• KSBB Journal
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• v.11 no.4
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• pp.405-410
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• 1996

This paper discussed the dispersion effect according to the geometrical variation of an internal-loop spparatus by the method of pulse injection of a tracer. The Bodenstein number, which is the dimensionless group characterizing the effect of dispersion, was decreased with increasing the superficial gas velocity in the 50L and the 500L apparatus. But, in the 5L apparatus, the Bodenstein number was increased with increasing the superficial gas velocity in the range of 0 to 2cm/sec but above that range the rate of increase was dropped down to give a constant value because of the phenomenon of gas disengagement. The principle of similarity based on dimensional analysis was applied to design a pilot scale internal-loop apparatus. The effect of dispersion was examined in three different internal-loop apparatus to give the following correlation with major geometric and fluid dynamic properties as variables. B0=4.4014ReG0.117 ReL-0.0065(Hr/Dr)0.76(Dd/Dr)-0.76

• Korean Institute of Interior Design Journal
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• no.6
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• pp.45-52
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• 1995

The presentation of the method by which the furniture and the architecture can be unified in one category, and the study and the verification on the mutual relation in the shape and the function are having been consistently made till the late twenties. The change of the social structure such as increasing the unit dwelling space with the small scale comes to need the efficiency in using space and the open dwelling space by the systematic spa-cial formation. Therefore, the understanding of the mean-ing and the characteristics of system furnitures as the design method which can meet such needs will be made here in this study. The application of the systematic consideration as the method of interior design means the formation of the firm image on the spacial environment through the mix-ture and link of the heterogeneous factors, the organic connection of each surface, the establishment of the natu-ral relation by linking the heterogeneous materials mutu-ally. and the easiness of the entire plan in the end. This study aims at analyzing and studying the typical charac-teristics by understanding the historical background and methodical principle which enabled the appearance of this kind of thought, and the adapted cases of the wood and metal material system furniture. There may be difference between the structural sub-stance and formative consideration. Transformative furni-ture which consists of the factors is the concept for the encrease of the multi purpose value by mixing the unit cabinets. One system can be separated horizontally, verti-cally, and to the drawers, and it gives us the disengage-ment from the artificial environment, since all the heights and width can be transformed as per each situa-tion of the space. The factors which can not be found in the other existing furniture are as follows. 1. disengagement from the artificial environment. 2. establishing the new productiosn trend as freed from the customers' fashion trend. 3. presenting the producing condition which leads the exact technology. 4. flexibility of the furniture which enables the reduction and enlargement in each situation.

• Tribology and Lubricants
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• v.33 no.1
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• pp.1-8
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• 2017

Drag torque reduction in a wet clutch pack is a key aspect of the design process of the dual clutch transmission (DCT) system. In order to reduce the drag torque caused by lubricant shear resistance, recently developed wet clutch pack systems of DCT, as well as automatic transmission and other four-wheel drive (4WD) couplings, frequently utilize wavy wet clutch pads. Therefore, wavy shape of friction pad are made on the groove patterns like waffle pattern for the reduction of drag torque. Additionally, the groove patterns are designed with larger channels at several locations on the friction pad to facilitate faster outflow of lubricant. However, channel performance is a function of the waviness of the friction pad at the location of the particular channel. This is because the discharge sectional area varies according to the waviness amplitude at the location of the particular channel. The higher location of the additional channel on the friction pad results in a larger cross-sectional area, which allows for a larger flow discharge rate. This results in reduction of the drag torque caused by the shear resistance of DCTF, because of marginal volume fraction of fluid (VOF) in the space between the friction pad and separator. This study computes the VOF in the space between the friction pad and separator, the hydrodynamic pressure developed, and the shear resistance of friction torque, by using CFD software (FLUENT). In addition, the study investigates the dependence of these parameters on the location and waviness amplitude of the channel pattern on the friction pad. The paper presents design guidelines on the proper location of high waviness amplitude on wavy friction pads.

