• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제4권1호
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• pp.133-142
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• 2000

In this note we define typical set and differential entropy for continuous random variables. Using Markov chain, we show that the various properties of the mutual information and entropies (theorems 3.2 and 3.4 ) and show the properties of typical set in continuous random variables( lemma 4.2 and theorem 4.3.)

• 한국전기전자재료학회논문지
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• 제30권6호
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• pp.372-375
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• 2017

ZnO thin films were deposited by RF magnetron sputtering and then diffused by using an As source in the ampouletube. Also, the ZnO p-n homojunction was made by using As-doped ZnO thin films, and its properties were analyzed. After the As doping, the surface roughness increased, the crystal quality deteriorated, and the full width at half maximum was increased. The As-doped ZnO thin films showed typical p-type properties, and their resistivity was as low as $2.19{\times}10^{-3}{\Omega}cm$, probably because of the in-diffusion from an external As source and out-diffusion from the GaAs substrate. Also, the ZnO p-n junction displayed the typical rectification properties of a p-n junction. Therefore, the As diffusion method is effective for obtaining ZnO films with p-type properties.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 1999년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Fall
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• pp.186-192
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• 1999

Safety-related equipments of nuclear power plant must be seismically qualified to demonstrate their ability to function as required during and/or after the earthquake, The seismic qualification is usually achieved through analysis and testing. Analysis method is preferably adopted for structurally simple equipments which are easy to be mathematically modeled. However even for relatively complex equipments analysis method is occasionally used for computing the input motion or supporting information for the component test followed. Electrical cabinet is a typical example for which analysis method is combinedly used with test to get modal properties of the enclosing cabinet structure. Usually the structural elements and doors of the cabinet are loosely interconnected with small-size bolts or spot welding. Therefore cabinet-type equipment usually has high and complex nonlinear properties which are not easily idealized by simple practical modeling techniques. in this paper with respect to a typical cabinet-type structure(instrumentation cabinet of nuclear power plant) a comparative study has been performed between three different state-of-the -art modeling techniques: lumped mass model frame model and FEM modal. Form the study results it has been found that modal properties of the cabinet-type structure in the elastic behavior range can be reasonably computed through any type of modeling techniques in the practice with slight modification of model properties to get better accuracy. However it needs additional modeling techniques to get reasonable results up to nonlinear range.

• 한국경영과학회지
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• 제12권1호
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• pp.10-18
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• 1987

This paper discusses algorithmic properties of a class of complementarity programs involving strictly diagonally isotone and off-diagonally isotone functions, i. e., functions whose Jacobian matrices have positive diagonal elements and nonnegative off-diagonal elements, A typical traffic equilibrium under elastic demands is cast into this class. Algorithmic properties of these complementarity problems, when a Jacobi-type iteration is applied, are investigated. It is shown that with a properly chosen starting point the generated sequence are decomposed into two converging monotonic subsequences. This and related will be useful in developing solution procedures for this class of complementarity problems.

• 한국전기전자재료학회논문지
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• 제24권11호
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• pp.895-899
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• 2011

Multiferroic BFO/PZT(5/95) multilayer films were fabricated by spin-coating method on the Pt/Ti/$SiO_2$/Si substrate alternately using BFO and PZT(9/95) alkoxide solutions. The structural and dielectric properties were investigated with variation of the solvent and the number of coatings. All films showed the typical XRD patterns of the perovskite polycrystalline structure without presence of the second phase such as $Bi_2Fe_4O_3$. BFO/PZT multilayer thin films showed the typical dielectric relaxation properties with increase an applied frequency. The average thickness of 6-coated BFO/PZT multilayer film was about 600 nm. The dielectric properties such as dielectric constant, dielectric loss and remnant polarization were superior to those of single composition BFO film, and those values for BFO/PZT multilayer film were 1199, 0.23% and 12 ${\mu}C/cm^2$.

