• Journal of the Korean Society for Precision Engineering
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• v.14 no.12
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• pp.143-152
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• 1997

The deflection of an end mill is very important in machining process and cutting simulation because it affects directly workpiece accuracy, cutting force, and chattering. In this study, the deflection of the end mill was studied both experimentally and by using finite element analysis. And the moment of inertia of cross sections of the helical end mill is calculated for the determination of the relation between geometry of radial cross section and rigidity of the tools. Using the Bernoulli-Euler beam theory and the concept of equivalent diameter, a deflection model is established, which includes most influences from tool geomety parameters. It was found that helix angle attenuates the rigidity of the end mill by the finite element analysis. As a result, the equivalent diameter is determined by tooth number, inscribed diameter ratio, cross sectional geometry and helix angle. Because the relation betweem equivalent diameter and each factor is nonlinear, neural network is used to decide the equivalent diameter. Input patterns and desired outputs for the neural network are obtained by FEM analysis in several case of end milling operations.

• The Journal of Industrial Distribution & Business
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• v.12 no.1
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• pp.31-46
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• 2021

Purpose: The purpose of the study is to analyze the characteristics of emotional intelligence and the variables related to emotional intelligence in a comprehensive manner. In addition, the study intends to present research trends and future research directions of emotional intelligence in a Korean context by analyzing the effects of emotional intelligence and its mechanisms. Research Design, Data, and Methodology: 77 KCI listed studies were selected for the analysis, and the research perspective of emotional intelligence, measurement instruments, empirical research and research methods were analyzed. In addition, research directions were suggested based on the analysis results. Results: The results of the analysis were as follows: First, previous researchers used the ability model of emotional intelligence the most. Second, Previous studies tended to focus on behavioral factors as dependent variables affected by emotional intelligence, in addition to attitudes, affection. Third, there were few studies on the antecedents of emotional intelligence, however, most studies dealt with the consequences of emotional intelligence. Fourth, few studies dealt with moderators between emotional intelligence and dependent variables. Fifth, on the research type, most studies were quantitative studies, however, a few of them were qualitative studies (Literature review, in-depth interview). Sixth, with regard to the analysis level, almost all studies were conducted on the individual level of emotional intelligence, and most studies featured a cross-sectional research design (longitudinal research design was rare). Conclusion: First, from the perspective of emotional intelligence, additional research should be focused on not only the ability model of emotional intelligence but also on the trait model or the mixed model in the future. Second, since emotional intelligence is a multidimensional construct, it is necessary to study the profile of emotional intelligence by employing people-centered as well as variable-centered methods. Third, with regard to empirical studies, additional research is needed with respect to not only the emotional intelligence of the subordinate, but also the emotional intelligence of the supervisor (leader) and the emotional intelligence of the group. Fourth, it is necessary to actively utilize not only cross-sectional design but also longitudinal design, and qualitative research and meta-analysis methods should also be adopted.

• Proceedings of the KSME Conference
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• 2001.06e
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• pp.341-348
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• 2001

The purpose of present study is to investigate for reducing pressure fluctuations in the case of installing the air-shafts on the side wall of the tunnel with small cross-sectional area on conventional line. Experiments were performed with a 1/61-scale moving model rig for the tunnel of 0.764 km length in the condition of tunnel cross-section area of $28 m^2$. According to the results, the maximum pressure fluctuation is reduced by 45 % for 19 air-shafts. This results have the speed-up effects of about 33.4 km/h for the train running in tunnel.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.883-886
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• 1997

In all Rapid Prototyping (RP) processes, a CAD solid model is sliced ito thin layers of uniform, but not necessarily constant, thickness in the building direction. Each cross-sectional layer is successively deposited and, at the same tim, bonded onto the previous layer; the stacked layers form a physical part of the model. The objective of this study is to develop a methode for calculating the rotational angle(θ/sub x/, θ/sub y/) of the linear hotwire cutting system in the three-dimensional space for the Variable Lamination Manufacturing process using expandable polystyrene foam sheet (VLM-S). In order to examine the applicability of the developed method to VLM-S, various three-dimensional shapes, such s a screw, an extruded cross, and a figure of Sonokong, were made using the data obtaiend from the method.

• Korean Journal of Computational Design and Engineering
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• v.14 no.4
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• pp.281-289
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• 2009

Topology optimization has been widely used for the optimal structure design for weight reduction and high performance. Since the result of three-dimensional topology optimization is represented by the discrete material distribution in finite elements, it is hard to interpret from a design point of view. In this paper, the method for interpreting three-dimensional topology optimization resuIt into a series of cross-sectional curve representation is proposed and interfaced with the existing CAD system for the practical use. The concept of node density and virtual grid is introduced to transform element density values into grid density and material boundaries in each cross section are identified based on the element volume rate to satisfy the amount of material specified in the original design intent. Design exampIes show that three-dimensional topology result can be converted into a form of curve CAD model and the seamless interface with CAD software can be achieved.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1885-1888
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• 2004

In order to render 3D model of the bone, the stack of cross-sectional images must be reconstructed from a series of X-ray radiographs, served as the projections. In the case where the distance between x-ray source and detector is not infinite, image reconstruction from projection based on parallel-beam geometry provides an error in the cross-sectional image. In such case, image reconstruction from projection based on conebeam geometry must be exercised instead. This paper is devoted to the determination of detector center for SART conebeam Technique which is critically effect the performance of the resulting 3D modeling.