• Journal of Convergence for Information Technology
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• v.9 no.10
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• pp.203-212
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• 2019

The purpose of this study was to identify the effects of stress factors of student pilots on mental health, and to reduce the safe and efficient misconduct education and psychological disharmony by identifying the psychological buffering role of stress coping style and social support. In order to achieve the research purpose, a research model and hypothesis were presented based on previous studies, and regression analysis and mediation effect verification were conducted through a questionnaire survey of 202 student pilots. As a result of the analysis, factors such as flight stress, values stress, professor stress, and friend relationship stress have been shown to affect emotional conditions or psychological well-being. Also we found that the parameters of disengagement coping, family/friend support and organization Support had a mediating effect on the factors between student pilot stress and psychological health. Therefore, student pilots need to manage problems and negative emotions that may cause from flight training, value distractions, professor and friendships' relationship and it is suggested that organization support for training and safety related to emotional support and delinquency of family and friends.

• Korean Journal of Culture and Social Issue
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• v.14 no.1_spc
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• pp.223-253
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• 2008

This article examines the cost of pressure to achieve in Korea, which is the theme of the special issue focusing on the psychological dynamics and factors influencing delinquent behavior among Korea adolescents. This article reviews empirical studies of delinquent behavior among Korean adolescent and articulate policy and programs necessary to prevent the rising trend. First, in order to prevent delinquent behavior and enhance their self-efficacy, programs need to be developed to allow them to succeed in non-academic areas. Second, adolescents who engage in delinquent behavior are likely to experience problems in interpersonal, such as parental rejection, social exclusion from friends and hostility from teachers. Third, adolescents delinquent behaviors are influenced by negative parental socialization practices, delinquent behavior of their peers, moral disengagement and their previous participation in delinquent behavior. Fourth, the importance of indigenous psychological approach to increase the quality of life for adolescents who engage in delinquent behavior is outlined.

• Science of Emotion and Sensibility
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• v.21 no.2
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• pp.73-88
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• 2018

The present study examined how processing features of visual information near the hand would affect task switching. Recent studies reported enhanced cognitive control of visual information presented the near hands. To investigate the enhancement of cognitive control based on the relationship between hand proximity and attention, we implemented 2 experiments. In the task switching performance experiment, the hand proximity effect depended on modality of cue and target. The first experiment showed that stimuli near the hand received greater cognitive control than stimuli far from the hand, resulting in smaller switch cost. The result could rule out the feature-binding problem, which identifies reduced switch cost as the cause instead of hand proximity. Our results show that hand proximity actually reduced switch cost. In the second experiment, we examined the effects of hand nearness, modality, and their interaction on switch cost. In task switching, the target was always visual, and the cue was presented either visually or auditorily. In addition, we manipulated the cue-target interval to observe the preparation effect of cue. The results showed that a visual cue near the hand reduced switch cost by shortening task preparation time. Also, modality switching between an auditory cue and visual target was remarkable in a hand-near condition. The results for the visual cue could be interpreted as a benefit of rapid visual attention orienting. On the other hand, the results for the auditory cue could be interpreted as the cost of interference of modality switching by slower attentional disengagement of stimuli near the hands. Finally, modulation of switch cost by attention induced by hand nearness was discussed.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.12
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• pp.1005-1011
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• 2016

The fundamental reason for gear noise is transmission error. Transmission error occurs because of STE (static transmission error) and DTE (dynamic transmission error), while a pair of gears is meshing. These errors are generated by the deflection of the teeth and the friction on the surface of the teeth. In addition, the vibration generated by transmission error leads to excited bearings. The bearings support the shafts, and the noise is radiated after exciting the gear casing. The analysis of the contact stress in helical gear tooth flanks indicates that it is due to impact loading, such as the sudden engagement and disengagement of a gear. Stress analysis is performed for different roll positions, in order to determine the most critical roll angle. Dynamic analysis is performed on this critical roll position, in order to evaluate variation in stresses and tooth contact force, with respect to time. In this study, transmission error analysis was implemented on a spur and helical gear with involute geometry and a modified geometry profile. In addition, in order to evaluate the intensity of impact due to sudden engagement and significant backlash, the impact factor was calculated using the finite element analysis results of static and dynamic maximum bending stresses.

