• Title/Summary/Keyword: dual theory

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Counter-examples and dual operator algebras with properties $(A_{m,n})$

  • Jung, Il-Bong;Lee, Hung-Hwan
    • Journal of the Korean Mathematical Society
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    • v.31 no.4
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    • pp.659-667
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    • 1994
  • Let $H$ be a separable, infinite dimensional, complex Hilbert space and let $L(H)$ be the algebra of all bounded linear operators on $H$. A dual algebra is a subalgebra of $L(H)$ that contains the identity operator $I_H$ and is closed in the ultraweak operator topology on $L(H)$. Note that the ultraweak operator topology coincides with the weak topology on $L(H) (cf. [6]). Several functional analysists have studied the problem of solving systems of simultaneous equations in the predual of a dual algebra (cf. [3]). This theory is applied to the study of invariant subspaces and dilation theory, which are deeply related to the classes $A_{m,n}$ (that will be defined below) (cf. [3]). An abstract geometric criterion for dual algebras with property $(A_{\aleph_0}, {\aleph_0})$ was first given in [1].

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Dual-phase-lag model on microstretch thermoelastic medium with diffusion under the influence of gravity and laser pulse

  • Othman, Mohamed I.A.;Abd-Elaziz, Elsayed M.;Mohamed, Ibrahim E.A.
    • Structural Engineering and Mechanics
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    • v.75 no.2
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    • pp.133-144
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    • 2020
  • This investigation is to study the effect of gravitational field and diffusion on a microstretch thermoelastic medium heating by a non-Gaussian laser beam. The problem was studied in the context of the dual-phase-lag model. The normal mode analysis is used to solve the problem to obtain the exact expressions for the non-dimensional displacement components, the micro-rotation, the stresses, and the temperature distribution. The effect of time parameter, heat flux parameter and gravity response of three theories of thermoelasticity i.e. dual-phase-lag model (DPL), Lord and Shulman theory (L-S) and coupled theory (CT) on these quantities have been depicted graphically for a particular model.

Influence of gravity, locality, and rotation on thermoelastic half-space via dual model

  • Samia M. Said
    • Structural Engineering and Mechanics
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    • v.89 no.4
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    • pp.375-381
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    • 2024
  • In this paper, Eringen's nonlocal thermoelasticity is constructed to study wave propagation in a rotating two-temperature thermoelastic half-space. The problem is applied in the context of the dual-phase-lag (Dual) model, coupled theory (CD), and Lord-Shulman (L-S) theory. Using suitable non-dimensional fields, the harmonic wave analysis is used to solve the problem. Comparisons are carried with the numerical values predicted in the absence and presence of the gravity field, a nonlocal parameter as well as rotation. The present study is valuable for the analysis of nonlocal thermoelastic problems under the influence of the gravity field, mechanical force, and rotation.

A Study on the Internet User's Economic Behavior of Provision of Personal Information: Focused on the Privacy Calculus, CPM Theory (개인정보 제공에 대한 인터넷 사용자의 경제적 행동에 관한 연구: Privacy Calculus, CPM 이론을 중심으로)

  • Kim, Jinsung;Kim, Jongki
    • The Journal of Information Systems
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    • v.26 no.1
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    • pp.93-123
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    • 2017
  • Purpose The purpose of this study is to deduct the factors for explaining the economic behavior of an Internet user who provides personal information notwithstanding the concern about an invasion of privacy based on the Information Privacy Calculus Theory and Communication Privacy Management Theory. Design/methodology/approach This study made a design of the research model by integrating the factors deducted from the computation theory of information privacy with the factors deducted from the management theory of communication privacy on the basis of the Dual-Process Theory. In addition, this study, did empirical analysis of the path difference between groups by dividing Internet users into a group having experience in personal information spill and another group having no experience. Findings According to the empirical analysis result, this study confirmed that the Privacy Concern about forms through the Perceived Privacy Risk derived from the Disposition to value Privacy. In addition, this study confirmed that the behavior of an Internet user involved in personal information offering occurs due to the Perceived Benefits contradicting the Privacy Concern.

DUALITY IN THE OPTIMAL CONTROL PROBLEMS FOR HYPERBOLIC SYSTEMS

  • Kim, Hyun-Min;Park, Jong-Yeoul;Park, Sun-Hye
    • East Asian mathematical journal
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    • v.17 no.2
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    • pp.375-383
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    • 2001
  • In this paper we deal with the duality theory of optimality for an optimal control problem governed by a class of second order evolution equations. First we establish the dual control systems by using conjugate functions and then associate them to the original optimization problem.

