• Title/Summary/Keyword: converse

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REGULAR INJECTIVITY AND EXPONENTIABILITY IN THE SLICE CATEGORIES OF ACTIONS OF POMONOIDS ON POSETS

  • Farsad, Farideh;Madanshekaf, Ali
    • Journal of the Korean Mathematical Society
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    • v.52 no.1
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    • pp.67-80
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    • 2015
  • For a pomonoid S, let us denote Pos-S the category of S-posets and S-poset maps. In this paper, we consider the slice category Pos-S/B for an S-poset B, and study some categorical ingredients. We first show that there is no non-trivial injective object in Pos-S/B. Then we investigate injective objects with respect to the class of regular monomorphisms in this category and show that Pos-S/B has enough regular injective objects. We also prove that regular injective objects are retracts of exponentiable objects in this category. One of the main aims of the paper is to draw attention to characterizing injectivity in the category Pos-S/B under a particular case where B has trivial action. Among other things, we also prove that the necessary condition for a map (an object) here to be regular injective is being convex and present an example to show that the converse is not true, in general.

Gf-SPACES FOR MAPS AND POSTNIKOV SYSTEMS

  • Yoon, Yeon Soo
    • Journal of the Chungcheong Mathematical Society
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    • v.22 no.4
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    • pp.831-841
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    • 2009
  • For a map f : A $\rightarrow$ X, we define and study a concept of $G^f$-space for a map, which is a generalized one of a G-space. Any G-space is a $G^f$-space, but the converse does not hold. In fact, $S^2$ is a $G^{\eta}$-space, but not G-space. We show that X is a $G^f$-space if and only if $G_n$(A, f,X) = $\pi_n(X)$ for all n. It is clear that any $H^f$-space is a $G^f$-space and any $G^f$-space is a $W^f$-space. We can also obtain some results about $G^f$-spaces in Postnikov systems for spaces, which are generalization of Haslam's results about G-spaces.

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Vibration suppression of rotating blade with piezocomposite materials (Piezocomposite 재료를 사용한 회전하는 블레이드의 진동억제)

  • Choi Seung-Chan;Kim Ji-Hwan
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2004.10a
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    • pp.282-285
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    • 2004
  • The main purpose of this study is the vibration suppression of rotating composite blade containing distributed piezoelectric sensors and actuators. The blade is modeled by thin-walled, single cell composite beam including the warping function, centrifugal force, Coriolis acceleration and piezoelectric effect. Further, the numerical study is performed m ing finite element method. The vibration of composite rotor is suppressed by piezocomposite actuators and PVDF sensors that are embedded between composite layers. A velocity feedback control algorithm coupling the direct and converse piezoelectric effect is used to actively control the' dynamic response of an integrated structure through a closed control loop. Responses of the rotating blade are investigated. Newmark time integration method is used to calculate the time response of the model. In the numerical simulation, the effect of parameters such as rotating speed, fiber orientation of the blade and size of actuators are studied in detail.

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G'p-SPACES FOR MAPS AND HOMOLOGY DECOMPOSITIONS

  • Yoon, Yeon Soo
    • Journal of the Chungcheong Mathematical Society
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    • v.28 no.4
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    • pp.603-614
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    • 2015
  • For a map $p:X{\rightarrow}A$, we define and study a concept of $G^{\prime}_p$-space for a map, which is a generalized one of a G'-space. Any G'-space is a $G^{\prime}_p$-space, but the converse does not hold. In fact, $CP^2$ is a $G^{\prime}_{\delta}$-space, but not a G'-space. It is shown that X is a $G^{\prime}_p$-space if and only if $G^n(X,p,A)=H^n(X)$ for all n. We also obtain some results about $G^{\prime}_p$-spaces and homology decompositions for spaces. As a corollary, we can obtain a dual result of Haslam's result about G-spaces and Postnikov systems.

Finite Element Modeling for Free Vibration Control of Beam Structures using Piezoelectric Sensors and Actuators (압전감지기와 압전작동기를 이용한 보구조물의 자유진동제어에 대한 유한요소 모형화)

  • 송명관;한인선;김선훈;최창근
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2003.04a
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    • pp.269-278
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    • 2003
  • In this study, the method of the finite element modeling for free vibration control of beam-type smart structures with bonded plate-type piezoelectric sensors and actuators is proposed. Constitutive equations for the direct piezoelectric effect and converse piezoelectric effect of piezoelectric materials are considered. By using the variational principle, the equations of motion for the smart beam finite element are derived, The proposed 2-node beam finite element is an isoparametric element based on Timoshenko beam theory. Therefore, by analyzing beam-type smart structures with smart beam finite elements, it is possible to simulate the control of the structural behavior by applying voltages to piezoelectric actuators and monitoring of the structural behavior by sensing voltages of piezoelectric sensors. By using the smart beam finite element and constant-gain feed back control scheme, the formulation of the free vibration control for the beam structures with bonded plate-type piezoelectric sensors and actuators is proposed.

