• Title/Summary/Keyword: DES[2]

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On transverse matrix cracking in composite laminates loaded in flexure under transient hygrothermal conditions

  • Khodjet-Kesba, M.;Benkhedda, A.;Adda Bedia, E.A.;Boukert, B.
    • Structural Engineering and Mechanics
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    • v.67 no.2
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    • pp.165-173
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    • 2018
  • A simple predicted model using a modified Shear-lag method was used to represent the moisture absorption effect on the stiffness degradation for $[0/90]_{2s}$ composite laminates with transverse cracks and under flexural loading. Good agreement is obtained by comparing the prediction model and experimental data published by Smith and Ogin (2000). The material properties of the composite are affected by the variation of temperature and moisture absorption. The transient and non-uniform moisture concentration distribution give rise to the transient elastic moduli of cracked composite laminates. The hygrothermal effect is taken into account to assess the changes in the normalised axial and flexural modulus due to transverse crack. The obtained results represent well the dependence of the stiffness properties degradation on the cracks density, moisture absorption and operational temperature. The composite laminate with transverse crack loaded in axial tension is more affected by the hygrothermal condition than the one under flexural loading. Through this theoretical study, we hope to contribute to the understanding of the moisture absorption on the composite materials with matrix cracking.

ASSESSMENT OF URANS AND DES SIMULATIONS FOR TWO-DIMENSIONAL BACKWARD FACING STEP FLOW (2차원 후항계단유동에 대한 URANS와 DES의 수치해석 평가)

  • Song C.S.;Park S.O.
    • Journal of computational fluids engineering
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    • v.11 no.2 s.33
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    • pp.25-31
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    • 2006
  • A two-dimensional backward facing step flow is simulated by using URANS and Detached Eddy Simulations(DES) approaches. Turbulence models adopted for URANS and DES simulations are Spalart-Allmaras(S-A) model and Shear Stress Transport(SST) model. The target flow with ER=1.125, $Re_H=37,500$ is experimentally studied by Driver & Seegmiller. Various versions of DES have been tested in this paper. Results of the simulations are compared with the experimental data available to evaluate the merits and demerits of URANS and several versions of DES. URANS simulation converges to a steady state and hence unsteady characteristics are not featured. DES simulations in general successfully mimic large scale structures and oscillation characteristics of the flow.

A Study on a S Box Redesign using DES Key Expansion (DES 키 확장을 이용한 S Box 재설계에 관한 연구)

  • Lee, Jun
    • Journal of the Korea Institute of Military Science and Technology
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    • v.14 no.2
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    • pp.238-245
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    • 2011
  • We suggest a DES key expansion algorithm which is strong enough to overcome Differential Cryptanalysis(DC) and Linear Cryptanalysis(LC). Checking the weak points of DES, we found that the opened S box provide all information on the various kinds of attack. Using the key expansion we redesigned the S box which is not open to anybody who has no key. DC and LC can not be applied to the suggested algorithm without the redesigned S box information. With the computer experiments we show that the efficiency of this algorithm is almost the same as that of DES with respect to the crypto speed.

Simulation and Modelling of the Write/Erase Kinetics and the Retention Time of Single Electron Memory at Room Temperature

  • Boubaker, Aimen;Sghaier, Nabil;Souifi, Abdelkader;Kalboussi, Adel
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.10 no.2
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    • pp.143-151
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    • 2010
  • In this work, we propose a single electron memory 'SEM' design which consist of two key blocs: A memory bloc, with a voltage source $V_{Mem}$, a pure capacitor connected to a tunnel junction through a metallic memory node coupled to the second bloc which is a Single Electron Transistor "SET" through a coupling capacitance. The "SET" detects the potential variation of the memory node by the injection of electrons one by one in which the drainsource current is presented during the memory charge and discharge phases. We verify the design of the SET/SEM cell by the SIMON tool. Finally, we have developed a MAPLE code to predict the retention time and nonvolatility of various SEM structures with a wide operating temperature range.

Isolation and Identification of a Novel Anticancer Compound from Solanum nigrum (용규(Solanum nigrum)에서 HT29 세포에 대한 신규 항암 활성 단일 물질 분리)

  • Yun, Hee Jung;Jung, Jong Hun;Hyun, Sook Kyung;Kim, Byung Woo;Kwon, Hyun Ju
    • Journal of Life Science
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    • v.24 no.3
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    • pp.234-241
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    • 2014
  • To identify and isolate anticancer active compounds from Solanum nigrum, S. nigrum was extracted with MeOH and then fractionated with various organic solvents ($CH_2Cl_2$, EtOAc, n-BuOH, and $H_2O$). The cytotoxic effects of the MeOH extracts from S. nigrum and its organic solvent-soluble fractions were also tested in HT29 cells. All the MeOH extracts of S. nigrum and its organic-solvent extracts induced cytotoxicity in the HT29 cells. Among the extracts, $H_2O$ was the most effective. The $H_2O$ extract was purified further by repeated silica gel, Sephadex LH-20, Diaion HP- 20, and RP-18 column chromatography. An active anticancer compound, Des-N-26-methylene-dihydrotomatidine, was isolated with a molecular weight of 416 and a molecular formula of $C_{28}H_{48}O_2$. Analysis of the cytotoxic effects of Des-N-26-methylene-dihydrotomatidine on the HT29 cells compared to those of tomatine and tomatidine are similar in its structure, is higher than tomatidine above the 40 ${\mu}g/ml$ concentration, but lower than tomatine. This is the first study to describe the anticancer activity of Des-N-26-methylene-dihydrotomatidin, isolated from S. nigrum. Des-N-26- methylene-dihydrotomatidine seems to have potential as a natural bioactive compound.

