• Tribology and Lubricants
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• v.30 no.1
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• pp.59-63
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• 2014

Laser Surface Texturing(LST) is a surface engineering process used to improve tribological characteristics of materials by creating patterned microstructures on the mechanical contact surface. In LST technology, a pulsated laser beam is used to create arranged dimples on a surface by a material ablation process, which can improve such as load capacity, wear resistances, lubrication lifetime, and reduce friction coefficients. In the present study, the effect of multi-scale LST on lubricant regime was investigated. A pulsed Nd:YAG laser was applied on the bearing steel(AISI 52100) to create arranged dimples. To optimize the surface texturing effect on friction, multi-scale texture dimples with some specific formula arrays were fabricated by combining circles, ellipses and the laser ablation process. The tribological testing of multi-scale textured surface was performed by a flat-on-flat unidirectional tribometer under lubrication and the results compared with that of the non-textured surface. Through an increase in sliding speed, the beneficial effect of multi-scale LST performance was achieved. The multi-scale textured surface had lower friction coefficient performances than the non-textured surface due to the hydrodynamic lubrication effect.

• Physical Therapy Korea
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• v.15 no.2
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• pp.44-53
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• 2008

The purpose of this preliminary study was to develop a measurement for assessing risk factors for falling in community-dwelling elderly persons. Rasch analysis and principal component analysis were performed to examine whether items on the Activities-Specific Balance Confidence (ABC), assessing self-efficacy, and items on the Berg Balance Scale (BBS), assessing balance function, contribute jointly to a unidimensional construct in the elderly. A total of 35 elderly persons (4 men, 31 women) participated. In this study, each item of ABC (16 items) and BBS (14 items) was scored on a 5-point ordinal rating scale from 0 to 4. The initial Rasch and principal component analysis indicated that 3 of the ABC items and 2 of the BBS items were misfit for this study. These 5 items were excluded from further study. After combining ABC and BBS, Rasch and principal component analyses were examined and finally 23 items selected; 12 items from ABC, 11 items from BBS. The 23 combined ABC-BBC items were arranged in order of difficulty. The hardest item was 'walk outside on icy sidewalks' and the easiest item was 'pivot transfer'. Although structural calibration of each 5 rating scale categories was not ordered, the other three essential criteria of Linacre's optimal rating scale were satisfied. Overall, the ABC-BBS showed sound item psychometric properties. Each of the 5 rating scale categories appeared to distinctly identify subjects at different ability levels. The findings of this study support that the new ABC-BBS scale measure balance function and self-efficacy. It will be a clinically useful assessment of risk factors for falling in the elderly. However, the number of subjects was too small to generalize our results. Further study is needed to develop a new assessment considering more risk factors of falling in elderly.

• Korean Journal of Child Studies
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• v.9 no.2
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• pp.1-28
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• 1988

The purpose of this study was to develop a behavior rating scale for the evaluation of children's development for utilization by preschool teachers. The procedures for the study included content validation, pilot test, and main study. A total of 97 items were retained after the content validation and pilot test. The items of the scale were grouped into five areas (physical, language, cognitive, emotional, and social development) and 11 sub-areas. The resulting "Behavior Rating Scale for Preschool Children" was administered to 479 boys and girls, 3-6 through 6-5 years of age, selected from 10 different kindergartens and early education centers in Seoul, Pusan, and Chonju. The analysis of data was done with SPSS computer programs, including item analysis, Cronbach's ${\alpha}$ for reliability, factor analysis to test construct validity, two-way ANOVA to test age and sex differences, and percentile norms. The 97 items of the scale were found to be satisfactory in terms of item discrimination with indices ranging from .31 to .73. Cronbach's ${\alpha}$ was .98 for the total scale and ranged from .87 to .93 in specific domains, which was considered satisfactory. The factors extracted from each area were consistent with the educational objectives of the Yonsei Open Education Program except for emotional development. The intercorrelations among the domains were relatively high, ranging from .56 to .81. Age differences were significant in cognitive, physical, and language development, but not significant in social and emotional development. Sex differences were significant in all areas with girls higher on the average than the boys. Percentile ranks were drived from the total score for each age group and quartiles were calculated for sub-scores in each domain.

