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ON CHARACTERIZATIONS OF THE WEIBULL DISTRIBUTION BY THE UPPER RECORD VALUES

  • Chang, Se-Kyung;Lee, Min-Young;Park, Young-Seo
    • Journal of applied mathematics & informatics
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    • v.26 no.1_2
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    • pp.437-443
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    • 2008
  • In this paper, we establish detailed characterizations of the Weibull distribution by the independence of the upper record values. We prove that X $\in$ W EI($\alpha$), if and only if $\frac{X_{U(n)}}{X_{U(n+1)}+X_{U(n)}}$ and $X_{U(n+1)}$ are independent for n $\geq$ 1. And we show that X $\in$ W EI($\alpha$), if and only if $\frac{X_{U(n+1)}-X_{U(n)}}{X_{U(n+1)}+X_{U(n)}}$ and $X_{U(n+1)}$ are independent for n $\geq$ 1.

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A Study on u-City Ecosystem Model for Seong-Nam City (성남시 사례로 본 u-City 생태계 모델연구)

  • Won, dong-kyu;You, sun-hee;Lim, jong-yeon
    • Proceedings of the Korea Contents Association Conference
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    • 2011.05a
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    • pp.165-166
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    • 2011
  • u-City 사업 시행주체와 지자체의 경영난에 따른 u-City 인프라 구축 및 운영난이 함께 맞물려 새로운 돌파구가 필요한 시점이다. 즉 u-보건의료, u-방범, u-교통, u-환경 등의 복지에 대한 수요 충족과 지역의 u-City산업발전을 통한 지역생산성 제고 등 새로운 딜레마를 어떻게 극복해 나갈 것인가 하는 모색이 필요하다. 본 연구는 성남시를 사례로 이러한 딜레마 극복을 위한 대안을 제시하고자 한다.

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On Commutativity of σ-Prime Γ-Rings

  • DEY, KALYAN KUMAR;PAUL, AKHIL CHANDRA;DAVVAZ, BIJAN
    • Kyungpook Mathematical Journal
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    • v.55 no.4
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    • pp.827-835
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    • 2015
  • Let U be a ${\sigma}$-square closed Lie ideal of a 2-torsion free ${\sigma}$-prime ${\Gamma}$-ring M. Let $d{\neq}1$ be an automorphism of M such that $[u,d(u)]_{\alpha}{\in}Z(M)$ on U, $d{\sigma}={\sigma}d$ on U, and there exists $u_0$ in $Sa_{\sigma}(M)$ with $M{\Gamma}u_0{\subseteq}U$. Then, $U{\subseteq}Z(M)$. By applying this result, we generalize the results of Oukhtite and Salhi respect to ${\Gamma}$-rings. Finally, for a non-zero derivation of a 2-torsion free ${\sigma}$-prime $\Gamma$-ring, we obtain suitable conditions under which the $\Gamma$-ring must be commutative.

An Experimental Study on the Sorption of U(VI) onto Granite

  • Min-Hoon Baik;Pil-Soo Hahn
    • Nuclear Engineering and Technology
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    • v.34 no.5
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    • pp.445-454
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    • 2002
  • The sorption of U(Vl) on a domestic granite is studied as a function of experimental conditions such as contact time, solution-solid ratio, ionic strength, and pH using a batch procedure. The distribution coefficients, $K_{d}$'s, of U(VI) are about 1-100mL/g depending on the experimental conditions. The sorption of U(VI) onto granite particles is greatly dependent upon the contact time, solution-solid ratio, and pH, but very little is dependent on the ionic strength. It is noticed that an U(VI)-carbonate ternary surface complex can be formed in the neutral range of pH. In the alkaline range of pH above 7, U(VI) sorption onto granite particles is greatly decreased due to the formation of anionic U(VI)-carbonate aqueous complexes.s.

A Study on a Strategy for Reducing Operating Costs of u-City (u-City 운영비 절감방안에 관한 연구)

  • Park, Kwang-Ho;Kim, Yun-Hyung
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.33 no.1
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    • pp.24-32
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    • 2010
  • The first full-scale u-City operation has started in Dongtan u-City. As local cities take over and operates the u-City, unexpected issues arise such as securing the budget of operating costs and self-providing the costs with business models utilizing the u-City assets. The paper presents a strategy for solving these issues. The strategy provides a foundation(infrastructure) for long-term operation models which may reduce the long-term operation costs. In order to establish the economic operating framework of u-City, suggested are some cost-reduction models based on the operating costs structure. For each model, a base framework with comparative analysis of operating costs is provided. With these models, each u-City may select a relevant model according to the characteristics of it. We hope that the framework provides the foundation for efficient and sustainable u-City operations.

Process of the Encryption key using a Physical Information in the U-Healthcare Service (원격의료서비스에서 생체정보를 이용한 암호화키 생성방법 연구)

  • Song, Chung-Geon;Lee, Keun-Ho;Ryu, Gab-Sang
    • Journal of Digital Convergence
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    • v.12 no.1
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    • pp.573-578
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    • 2014
  • Recently as we enter into the world of an aging society, the U-Healthcare service is newly spotlighted. In order to secure this U-Healthcare, a development of security solution that is suitable for the U-Healthcare environment is required. But the U-Healthcare environment is difficult to apply the existing security solution with the lack of standards, a security solution with high completeness was not developed. At this point, in order to structure the safe U-Healthcare environment, a generating method of an encryption key using the body information that helps the effective key management and ensuring the confidentiality of the data is proposed.

