• Title/Summary/Keyword: Dos

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A Secure Protocol for the Electronic Auction (전자경매를 위한 보안 프로토콜)

  • Shi, Wenbo;Jang, In-Joo;Yoo, Hyeong-Seon
    • The Journal of Society for e-Business Studies
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    • v.12 no.4
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    • pp.29-36
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    • 2007
  • Recently, Jaiswal et al. proposed a protocol to improve the multi-agent negotiation test-bed which was proposed by Collins et al. Using publish/subscribe system, time-release cryptography and anonymous communication, their protocol gives an improvement on the old one. However, it is shown that the protocol also has some security weaknesses: such as replay data attack and DOS (denial-of-service) attack, anonymity disclosure, collusion between customers and a certain supplier. So proposed protocol reduces DOS attack and avoids replay data attack by providing ticket token and deal sequence number to the supplier. And it is proved that the way that market generates random number to the supplier is better than the supplier do by himself in guaranteeing anonymity. Market publishes interpolating polynomial for sharing the determination process data. It avoids collusion between customer and a certain supplie

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Characterization of Density-of-States in Polymer-based Organic Thin Film Transistors and Implementation into TCAD Simulator

  • Kim, Jaehyeong;Jang, Jaeman;Bae, Minkyung;Lee, Jaewook;Kim, Woojoon;Hur, Inseok;Jeong, Hyun Kwang;Kim, Dong Myong;Kim, Dae Hwan
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.13 no.1
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    • pp.43-47
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    • 2013
  • In this work, we report extraction of the density-of-states (DOS) in polymer-based organic thin film transistors through the multi-frequency C-V spectroscopy. Extracted DOS is implemented into a TCAD simulator and obtained a consistent output curves with non-linear characteristics considering the contact resistance effect. We employed a Schottky contact model for the source and drain to fully reproduce a strong nonlinearity with proper physical mechanisms in the output characteristics even under a very small drain biases. For experimental verification of the model and extracted DOS, 2 different OTFTs (P3HT and PQT-12) are employed. By controlling the Schottky contact model parameters in the TCAD simulator, we accurately reproduced the nonlinearity in the output characteristics of OTFT.

Aggressive unicystic ameloblastoma affecting the posterior mandible: late diagnosis during orthodontic treatment

  • Lopes, Sergio Lucio Pereira de Castro;Flores, Isadora Luana;Gamba, Thiago de Oliveira;Ferreira-Santos, Rivea Ines;Moraes, Mari Eli Leonelli de;Cabello, Aline Alvarez;Moutinho, Paula Nascimento
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.43 no.2
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    • pp.115-119
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    • 2017
  • Maxillofacial images must be examined to find pathologies not identified during clinical examination. Unicystic ameloblastoma (UA) extending to the mandibular body and ramus was neglected on initial panoramic radiographic examination. After orthodontic therapy, a huge lesion was observed clinically and through imaging exams. After the conservative surgery, no recurrence was observed during five years of follow-up. This case emphasized the need for careful evaluation of patient images focusing on the oral diagnosis before any dental treatment planning, including orthodontic therapy.

Sensitivity to Intergranular Corrosion According to Heat Treatment of 304L Stainless Steel (304L 스테인리스강의 열처리에 따른 입계부식민감도 연구)

  • Jang, Hyung-Min;Kim, Dong-Jin;Kim, Hong-Pyo
    • Corrosion Science and Technology
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    • v.19 no.1
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    • pp.37-42
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    • 2020
  • Even though 304 low-carbon (304L) stainless steel was developed to enhance the resistance to intergranular corrosion and stress corrosion cracking, it is occasionally subject to degradation in harsh environments. The degree of sensitization (DOS) of 304L stainless steel was studied as a function of sensitization using a double-loop electrochemical potentiokinetic reactivation (DL-EPR) method. Sensitizing heat treatment was performed in an Ar atmosphere at 500℃, 600℃, and 700℃, with heat treatment times varying from 0 to 96 h. DOS was measured by the ratio of the peak current density value of the forward scan to that of the reverse scan. After the EPR experiment, the specimen surface was observed by scanning electron microscopy and energy dispersive spectroscopy. The DOS of the specimens heat-treated at 600℃ increased with heat treatment times up to 48 h and then decreased due to a self healing effect. The DOS was higher in specimens heat-treated at 600℃ than those at 500℃ or 700℃. Corrosion of the sensitized specimens occurred mainly at the δ-γ phase boundary. The corrosion morphology at the δ-γ phase boundary changed with sensitizing heat-treatment conditions due to differences in chromium activity in γ austenite and δ ferrite.

Study on Property Modification with Kind and Additive Amount of Plasticizer in the Manufacture of Compounds for Cable Sheath (전선피복용 컴파운드의 제조에서 가소제의 종류와 첨가량에 따른 물성 변화 연구)

  • Li, Xiangxu;Lee, Sang Bong;Cho, Ur Ryong
    • Journal of the Semiconductor & Display Technology
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    • v.18 no.2
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    • pp.11-16
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    • 2019
  • The four different polymer compounds were manufactured with the two kinds of plasticizers [(di-2-ethylhexyl sebacate(DOS), and di-2-butyl sebacate(DBS)] and two different additive amounts(18, 26 phr) of the same plasticizer for making cable sheath for ship. Ethylene-vinylacetate, ethylene-propylene-diene-copolymer as matrix polymers and ethylene-vinylacetate grafted maleic anhydride as coupling agent were selected for compounding with fire retardant, closslinking agent, filler, and other additives besides plasticizer. The compound including DOS showed the higher ${\Delta}T$ than that including DBS at the same additive amount in the rheology test. And with increasing plasticizer, the compounds resulted in lower tensile strength and higher elongation by lubricating effect of plasticizer. DOS yielded better aging resistance and cold resistance than DBS due to the good heat resistance and low solidifying point of DOS compared to DBS.

