• Proceedings of the KSR Conference
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• 2004.06a
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• pp.1303-1307
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• 2004

MAGLEV is the vehicle which can run in levitated condition by the electro-magnets, and the vehicle can run without any contact condition. In MAGLEV system achieving a high magnetic field for minimum weight is a noteworthy goal. Unfortunately the two aspects of this goal high field and low weight are contradictory. Suitable designs must be sought using optimization techniques. In this paper, magnet attraction force is calculated and conformed by experimental data for designing a electro-magnet.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.51 no.10
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• pp.545-553
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• 2002

This paper is about the analysis of 3-dimensional magnetic field distribution in CPM(Convergence Purity Magnet) considering magnetization vector and the optimum design of CPM. The magnetization vector of CPM is obtained using 2-dimensional magnetization FEA(Finite Element Analysis) coupled with Priesach model. Using this magnetization vector of CPM, we analysed the 2-dimensional and 3-dimensional magnetostatic field of CPM and know that these analysis results are not equal. From experimental result, we know that the 3-dimensional analysis is accurate because the magnetic field distribution in CPM cannot be considered correctly by 2-dimensional analysis because of the shape of CPM. Finally, the optimum designing of CPM which control accurately the electron beam deflection in CRT(Cathode Ray Tube) was possible using 3-dimensional magnetic field analysis result.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.23 no.1
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• pp.87-93
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• 2014

This paper provides a methodology for extracting design data from the three-dimensional design software SolidWorks$^{(R)}$, which is based on the existing trochoid pump design equations that are used by hydraulic field engineers. The data extracted from the SolidWorks$^{(R)}$ model are input to a hydraulic analysis software AMESim model to determine the design factors that can influence the properties of a trochoid pump. On the basis of the simulation results, this paper proposes a method to reduce the flow loss by adjusting the outlet angle of the trochoid pump. This proposal was verified by using actual experimental results, which confirmed that adjusting the outlet angle can increase the flow rate. Hence, the results presented in this paper can contribute to the prototyping of a trochoid pump by reducing the cost associated with a trial-and-error design.

• The Journal of the Convergence on Culture Technology
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• v.10 no.3
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• pp.901-907
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• 2024

The desire to be beautiful naturally focuses on aesthetics, and the beauty industry is growing significantly accordingly. Among them, art makeup is developing in the beauty field as a creative and experimental art field that breaks away from the fixed framework centered on color and expression. Art makeup is a field that requires research on a new artistic form of art makeup that applies formative principles through design ideas based on integrated arts such as fashion, architecture, and art according to formative principles. Formative principles were classified into balance, unity, emphasis, and rhythm, and practical cases based on his applied integrated arts were divided into landscaping, architecture, flowers, painting, fashion, and interior design, and art makeup design using formative principles was analyzed. Accordingly, we aim to contribute to the development of new designs by explaining how makeup design forms that apply formative principles are being applied in the field of art makeup, exploring expansion into creative areas, and providing academic theoretical foundations and basic materials for the development of art makeup.

• Journal of Convergence for Information Technology
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• v.10 no.2
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• pp.193-200
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• 2020

This study proposes the Field Oriented Capacity Upgrade Program, an educational model for improving clinical practice of occupational therapy. The effectiveness of the self-directed learning ability and problem solving ability of students was compared by comparing the proposed educational model with the traditional teaching method. The research method was divided into the experimental group who participated in the model education and the control group who participated in the lecture class, and conducted similar experimental studies using the nonequivalent control group pretest-posttest design. In addition, the study participants conducted a preliminary and follow-up survey of a total of 135 students who participated in the education over three semesters. As a result of training using the proposed learning method, the experimental group improved self-directed learning ability and problem solving ability by 22% and 18%, respectively, compared to the control group. This study developed and proposed a new teaching-learning method to improve clinical practice of occupational therapy, and it is meaningful as a basic data of teaching-learning method to improve the ability required in various jobs.

• Journal of The Korean Society of Integrative Medicine
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• v.2 no.3
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• pp.23-30
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• 2014

Purpose : The purpose of this study was to grasp the general status and trend of the driving rehabilitation research focusing on interested topics, study subjects, therapeutic approaches, study designs, etc. Methods : It targeted 18 papers published in the RISS (Research Information Service System) from 2000 to 2014, and performed a descriptive statistical analysis by classifying these papers to topics, study subjects, study forms, study designs, study fields, and researchers. Results : As a result of the analysis, for the study form in the driving rehabilitation field, the rate of experimental papers was 61.1%, the highest. Major study subjects turned out to be occupational therapists, the disabled, and the aged, in order. For the study quality and design, the rate of survey and non randomized-single experimental study, which correspond to stage IV, was the highest, and the general study quality was found to be low. For the study field, the rates of the roles and recognition of occupational therapists, evaluation on driving ability of the disabled, and institutional improvement and future measures were the highest, each of which being 16.7%. Conclusion : Through this study, major study subjects and study quality in the driving rehabilitation field could be grasped, and it could be found that for development of the driving rehabilitation field, higher quality researches on more various study subjects would be needed in the future.

