• Journal of the Optical Society of Korea
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• 제19권6호
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• pp.592-603
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• 2015

In this paper, an optical implementation of a novel asymmetrical cryptosystem combined with D-H secret key sharing and triple DES is proposed. The proposed optical cryptosystem is realized by performing free-space interconnected optical logic operations such as AND, OR and XOR which are implemented in Mach-Zehnder type interferometer architecture. The advantage of the proposed optical architecture provides dual outputs simultaneously, and the encryption optical setup can be used as decryption optical setup only by changing the inputs of SLMs. The proposed cryptosystem can provide higher security strength than the conventional electronic algorithm, because the proposed method uses 2-D array data, which can increase the key length surprisingly and uses 3DES algorithm, which protects against “meet in the middle” attacks. Another advantage of the proposed asymmetrical cryptosystem is that it is free to change the user’s two private random numbers in generating the public keys at any time. Numerical simulation and performance analysis verify that the proposed asymmetric cryptosystem is effective and robust against attacks for the asymmetrical cipher system.

• Journal of Electrochemical Science and Technology
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• 제10권3호
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• pp.257-270
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• 2019

The inhibition performance of sodium gluconate (SG), cetyltrimethylammonium bromide (CTAB) and their mixture (SG/CTAB) on the corrosion behavior of ${\alpha}$-brass in 0.5 M $H_2SO_4$ solution has been investigated by potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), Scanning Electron Microscope with Energy-Dispersive Spectrometer (SEM-EDS), Inductively Coupled Plasma Spectrometry (ICPS) and molecular dynamics (MD) simulation techniques. The results reveal that SG with 5ppm CTAB, noted SG/CTAB, acts as a good corrosion inhibitor and its inhibition efficiency reached 89% after 24 h immersion in sulfuric acid solution, but slightly decreased at higher temperatures. The polarization curves displayed that SG/CTAB acts as a cathodic-kind inhibitor. Electrochemical impedance spectroscopy (EIS) studies revealed that the addition of 5ppm CTAB to different concentrations of SG considerably increases the corrosion resistance of ${\alpha}$-brass. The SEM-EDS and ICPS analyses support the experimental results. Further, molecular dynamics (MD) simulations were used to understand the adsorption profiles of SG/CTAB on Cu(111) and Zn(111) surfaces.

• 법제연구
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• 제44호
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• pp.283-314
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• 2013

행정소송법은 1951월 8월 24일 처음 제정된 이후 수차례의 개정이 있었으나, 2013년 3월 30일 입법예고된 개정안은 1984년 개정 이후 대략 30년만의 개정으로 그 동안의 학계의 연구 성과와 축적된 판례이론 등을 반영하고 있다는 점에서 중요한 의미를 가진다. 그러나 이 개정안은 법무부 행정소송법 개정위원회의 개정안과도 상당한 차이가 있을 뿐만 아니라, 이론적으로도 적지 않은 문제점이 있다. 우선 새로운 원고적격의 개념과 범위가 명확하지 않다. 또한 입법예고안 제12조에서 원고적격과 협의의 소익의 관계를 동일하게 규정함으로써, 협의의 소익의 개념은 오히려 좁게 해석될 여지가 있다. 의무이행소송의 도입은 환영할 만하나, 부작위위법확인소송이나주제어:원고적격, 권리보호필요, 의무이행소송, 부작위, 가구제, 집행정지, 예방적 금지소송거부처분에 대한 취소소송이 인정되고 있어 다소 혼란스럽다. 부작위의 개념은 불필요하며, 또한 엄격하다. 가구제제도는 국민의 권익구제를 위한 방향으로 전환되어야 하며, 일본의 입법례를 그대로 답습하는 것은 지양할 필요가 있다. 가구제제도의 구성이나 체계가 명확하지 않은데, 대상 및 소송유형별로 가구제 제도를 정비할 필요가 있다. 권력분립원칙이나 행정청의 독자적 판단권 존중 등을 이유로 예방적 금지소송의 도입을 반대하는 것은 설득력이 낮다. 그 밖에 ADR에 대한 진취적인 자세가 필요하며, 행정소송상 조정제도에 관한 근거규정을 마련하는 것이 필요하다.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.327-327
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• 2006

Methyl glycidyl ether has been polymerized in a controlled fashion at low temperature in toluene using the combination of tetraoctyl ammonium bromide and triisobutyl aluminum. Poly(glycidyl methyl ether)s with molar masses ranging from 3 000 to about 90 000 g/mol and narrow polydispersities (<1.2) were prepared and the dependence of their solubility and LCST in water as a function on their molar masses investigated.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2005년도 춘계 학술대회논문집
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• pp.148-152
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• 2005

The three-dimensional incompressible flow past an open cavity in a channel is investigated using Detached Eddy Simulation(DES). The length to depth ratio of the cavity is 2 and the Reynolds number defined with the cavity depth is 3,360. The DES methods are based on the Mentor's SST model. In the present work, two types of inflow conditions are used; one is RANS profile, the other is LES inflow from another Large Eddy Simulation(LES) of fully developed channel flow. The results are compared with experimental data and LES results in terms of the mean statistics and temporal physics of the flow.