• Elastomers and Composites
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• v.34 no.1
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• pp.45-52
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• 1999

This paper describes how the gold particles self assemble on the specific phase on the microphase separated block copolymer thin film and form a well ordered patterns. For this study, polystyrene-polybutadiene-polystyrene (PS-PB-PS) triblock copolymer (30wt % PS) thin films (${\sim}100nm$) having a cylindrical morphology were cast from 0.1wt% toluene solution to be used as polymer thin film templates. The films having either vertical PS cylinders or in-plane PS cylinders in PB matrix from each different solvent evaporation condition were obtained. Cross-sectional transmission electron microscopy(TEM) was used to study the surface and bulk morphologies of block copolymer thin films. Small amount of gold particles was evaporated on a block copolymer thin film template to obtain a nano-scale pattern. When an as-cast thin film template was used, gold particles preferentially self assemble on the low surface tension PB phase and a relatively well ordered pattern in nano-scale was produced. However, after the formation of a low surface energy PB rich layer upon annealing, a gold self-assembled pattern was not observed.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.15 no.5
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• pp.299-307
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• 2022

Harmony Search (HS) is a relatively recently developed meta-heuristic optimization algorithm, and various studies have been conducted on it. HS is based on the musician's improvisational performance, and the objective variables play the role of the instrument. However, each instrument is given only a sound range, and there is no concept of a scale that can be said to be the basis of music. In this study, the performance of the algorithm is improved by introducing a scale to the existing HS and quantizing the bandwidth. The introduced scale was applied to HM initialization instead of the existing method that was randomly initialized in the sound band. The quantization step can be set arbitrarily, and through this, a relatively large bandwidth is used at the beginning of the algorithm to improve the exploration of the algorithm, and a small bandwidth is used to improve the exploitation in the second half. Through the introduction of scale and bandwidth quantization, it was possible to reduce the algorithm performance deviation due to the initial value and improve the algorithm convergence speed and success rate compared to the existing HS. The results of this study were confirmed by comparing examples of optimization values for various functions with the conventional method. Specific comparative values were described in the simulation.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.1D
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• pp.91-100
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• 2009

The aim of this paper is to examine satisfaction of residents and preference on the outdoor space's design by multi-family housing complex scale. So we divide outdoor space into space for green land, space for physical training and play, space for walking and space for rest and landscape facilities. The major findings of this analysis are follows : Multi-family housing complex scale is the bigger, it is recognized by same ratio on specific outdoor space in housing complex that are space for green land, space for physical training and play, space for rest and landscape facilities. And space for physical training and play is found commonly into the poorest space in housing complex. Evaluation for resident's perception on outdoor space by multifamily housing complex scale shows that housing complex scale is the bigger, resident's satisfaction is the lower. That means that housing complex of large scale can't satisfy the diverse resident's demand.

• The Journal of Engineering Geology
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• v.32 no.4
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• pp.449-466
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• 2022

The establishment of a complete geological model that includes information about all the various components at a site (such as underground structures and the compositions of rock and soil underground space) is difficult, and geological modeling is a developing field. This study uses commercial software for the relatively easy composition of geological models. Our digital modeling process integrates a model of Jeju Island's 3D geological information, models of cave shapes, and information on the state of a road at the site's upper surface. Among the numerous natural caves that exist in Jeju Island, we studied the Jaeamcheon lava tube near Hallim town, and the selected site lies below a road. We developed a digital model by applying the principles of building information modeling (BIM) to the cave (CaveBIM). The digital model was compiled through gathering and integrating specific data: relevant processes include modeling the cave's shape using a laser scanner, 3D geological modeling using geological information and geophysical exploration data, and modeling the surrounding area using drones. This study developed a global-scale model of the Hallim region and a local-scale model of the Jaeamcheon cave. Cross-validation was performed when constructing the LSM, and the results were compared and analyzed.

