was 56%. They chose confectionery and fruits as their favorite snacks. The proportion of study subject with the sensitivity to the food colors and smells when they ate was 54%, unskilled using spoon and fork was 58%, and having medications was 20%. When we asked them whether their parents used the food as compensation means or not, 32% of them said that they did it often or sometimes. For the nutrient intake, energy was 1,703 $\pm$ 511kcal, carbohydrate was 242.5 $\pm$ 69.3g, protein was 61.3 $\pm$ 17.5g, lipid was 50.0 $\pm$ 24.4g. As the nutrient intake, it was compared with RDA. The intake of vitamin A and calcium were below RDA. Intake of protein was more than 150% of RDA. The proportion of subject with more than 125% of RDA was 72% for the phosphorus, 62% for the protein, 60% for the Vitamin A and calcium were below 0.75 and that of the others was above 0.75. The mean adequacy ratio(MAR) was 0.88. As we sum up the results of the research, the developmentally disabled children were shorter and lighter than the reference, were having medications, had excessive appetites, and had unbalanced diets. Also they had the bad food habit. As for the nutritional intake, vitamin A and calcium intake were a little less than RDA, and protein and phosphorus intake were too much. With the results of the above research for the disabled children, we can conclude that there are need to take some necessary measures for those children. To establish some programs measures for their better food environment, it is thought that much more research should be done in the future. (Korean J Nutrition 34(2) : 188-197, 2001)

• Journal of the Korean Geotechnical Society
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• v.29 no.8
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• pp.5-14
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• 2013

Coarse granular geomaterials containing large gravels are broadly used for construction of large geotechnical systems such as dams, levees, railways and backfills. It is necessary to evaluate deformation characteristics of these materials for dynamic analysis, e.g. seismic design. This study presents evaluation of dynamic deformation characteristics of coarse materials using large scale resonant column testing apparatus, which uses specimens with 200 mm in diameter and 400 mm in height, and the effects of gradation characteristics on maximum shear modulus, shear modulus reduction curve and damping characteristics were investigated. From experimental study using rock-fill materials for a dam, we could see that the largest or mean particle size affects the shape of shear modulus reduction curve. When the specimens are prepared under the same conditions for maximum particle size, the coefficient of uniformity affects the confining stress exponent of maximum shear modulus. It could be concluded that the maximum particle size is an factor which affects shear modulus reduction curve, and that the coefficient of uniformity is for small strain shear modulus, especially for the sensitivity to confining stress.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.17 no.3
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• pp.319-332
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• 2004

Due to their high strength to weight ratios and excellent durability, fiber reinforced polymer(FRP) is widely used in construction industries. In this paper, a shape optimum design of FRP bridge decks haying pultruded cellular cross-section is presented. In the problem formulation, an objective function is selected to minimize the volumes. The cross-sectional dimensions and material properties of the deck of FRP bridges are used as the design variables. On the other hand, deflection limits in the design code, material failure criteria, buckling load, minimum height, and stress are selected as the design constraints to enhance the structural performance of FRP decks. In order to efficiently treat the optimization process, the cross-sectional shape of bridge decks is assumed to be a tube shape. The optimization process utilizes an improved Genetic Algorithms incorporating indexing technique. For the structural analysis using a three-dimensional finite element, a commercial package(ABAQUS) is used. Using a computer program coded for this study, an example problem is solved and the results are presented with sensitivity analysis. The bridge consists of a deck width of 12.14m and is supported by five 40m long steel girders spaced at 2.5m. The bridge is designed to carry a standard DB-24 truck loading according to the Standard Specifications for Highway Bridges in Korea. Based on the optimum design, viable cross-sectional dimensions for FRP decks, suitable for pultrusion process are proposed.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.6
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• pp.779-783
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• 2006

The adiponectin gene is known to be involved in the regulation of energy homeostasis involving food intake, carbohydrate and lipid metabolism. Human adiponectin gene polymorphisms have been recently reported to be associated with obesity, insulin sensitivity and the risk of type 2 diabetes. The present study was carried out to investigate the porcine adiponectin gene as a candidate gene for fat deposition and carcass traits. A mutation of A178G of the porcine adiponectin gene that resulted in substitution of the amino acid Isoleucine to Valine was identified. AcyI PCR-RFLP was used to detect the polymorphism of the genotypes in five different pig populations (Large White, Landrace, Duroc, Chinese breeds Meishan and Qingping). The A allele frequency was significantly higher among subjects from Chinsese lard type breeds, while the G allele was the only one present in those from Western lean type breeds. To determine if there was an association of the polymorphism with phenotypic variation, the mutation was tested in 267 pigs of the "Large $White{\times}Meishan$" F2 resource population. The results of association analyses showed significant associations of the genotypes with fat deposition and carcass traits. Allele G was significantly associated with increase in loin eye height, loin eye area and lean meat percentage and bone percentage, and decrease in fat mean percentage, ratio of lean to fat, shoulder fat thickness, 6-7 rib fat thickness, thorax-waist fat thickness and buttock fat thickness. The substitution of A178G (Ile60Val) happened to be located at amino acid 60 in the collagenous domain of porcine adiponectin which might affect the association into higher-order structures, and accordingly affect the posttranslational modifications and optimal biological activity of the multimeric forms. The identified functional polymorphism provides new evidence of adiponectin as an important candidate gene affecting fat deposition and carcass traits in pigs.