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The Method of Searching Unified Medical Language System Using Automatic Modified a Query (자동 질의수정을 통한 통합의학언어 시스템 검색)

  • 김종광;하원식;이정현
    • Proceedings of the IEEK Conference
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    • 2003.11b
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    • pp.129-132
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    • 2003
  • The metathesaurus(UMLS, 2003AA edition) supports multi language and includes 875, 233 concepts, 2, 146, 897 concept names. It is impossible for PubMed or NLM serve searching of the metatheaurus to retrieval using a query that is not to be text, a fault sentence structure or a part of concept name. That means the user notice correctly suitable medical words in order to get correct answer, otherwise she or he can't find information that they want to find I propose that the method of searching unified medical language system using automatic modified a query for problem that I mentioned. This method use dictionary that is standard for automation of modified query gauge similarity between query and dictionary using string comparison algorithm. And then, the tested term converse the form of metathesaurus for optimized result. For the evaluation of method, I select some query and I contrast NLM method that renewed Aug. 2003.

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Introduction to Coagulation System (혈액응고 기전에 대한 고찰)

  • Lyu, Chuhl-Joo
    • Neonatal Medicine
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    • v.18 no.1
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    • pp.1-5
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    • 2011
  • Coagulation involves the regulated sequence of proteolytic activation of a series of proteins to achieve appropriate and timely hemostasis in an injured vessel. In the non-pathological state, the inciting event involves exposure of circulating factor VIIa to extravascularly expressed tissue factor, which brings into motion the series of steps which results in cell based model of coagulation. In the new concepts of coagulation system, initiation, amplification and propagation steps are involved to converse of fibrinogen to fibrin. The precisely synchronized cascade of events is counter-balanced by a system of anticoagulant mechanisms. Developmental hemostasis refers to the age-related changes in the coagulation system that are most marked during neonate and childhood. An understanding of these changes in crucial to the accurate diagnosis of hemostatic abnormalities in neonate and children. This review aims to elucidate the main events within the coagulation cascade as it is currently understood to operate in vivo, and also a short review of the anticoagulants as they relate to this model. Also this paper describes the common pitfalls observed in the clinical data related to the coagulation system in neonate to children.

The metric approximation property and intersection properties of balls

  • Cho, Chong-Man
    • Journal of the Korean Mathematical Society
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    • v.31 no.3
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    • pp.467-475
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    • 1994
  • In 1983 Harmand and Lima [5] proved that if X is a Banach space for which K(X), the space of compact linear operators on X, is an M-ideal in L(X), the space of bounded linear operators on X, then it has the metric compact approximation property. A strong converse of the above result holds if X is a closed subspace of either $\elll_p(1 < p < \infty) or c_0 [2,15]$. In 1979 J. Johnson [7] actually proved that if X is a Banach space with the metric compact approximation property, then the annihilator K(X)^\bot$ of K(X) in $L(X)^*$ is the kernel of a norm-one projection in $L(X)^*$, which is the case if K(X) is an M-ideal in L(X).

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SUPERQUADRATIC FUNCTIONS AND REFINEMENTS OF SOME CLASSICAL INEQUALITIES

  • Banic, Senka;Pecaric, Josip;Varosanec, Sanja
    • Journal of the Korean Mathematical Society
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    • v.45 no.2
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    • pp.513-525
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    • 2008
  • Using known properties of superquadratic functions we obtain a sequence of inequalities for superquadratic functions such as the Converse and the Reverse Jensen type inequalities, the Giaccardi and the Petrovic type inequalities and Hermite-Hadamard's inequalities. Especially, when the superquadratic function is convex at the same time, then we get refinements of classical known results for convex functions. Some other properties of superquadratic functions are also given.

A BORSUK-ULAM TYPE THEOREM OVER ITERATED SUSPENSIONS OF REAL PROJECTIVE SPACES

  • Tanaka, Ryuichi
    • Journal of the Korean Mathematical Society
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    • v.49 no.2
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    • pp.251-263
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    • 2012
  • A CW complex B is said to be I-trivial if there does not exist a $\mathbb{Z}_2$-map from $S^{i-1}$ to S(${\alpha}$) for any vector bundle ${\alpha}$ over B a any integer i with i > dim ${\alpha}$. In this paper, we consider the question of determining whether $\Sigma^k\mathbb{R}P^n$ is I-trivial or not, and to this question we give complete answers when k $\neq$ 1, 3, 8 and partial answers when k = 1, 3, 8. A CW complex B is I-trivial if it is "W-trivial", that is, if for every vector bundle over B, all the Stiefel-Whitney classes vanish. We find, as a result, that $\Sigma^k\mathbb{R}P^n$ is a counterexample to the converse of th statement when k = 2, 4 or 8 and n $\geq$ 2k.