• Korean Journal of Materials Research
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• v.28 no.11
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• pp.671-679
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• 2018

Finite element analyses are carried out to understand the piezoelectric behaviors of ZnO nanowires. Three different types of ZnO nanowires, with aspect ratios of 1:2. 1:31, and 1:57, are analyzed for uniaxial compression, pure bending, and buckling. Under the uniaxial compression with a strain of $1.0{\times}10^{-4}$ as the reference state, it is predicted that all three types of nanowires develop the same magnitude of the piezoelectric fields, which suggests that longer nanowires exhibit higher piezoelectric potential. However, this prediction is not in agreement with the experimental results previously reported in the literature. Such discrepancy is understood when the piezoelectric behaviors under bending and buckling are considered. When only the strain field due to bending is present in bending or buckling, the antisymmetric nature of the through-thickness stain distribution indicates that two piezoelectric fields, the same in magnitude and opposite in sign, develop along the thickness direction, which cancels each other out, resulting in a zero net piezoelectric field. Once additional strain contribution due to axial deformation is superposed on the bending, such field cancelling is compensated for due to the axial component of the piezoelectric field. Such numerical predictions seem to explain the reported experimental results while providing a guideline for the design of nanowire-based piezoelectric devices.

• Structural Engineering and Mechanics
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• v.89 no.2
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• pp.199-211
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• 2024

The loading capacity of engineering structures/components reduces after the initiation and propagation of crack eventually leads to the final failure. Hence, it becomes essential to deal with the crack and its effects at the design and simulation stages itself, by detecting the prone area of the fracture. The phase-field (PF) method has been accepted widely in simulating fracture problems in complex geometries. However, most of the PF methods are formulated with second order continuity theoryinvolving C⁰ continuity. In the present study, PF method based on fourth-order (i.e., higher order) theory, maintaining C¹ continuity has been proposed for ductile fracture simulation. The formulation includes fourth-order derivative terms of phase field variable, varying between 0 and 1. Applications of fourth-order PF theory to ductile fracture simulation resulted in novelty in this area. The proposed formulation is numerically solved using a two-dimensional finite element (FE) framework in 3-layered manner system. The solutions thus obtained from the proposed fourth order theory for different benchmark problems portray the improvement in the accuracy of the numerical results and are well matched with experimental results available in the literature. These results are also compared with second-order PF theory and a comparison study demonstrated the robustness of the proposed model in capturing ductile behaviour close to experimental observations.

• Applied Chemistry for Engineering
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• v.29 no.2
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• pp.215-224
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• 2018

Influences of the magnetic field on 5, 10 and 15 wt% (1.5, 3 and 4.5 M) HCl solution behaviour, which has widespread applications in petroleum well acidizing, were investigated in various conditions. Differences in the pH of magnetized hydrochloric acid compared to that of normal hydrochloric acid were measured. Taguchi design of experimental (DoE) method were used to model effects of the magnetic field intensity, concentration, velocity and temperature of acid in addition to the elapsed time. The experimental results showed that the magnetic field decreases [$H^+$] concentration of hydrochloric acid up to 42% after magnetization. Increasing the magnetic field intensity (with 28% contribution), concentration (with 42% contribution), and velocity of acid increases the effect of magnetic treatment. The results also demonstrated that the acid magnetization was-not influenced by the fluid velocity and heating. It was also displayed that the acid preserves its magnetic memory during time. The optimum combination of factors with respect to the highest change of [$H^+$] concentration was obtained as an acid concentration of 10% and an applied magnetic field of 4,300 Gauss. Due to the reduction of HCl reaction rate under the magnetization process, it can be proposed that the magnetized HCl is a cost effective and reliable alternative retarder in the matrix acidizing of hydrocarbon (crude oil and natural gas) wells.

• Journal of the Korean Society for Library and Information Science
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• v.25
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• pp.325-341
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• 1993

The experimental method, when carried out properly, is the most powerful way of seeking answers to research questions. The purpose of this study is to provide practical and theoretical insights as well as to discuss technical skills needed to design and implement the experimental research in library and information science. The levels of empirical research methods, the logic and types of the experimental designs, the application status of the experimental methods through content analysis of the published papers, and strategies to plan the research and to collect and analyze data are examined. This study also brings suggestions how experimental research can be made more meaningful and puts emphasis on the need of the research method education in library and information science field.