• The KSFM Journal of Fluid Machinery
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• v.9 no.6 s.39
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• pp.29-34
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• 2006

Propeller type pump has been widely used for pumping water in agricultural and manufacturing industry. Since a propeller type pump contains a screw impeller inside a circular casing, the numerical analysis becomes complex. However, the accurate prediction of viscous flow is essential for computing hydrodynamic performances. To analysis the flow and the performance of the propeller type pump, the present work has solved 3D incompressible RANS equations on the multiblocked grid. From the present calculation, small amount of flow separation was shown near hub and the flow was recovered to nearly uniform inflow after one diameter downstream. Torque and thrust coefficient were computed and compared with experiments.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.932-937
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• 2008

The pulsation of a reciprocating type hydrogen compressor is occurred from the mechanism and this pulsation makes much noise and vibration. To reduce this pulsation, snubber is usually installed on that. To maintain the efficiency in the reciprocating type hydrogen compressor, the pulsation and vibration should be reduced. so it is necessary to research about the characteristic of pulsation and vibration. Therefore in this paper, the vibration characteristic of the snubber is analyzed in the base of optimized modeling condition through the flowing analysis of existing snubber. The prototype of reciprocating type hydrogen compressor is analyzed with numerical analysis. And making sure the present condition of hydrogen compressor through measurement of vibration and noise, and then it is established that the vibration characteristic data base on numerical analysis which will be develope.

• Journal of Technologic Dentistry
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• v.42 no.4
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• pp.388-393
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• 2020

Purpose: This study aims to understand the relationship between university major satisfaction and job preference according to DISC behavior patterns. Methods: To conduct our evaluation, we surveyed a group of 118 students from the Department of Dental Laboratory Technology at the college of Jinju city from August 31 to September 11, 2020. The collected data was evaluated through frequency analysis, descriptive statistics analysis, one-way ANOVA, and regression analysis. Results: The analysis revealed that the steadiness type had the highest and the dominance type had the lowest major satisfaction level by DISC behavior type. The job preference was different for each DISC behavior type, and higher the preference for stability and development, the higher the degree of satisfaction with the major. Conclusion: These results suggest that DISC behavior type, major satisfaction, and job preference are all related. Therefore, these factors should be considered when implementing career guidance and educational programs for college students.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.25 no.1
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• pp.89-95
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• 2016

This study investigated the design factors of the opening area in order to consider the kinematic stability of a valve plate, conducting an analysis of the reduction effects of pressure pulsation and flow ripple depending on the design factors, using the $SimulationX^{(R)}$ (Germany) hydraulic analysis program. Further, we performed a structure analysis to confirm the kinematic stability of the valve plate in a swash plate type piston pump, and analyzed the effects of pulsation on a 1-step V-type notch, 2-step V-type notch, and 2-step U-type notch to determine the effects of pulsation reduction. Finally, we show the effectiveness of our proposed design of the pre-compression sections on a valve plate in terms of low pulsation by using the hydraulic analysis program, $SimulationX^{(R)}$.

• Journal of KSNVE
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• v.8 no.5
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• pp.949-956
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• 1998

Complex and large lattice type structures are frequently used in design of bridge, tower, crane and aerospace structures. In general, in order to analyze these structures we have used the finite element method(FEM). This method is the most widely used and powerful method for structural analysis lately. However, it is necessary to use a large amount of computer memory and computational time because the FEM requires many degrees of freedom for solving dynamic problems exactly for these complex and large structures. For analyzing these structures on a personal computer, the authors developed the transfer stiffness coefficient method(TSCM). This method is based on the concept of the transfer of the nodal dynamic stiffness coefficient matrix which is related to force and displacement vector at each node. And we suggested TSCM for free vibration analysis of complex and large lattice type structures in the previous report. In this paper, we formulate forced vibration analysis algorithm for complex and large lattice type structures using extened TSCM. And we confirmed the validity of TSCM through computational results by the FEM and TSCM, and experimental results for lattice type structures with harmonic excitation.

• Journal of the Ergonomics Society of Korea
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• v.23 no.4
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• pp.23-34
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• 2004

The importance of the industrial safety has been growing gradually as well as the prevention activities on industrial accidents. Industrial accident rates have been decreasing by the prevention activities. However, the fatal industrial accidents such as the death tend to increase and risk per accident has increased. The previous studies on the industrial accidents focus on the entire accidents. However, these studies are lacking for the fatal industrial accidents such as the death. The purpose of this paper is to analyze the characteristics and trend of death which occurred by industrial accident, based on the real data of deaths collected last 5 years from 1999 to 2003 in korea. This paper suggests a analysis method using MDS(MultiDimensional Scaling) that considers accidents variables and properties simultaneously. We evaluate MDPREF (Multidimensional Analysis of Preference Data), one of the MDS analysis, to know the relations between the type of industry and region as well as the type of industry and occupation. This paper finds the type of industry which has high possibilities of death by regional groups. In addition, we find the type of occupation which has high possibilities of death by the type of industry. These findings indicate that industrial classification should be differently controled according to type of occupation and region.