• Archives of Plastic Surgery
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• v.34 no.4
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• pp.466-470
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• 2007

Purpose: Active prevention is an essential component in reducing the development of pressure sores. For the high-risk patient group, following the certified pressure sore screening scale as well as educating the patient and the nurses who care for them can lead to optimal management of these patients. Applying a risk assessment scale along with a prevention strategy can reduce medical costs and length of stays at the hospital. The purpose of this study is to evaluate the efficacy of a new pressure sore risk assessment scale based on the universally recommended Braden scale and our prevention program. Methods: From June to August, 2003, our pressure ulcer risk assessment scale was applied to a total of 1882 patients admitted to the experimental group (intensive care unit, neurosurgery, general surgery, and oncology units). It was based on Braden scale. We analysed sensitivity, specificity, positive and negative predictive value and ROC curve to evaluate its efficacy. Pressure ulcer prevention program was composed of patient's education using protocol and specific nursing care. The incidence of pressure ulcers was also measured during the 3 months period, and those were compared to the control group of 1789 patients from March to May, 2002. Results: 118(6.27%) of the experimental group were high-risk with an incidence of pressure ulcers measuring 4 (0.21%). Sensitivity, specificity, positive and negative predictive value of our scale were 100%, 94%, 4%, 100%, respectively, and AUC(area under the curve) was 0.992. In the control group, the incidence of pressure ulcers was 11(0.61%). Statistical analyses using chisquared tests with a significance level of 5%, the results were such that ${\chi }^2=3.6482$(p=0.0561). The results proved to be statistically significant in borderline. Conclusion: The results from this study proved that pressure sore risk assessment scale based on Braden scale has an excellent efficacy, and shows that our pressure ulcer prevention program is partially effective in reducing pressure ulcer incidence.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.7 no.2
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• pp.332-344
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• 2000

The subjects of this study were 100 elderly people who were over 60 years of age and had chronic pain. The study examined the matter of quality of life and self-efficacy of elderly patients with chronic pain including the influence of related factors on these variables. Also, by examining their relation, it provides basic data for the development of efficient nursing interventions for the elderly patients with chronic pain. The tools were the general self-efficacy scale by Sherer & Maddux(1982) and a specific self-efficacy Scale(Lorig et al, 1989) modified to better suit the subjects of this study. The quality of life scale by You-Ja Ro(1988) modified to better suit the subjects of this study was used. The data were collected from August to October 1999. Four researchers and two research assistants developed a data collection protocol subjected to a pilot study for confirmation of validity. In this study, the research assistants read the questionaire to the subjects and recorded the responses themselves. The interviews lasted 40-50 minutes on an average. The data thus collected were analyzed in terms of t-test, ANOVA, Pearson's correlation coefficient, using the SAS PC program. The major findings are as follows: 1) For self-efficacy it was found that males had higher self-efficacy than females for specific self-efficacy. But for general efficacy, males and females showed similar results. The the quality of life was found to be higher for males than females. 2) A positive correlation was identified between the specific self-efficacy, general self-efficacy and quality of life. 3) The general characteristics affecting the self-efficacy of elderly patients with chronic pain were employment, age, level of education, spouse, economic status and income. Self-efficacy was higher among those who were employed, aged between 66-70, well-educated, married and rich or having their own income. 4) The general characteristics affecting the quality of life of elderly patients with chronic pain were lodging with children, religion, level of education and economic status. The quality of life was higher among those who lived with their children and were Buddhists, were well-educated and rich.

• Journal of the Korean Association of Geographic Information Studies
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• v.16 no.3
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• pp.193-210
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• 2013

This study aims to assess the slope stability variation of Jeollabuk-do drainage areas by RCM model outputs based on A1B climate change scenario and infinite slope stability model based on the specific catchment area concept. For this objective, we downscaled RCM data in time and space: from watershed scale to rain gauge scale in space and from monthly data to daily data in time and also developed the GIS-based infinite slope stability model based on the concept of specific catchment area to calculate spatially-distributed wetness index. For model parameterization, topographic, geologic, forestry digital map were used and model parameters were set up in format of grid cells($90m{\times}90m$). Finally, we applied the future daily rainfall data to the infinite slope stability model and then assess slope stability variation under the climate change scenario. This research consists of two papers: the first paper focuses on the methodologies of climate change scenario preparation and infinite slope stability model development.