• Journal of the Korean Magnetics Society
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• v.6 no.2
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• pp.106-111
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• 1996

Electric machines such as motors which have rmving parts are designed for producing mechanical force or torque. The accurate calculations of electromagnetic force and torque are important in the design these machines. Electromagnetic force calculation method using the results of Finite Element Method(FEM) has been presented variously in 2-D problems. Typically the Maxwell's Stress Tensor method and the method of virtual work are used. The former calculates forces by integrating the surface force densities which can be expressed in terms of Maxwell Stress Tensor(MST), and the latter by differentiating the electromagnetic energy with respect to the virtual dis¬placement of rigid bodies of interest. In the problems including current source, magnetic vector potentials(MVP) have rmstly been used as unknown variables for field analysis by a numerical method; e. g. FEM. This paper, thus, introduces the two both methods using MVP in 3-D case. To verify the usefulness of presented methods, a solenoid model is chosen and analyzed by 3-D and axisymmetric FEM. It is found that the force calculation results are in good agreement for several mesh schemes.

• Journal of the Korean Geophysical Society
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• v.2 no.2
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• pp.123-134
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• 1999

Magnetotelluric responses may be affected by strong anisotropy of the high-conductivity layers (HCL) in the upper mantle or lower crust. We have studied two-dimensional anisotropy MT modelling to examine the effect of high anisotropic media. Electrical properties of a homogeneous anisotropic body are defined by a symmetric conductivity tensor and the problem is described by coupled diffusion equation in the frequency domain. In two-dimensional anisotropic environments, diagonal elements of the impedance tensor have higher values than those in isotropic environments. In some cases, TM mode phases reach more than 90°and apparent resistivities decrease for some frequency range because of telluric distortion. GB decomposition may be used to recover regional responses, but can be affected by the regional anisotropic effect. Considering these results, BC87 dataset was interpreted with a modified anisotropic model.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.6
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• pp.1027-1034
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• 2017

In this paper, we propose a new function embedding method that can measure mathematical projections of probability amplitude, probability, average expectation and matrix elements of stationary-state unit matrix at all control operation points of quantum gates. The function embedding method in this paper is to embed orthogonal normalization condition of probability amplitude for each control operating point into a binary scalar operator by using Dirac symbol and Kronecker delta symbol. Such a function embedding method is a very effective means of controlling the arithmetic power function of a unitary gate in a unitary transformation which expresses a quantum gate function as a tensor product of a single quantum. We present the results of evolutionary operation and projective measurement when we apply the proposed function embedding method to the ternary 2-qutrit cNOT gate and compare it with the existing methods.

• Journal of the Korean Magnetics Society
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• v.18 no.3
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• pp.89-93
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• 2008

Ferrimagnetic Copper-Iron-Chromium Oxide $CuFe_{0.9}Cr_{1.1}O_4$ has been investigated over a temperature range from liquid nitrogen temperature upto $N{\acute{e}}el$ temperature using the Mossbauer technique. Its $N{\acute{e}}el$ temperature is found to be 355 K. Above the $N{\acute{e}}el$ temperature the quadrupole splitting is found to be 0.50 mm/s. On the other hand, all the electric quadrupole shift values are zero below the $N{\acute{e}}el$ temperature within experimental error. These seemingly contradictory phenomena have been explained by the model that the magnetic hyperfine field is randomly oriented with respect to the principal axes of the electric-field-gradient tensor.

• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.4
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• pp.106-112
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• 1989

In this paper, voltage and current measurement systems which utilize linear electrooptic and magnetooptic effects of BSO and ZnSe crystals are theoretically analyzed and experimented. In experiments, BSO voltage sensor has maximum 2% error within the applied voltage of 500V, and ZnSe current sensor has maximum 4% error within 1,000 A range. And temperature dependences of sensitivity for voltage and current in the temperature range from $-5^{circ}C\;to\;60^{circ}$C are measured +1.8% and 2.73%, respectively.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.26 no.1
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• pp.79-87
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• 2013

An isogeometric topological shape optimization method is developed using the level sets and Heaviside enrichments. In the level set method, the initial domain is kept fixed and its boundary is represented by an implicit moving boundary embedded in the level set functions, which facilitates to handle complicated topological shape changes. The Heaviside enrichment improves the isogeometric analysis by adding some enrichment functions to model the internal boundaries. The proposed topological shape optimization method has several benefits: exact geometric models can be obtained using the isogeometric approach and the limitation of tensor-product patches can be overcome using the Heaviside enrichments to represent the internal voids. Even in a single patch, discontinuous displacement fields as well as smooth stress field can be obtained. Since the level sets offer the implicit moving boundary inside the domain, it is easy to represent the topological shape variations in the isogeometric analysis using Heaviside enrichments.

