• Korean Journal of Geomatics
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• v.1 no.1
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• pp.7-13
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• 2001

Geospatial Information Systems (GIS) have been employed to systematically manage and design land use in urban areas. This has increased the need for more accurate vector and raster data. In Korea, l/l,000-scale digital maps are used as vector data for the facility management in urban areas. This has increased the need for large scale orthoimages. Orthoimages generated from aerial imagery can provide accurate information, making possible the more effective city management. However, there is a large problem in using the orthoimages, i.e., currently available conventional orthoimages have not been generated based on Digital Elevation Model (DEM) that takes into account the building heights. So this causes the displacements of building image in large scale orthoimages. The present study is an attempt to generate the large scale orthoimages based on building DEM. The semiautomatic building extraction method can detect building outlines by mouse clicking on either building roofs or corners. Building DEM, based on the outline and calculated building height, was used to produce the large scale orthoimages with the corrected building occlusion.

• Wind and Structures
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• v.14 no.1
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• pp.15-34
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• 2011

Three wind-tunnel simulations of the atmospheric boundary layer (ABL) flow in suburban country exposure were generated for length scale factors 1:400, 1:250 and 1:220 to investigate scale effects in wind-tunnel simulations of the suburban ABL, to address recommended wind characteristics for suburban exposures reported in international standards, and to test redesigned experimental hardware. Investigated parameters are mean velocity, turbulence intensity, turbulent Reynolds shear stress, integral length scale of turbulence and power spectral density of velocity fluctuations. Experimental results indicate it is possible to reproduce suburban natural winds in the wind tunnel at different length scales without significant influence of the simulation length scale on airflow characteristics. However, in the wind tunnel it was not possible to reproduce two characteristic phenomena observed in full-scale: dependence of integral length scales on reference wind velocity and a linear increase in integral length scales with height. Furthermore, in international standards there is a considerable scatter of recommended values for suburban wind characteristics. In particular, recommended integral length scales in ESDU 85020 (1985) are significantly larger than in other international standards. Truncated vortex generators applied in this study proved to be successful in part-depth suburban ABL wind-tunnel simulation that yield a novel methodology in studies on wind effects on structures and air pollution dispersion.

• Atmosphere
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• v.25 no.3
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• pp.435-447
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• 2015

This study explores the synoptic characteristics of cold days over South Korea and their relationship with large-scale climate variability. The cold day, which is different from cold surge, is defined when daily-mean surface air temperature, averaged over 11 KMA stations, is colder than 1-percentile temperature in each year by considering its long-term trend over 1960~2012. Such event is detected by quantile regression and the related synoptic patterns are identified in reanalysis data. Composite geopotential height anomalies at 500 hPa show that cold days are often preceded by positive anomalies in high latitudes and negative anomalies in midlatitudes on the west of Korea. While the formers are quasi-stationary and quasi-barotropic, and often qualified as blocking highs, the latters are associated with transient cyclones. At cold days, the north-south dipole in geopotential height anomalies becomes west-east dipole in the lower troposphere as high-latitude anticyclone expands equatorward to the Northern China and mid-latitude cyclone moves eastward and rapidly develops over the East Sea. The resulting northerlies cause cold days in Korea. By performing composite analyses of large-scale climate indices, it is further found that the occurrence of these cold days are preferable when the Arctic Oscillation is in its negative phase and/or East Asian monsoon circulation and Siberian high are anomalously strong.

• Journal of Ocean Engineering and Technology
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• v.35 no.4
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• pp.273-286
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• 2021