Analysis of Shear Modulus(G)-Shear Strain(γ)-Degree of Saturation(S) Characteristics of Compacted Subgrade Soil used as Railway Trackbed (다짐된 궤도 흙노반 재료의 전단탄성계수(G)-전단변형률(γ)-포화도(S) 관계특성 분석)

  • Choi, Chan Yong;Lee, Seong Hyeok;Lim, Yu Jin;Kim, Dae Sung;Park, Jae Beom
    • Journal of the Korean Society for Railway
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    • v.18 no.2
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    • pp.127-138
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    • 2015
  • It is important to evaluate the stiffness characteristics of compacted subgrade soil under track that is loaded dynamically. Using a mid-size Resonant Column test apparatus, normalized shear modulus and shear modulus variation with changing of confining pressure were investigated with change of degree of saturation (DOS). From an analysis of the test results, it was verified that the maximum shear modulus decreased with increases of DOS. However, normalized shear modulus increased with increases of DOS. Using the test results, a relation of G~${\gamma}$~DOS can be constructed and characterized. In the future, by performing tests with soils used as trackbed broadly in the field, a prediction model for DOS~G~${\gamma}$ can be proposed.

The Effect of Alloying Elements and Heat Treatment on the Intergranular Corrosion of 440A Martensitic Stainless Steel(II) (440A 강의 입계부식에 미치는 합금원소와 열처리의 영향(II))

  • Kim,, Y.C.;Jung, B.H.;Kang, C.Y.
    • Journal of Power System Engineering
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    • v.15 no.3
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    • pp.52-57
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    • 2011
  • 440A martensitic stainless steels which were modified with reduced carbon content(~0.5wt.%) and addition of small amount of vanadium, tungsten and molybdenum 0.4wt.%, 0.4wt.% and 0.68wt.% respectively were manufactured. Effects of alloying elements and tempering temperatures on the intergranular corrosion were investigated through the method of DL-EPR(Double-electrochemical potentiodynamic reactivation). It was thought that the highest DOS(Degree of sensitization) of specimens was obtained at the tempering temperature of $450^{\circ}C$ regardless of types of alloy because of the precipitation of Cr7C3. Addition of vanadium lowered DOS a little above the tempering temperature of $550^{\circ}C$. It was considered to be effected by precipitation of VC carbides. Intergranular corrosion was influenced more by tempering temperature than by alloying elements of V, W and Mo.

Identification of 2-Deoxy-scyllo-inosose Synthase in Aminoglycoside Producer Streptomyces

  • Kharel, Madan-Kumar;Subba, Bimala;Lee, Hei-Chan;Liou, Kwang-Kyoung;Woo, Jin-Suk;Kim, Dong-Hwan;Moon, Young-Ho;Sohng, Jae-Kyung
    • Journal of Microbiology and Biotechnology
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    • v.13 no.5
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    • pp.828-831
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    • 2003
  • Although most of the DOS containing aminoglycosides are produced by Streptomyces, very little information is available about their biosynthesis. In the present paper, we report a method to isolate DOI synthase, a key enzyme in the biosynthesis of DOS, from aminoglycoside producer Streptomyces. PCR primers based on conserved region of DOI synthases were specific and reliable for the isolation of the biosynthetic genes of DOS containing aminoglycosides or the screening of the aminoglycoside producers. The use of DOI synthase as a probe could save both time and cost of cloning aminoglycoside biosynthetic genes.

Wireless Remote Control System for DOS Client (도스 단말기의 무선 원격제어 시스템 설계)

  • Kim, Chang-Hoon;Byeon, Jeong-Sik;Han, Byung-Jun;Min, Byung-Ki;Kim, Seung-Jun
    • Proceedings of the Korea Multimedia Society Conference
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    • 2012.05a
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    • pp.93-96
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    • 2012
  • 본 논문에서는 유선기반 DOS(Disk Operating System) 제어의 다양한 단점들을 극복하기 위해 무선기반의 도스 원격제어 시스템을 제안한다. 제안한 시스템은 비디오 전송기, 가상 네트워크 드라이버, 무선 키보드 모듈로 구성되며 도스와 윈도우즈 컴퓨터간의 중계기 역할을 수행한다. 무선 랜 환경(802.11n)에서 성능을 측정한 결과 약 15Mbps 통신환경에서 영상의 경우 초당 10 ~ 15 프레임을 전송하고, 네트워크 드라이버의 연결속도는 약 8Mbps이며, 키보드 입력의 경우 실시간 처리가 가능하다. 따라서 본 논문에서 제안한 시스템은 DOS기반 어플리케이션의 원격제어 솔루션으로 매우 적합하다 할 수 있다.

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Ab initio calculation of half-metallic ferrocene-based nanowire

  • Kim, Seongmin;Park, Changhwi
    • Proceeding of EDISON Challenge
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    • 2014.03a
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    • pp.425-429
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    • 2014
  • Half-metallic nanostructure is highly applicable in the field of Spintronics and electronic device technology. We examine the electronic properties of a ferrocene-based nanowire as a possible candidate for a half-metallic nanostructure using VASP and SIESTA. Ferrocene-based nanowire shows high stability in both binding energy simulation and molecular dynamics (MD) simulation. The density of states (DOS) and the projected DOS of the ferrocene-based nanowire indicate that one-dimensional clustering of ferrocene molecules can be explained because of p-d orbital hybridization between iron and carbon. Half-metallic property and energy dispersion at the Fermi level due to one-dimensional structure is also observed from the DOS results.

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