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Investigating the Privacy Paradox in Facebook Based on Dual Factor Theory (페이스북에서의 프라이버시 패러독스 현상 연구 : 듀얼팩터이론을 중심으로)

  • Yu, Jae Ho;Lee, Ae Ri;Kim, Kyung Kyu
    • Knowledge Management Research
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    • v.17 no.1
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    • pp.17-47
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    • 2016
  • People use social network services (SNSs) for various purposes, for example, to share information, to express themselves, and to strengthen social relationships with others. Meanwhile, problems of personal information leakage and privacy infringement become a social issue and thus information privacy concerns about inappropriate collection and use of personal information increase in SNSs (e.g., Facebook). Although people have privacy concerns in SNSs, they behave in a contradictory way, voluntarily presenting themselves and disclosing personal information. This phenomenon is called 'privacy paradox'. Using dual factor theory, this study investigates the phenomenon of privacy paradox by looking into enablers (e.g., self-presentation) and inhibitors (e.g., information privacy concern) for continuous use of Facebook that can co-exist independently of each other. It also includes antecedents of self-presentation (i.e., narcissism, need for affiliation, involvement, and self-efficacy) and those of information privacy concern (i.e., previous experience of privacy infringement, privacy awareness, and privacy control). The results show that most hypothesized relationships were supported. These findings provide strategic implications for SNS providers who want to promote continuous use of SNS. Under the current circumstances in which enhanced privacy policies are required, this study would be a useful reference for future research on information privacy issues in SNSs.

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The Differentiating Effects of Job Seekers' Spec on Actual Employment: Focusing on Screening Hypothesis and Dual Labor Market Theory (구직자의 취업스펙이 실제취업에 미치는 영향에 대한 탐색적 연구: 선별이론 및 이중노동시장이론을 중심으로)

  • Jisung Park;Chiho Ok
    • Asia-Pacific Journal of Business
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    • v.13 no.4
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    • pp.11-24
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    • 2022
  • Purpose - The purpose of this study was to examine how job seekers' spec influence their actual employment especially focusing on the differentiating effects of applicants' specs depending on whether general or decent job employment. Design/methodology/approach - This study conducted analyses on 54,443 samples that incorporated data from the Graduates Occupational Mobility Survey for three years (2017-2019) collected by the Korea Employment Information Service. The linear probability model and logit model were used to examine the research questions. Findings - The results analyzed with the hierarchical regression model showed that most job seekers' specs were statistically significant in predicting employment status. Interestingly, there is a difference between the factors predicting employment for a general job and a decent job. This study suggests academic and practical implications for future research in the selection/ recruitment field by clarifying the critical factors to influence applicants' employment. Research implications or Originality The results of this study follow the screening hypothesis which explains that the applicants' specs have significant impacts on actual employment. Also, the dual labor market theory, which explains that applicants' specs differently affect actual employment between general and decent jobs, was reaffirmed.

A DUAL ALGORITHM FOR MINIMAX PROBLEMS

  • HE SUXIANG
    • Journal of applied mathematics & informatics
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    • v.17 no.1_2_3
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    • pp.401-418
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    • 2005
  • In this paper, a dual algorithm, based on a smoothing function of Bertsekas (1982), is established for solving unconstrained minimax problems. It is proven that a sequence of points, generated by solving a sequence of unconstrained minimizers of the smoothing function with changing parameter t, converges with Q-superlinear rate to a Kuhn-Thcker point locally under some mild conditions. The relationship between the condition number of the Hessian matrix of the smoothing function and the parameter is studied, which also validates the convergence theory. Finally the numerical results are reported to show the effectiveness of this algorithm.

A Dual Problem and Duality Theorems for Average Shadow Prices in Mathematical Programming

  • Cho, Seong-Cheol
    • Journal of the Korean Operations Research and Management Science Society
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    • v.18 no.2
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    • pp.147-156
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    • 1993
  • Recently a new concept of shadow prices, called average shadow price, has been developed. This paper provides a dual problem and the corresponding duality theorems justifying this new shadow price. The general duality framework is used. As an important secondary result, a new reduced class of price function, the pp. h.-class, has been developed for the general duality theory. This should be distinguished from other known reductions achieved in some specific areas of mathematical programming, in that it sustains the strong duality property in all the mathematical programs. The new general dual problem suggested with this pp. h.-class provides, as an optimal solution, the average shadow prices.

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A Dual Mode Ultrasonic Transducer with a PZT Piezoelectric Seramics (PZT 압전 세라믹스를 사용한 2 중 모우드 초음파 변환기)

  • 김연보;노용래;남효덕
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1995.05a
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    • pp.1-4
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    • 1995
  • The most of conventional ultrasonic transducers are constructed to generate either longitudinal or shear waves, but not both of them. We investigated the mechanism of dual mode transducers that generates both of the longitudinal and shear waves simultaneously with a single PZT element. The study has been aimed to find the desired cut by the examining the piezoelectric properties. Theory predicts that a mixed P/S mode transducer can be constructed using a related Z-cut of a PZT ceramics. We studied the performance of a PZT element as a function of its rotation angle so that its efficiency is optimized to excite the two waves equally strongly. The results are verified by checking the impedance variation of the element with Finite Element Methods, and chocking the wave form by pulse-echo test simulation. Based upon the theory a rotated Z-cut was prepared and a transducer were fabricated. Validity of the theory calculation is verified through the

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