In recent years, as human casualties and property damage caused by hazardous waves have increased in the East Sea, precise wave prediction skills have become necessary. In this study, the Simulating WAves Nearshore (SWAN) third-generation numerical wave model was calibrated and optimized to enhance the accuracy of winter storm wave prediction in the East Sea. We used Source Term 6 (ST6) and physical observations from a large-scale experiment conducted in Australia and compared its results to Komen's formula, a default in SWAN. As input wind data, we used Korean Meteorological Agency's (KMA's) operational meteorological model called Regional Data Assimilation and Prediction System (RDAPS), the European Centre for Medium Range Weather Forecasts' newest 5th generation re-analysis data (ERA5), and Japanese Meteorological Agency's (JMA's) meso-scale forecasting data. We analyzed the accuracy of each model's results by comparing them to observation data. For quantitative analysis and assessment, the observed wave data for 6 locations from KMA and Korea Hydrographic and Oceanographic Agency (KHOA) were used, and statistical analysis was conducted to assess model accuracy. As a result, ST6 models had a smaller root mean square error and higher correlation coefficient than the default model in significant wave height prediction. However, for peak wave period simulation, the results were incoherent among each model and location. In simulations with different wind data, the simulation using ERA5 for input wind datashowed the most accurate results overall but underestimated the wave height in predicting high wave events compared to the simulation using RDAPS and JMA meso-scale model. In addition, it showed that the spatial resolution of wind plays a more significant role in predicting high wave events. Nevertheless, the numerical model optimized in this study highlighted some limitations in predicting high waves that rise rapidly in time caused by meteorological events. This suggests that further research is necessary to enhance the accuracy of wave prediction in various climate conditions, such as extreme weather.

• The Korean Journal of Pain
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• v.19 no.1
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• pp.56-62
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• 2006

Background: Balloon kyphoplasty is the new technique that helps to decrease the pain and improve mobility as well as restore the vertebral body height and kyphotic curve in fractured vertebrae. We evaluated the outcome of balloon kyphoplasty in the reduction of vertebral body height, kyphotic curve and clinical improvement in the patients with painful vertebral compression fractures. Methods: From July 2002 to February 2005, 84 levels of vertebral compression fractures in 66 patients were treated with balloon kyphoplasty. The assessment criteria were the changes over time in visual analogue scale (VAS) and mobility score. We evaluated the vertebral body height and kyphotic curve at preoperative 1 day and postoperative 1 day. Results: Procedures were performed in 66 patients with a total of 84 affected vertebral bodies. The anterior wall height was restored in 74 / 84 (88%) levels with a mean increment of 2.9 mm, and the mid-vertebral body height was restored in 79 / 84 (94%) levels with a mean increment of 4.2 mm. Kyphosis correction was achieved in 60 / 84 (71.4%) from 10.1 degrees to 7.5 degrees. Pain intensity reduced by 60% in one day after operation and by 75-85% in later time. Mobility scores of all patients were improved immediately after the procedure. Cement leakage occurred in 3 levels but there was no clinical problem. Conclusions: Kyphoplasty is an efficient and safe treatment of painful vertebral compression fracture in pain relief, mobility improvement, and reduction of deformity.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.8 no.1
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• pp.43-49
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• 1997

This study was designed to explore whether the temperament of a child influences the physical growth. The Korean version of the Parent Questionnaire for Children developed by Thomas, Chess and Korn was applied to 395 Korean children whose ages ranged from 3 years to 7 years. Simultaneously the height and the weight were measured for each child and converted into percentile scale according to the Growth Curve and the Weight Percentile Table for the Height of Korean children. Statistical analysis was performed among 9 temperamental categories, height and weight percentiles for the age and weight percentiles for the height using the first-order partial correlation analysis, controlling for the familial mean income per month. Results showed that the more temperamentally difficult a child is, the lower weight he has when compared with the children of the same age or the same height. Although there were some differences, the tendency of the above findings was maintained both in male and female children. These results show that the temperament may influence the physical growth as well as the psychological development.

• Journal of the Korea Fashion and Costume Design Association
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• v.19 no.3
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• pp.207-218
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• 2017

This study evaluates the difference in visual images according to changes in waist position and pants style. The researcher made twelve stimuli-combination of four pants styles (classic, baggy, skinny, bell-bottom) and three waist positions (0cm, -3cm, -5cm). The test involved 48 female college students. The stimuli were made using the i-Designer computer program. The panels tested the screen images of all manikins wearing pants. A 7-point scale was used to evaluate each image. For the data analysis, the ANOVA and Duncan-test were applied along with an SPSS program. The results of this study are as follows. The visual evaluations by pants style and waist position are composed of seven factors (attractiveness, attention, hip, activity, height, waist, abdomen). Among these factors, attractiveness is evaluated to be the most important factor. The mutual agreement of the visual effect (according to pants style and waist position) was indicated as four factors of attractiveness, attention, waist, and abdomen. The height factor is evaluated to be the most important factor by change in regards to waist position. The 0cm waist position of three styles (classic, baggy, bell-bottom) were evaluated positively in elongated height whereas the -3cm, -5cm waist position of the skinny style was evaluated positively in elongated height. The mutual agreements of visual effect (according to pants style and waist position) were not indicated.

