• 대한수학회논문집
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• 제27권1호
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• pp.47-56
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• 2012

In this article, we continue the study of tense symmetric Heyting algebras (or TSH-algebras). These algebras constitute a generalization of tense algebras. In particular, we describe a discrete duality for TSH-algebras bearing in mind the results indicated by Or lowska and Rewitzky in [E. Orlowska and I. Rewitzky, Discrete Dualities for Heyting Algebras with Operators, Fund. Inform. 81 (2007), no. 1-3, 275-295] for Heyting algebras. In addition, we introduce a propositional calculus and prove this calculus has TSH-algebras as algebraic counterpart. Finally, the duality mentioned above allowed us to show the completeness theorem for this calculus.

• Advances in materials Research
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• 제13권2호
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• pp.141-151
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• 2024

The aim of this work was to determine the behavior of alloy elements and compounds formed during solidification in the manufacturing process of the CuAgZrCr alloy under an oxidizing environment. Bulk and surface analysis techniques, such as Scanning Electron Microscopy (SEM), X-ray Photoelectron Spectroscopy (XPS), Raman and X-ray diffraction (XRD) were used to characterize the phases obtained in the solidification process. In order to focus the analysis on the on grain boundary interface, partial removal of the matrix phase by acid attack was performed. The compositional differences obtained by SEM-EDX, Raman and XPS on post-manufacturing materials allowed us to conclude that the composition of grain boundaries of the alloy is directly influenced by the oxidizing environment of alloy manufacturing.

• 비교문화연구
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• 제50권
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• pp.225-259
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• 2018

Institut d'Estudis Catalans에 따르면 카탈루냐어에서 사용하는 전통적 시각 표현 체계는 기본적으로 시간을 'quart(=quarter)'로 나누는 것에 기반을 두어 '8시15분/30분/45분'은 각각 '${\acute{E}}s$ un quart de nou.', '$S{\acute{o}}n$ dos quarts de nou.', '$S{\acute{o}}n$ tres quarts de nou.'라고 표현하며 '$S{\acute{o}}n$ les vuit i quinze.', '$S{\acute{o}}n$ les vuit i trenta/mitja.', '$S{\acute{o}}n$ les vuit i quaranta-cinc.'와 같은 구조를 사용하지 않는데 그 이유는 이와 같은 표현들은 방언에서 발견되는 변이형이나 소위 국제적 표기 방식으로 고려되는 표현이기 때문이다. 아울러 카탈루냐 전통적 시각표현 방식은 'cinc(=five)'와 'deu(=ten)'를 제외하고 다른 기수사의 사용은 허용하지 않는다. 이러한 언어적 현상은 결국 카탈루냐인들만이 공감하고 이해할 수 있는 독특한 디지털시계의 발명과 아날로그시계의 디자인 까지 영향을 미치게 되었다. 카탈루냐어 회화체에서 'quart' 체계는 일상생활에서 흔히 접할 수 있는 '$S{\acute{o}}n$ quarts of nou'과 같은 문장이나 'entre dos i tres quarts'와 같은 표현도 16분과 44분 사이에 어떤 시각을 구체적으로 의미하는지를 판단하기 어려운 해석상의 모호성을 야기한다. 본 연구는 카탈루냐어의 전통적 시각 표현은 감산방식을 사용하지 않으며 단어 'quart'는 어원적으로 타종체계와 관련이 있는 단어이므로 시계 체계와 관련되는 '15분'이란 구체적인 양적 의미는 원래 없다는 사실을 문법적 특수성과 대화상의 맥락 그리고 특수한 시계의 발명이나 아날로그시계의 디자인에서 나타나는 언어적 특수성 등을 통해 살펴보고자 한다.

• Coupled systems mechanics
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• 제9권2호
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• pp.125-145
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• 2020

In this paper, we present a 3D thermo-hydro-mechanical coupled discrete beam lattice model of structure built of the nonisothermal saturated poro-plastic medium subjected to mechanical loads and nonstationary heat transfer conditions. The proposed model is based on Voronoi cell representation of the domain with cohesive links represented as inelastic Timoshenko beam finite elements enhanced with additional kinematics in terms of embedded strong discontinuities in axial and both transverse directions. The enhanced Timoshenko beam finite element is capable of modeling crack formation in mode I, mode II and mode III. Mode I relates to crack opening, mode II relates to in-plane crack sliding, and mode III relates to the out-of-plane shear sliding. The pore fluid flow and heat flow in the proposed model are governed by Darcy's law and Fourier's law for heat conduction, respectively. The pore pressure field and temperature field are approximated with linear tetrahedral finite elements. By exploiting nodal point quadrature rule for numerical integration on tetrahedral finite elements and duality property between Voronoi diagram and Delaunay tetrahedralization, the numerical implementation of the coupling results with additional pore pressure and temperature degrees of freedom placed at each node of a Timoshenko beam finite element. The results of several numerical simulations are presented and discussed.