• Structural Engineering and Mechanics
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• 제56권2호
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• pp.223-240
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• 2015

In this work, a nonlocal quasi-3D trigonometric plate theory for micro/nanoscale plates is proposed. In order to introduce the size influences, the Eringen's nonlocal elasticity theory is utilized. In addition, the theory considers both shear deformation and thickness stretching effects by a trigonometric variation of all displacements within the thickness, and respects the stress-free boundary conditions on the top and bottom surfaces of the plate without considering the shear correction factor. The advantage of this theory is that, in addition to considering the small scale and thickness stretching effects (${\varepsilon}_z{\neq}0$), the displacement field is modelled with only 5 unknowns as the first order shear deformation theory (FSDT). Analytical solutions for vibration of simply supported micro/nanoscale plates are illustrated, and the computed results are compared with the available solutions in the literature and finite element model using ABAQUS software package. The influences of the nonlocal parameter, shear deformation and thickness stretching on the vibration behaviors of the micro/nanoscale plates are examined.

• Journal of Microbiology and Biotechnology
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• 제18권9호
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• pp.1555-1563
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• 2008

A novel $\alpha$-amylase ($\alpha$-1,4-$\alpha$-D-glucan glucanohydrolase, E.C. 3.2.1.1), ScAmy43, was found in the culture medium of the phytopathogenic fungus Sclerotinia sclerotiorum grown on oats flour. Purified to homogeneity, ScAmy43 appeared as a 43 kDa monomeric enzyme, as estimated by SDS-PAGE and Superdex 75 gel filtration. The MALDI peptide mass fingerprint of ScAmy43 tryptic digest as well as internal sequence analyses indicate that the enzyme has an original primary structure when compared with other fungal a-amylases. However, the sequence of the 12 N-terminal residues is homologous with those of Aspergillus awamori and Aspergillus kawachii amylases, suggesting that the new enzyme belongs to the same GH13 glycosyl hydrolase family. Assayed with soluble starch as substrate, this enzyme displayed optimal activity at pH 4 and $55^{\circ}C$ with an apparent $K_m$ value of 1.66 mg/ml and $V_{max}$ of 0.1${\mu}mol$glucose $min^{-1}$ $ml^{-1}$. ScAmy43 activity was strongly inhibited by $Cu^{2+}$, $Mn^{2+}$, and $Ba^{2+}$, moderately by $Fe^{2+}$, and was only weakly affected by $Ca^{2+}$ addition. However, since EDTA and EGTA did not inhibit ScAmy43 activity, this enzyme is probably not a metalloprotein. DTT and $\beta$-mercaptoethanol strongly increased the enzyme activity. Starting with soluble starch as substrate, the end products were mainly maltotriose, suggesting for this enzyme an endo action.

• Journal of Microbiology and Biotechnology
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• 제5권3호
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• pp.154-157
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• 1995

MRK-22, an inhibitor of aminopeptidase M was isolated from the culture broth of Streptomyces sp. SL20209. The structure of MRK-22 was defined to be 3-amino-2-hydroxy-5-methylhexanoyl-valyl-valine, des-$Asp^4$-amastatin, by spectroscopic analysis and this was also confirmed by solid phase synthesis of the inhibitor. The molecular formula and weight of MRK-22 were $C_17H_33N_3O_5$ and MW 359($M^+$), respectively, and its $IC_50$ value against hog kidney AP-M was 0.79 $\mu$ g/ml.

• Steel and Composite Structures
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• 제22권5호
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• pp.975-999
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• 2016

This work investigates a thermomechanical bending analysis of functionally graded sandwich plates by proposing a novel quasi-3D type higher order shear deformation theory (HSDT). The mathematical model introduces only 5 variables as the first order shear deformation theory (FSDT). Unlike the conventional HSDT, the present one presents a novel displacement field which includes undetermined integral variables. The mechanical properties of functionally graded layers of the plate are supposed to change in the thickness direction according to a power law distribution. The core layer is still homogeneous and made of an isotropic ceramic material. The governing equations for the thermomechanical bending investigation are obtained through the principle of virtual work and solved via Navier-type method. Interesting results are determined and compared with quasi-3D and 2D HSDTs. The influences of functionally graded material (FGM) layer thickness, power law index, layer thickness ratio, thickness ratio and aspect ratio on the deflections and stresses of functionally graded sandwich plates are discussed.

• 한국정보통신학회논문지
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• 제10권2호
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• pp.333-337
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• 2006

대칭키 암호 알고리즘들은 전치와 치환의 연속적인 반복 과정이며, 동작방식에 따라 CBC, ECB, CFB, OFB의 네가지 모드가 있다. 또한 이들 알고리즘들에서는 내부적으로 여러 라운드의 연산을 반복적으로 수행해야 최종 암호문이 완성되기 때문에, 많은 연산 시간이 소요된다. 본 논문에서는 블록 암호 알고리즘의 ECB 모드에서 암호 연산을 가속화할 수 있는 파이프라인드 설계 방법을 제시한다. 제안된 방법에서는 여러 라운드의 암호 연산 블록을 파이프라인드 구조로 구성하고 연속적으로 실행하기 때문에 전체 연산 속도를 매우 높일 수 있다. 또한 파이프라인드 구조로 암호칩을 설계한 후 검증한 결과, 수십 배의 성능 향상이 가능하다는 것을 알 수 있다.