• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 ITC-CSCC -2
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• pp.583-586
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• 2000

A passive RF smart card incorporating a non volatile memory element is powered by inductive coupling to a proximately located RF reader. Therefore, the power consumption in the smart card should be low. In this study, we designed the low power passive RF smart card that is operated at 125kHz to apply to the subway ticket system.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2002년도 봄 학술발표회 논문집
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• pp.470-477
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• 2002

Possibility of passive piezoelectric damping based on a new shunting parameter estimation method is studied using finite element analysis. The adopted tuning method is based electrical impedance that is found at piezoelectric device and the optimal criterion for maximizing dissipated energy at the shunt circuit. Full three dimensional finite element model is used for piezoelectric devices with cantilever plate structure and shunt electronic circuit is taken into account in the model. Electrical impedance is calculated at the piezoelectric device, which represents the structural behavior in terms of electrical field, and equivalent electrical circuit parameters for the first mode are extracted using PRAP (Piezoelectric Resonance Analysis Program). After the shunt circuit is connected to the equivalent circuit for the first mode, the shunt parameters are optimally decided based on the maximizing dissipated energy criterion. Since this tuning method is based on electrical impedance calculated at piezoelectric device, multi-mode passive piezoelectric damping can be implemented for arbitrary shaped structures.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 가을 학술발표회 논문집
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• pp.604-607
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• 2003

Recently, hybrid concrete structures such as a concrete-filled steel tubular(CFT), a steel reinforced concrete(SRC) and a composite material are popular in structure applications. They also have merit of high strength, high ductility, and large energy absorption capacity. But the analysis of hybrid concrete structures is very difficult owing to the complex behavior of concrete under passive confinement. This paper has analyzed CFT, which receives passive confinement using Tri-Surface concrete model for three dimension finite element analysis. By the result of that, the proposed model was properly forecasted a concrete behavior that receives passive restraint as well as non-linear analysis of concrete which receive uniaxial stress and high active confinement of 400Mpa. If the model through the steady study is set up especially on the factor of concrete under passive confinement, the proposed concrete model will be surely useful for analysis of the hybrid concrete structures.

• 한국태양에너지학회 논문집
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• 제35권6호
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• pp.35-42
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• 2015

The proper use of the passive and active design elements are important for the realization of green buildings. The G-SEED (Green Standard for Energy and Environmental Design) has been implemented in Korea to promote green building construction reflecting these design elements. In this paper, evaluation items of G-SEED which related to the passive design were selected. And improvement direction for the G-SEED was proposed through the analysis of the application status of the passive design elements for the G-SEED certified buildings. This results can be used for developing study on the future improvement of the assessment criteria of G-SEED.

• 한국산학기술학회논문지
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• 제8권2호
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• pp.324-332
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• 2007

본 연구에서는 원격 실험실에서 사용될 수동소자인 저항, 인덕터, 캐패시터의 소자값을 원격으로 제어할 수 있는 소자를 개발하였으며, 이 소자를 이용한 회로이론 원격 실험실을 구현하였으며, 원격제어용 수동소자 R, L, C를 사용한 RLC 직렬회로 원격실험실의 예로 실험의 효용성을 보였다. 따라서 제안한 원격 실험실을 통해 학생들은 원격으로 다양한 소자값을 변경시켜가면서 실제 실험을 수행할 수 있게 되므로, 가상실험실이 안고 있는 실제 실험값을 얻을 수 없는 문제점을 해결할 수 있으며, 특히 학생 개개인이 실험할 수 없는 어떤 환경에서도 실험을 할 수 있는 환경을 제시하였다.

• 한국해양공학회지
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• 제35권2호
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• pp.131-140
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• 2021

The paper deals with comparative study of various surrogate models based approximate optimization in the structural design of the passive type deck support frame under design load conditions. The passive type deck support frame was devised to facilitate both transportation and installation of 20,000 ton class topside. Structural analysis was performed using the finite element method to evaluate the strength performance of the passive type deck support frame in its initial design stage. In the structural analysis, the strength performances were evaluated for various design load conditions. The optimum design problem based on surrogate model was formulated such that thickness sizing variables of main structure members were determined by minimizing the weight of the passive type deck support frame subject to the strength performance constraints. The surrogate models used in the approximate optimization were response surface method, Kriging model, and Chebyshev orthogonal polynomials. In the context of numerical performances, the solution results from approximate optimization were compared to actual non-approximate optimization. The response surface method among the surrogate models used in the approximate optimization showed the most appropriate optimum design results for the structure design of the passive type deck support frame.