• Korean Journal of Culture and Social Issue
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• v.28 no.2
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• pp.107-131
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• 2022

This study was conducted with the aim of developing and validating a measure of the workplace bullying bystander behavior. For the purpose, items were developed by referring to previous studies related to workplace bullying, and behavior subtypes were defined as pro-bullying, defending, and bystander behaviors. After confirming the content validity with the help of experts, a total of 31 preliminary items were composed. The final 26 items were selected by conducting an exploratory factor analysis and verifying the validity and reliability of the scale with a survey of 288 office workers who have directly or indirectly witnessed workplace bullying over the past three years. In this process, it was confirmed that defense behavior was distinguished into two types: Active and supportive. Confirmatory factor analysis was conducted with data from 518 office workers who have directly or indirectly witnessed workplace bullying over the past year, and the validity and reliability of the developed scale were confirmed. As a result of comparing the competing models to reconfirm the subtypes, it was confirmed again that active defense behavior and supportive defense behavior were distinguished. The criterion-related validity of all subtypes was confirmed by setting the criterion variables for workplace bullying behavior, altruistic behavior, pro-social behavior, fear of intervention, moral disengagement, guilt, and moral identity. Based on the result of this study, follow-up research tasks related to workplace bullying bystander behavior scale were suggested and the methods to prevent and intervene in workplace bullying while utilizing workplace bullying bystander behaviors were discussed.

• Korean Journal of Social Welfare
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• v.69 no.4
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• pp.41-65
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• 2017

This study aimed to examine the social transition, which is often metaphorized as the Fourth Industrial Revolution, within the context of social work practice and to explore measures to improve social work practice in such transition. Four social welfare researchers held seven discussions to predict the social changes in the near future centered on the Fourth Industrial Revolution and find the corresponding development strategies in social work practice; collective autobiography method was used to analyze the discussion. The analysis ascertained hyper connectivity, the advent and expansion of new communities, diversification and individualization, and the emergence of new criteria for the assessment of one's quality of life as the distinctive qualities of the near future. It was analyzed that humans and organic materials will be interconnected through spatial and temporal transcendence and that humans liberated from labor will seek for diverse communities while the number of atomized individual will increase simultaneously. Furthermore, the rise of new order of life accompanied by both the expansion of diversification and individualization and the ecological worldview brought forth by post materialistic trend was predicted. Meanwhile, the disengagement from macroscopic context, a biased inclination towards technique orientated professionalism, and individualistic social work practices without integrity were identified as the limitations of the current social work practice. This study presented three goals for social work practice to help it overcome its current shortcomings and correspond to the social changes: first, the rearrangement of practice knowledge, technique, and value so that it is based on humans and society, which are the essence of social practice work; second, the practice, such as sharing economy, that expands the individuals' boundaries of life to the community; three, the restoration of the desirability of professional social works by examining its special nature.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.5
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• pp.182-199
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• 2023

Since 2021, government departments have been promoting Automated Driving Technology Development and Innovation Project as national research and development(R&D) project. The automated vehicles and service technologies developed as part of these projects are planned to be subsequently provided to the public at the selected Living Lab City. Therefore, it is important to determine a spatial area and operation section that enables safe and stable automated driving, depending on the purpose and characteristics of the target service. In this study, the static Operational Design Domain(ODD) elements for Level 4 automated driving services were reclassified by reviewing previously published papers and related literature surveys and investigating field data. Spatial analysis techniques were used to consider the reclassified ODD elements for level 4 in the real area of level 3 automated driving services because it is important to reflect the spatial factors affecting safety related to real automated driving technologies and services. Consequently, a total of six driving mode changes(disengagement) were derived through spatial information analysis techniques, and the factors affecting the safety of automated driving were crosswalk, traffic light, intersection, bicycle road, pocket lane, caution sign, and median strip. This spatial factor analysis method is expected to be useful for determining special areas for the automated driving service.