• Physical Therapy Korea
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• v.28 no.3
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• pp.177-185
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• 2021

Background: Muscle undergoes change continuously with aging. Sarcopenia, in which muscle mass decrease with aging, is associated with various diseases, the risk of falling, and the deterioration of quality of life. Obesity and sarcopenia also have a synergy effect on the disease of the older adults. Objects: This study examined the risk factors for sarcopenia, sarcopenic obesity, and sarcopenia without obesity and developed prediction models. Methods: This machine-learning study used the 2008-2011 Korea National Health and Nutrition Examination Surveys in the analysis. After data curation, 5,563 older participants were selected, of whom 1,169 had sarcopenia, 538 had sarcopenic obesity, and 631 had sarcopenia without obesity; the remaining 4,394 were normal. Decision tree and random forest models were used to identify risk factors. Results: The risk factors for sarcopenia chosen by both methods were body mass index (BMI) and duration of moderate physical activity; those for sarcopenic obesity were sex, BMI, and duration of moderate physical activity; and those for sarcopenia without obesity were BMI and sex. The areas under the receiver operating characteristic curves of all prediction models exceeded 0.75. BMI could predict sarcopenia-related disease. Conclusion: Risk factors for sarcopenia-related diseases should be identified and programs for sarcopenia-related disease prevention should be developed. Data-mining research using population data should be conducted to enhance the effectiveness of early treatment for people with sarcopenia-related diseases through predictive models.

• Journal of The Korean Digital Architecture Interior Association
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• v.9 no.3
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• pp.95-102
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• 2009

An architectural space can be considered a life form that interconnects a number of architectural elements such as the humans who live in it. It is difficult to understand and evaluate the complexity of the interrelation between each element, but there have been various attempts to understand and evaluate this architectural space. The Space Syntax that emerged in 1980s has been studied and used more frequently than other methods. Space Syntax is the space analysis tool that analyzes the physical structure of space and represents it as a graph. Space syntax enables its various applications in space analysis by quantifying each spatial property of a whole structure, analyzing it systemically and objectively based on mathematical logic, and representing the results as a quantitative value. Integration of Space Syntax, a widely used index, reflects human behavior in spatial configuration. Meanwhile, there have been various studies in the field of architectural environmental psychology about the relationships between space and human behavior by applying behavioral science to architectural plan. One of the most widely used one is spatial behavior simulation which uses models and simulates the behavioral characteristics to anticipate practical situations and investigate the behavior related spatial problems. In this study, which focuses on the accessibility of the space syntax model, the usefulness of space will be analyzed through the simulation of human behavior that moves through each space. Furthermore, the validity of index will be verified by displaying several examples and compared with integration in space syntax, which represents the usefulness of space.

• Journal of Korean Society of Rural Planning
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• v.19 no.3
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• pp.51-59
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• 2013

The objective of this study was to make a map of farmland vulnerability to flood inundation based on morphologic characteristics from the flood-damaged areas. Vulnerability mapping based on the records of flood damages has been conducted in four successive steps; data preparation and preprocessing, identification of morphologic criteria, calculation of inundation vulnerability index using a fuzzy membership function, and evaluation of inundation vulnerability. At the first step, three primary digital data at 30-m resolution were produced as follows: digital elevation model, hill slopes map, and distance from water body map. Secondly zonal statistics were conducted from such three raster data to identify geomorphic features in common. Thirdly inundation vulnerability index was defined as the value of 0 to 1 by applying a fuzzy linear membership function to the accumulation of raster data reclassified as 1 for cells satisfying each geomorphic condition. Lastly inundation vulnerability was suggested to be divided into five stages by 0.25 interval i.e. extremely vulnerable, highly vulnerable, normally vulnerable, less vulnerable, and resilient. For a case study of the Jinju, farmlands of $138.6km^2$, about 18% of the whole area of Jinju, were classified as vulnerable to inundation, and about $6.6km^2$ of farmlands with elevation of below 19 m at sea water level, slope of below 3.5 degrees, and within 115 m distance from water body were exposed to extremely vulnerable to inundation. Comparatively Geumsan-myeon and Sabong-myeon were revealed as the most vulnerable to farmland inundation in the Jinju.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.11
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• pp.50-57
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• 1997

In order to make unmanned machining systems with satisfactory performances, it is necessary to incorporate appropriate condition monitoring systems in the machining workstations to provide the required intelligence of the expert. This paper deals with condition monitoring for chatter, tool wear and breakage during turning operation. To develop economic sensing and identiffication methods for turning processes, sound pressure measurement and digital signal processing technique were proposed. We suppressed chatter by stability control methodology, which was studied through manipulation of spindle speeds regarding to chatter frequencies. It was shown that tool wear and fracture were identified and to be estimated by using the wear indices. The validity of the proposed system was confirmed through the large number of cutting tests.

