• 한국공작기계학회논문집
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• 제17권5호
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• pp.23-29
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• 2008

Magnetic abrasive polishing is one of the nontraditional machining technologies newly developed. But it was very difficult to cut non-magnetic materials using MAP process because the process was fundamentally possible by help of a magnetic farce. In this study, we aimed to verify analytically formation of the magnetic field in a case of the nonmagnetic materials especially focused on an aluminum alloy. And also an improving strategy of the magnetic force for the non-magnetic materials was proposed and experimentally verified. Design of experimental method was adopt for assessment of parameters' effect on the MAP results of the aluminum alloy.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 춘계학술대회 논문집
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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.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제51권10호
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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.

• 한국생산제조학회지
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• 제23권1호
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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.

• 문화기술의 융합
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• 제10권3호
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• pp.901-907
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• 2024

아름다워지고자 하는 욕구는 자연스럽게 미적으로 관심이 중시되고 그에 따라 뷰티산업도 크게 성장하고 있다. 그 중 아트메이크업은 색채와 표현을 중심으로 고정된 틀에서 벗어나 독창적이고 실험성이 있는 예술분야로 뷰티영역에서 발전하고 있다. 아트메이크업은 조형원리에 따라 통합예술을 토대로 한 패션, 건축, 미술 등을 모티브로 디자인 발상을 통해 조형원리를 적용한 아트메이크업에 대한 새로운 예술적인 형태 연구가 필요한 분야이다. 조형원리를 균형, 통일, 강조, 리듬으로 분류하여 그의 적용된 통합예술을 토대로 한 실질적 사례를 조경, 건축, 화훼, 회화, 패션, 인테리어로 구분하여 알아보고, 조형원리를 적용한 아트메이크업 디자인 분석하였다. 이에 아트메이크업 분야에서 조형원리를 적용한 메이크업 디자인 형태가 어떻게 적용되고 있는지와 창의적 영역으로의 확대모색과 아트메이크업 발전에 학문적으로 이론적 토대와 기초자료를 제공함으로 새로운 디자인 개발에 기여하고자 한다.

• 융합정보논문지
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• 제10권2호
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• pp.193-200
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• 2020

본 연구는 작업치료의 임상중심 실무능력 향상을 위한 교육모델인 Field Oriented Capacity Upgrade Program을 제안하였다. 제시한 교육모델과 전통적인 강의식 교육방식을 비교하여 학생의 자기주도 학습능력과 문제해결능력에 미치는 효과성을 검증하였다. 연구방법은 제시한 모델교육에 참여한 실험집단과 강의식 수업에 참여한 대조 집단으로 나누어 비동등성 대조군 전후 설계(nonequivalent control group pretest-posttest design)를 이용한 유사 실험연구로 진행하였다. 또한 연구 대상은 3학기에 걸쳐 교육에 참여한 총135명의 학생을 대상으로 사전조사와 사후조사를 진행하였다. 제시한 학습방식을 적용하여 교육한 결과 실험군이 대조군에 비해 자기주도 학습능력과 문제해결능력이 각각 22%, 18%향상된 결과를 얻었다. 이번 연구는 작업치료 임상실무능력을 향상하기 위한 새로운 교수-학습방법을 개발하여 제안하였고, 다양한 직무에서 요구하는 능력을 향상시킬 수 있는 교수-학습방법의 기초 자료로 의미가 있겠다.

• 대한통합의학회지
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• 제2권3호
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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.

• 한국재료학회지
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• 제28권11호
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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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• 제89권2호
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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.

• 공업화학
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• 제29권2호
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• pp.215-224
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• 2018

염산 5, 10, 15 wt% 용액(1.5, 3.0, 4.5 M; 석유정 산성화에 사용되는 범위)에 대하여 여러 가지 조건에서 자기장이 미치는 영향을 연구하였다. 자화된 염산의 pH 변화를 정상적인 염산과 비교하였다. Taguchi 실험 설계법을 사용하여 자장강도, 농도, 유속, 온도 및 시간의 영향을 모델링하였다. 실험 결과 자화에 따라 염산의 $H^+$ 농도가 42%까지 감소하였다. 자장 강도(기여도 28%), 염산의 농도(기여도 42%), 유속이 커지면 자기장 적용의 효과가 증가하였다. 염산에 대한 자기장의 영향은 용액의 유속과 가열에 의하여 영향받지 않았으며 시간에 따른 자기장 메모리가 유지되는 것으로 나타났다. 최대 $H^+$ 농도 변화에 대한 최적의 조합은 10% 염산 용액 및 4,300 Gauss일 때로 얻어졌다. 자화 과정 중 염산의 반응 속도가 감소하므로 자화된 염산은 탄화수소(원유 및 천연가스)정의 매질 산성화에 대한 대체 지연제로 비용면에서 경제적이고 신뢰성 있는 방법이 될 것으로 제안한다.