• 제목/요약/키워드: Logarithm

검색결과 474건 처리시간 0.021초

PRECISE ASYMPTOTICS FOR THE MOMENT CONVERGENCE OF MOVING-AVERAGE PROCESS UNDER DEPENDENCE

  • Zang, Qing-Pei;Fu, Ke-Ang
    • 대한수학회보
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    • 제47권3호
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    • pp.585-592
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    • 2010
  • Let {$\varepsilon_i:-{\infty}$$\infty$} be a strictly stationary sequence of linearly positive quadrant dependent random variables and $\sum\limits\frac_{i=-{\infty}}^{\infty}|a_i|$<$\infty$. In this paper, we prove the precise asymptotics in the law of iterated logarithm for the moment convergence of moving-average process of the form $X_k=\sum\limits\frac_{i=-{\infty}}^{\infty}a_{i+k}{\varepsilon}_i,k{\geq}1$

이동 에이전트에 대한 신뢰 센터 기반 단방향 엔티티 인증 기법 (Trusted Third Party(TTP) Based Mono-directional Entity Authentication Scheme in Mobile Agent)

  • 이기현;노환주
    • 한국정보처리학회논문지
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    • 제6권11S호
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    • pp.3356-3366
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    • 1999
  • Electric commerce system based on distributed mobile on object such as mobile agents need both precise identification and secure authentication scheme on remotemobile entities. In this paper, existing discrete logarithm based Schnorr like entity authentication schemes are improved by the analysis of performance and security on the bi-directional interactive proofs. And ElGamal like schemes are also proposed. Then, there are enhanced with oblivious transfer based mono-directional authentication schemes based on trusted third party for applying to the mobile agent based computing systems. Therefore, proposed schemes provide compatible performance and safety on mobile entity authentication process.

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전자상거래 인증 서비스를 위한 검증 가능한 자체인증 방식 (Verifiable Self-Certified Schemes for Authentication Service of Electronic Commerce)

  • 주미리;이보영;양형규;원동호
    • 한국정보처리학회논문지
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    • 제7권9호
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    • pp.2894-2902
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    • 2000
  • 본 논문에서는 전자성거래 인증 서비스를 제공하기 위하여 인증서에 기반한 방식의 정점과 Girault의 자체인증 공개키 방식의 장점을 결합한 검증 가능한 자체인증 방식을 고차잉여류 문제에 기반하여 제안한다. 제안한 방식의 안전성은 고차잉여류 문제와 이산대수 문제에 기반을 두고 있다.

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공정분산 관리를 위한 누적합 관리도 (Cusum Control Chart for Monitoring Process Variance)

  • 이윤동;김상익
    • 품질경영학회지
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    • 제33권3호
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    • pp.149-155
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    • 2005
  • Cusum control chart is used for the purpose of controling the process mean. We consider the problem related to cusum chart for controling process variance. Previous researches have considered the same problem. The main difficulty shown in the related researches was to derive the ARL function which characterizes the properties of the chart. Sample variance, differently with sample mean, follows chi-squared type distribution, even when the quality characteristics are assumed to be normally distributed. The ARL function of cusum is described by a type of integral equation. Since the solution of the integral equation for non-normal distribution is not known well, people used simulation method instead of solving the integral equation directly, or approximation method by taking logarithm of the sample variance. Recently a new method to solve the integral equation for Erlang distribution was published. Here we consider the steps to apply the solution to the problem of controling process variance.

Pseudomonas delafieldii가 생성하는 다당류의 레올로지 특성 (Rheological Properties of Biopolymer Produced by Pseudomonas delafieldii)

  • Yoo, Jin-Young;Chung, Dong-Hyo
    • 한국미생물·생명공학회지
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    • 제17권5호
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    • pp.475-480
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    • 1989
  • Pseudomonas delafieldii이 배양액으로부터 분리한 다당류 용액의 물성을 검토하였다. 본 다당류는 매우 점도가 높은 의가소성 물질로 1% 용액의 겉보기 점도는 42sec$^{-1}$에서 1769mpaㆍs이었다. 이 용액은 pH에 대한 안정성은 있으나 열 안정성은 보이지 않았다. 이 용액의 유동 활성에너지는 4.44kacl/mole 이고, 농도의존성은 double 1logarithm으로 포현되었다.