• Journal of Korea Water Resources Association
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• v.36 no.4
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• pp.623-631
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• 2003

A large scale hydrological laboratory model tests for the geotextile tube were conducted to investigate the stability of geotextile tube and the capability of breakwater with variations of significant wave height, percentage of soil filling, and the water level above geotextile tube. The sliding displacement of geotextile tube is measured to check the stability of geotextile tube for given the various significant wane heights. The marked mash was laid out at the bottom of water channel to measure the displacement of geotextile tube. The bench mark was furnished in the upper part of water channel and the initial location was marked every 10cm interval to measure the displacement of geotextile tube. The wane transmit ratios are analyzed with the variations of soil filling of tube and of the top crown height wave above the geotextile tube in order to study the performance of brekwater before and after the installation of geotextile tube.

• Physical Therapy Rehabilitation Science
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• v.10 no.2
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• pp.235-243
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• 2021

Objective: This study aimed to investigate the short-term effects of flexion-distraction spinal manipulation on intervertebral height, pain, spine mobility in patients with lumbar degenerative disc disease. Design: Randomized controlled trial with a pretest-posttest control group design Methods: A total of 96 participants with degenerative disc disease participated in the study and were randomly divided into two groups. Both groups received intervention for 3-5 minutes a day. The experimental group (n=48) underwent flexion-distraction spinal manipulation for 3-5 minutes, and the control group (n=48) was maintained in the same position as the experimental group for 5 minutes without any intervention. The intervertebral height was measured by computed tomography, pain was assessed using visual analog scale, and the spine in flexion mobility was measured using the finger-to-floor distance test and passive straight leg raise test. Pre-test and post-test measurements were obtained. Results: The experimental group showed significant improvement in intervertebral height, degree of pain, and spinal mobility (p<0.05). The intervertebral height increased from 6.32±1.90 to 6.93±1.85 mm (p<0.05), lower back pain decreased from 69.17±13.35 mm to 48.48±12.20 mm (p<0.05), lumbar spine mobility changed from 17.37±4.49 to 12.69±4.34 cm (p<0.05), and passive straight leg raise test range increased from 46.94±13.05° to 56.01±12.20° (p<0.05). Conclusions: This study suggests that flexion-distraction spinal manipulation could be an effective treatment for decreasing pain and improving function in patients with degenerative disc disease.

• Structural Engineering and Mechanics
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• v.81 no.6
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• pp.691-703
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• 2022

To obtain the seismic response of lead-cored rubber, shape memory alloy (SMA)-rubber isolation Plate-shell Integrated Concrete Liquid-Storage Structure (PSICLSS), based on a PSICLSS in a water treatment plant, built a scale experimental model, and a shaking table test was conducted. Discussed the seismic responses of rubber isolation, SMA-rubber isolation PSICLSS. Combined with numerical model analysis, the vibration characteristics of rubber isolation PSICLSS are studied. The results showed that the acceleration, liquid sloshing height, hydrodynamic pressure of rubber and SMA-rubber isolation PSICLSS are amplified when the frequency of seismic excitation is close to the main frequency of the isolation PSICLSS. The earthquake causes a significant leakage of liquid, at the same time, the external liquid sloshing height is significantly higher than internal liquid sloshing height. Numerical analysis showed that the low-frequency acceleration excitation causes a more significant dynamic response of PSICLSS. The sinusoidal excitation with first-order sloshing frequency of internal liquid causes a more significant sloshing height of the internal liquid, but has little effect on the structural principal stresses. The sinusoidal excitation with first-order sloshing frequency of external liquid causes the most enormous structural principal stress, and a more significant external liquid sloshing height. In particular, the principal stress of PSICLSSS with long isolation period will be significantly enlarged. Therefore, the stiffness of the isolation layer should be properly adjusted in the design of rubber and SMA-rubber isolation PSICLSS.