• 마이크로전자및패키징학회지
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• 제10권2호
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• pp.27-31
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• 2003

플립 칩 패키징에 있어 CPW배선 구조에 본딩 패드를 구성하여 1GHz부터 35GHz 범위에서 고주파 특성 변화를 관찰하였다. 본딩 패드로 구성된 구조들에 대한 시뮬레이션을 수행하고, 제작된 CPW의 S 파라미터를 측정하였다. 측정 결과 접지선과 신호선에 본딩 패드를 구성한 패턴은 기존 CPW의 S 파라미터 특성과 대등한 $S_{11}$은 -31 dB 이하, $S_{21}$은 -0.19 dB 이상이 관찰되었다. 아울러 접지선 폭에 따른 고주파 특성에서는 접지선 폭의 증가가 고주파 특성 개선을 가져왔다. 고주파 대역에서 플립 칩의 배선 구조로 제안된 본 연구의 본딩 패턴은 유효하였다.

• Journal of Welding and Joining
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• 제30권3호
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• pp.32-37
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• 2012

Lead frame which has a high thermal conductivity and high mechanical strength is one of core technology for ultra-thin electronics such as LED lead frames, memory devices of semiconductors, smart phone, PDA, tablet PC, notebook PC etc. In this paper, we fabricated a Cu/STS/Cu 3-layered clad metal for lead frame packaging materials and characterized the mechanical properties and thermal conductive properties of the clad metal lead frame material. The clad metal lead frame material has a comparable thermal conductivity to typical copper alloy lead frame materials and has a reinforced mechanical tensile strength by 1.6 times to typical pure copper lead frame materials. The thermal conductivity and mechanical tensile strength of the Cu/STS/Cu clad metal are 284.35 W/m K and $52.78kg/mm^2$, respectively.

• 한국식품과학회지
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• 제51권6호
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• pp.584-591
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• 2019

Of all the various types of tea that are available, Pu-erh tea has attracted much attention because of its healthpromoting effects. The objective of this study was to investigate the physicochemical and antioxidant properties of two types of Pu-erh tea, Gushu Pu-erh and typical Pu-erh, extracted at 80 and 100℃, respectively. The Gushu Pu-erh extracts showed lower pH but higher antioxidant potential at both the temperatures, as compared to the typical Pu-erh. The mineral content of the tea extracts was greater at 100℃ than at 80℃. Among the seven categories of the flavor compounds that were detected, the peak area of esters was the highest in the Gushu Pu-erh extracts. The type of tea and the extraction temperature significantly affected the physicochemical and functional properties of these tea extracts. This study revealed that Gushu Pu-erh extracted at 100℃ for 3 min with 30 s of shaking provides better results in terms of the antioxidant potential and mineral content.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2000년도 추계학술대회 논문집
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• pp.84-89
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• 2000

Thermal simulation of typical stack-type and newly proposed planar-type micro-gas sensors were studied by FEM method. The thermal analyses for the proposed planar structure including temperatur distribution over the sensing layer and power consumption of the heater were carried using finite element method by computer simulation and well compared with those of typical stack-type micro-gas sensor. The thermal properties of the microsensor from thermal simulation were compared with those of a actual device to investigate the acceptability of the computer simulation.

• 한국해양공학회지
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• 제7권2호
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• pp.162-172
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• 1993

In the present paper, the overall state of the arts of ice mechanics which is the most typical research topic of the artic engineering field was studied. And also, ice loads genrated by ice-structure interaction were estimated using numerical approach. The effects of viscous property of ice sheets to the ice load were investigated. The time dependent deformation behaviors of ice was modeled by visco-plastic problem using the finite element formalism. Constitutive model representing the material properties of ice was idealized by comblned rheological model with Maxwell and Voigt models. Numerical calculations for the bending and crushing behavior of ice sheet which are the most typical interaction modes between ice sheets and structures were carried out. The time dependent viscous behaviors of ice sheets interaction forces acting on structures were analyzed and the results were studied in detail.