La Recherche sur La France Décentralisation (초기 프랑스 지방분권(地方分權)에 관한 연구 -1999년을 중심(中心)으로-)

  • Baek, Yun-Chul;Jung, Sung Bum
    • Journal of the Korea society of information convergence
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    • v.6 no.2
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    • pp.67-87
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    • 2013
  • La France est un Etat unitaire $r{\acute{e}}agi$ par la Constitution. La $r{\acute{e}}forme$ de la $d{\acute{e}}centralisation$ a $d{\acute{e}}but{\acute{e}}$ par la $d{\acute{e}}claration$ 'des droits et $liber{\acute{e}}s$ des communes, des $d{\acute{e}}partements$ et des $r{\acute{e}}gions'$ qui influence plusieurs domaines de l' administration locale: la suppression du $contr\hat{o}le$ a priori et l' exercice du $contr\hat{o}le$ a posteriori par le commissaire de la Republique et par le Cour des comptes; le transfert des competences de l' Etat vers les communes, les $d{\acute{e}}partements$ et les $r{\acute{e}}gions$ avec la transmission du pouvoir de $d{\acute{e}}cision$; le transfert de moyens financiers pour financer les $d{\acute{e}}penses$ relatives aux $comp{\acute{e}}tences$ acquises; la $r{\acute{e}}forme$ du $syst{\acute{e}}me$ des fonctionnaires territoraux; le paiement des honoraires aux ${\acute{e}}lus$ locaux; la limitation du cumul des mandats.

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Theorie des Spracherwerbs und der Erwerb des Deutschen (언어습득론과 독일어의 습득)

  • Hong Upyong
    • Koreanishche Zeitschrift fur Deutsche Sprachwissenschaft
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    • v.2
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    • pp.343-370
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    • 2000
  • Im Rahmen der Prinzipien- und Parametertheorie (PPT) stellt man sich vor, $da\ss$ dem Menschen die Universalgrammatik (UG) angeboren ist, die aus einer kleinen Anzahl sprachuniversieller Prinzipien und je nach der Sprache unterschiedlich zu belegender offener Parameter besteht. Die UG Prinzipien $m\"{u}ssen$ demnach nicht gelemt werden; sie bilden von vomherein eine invariante Komponente des sprachlichen Wissens. $Demgegen\"{u}ber$ sollen die jeweilige Parameter der UG im Verlauf des Spracherwerbs aufgrund des sprachlichen Inputs mit Werten der Zielsprache belegt werden. Nach dieser Ansicht ist der Spracherwerb im Grunde als $Proze{\ss}$ der 'Parameterbelegungen' aufzufassen. In der vorliegenden Arbeit ist demonstriert worden, $da{\ss}$ die PPT eine vielversprechende Grundlage fur die empirische Untersuchung zum Erwerb des Deutschen bietet. Bisherige Ergebnisse aus Untersuchungen zum Erwerb der Reflexiv-Bindung beim Erst- sowie Zweitspracherwerb wurden vorgestellt und im Hinblick auf die $M\"{o}glichkeit$ der weiteren Untersuchung zum Zweitspracherwerb des Deutschen durch Koreaner diskutiert. Der Schwerpunkt der Diskussion wurde auf die Frage gelegt, wie die Theorie des Parameters mit Ergebnissen aus Untersuchungen zur Parameterbelegung beim Spracherwerb interagiert. Auf psychologisch bzw. kognitionswissenschaftlich orientierte $Ans\"{a}tze$ zum Spracherwerb konnte in der vorliegenden Arbeit nicht eingagangen werden. Durch die $Mitber\"{u}cksichtigung\;beider\;Ans\"{a}tze\;w\"{u}rde$ jedoch das Thema 'der Erwerb des Deutschen' die Angewandte Deutsche Sprachwissenschaft in Korea noch mehr anreichern.

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L'analyse de la Fracure et la Typologie des Galets Casses Decouverts de la Grotte do Lazaret a Nice (France) (라자레 동굴(니스, 프랑스) 유적에 나타난 전기 구석기시대 깨진 자갈등의 유물의 분석과 형식 분류)

  • 한창균
    • The Korean Journal of Quaternary Research
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    • v.2 no.1
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    • pp.1-11
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    • 1988
  • L'analyse des galets fractures decouverts sur les sols d'habitat de la grotto du Lazaret permet de penser que la cassure des galets se serait produite sur place dans la grotte, soit par des actions naturelles, soit par des actions des hommes prehistoriques. D'apres la comparaison des resultats obtenus par 1'etude exprimentale, les cassures des galets sont liees a plusieurs modes de fraturation. On peut seulement dire que les trois modes (1,3 et 5) sont susceptibles de donner des indications sur 1'aspect intentionnel de certains types de fracturation.

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