• Applied Biological Chemistry
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• 제11권
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• pp.105-108
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• 1969

본(本) 실험(實驗)에 사용(使用)된 Gel로는 Sephadex G-200, G-100과 G-75로써 fractionation은 대체(大體)로 호조건에서 이루어 졌다. G-200과 G-100의 경우에 있어서는 갈색색소의 분자크기가 서로 다른 2개(個)의 Peak를 얻을 수 있었고 Colume에 투입된 시료(試料)는 완전(完全)히 회수(回收)되었다. G-75의 경우에는 갈색색소와 분자 크기가 작은 다른 물질(物質)과를 분리(分離)할 수 있었으나 약간의 시료(試料)는 Gel에 흡착되어 완전(完全)히 회수(回收)할 수 없었다. 발효실험의 결과를 종합해 보면 우선 갈색색소를 함유하늘 모든 fraction은 발효초기에 활성(活性)을 보이며 분자크기가 작은 물질의 구획(區劃)에서는 강하고도 점증되는 활성(活性)을 관찰할 수 있었다. Sephadex Gel에 의(依)한 fractionation은 첫째로 작업(作業)도중에 시료(試料)의 변질현상(變質現象)이 없다는 것과 둘째로 갈색색소를 그들의 분자크기에 따라 분획(分劃)할 수 있다는 이점(利點)들이 있다.

• Journal of Power Electronics
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• 제11권3호
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• pp.381-388
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• 2011

This article presents the development of a model for SiC power diodes based on the physics of the semiconductor. The model is able to simulate the behavior of the dynamics of the charges in the N- region based on the stored charge inside the SiC power diode, depending on the working regime of the device (turn-on, on-state, and turn-off). The optimal individual calculation of the ambipolar diffusion length for every phase of commutation allows for solving the ambipolar diffusion equation (ADE) using a very simple approach. By means of this methodology development a set of differential equations that models the main physical phenomena associated with the semiconductor power device are obtained. The model is developed in Pspice with acceptable simulation times and without convergence problems during its implementation.

• 대한수학회지
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• 제41권1호
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• pp.209-229
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• 2004

Let $\Sigma_{$\mid$\alpha$\mid$=m}\;s_{\alpha}z^{\alpha},\;z\;{\in}\;{\mathbb{C}}^n$ be a unimodular m-homogeneous polynomial in n variables (i.e. $$\mid$s_{\alpha}$\mid$\;=\;1$ for all multi indices $\alpha$), and let $R\;{\subset}\;{\mathbb{C}}^n$ be a (bounded complete) Reinhardt domain. We give lower bounds for the maximum modules $sup_{z\;{\in}\;R\;$\mid$\Sigma_{$\mid$\alpha$\mid$=m}\;s_{\alpha}z^{\alpha}$\mid$$, and upper estimates for the average of these maximum moduli taken over all possible m-homogeneous Bernoulli polynomials (i.e. $s_{\alpha}\;=\;{\pm}1$ for all multi indices $\alpha$). Examples show that for a fixed degree m our estimates, for rather large classes of domains R, are asymptotically optimal in the dimension n.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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• pp.718-719
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• 2006

Two different commercial aluminium powder grades have been densified by direct hot extrusion. The extrusion temperature was $425^{\circ}C$, with an extrusion ratio of 1:16. Prior to extrusion, some green compacts were pre-sintered ($500^{\circ}C$). The evolution of the extrusion load during the process and the hardness of the final products have been investigated. Additionally, microstructural characterization by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and Electron Backscattered Diffraction (EBSD) was carried out. The obtained results evidence grain refinement. Additionally, inter-metallic precipitation, dynamic recovery and geometric dynamic recrystallization take place depending on some process variables, powder composition, heat treatment, strain $\ldots$

• 건축역사연구
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• 제5권1호
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• pp.113-122
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• 1996

Cette etude vise a reveler une verite du Nouveau Brutalisme des Smithson (Alison et Peter). Nous examinerons donc d'abord l'universalitf de leur oeuvre representatif, Ecole Secondaire de Hunstanton(projet, 1949; concours, 1950; construction, 1951-1954) et projet de Maison Soho a Londres(1952) comme un mouvement architectural. Et apres nous trouverons la faussete de leur but, realisation de l'ethique architecturale, sur ce mouvement en comparant les oeuvres des Smithson avec les deux constructions considerees souvent comme la categorie du Nouveau Brutalisme, la Calorie d'Art de l'Universite Yale(1951-1953) realisee par Louis I. Kahn(1901-1974) et le Centre Cuturelle de Georges-Pompodou(1971-1977) par Renzo Piano et Richard Rogers. En resultat, l'etique de Nouveau Brutalisme soutenue par les Smithson et defendue par Reyner Banham etait seulement pour cacher low limite architecturale et sa faiblesse. Ce mouvement etait aussi un mouvement personel plutot que general. On ne pourrait pas donc considerer les Smithson comme nouveaux brutalistes.

• Steel and Composite Structures
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• 제26권2호
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• pp.213-226
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• 2018

This paper focuses on the seismic protection of slender old masonry structures by the implementation of prestressing devices at key locations. The devices are vertically and externally located inside the towers in order to be reversible and calibrated. An extensive parametric study on a selected slender tower is carried out based on more than 100 nonlinear static simulations aimed at investigating the impact of different parameters on the seismic performance: (i) different prestressing levels; (ii) shape memory alloy superelasticity and (iii) changes in prestressing-forces in all the stages of the analysis until failure and masonry toe crushing. The tendon materials under analysis are conventional prestressing steel, fiber-reinforced polymers of different fibers and shape memory alloys. The parametric study serves to select the most suitable prestressing device and optimal prestressing level able to dissipate more earthquake energy. The seismic energy dissipation is evaluated by comparing the structural capacity curves in original state and retrofitted.