• Journal of Digital Convergence
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• v.20 no.1
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• pp.221-229
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• 2022

This study is to develop and validate the academic motivation scale for medical students(AMSMS) based on self-determination theory. After composing preliminary questions from 74 students, a preliminary and main survey were conducted with 148 and 300 students from September to November 2020. Factor analysis, reliability analysis, and correlation analysis were used. As a result of exploratory and confirmatory factor analysis, construct validity was verified. The fitness index of the five-factor model of amotivation, external regulation, introjected regulation, identified regulation, intrinsic motivation was good. The reliability of each factor was ranged from 0.760 to 0.933. The criterion validity of AMSMS was verified by showing a correlation with academic self-efficacy and school life satisfaction. This results show that the AMSMS is both valid and reliable, and it is expected to be used in research related to academic motivation of medical students in the future.

• Journal of Digital Convergence
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• v.16 no.12
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• pp.505-510
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• 2018

This study aimed to compare the elimination effect of dental plaque between general toothbrushes and chewing toothbrushes, so as to investigate whether the chewing toothbrushes have the practicality as the alternatives of general toothbrushes and their utilities in the real life. The study subjects were 30 healthy adults in their 20s who maintained the good dental condition over 16 teeth without systemic diseases, and the decline rates of dental plaque index after usages of general and chewing toothbrushes were calculated. Upon the comparisons of dental plaque decline rates before and after the usages of general and chewing toothbrushes, PHI index was declined from 7.02 to 1.91 in case of the general toothbrush demonstrating dental plaque decline by 72.79%, while it was declined from 6.72 to 4.08 in the chewing toothbrush demonstrating decline by 39.29%. Currently, a variety of dental care items are available in the Korean market, hence, various studies are required on the dental care items so as for the people to properly choose the items.

• Journal of Korean Society of Forest Science
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• v.109 no.4
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• pp.361-370
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• 2020

Long-term observation of the life cycle of plants allows the identification of critical signals of the effects of climate change on plants. Indeed, plant phenology is the simplest approach to detect climate change. Observation of seasonal changes in plants using digital repeat imaging helps in overcoming the limitations of both traditional methods and satellite remote sensing. In this study, we demonstrate the utility of camera-based repeat digital imaging in this context. We observed the biological events of plants and quantified their phenophases in the northern temperate type deciduous broadleaf forest of Jeombong Mountain. This study aimed to identify trends in seasonal characteristics of Quercus mongolica (deciduous broadleaf forest) and Pinus densiflora (evergreen coniferous forest). The vegetation index, green chromatic coordinate (GCC), was calculated from the RGB channel image data. The magnitude of the GCC amplitude was smaller in the evergreen coniferous forest than in the deciduous forest. The slope of the GCC (increased in spring and decreased in autumn) was moderate in the evergreen coniferous forest compared with that in the deciduous forest. In the pine forest, the beginning of growth occurred earlier than that in the red oak forest, whereas the end of growth was later. Verification of the accuracy of the phenophases showed high accuracy with root-mean-square error (RMSE) values of 0.008 (region of interest [ROI]1) and 0.006 (ROI3). These results reflect the tendency of the GCC trajectory in a northern temperate type deciduous broadleaf forest. Based on the results, we propose that repeat imaging using digital cameras will be useful for the observation of phenophases.

• Journal of Digital Convergence
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• v.14 no.10
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• pp.137-145
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• 2016

The explosive growth of social networking services based on smart devices popularize these relationships and activities online in accordance with the far larger impact of this on the real life offline, the interest and importance for the online activity is increasing. In this study, factors affecting the SNS activity are defined by object, user, influence direction, influence distance and proposed a method to measure organic terms in effect between the SNS users. Influence Direction and Influence Strength (or Distance) are elaborated by using the existing influence measurement element such as structured data - the number of friends, the difference between the number of contacts - and the new influence measurement element such as unstructured data - gap between the former time and the latter time, preference and type of response behavior - that occur in social network service. In addition, the system for collecting and analysing data for measuring influence from social network service and the process model on the method for measuring influence is tested by using sample data on Facebook and explained the implementation probability.

• Journal of Digital Convergence
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• v.18 no.5
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• pp.375-382
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• 2020

The purpose of this study was to analyze the prevalence, and determine factors associated with metabolic syndrome risk among kidney transplantation recipients. This study data were collected by means of retrospective chart reviews for 111 kidney recipients at an organ transplantation center in South Korea. Data were analyzed using descriptive statistics, t-test or chi-squared test, and Pearson's correlation or Point biserial correlation. The prevalence of metabolic syndrome in our subjects was 65.8%. Metabolic syndrome was related with age, body mass index of before and after Kidney transplantation, and smoking. Study results indicate that intervention for modifying individual lifestyle behaviors is required to prevent and reduce their prevalence of metabolic syndrome after kidney transplantation.

• Journal of Digital Convergence
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• v.13 no.5
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• pp.31-39
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• 2015

In the modern society, as development innovative technology consumers could access various information. It make consumers empower in the market, and information asymmetry problem were solving more and more. In the technical information, however, there are still information asymmetry because technical information is very difficult to understand, and those are related with professional knowledge such as financial information. This study used the dataset which was collected to track Korean consumers consumption index by KCA(Korea Consumer Agency) which included consumer's problem experience at financial field. The results are followings. Firstly, consumers want to get exact and important information to decide purchase or not and comparative information in technical information area. Secondly, age is the influence variable to experience more problems in technical information section. Thirdly, consumer's subjective financial competency is major influence factor to reduce problem experience.