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Finite element analysis of 2D turbulent flows using the logarithmic form of the κ-ε model

  • Hasebe, Hiroshi;Nomura, Takashi
    • Wind and Structures
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    • 제12권1호
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    • pp.21-47
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    • 2009
  • The logarithmic form for turbulent flow analysis guarantees the positivity of the turbulence variables as ${\kappa}$ and ${\varepsilon}$ of the ${\kappa}-{\varepsilon}$ model by using the natural logarithm of these variables. In the present study, the logarithmic form is incorporated into the finite element solution procedure for the unsteady turbulent flow analysis. A backward facing step flow using the standard ${\kappa}-{\varepsilon}$ model and a flow around a 2D square cylinder using the modified ${\kappa}-{\varepsilon}$ model (the Kato-Launder model) are simulated. These results show that the logarithmic form effectively keeps adequate balance of turbulence variables and makes the analysis stable during transient or unsteady processes.

UNIFORM ASYMPTOTICS IN THE EMPIRICAL MEAN RESIDUAL LIFE PROCESS

  • Bae, Jong-Sic;Kim, Sung-Yeun
    • 대한수학회지
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    • 제43권2호
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    • pp.225-239
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    • 2006
  • In [5], Csorgo and Zitikis exposed the strong $uniform-over-[0,\;{\infty}]$ consistency, and weak $uniform-over-[0,\;{\infty}]$ approximation of the empirical mean residual life process by employing weight functions. We carry on the uniform asymptotic behaviors of the empirical mean residual life process over the whole positive half line by representing the process as an integral form. We compare our results with those of Yang [15], Hall and Wellner [8], and Csorgo and Zitikis [5].

유동관에 형성된 Cavity로부터의 입자확산현상 연구 (A Study of Particle Diffusion from a Cavity in Flow Tube)

  • 이진원;구재학;김현영
    • 설비공학논문집
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    • 제6권1호
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    • pp.29-38
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    • 1994
  • Particle contamination into and out of a cavity-cylindrical cavities with aspect ratios(width/depth) less than, equal to 1 and langer than 1, and also three dianensional T's attached to a cylindrical flow tube was studied numerically, using a finite difference method. In the process of unsteady particle diffusion, the particles contained in a concentration boundary layer near the tube wall plays an important role in the initial stage, after which a quasi-steady concentration profile is developed inside the cavity, resulting in an exponential change of concentration with time. Average concentration and its rate of change are observed to be closely correlated by a power law function in terms of Reynolds number and the logarithm of Schmidt number. Effects of the three parameters-Re, Sc, and aspect ratio-are analysed and well explained.

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전리수를 이용한 반도체 세정 공정 (Electrolyzed Water Cleaning for Semiconductor Manufacturing)

  • 류근걸;김우혁;이윤배;이종권
    • 반도체디스플레이기술학회지
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    • 제2권3호
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    • pp.1-6
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    • 2003
  • In the rapid changes of the semiconductor manufacturing technologies for early 21st century, it may be safely said that a kernel of terms is the size increase of Si wafer and the size decrease of semiconductor devices. As the size of Si wafers increases and semiconductor device is miniaturized, the units of cleaning processes increase. A present cleaning technology is based upon RCA cleaning which consumes vast chemicals and ultra pure water (UPW) and is the high temperature process. Therefore, this technology gives rise to environmental issue. To resolve this matter, candidates of advanced cleaning processes have been studied. One of them is to apply the electrolyzed water. In this work, electrolyzed water cleaning was compared with various chemical cleaning, using Si wafer surfaces by changing cleaning temperature and cleaning time, and especially, concentrating upon the contact angle. It was observed that contact angle on surface treated with Electrolyzed water cleaning was $4.4^{\circ}$ without RCA cleaning. Amine series additive of high pKa (negative logarithm of the acidity constant) was used to observe the property changes of cathode water.

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유리의 Flaking 생성기구에 관한 기구 (A Study on the Flaking Mechanism of Glass)

  • 김명석;심명재;김정환;이기강
    • 한국결정학회지
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    • 제11권4호
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    • pp.224-230
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    • 2000
  • We have been investigated the flaking mechanism of the soda-line glass. The pH of aqueous solution approached to 10 and increased with reaction time by ion exchange reaction between Na/sup +/ ion of glass and H/sup +/ ion of aqueous solution under the conditions of below pH 9 of start solution. The relationship between the pH of solution and reaction time shows logarithm. Total dissolution reaction of glass components by OH/sup -/ ion in aqueous seems to be dominant after the pH solution reached to 10 and the dissolution rate linearly increased with reaction time. The above tow reactions are simultaneously occurred. The dissolved Ca/sup 2+/ ions are reprecipitated on the glass surface to Ca-compound. The flakes are formed by the separation of leached layer of glass due to the different thermal expansion coefficient.

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