• Korean Journal of Adult Nursing
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• v.25 no.4
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• pp.389-399
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• 2013

Purpose: The purpose of the study was to examine the relationships between cognitive coping, hope, depression, and life satisfaction of hemodialysis patients based on the stress-coping model. Methods: For this cross-sectional survey, 142 participants were recruited from 10 local clinics in Seoul and Daegu during 2012-2013. The data collection instruments included the Cognitive Emotion Regulation Questionnaire, the Herth Hope Index, the Hospital Anxiety and Depression Scale, and the Satisfaction with Life Scale. The data were analyzed using descriptive statistics, t-test, ANOVA, Pearson's correlation analysis, and stepwise multiple regression. Results: The cognitive coping scores were significantly related to hope, depression, and life satisfaction. The coping strategies explained 80%, 37%, and 38% of the variances in hope, depression, and life satisfaction, respectively. The most powerful coping strategy was positive refocusing, explaining 73% in hope, 25% in depression, and 25% in life satisfaction. Conclusion: The results of the study indicate that cognitive coping plays an essential role for psychological adaptation of hemodialysis patients. Thus, interventions integrating positive refocusing would help instilling hope of hemodialysis patients in Korea.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.27 no.11
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• pp.679-685
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• 2014

For the measurements of surface shape milled using FIB (focused ion beam), the silicon bulk, $Si_3N_4/Si$, and Al/Si samples are used and observed the shapes milled from different sputtering rates, incident angles of $Ga^+$ ions bombardment, beam current, and target material. These conditions also can be influenced the sputtering rate, raster image, and milled shape. The fundamental ion-solid interactions of FIB milling are discussed and explained using TRIM programs (SRIM, TC, and T-dyn). The damaged layers caused by bombarding of $Ga^+$ ions were observed on the surface of target materials. The simulated results were shown a little bit deviation with the experimental data due to relatively small sputtering rate on the sample surface. The simulation results showed about 10.6% tolerance from the measured data at 200 pA. On the other hand, the improved analytical model of damaged layer was matched well with experimental XTEM (cross-sectional transmission electron microscopy) data.

• Earthquakes and Structures
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• v.4 no.2
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• pp.133-155
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• 2013

The earthquake responses are studied for the tall flexible structures such as TV towers when the vertical eccentricities between the discrete nodes and the corresponding centroids of investigated lumps are considered. In practical analyses, the tall flexible structures can be made into a spatial-discrete system of some certain length of beam elements with different lengths and cross-sectional areas. These elements are used to construct the investigated lumps in this paper. The different cross-sectional areas and the different lengths of two adjacent elements lead to the appearance of vertical eccentricity between the discrete node and the centroid of investigated lump within the same investigated lump. Firstly, the governing equations are established for a typical investigated lump. Secondly, the calculating formulae of the forces and moments acting on the investigated lump are derived and provided. Finally the new dynamic equilibrium equations with modified mass matrix and assemblage of stiffness matrix have been derived for the stick MDOF model based on beam theory when the existing vertical eccentricities are considered. Numerical results demonstrate that these vertical eccentricities should be considered in order to obtain the accurate earthquake responses for the tall flexible structures.

• Journal of Korea Foundry Society
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• v.26 no.2
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• pp.85-91
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• 2006

Inclusions in Ti investment castings are generally known to have detrimental effects on the performance of the castings. However, actual inclusions are infrequent and hard to be located. As a result, it is extremely difficult to obtain sufficient amount of fatigue test specimens of titanium investment castings having inclusions in the gage section. Thus, in-depth research of the adverse influence of inclusions is also hindered. To address this problem, a new casting methodology of specimens containing hard alpha inclusions was developed in this study. To guarantee successful introduction of an inclusion and casting, a carefully designed mold with 8 legs and a special tool were employed. After solidification, castings were cut, and X-ray radiography determined that the inclusions were successfully incorporated into the castings. The castings were further prepared to obtain multiple test specimens and they were fatigue-tested consecutively. Fractography analysis confirmed that fatigue cracks initiated at the hard alpha inclusion. In a nonlinear regression model, the fatigue life can be modeled as an exponential function with a negative exponent of the cross-sectional area of an inclusion. The fatigue life of Ti specimens containing inclusions is inversely proportional to the cross-sectional area of an inclusion.