• KIEAE Journal
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• 제15권6호
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• pp.27-36
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• 2015

Purpose: The definition and factors of passive design being the sustainable method of building plan through the preceding research is deducted and the effect of passive design within the public library by applying the deducted factors in the case of built public libraries and further the realization plan of green library aimed to be reviewed in this research. Method: This study is to induce common elements of architecture plan for public library and passive design, and assess application level of re-classified elements of sustainable public library in order to analyze present condition of passive design applied on facilities of public library. First, related laws and planning standards of public library will be reviewed, then the definition of passive design will be considered using advanced research. Through advanced research related to planing elements and passive design for library induced from various plans for library standards, a common ground of induced passive design element will be transformed into assessment items and practices to be analyzed. Result: Libraries which are and are not preliminarily certified by G-SEED will be compared with each other in order to analyze the effects of passive design on G-SEED. Even though various passive elements such as load reduction of air conditioning and energy efficiency exist, there are no assessment tool within G-SEED. The fact that there are only standards for temporary methods such as utilization of construction material and installation of equipment highlights the challenges in quantitative evaluation.

• Structural Engineering and Mechanics
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• 제70권4호
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• pp.381-394
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• 2019

If an alternative path would not be considered for redistribution of loads, local failure in structures will be followed by a progressive collapse. When a vertical load-bearing element of a steel structure fails, the beams connected to it will lose their support. Accordingly, an increase in span's length adds to the internal forces in beams. The mentioned increasing load in beams leads to amplifying the moments there, and likewise in their corresponding connections. Since it is not possible to reinforce all the elements of the structure against this phenomenon, it seems rational to use other technics like specified strengthened connections. In this study, a novel connection is suggested to handle the stated phenomenon which is introduced as a passive connection. This connection enables the structure to tolerate the added loads after failing of the vertical element. To that end, two experimental models were constructed and thereafter tested in half-scale, one-story, double-bay, and bolted connections in three-dimensional spaces. This experimental study has been conducted to compare the ductility and strength of a frame that has ordinary rigid connections with a frame containing a novel passive connection. At last, parametric studies have been implemented to optimize the dimensions of the passive connection. Results show that the load-bearing capacity of the frame increased up to 75 percent. Also, a significant decrease in the displacement of the node wherein the column is removed was observed compared to the ordinary moment resisting frame with the same loads.

• 조명전기설비학회논문지
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• 제26권2호
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• pp.92-98
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• 2012

As the increasing of non-linear load, filter is coming to be high gradually in order to reduce the harmonic which occurs from the power conversion. The maintenance of passive filter is easier than active filter and it has been widely used in the industrial site. This passive filter is connected with condenser and reactor by series and parallel and it is installed at the front of nonlinear load. The breakdown of passive filter occurs frequently at the reactor side rather than capacitor. So the breakdown cause close examination is necessary. In this paper, we analyzed that the electric stress of reactor which is considered magnetization saturation at the passive filter. We confirm that the reduction of harmonics and the electric stress of reactor is influenced by the linear and non-linear element of reactor.

• 한국초전도ㆍ저온공학회논문지
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• 제20권2호
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• pp.29-33
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• 2018

Although high-temperature superconducting (HTS) magnets have the potential merit of producing ultra-high field (>25 T), they have been not easy to apply to Nuclear Magnetic Resonance (NMR) because of the difficulty of field homogeneity improvement. This paper presents a design technique of passive shimming for HTS magnets. Ferromagnetic shimming design code was developed though MALAB, which includes the optimization algorithm. The proper shim element size was determined by a simulation. This design technique was verified by a case study design of a 3-T HTS magnet. We succeed to improve field homogeneity of the magnet from 634 ppm to 6.39 ppm at 10-mm diameter sphere volume. Feasibility of passive shimming for all-HTS NMR magnet was confirmed by this result.