• Journal of the Korean Home Economics Association
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• v.34 no.2
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• pp.183-199
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• 1996

The objective of this study was to provide fundamental data on somatotype for elderly women by classifying the somatotype and analysing the 3 characteristics of their somatotype. The subject were 368 women of 60~84 years old, they were analyzed indirect photography. To find out differences among the age groups, the 368 subjects were grouped into two age groups (Group 1 ; age 60 to 69, Group 2 ; aged 70 to 84). Data were analyzed using Factor analysis, Cluster analysis, duncan test and Analysis of variance. Through the factor analysis, 27 items from photometric measurements respectively. Cluster analysis was applied for classification of somatotype. The results of this study were as follows. 1. The characteristics of Elderly women's somatotype were bending of the upper-torso, fatness of the waist and abdomen, drooping of the bust and shoulder and hip. In addition, height, girth, depth and width items were decreased in their sizes respectively. 2. The characteristics of clusters were as follows. Type 1 was straight somatotype in which the plumb line through tragion, the bust depth and under bust depth region laterally. Type 2 was swayback somatotype in which the upper portion of protruding point on the back was bent forward but the lower portion of protruding point had a characteristics of turning over somatotype. Type 3 was bending somatotype. Namely, this type was shorter than average and below the average fatness. Generally, the lateral view silhouette of elderly women was the straight type and changed into bending type as the age increases.

• Journal of Power Electronics
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• v.17 no.4
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• pp.1027-1036
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• 2017

The brushless doubly-fed induction generator (BDFIG) is a new type of dual stator winding induction generator. In such a generator, both the power winding (PW) and the control winding (CW) are housed in the stator. This paper presents the performance characteristics of a stand-alone BDFIG operation system. A new T-type steady-state model of a BDFIG is proposed. This model is more suitable for the performance analysis of stand-alone BDFIGs than the conventional Π-type steady-state model and the simplified inner core steady-state model. The characteristics of the power flow and CW current are analyzed by detailed mathematical derivations on the basis of the proposed T-type steady-state model. The analysis results are verified by experiments, which are carried out on a prototype BDFIG. The results of the performance analysis contribute to simplifying the control circuit, improving the control performance, and selecting an appropriate BDFIG for actual industrial applications.

• The Journal of Information Systems
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• v.32 no.3
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• pp.41-61
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• 2023

Purpose This study aims to categorize the types of health, analyze the effects among health types based on network analysis find the most important type of health, and explain whether the results between health types vary depending on demographic characteristics. Design/methodology/approach This study investigated individual physical, clinical, mental, and social health(social capital and social support) levels through a survey of 100 people. Network analysis was applied to the survey data to confirm the degree centrality of nodes. Furthemore, we investigated the differences in core nodes according to gender and age groups. Findings According to the analysis result, social support was the most important health type in the entire group. Furthermore, the importance of health type was different depending on the characteristics of the groups. In the case of men, clinical health was the most important health type, and social support was analyzed to be the most important for women. In the case of young people, clinical health was the most important health type, and mental health was the most important health type in the middle-aged.

• Journal of the Korean housing association
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• v.20 no.1
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• pp.1-10
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• 2009

This paper documents research carried on the University students who are potential residents of the city to find out their preference for the ubiquitous residential functions, and categorize based on the life style to find out difference of their preference on ubiquitous residential functions. A survey was conducted on 324 university students in Gwangju city. The students were selected through purposive sampling and quota sampling by self-administered questionnaire sheets. The analysis analyzing methods using SPSS/PC 12.0 are frequency, percentage, factor analysis, cluster analysis, $x^2$(chaisquare)-test and one-way ANOVA (analysis of variance). For the survey, lifestyle types were categorized as: These are classified based on the analysis of facts regarding characteristics of student's lifestyles that are divided into nine types of facts and then make the four types through the cluster analysis as below. Energetic life type, Inactive life type, Family-oriented life type, Thrifty and Personality-oriented life type. The residential function of Ubiquitous is classified as Safety, Convenience, Comfortableness, Information, Health, Leisure and the residential space is divided into bedroom, livingroom, kitchen, bathroom. Considering the preference aspects for Ubiquitous residential function, among the bedroom, living room, kitchen, and bathroom, University student seek for safety from the living room, Convenience from the kitchen and Comfortableness from the living room, bedroom and kitchen. For Information, bedroom is most preferred among the bedroom, living room, and kitchen. For Health and Leisure, bedroom is preferred between bedroom and living room. In terms of the difference about the preferences for ubiquitous functions based on the four types of lifestyles; The Thrift-oriented type is commonly preferred to the Inactive type among the bedroom, living room and kitchen. The Family-oriented and the Thrift-oriented type were preferred to the Energetic and Inactive types in the bathroom. Also, in the entire residential space, the Ubiquitous functions is most preferred by the Thrifty and Personality-oriented life type.