Analysis and Approximation of Linear feedback control problems for the Boussinesq equations

  • 최영미;이형천
    • Proceedings of the Korean Society of Computational and Applied Mathematics Conference
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    • 2003.09a
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    • pp.6-6
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    • 2003
  • In this work we consider the mathematical formulation and numerical resolution of the linear feedback control problem for Boussinesq equations. The controlled Boussinesq equations is given by $$\frac{{\partial}u}{{\partial}t}-{\nu}{\Delta}u+(u{\cdot}{\nabla}u+{\nabla}p={\beta}{\theta}g+f+F\;\;in\;(0,\;T){\times}\;{\Omega}$$, $${\nabla}{\cdot}u=0\;\;in\;(0,\;T){\times}{\Omega}$$, $$u|_{{\partial}{\Omega}=0,\;u(0,x)=\;u_0(x)$$ $$\frac{{\partial}{\theta}}{{\partial}t}-k{\Delta}{\theta}+(u{\cdot}){\theta}={\tau}+T,\;\;in(0,\;T){\times}{\Omega}$$ $${\theta}|_{{\partial}{\Omega}=0,\;\;{\theta}(0,X)={\theta}_0(X)$$, where $\Omega$ is a bounded open set in $R^{n}$, n=2 or 3 with a $C^{\infty}$ boundary ${\partial}{\Omega}$. The control is achieved by means of a linear feedback law relating the body forces to the velocity and temperature field, i.e., $$f=-{\gamma}_1(u-U),\;\;{\tau}=-{\gamma}_2({\theta}-{\Theta}}$$ where (U,$\Theta$) are target velocity and temperature. We show that the unsteady solutions to Boussinesq equations are stabilizable by internal controllers with exponential decaying property. In order to compute (approximations to) solution, semi discrete-in-time and full space-time discrete approximations are also studied. We prove that the difference between the solution of the discrete problem and the target solution decay to zero exponentially for sufficiently small time step.

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Design of Improved U-Slotted Patch Antennas with EBG Ground Plane (EBG(Electromagnetic Band-Gap) 접지면을 갖는 개선된 U-Slotted 패치 안테나의 설계)

  • Park, Jong-Hwan;Lim, Seong-Bin;Choi, Hak-Keun
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.19 no.3
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    • pp.304-310
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    • 2008
  • Generally U-slotted patch antenna with PEC(Perfect Electric Conductor) ground plane is used for mobile telecommunication. However the improvement of the bandwidth is required to enlarge the capability of mobile telecommunication, In this paper, U-slotted patch antenna with EBG(Electromagnetic Band-Gap) ground plane is proposed to enlarge thr bandwidth and its radiation characteristics are investigated. To conform the bandwidth improvement, two kinds of U-slotted patch antennas with EBG and PEC ground plane are designed, fabricated, and radiation characteristics are measured. It is shown that the proposed antenna is wider than U-slotted patch antenna with PEC ground plane in bandwidth.

The LDA+U Effect on the Electronic Structure and Magnetism of Bulk, Monolayer, and Linear Chain of Iron (덩어리, 단층 및 사슬 구조 철의 전자구조와 자성에 대한 LDA+U 효과)

  • Landge, Kalpana K.;Bialek, Beata;Lee, Jae-Il
    • Journal of the Korean Magnetics Society
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    • v.19 no.3
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    • pp.81-84
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    • 2009
  • We examine the effect of U term (U = 3 eV) describing the Coulomb interactions between electrons on the results of electronic band structure calculations carried out for bcc Fe bulk, monolayer, and chain. We investigated the properties of the three Fe structures by using the all-electron total-energy full-potential linearized augmented plane wave method. The U term was included in the exchange - correlation functionals constructed on the basis of local density approximation (LDA) and general gradient approximation (GGA). We found that in the case of bcc Fe bulk structure inclusion of the U term leads to the overestimated values of magnetic moment on Fe atom. The values of magnetic moment calculated for Fe in monolayer and chain are in accordance with calculations in which the U term was not included. In general, for each system the calculated values of magnetic moment on Fe sites were larger when the U term was incorporated in the energy functional. In Fe bulk, the value of magnetic moment $2.54{\mu}_B$ for LDA+U larger than $2.25{\mu}_B$ for LDA.

On the solutions U$^+$ and U$_+$ of fuzzy relation equation (퍼지관계방정식의 해의 관계성)

  • Jeon, Jong-Duek;Kim, Hyun-Mee
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 1998.10a
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    • pp.27-30
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    • 1998
  • The purpose of this paper is to investigate solutions U$_+$ and U$^+$ for the fuzzy relation equation R$\circ$U= T in cases of R < T, R $\leq$ T, and R = T, when R is irreflexive, U$_+$ ($\chi$$_i$, $\chi$$_k$)=$\bigwedge$[R($\chi$$_i$, $\chi$$_k$) << T($\chi$$_i$, $\chi$$_k$)], U$^+$ ($\chi$$_i$, $\chi$$_k$)=$\bigwedge$[R($\chi$$_i$, $\chi$$_k$)->T($\chi$$_i$, $\chi$$_k$)].

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