• The Inventors News
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• no.50
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• pp.1-16
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• 2006

'제1회 여대생 발명캠프' 성황리에 마쳐/'발명으로 풍성한 가을을 맞이하시길'/IT기업, 국내 특허 30% 이상 넘었다/레이저 프린터 특허출원, 프린터 분야 중 최다/피부 보호하는 자외선 차단제, 특허출원 꾸준히 증가/액정표시장치 관련 특허 지속적 증가/진공청소기, 첨단 기술로 혁신 꾀해/소멸특허정보, 온.오프라인 제공/발명 지도자 양성 연수, 온라인에서 이루어진다/검색율증가로 활발한 지재권 활동 기대/'2006상표-디자인 전시회'/표준기술특허로 신제품 개발 쉬워져/김광림 전 차관, 세명대 총장에 취임/영양 살린 '기능성 국수' 눈길 끌어/특허청, 포스코와 혁신 파트너십 체결/한국특허정보원, 성과 관리제 도입으로 경영 성과 극대화/특허청, 상반기 미국 국제특허출원 심사 1백18건 유치/중소기업 48%, 고액 기술이전비 '지불 가능'/특허청, 고객눈높이 맞춘 민원서비스 제공/모범명세서 첨부제도로 특허 받기 쉬워져/'여성 발명인의 축제' 개최/'제5회 전국 대학발명 경진대회'/'미스터 차우' 둘러싼 상표권 분쟁 치열/외환은행, 외국인 근로자 해외송금서비스 특허 획득/재난 방지 시스템 구축 핵심기술, 특허출원 증가/비밀디자인 청구기간 확대/이젠, 여름용품 정리할 때/역사 속의 발명품/하루 10분 발명교실/특허Q&A/한경희 (주)한경희 생활과학 대표이사/특허청, 수해복구에 두 팔 걷고 나서/무선환경에서의 저작권보호 관련 외국인출원 급증/아이디어 착상 및 발명 기법/다림질 편하게 하는 요령 10가지/발명을 통한 사업화, 시대의 흐름과 인간의 마음을 담아야/스텐서의 전자레인지/3차원 구조물 만들수 있는 나노종이 개발/애플, 크리에이티브에 1억불 지급/흰 우유에 꽂으면 딸기맛 나는 '퍼니스토로우'/한올제약, 씹는 비만 치료제 특허 취득/음성군, 기술로 복숭아 털 알레르기 잡았다/향기로 소비자 마음을 사로잡는다/'독일 국제 아이디어.발명.신제품 전시회'/한국여성발명협회 회원사 발명품 가이드/코네쥬얼리, 우선심사 통해 특허등록/

• Journal of the Korean Geotechnical Society
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• v.27 no.11
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• pp.55-69
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• 2011

The importance of unsaturated state in various geo-engineering problems has led to the advance of mechanical constitutive model emulating behavior of unsaturated soils in response to thermo-hydro-mechanical loading. Elasto-plastic mechanical constitutive model for unsaturated soil is formulated based on Bishop's effective stress. Effective stress and temperature are main variables in constitutive equation, and incremental formulation of constitutive relationship is derived to compute stress update and stiffness tensor. Numerical simulations involving coupled THM processes are conducted to discuss numerical stability and applicability of developed constitutive model: one-dimensional test, tri-axial compression test, and clay-buffering at high level radioactive waste disposal. Numerical results demonstrated that developed model can predict very complex behavior of coupled THM phenomena and is applicable to geo-engineering problems under various environmental conditions, as well as interpret typical behavior of unsaturated soils.

• Magazine of the Korea Concrete Institute
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• v.7 no.5
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• pp.172-178
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• 1995

Concrete contains numerous microcracks at initially poured. The growth and propagation of nicrockacsk are believed tc finally incur the faiure of concrete. These processings are understood as a damage. Damage IS represented as a second-order tensor and crack is treated as a con tinuum phenomenon. In this paper, damage is characterized through the effective stress concept together with the hypothesis of elastic energy equivalence, and damage evolution law and constitutive equation of a damage model are derived by using the Helmholtz frte eriergy and the dissipation potential by means of the thermodynamic principles. The constitutive equation of the model includes the effects of elasticity, anisotropic damage and plasticity of concrete. There are two effective tangent stiffness tensors in this model : one is for elastic-darnage and the other for plastic damage. For the verification of the model, finite element analysis was performed for the analysis of concrete subjec:t to uniaxial and biaxial loading and the results obtained were compared with test results.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.4 no.4
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• pp.236-241
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• 2011

Mechanical properties of cancellous bone with a high porosity and cortical bone with a high fraction of solid are estimated by the measurement of ultrasonic wave propagation. The speed of sound (SOS) in ultrasonic waves is usually measured by two equations, bulk wave equation and bar wave equation. Bulk wave speed has almost same as the fast wave of Biot's theory. In this study, we examine whether the bulk wave speed is influenced by the anisotropy of bone matrix. The SOS when the bone matrix is isotropy is 0.69% faster than that when the bone matrix is transversely isotropy. We also examine if the use of bar equation is adequate for a cortical bone. In the previous paper, the bar wave speed is a function of Young's modulus or elastic coefficient tensor. In the same manner, the effect of bar wave speed to isotropic and anisotropic bone is estimated.