• 제목/요약/키워드: Maximal functions

검색결과 129건 처리시간 0.021초

ENDPOINT ESTIMATES FOR MAXIMAL COMMUTATORS IN NON-HOMOGENEOUS SPACES

  • Hu, Guoen;Meng, Yan;Yang, Dachun
    • 대한수학회지
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    • 제44권4호
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    • pp.809-822
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    • 2007
  • Certain weak type endpoint estimates are established for maximal commutators generated by $Calder\acute{o}n-Zygmund$ operators and $Osc_{exp}L^{\gamma}({\mu})$ functions for ${\gamma}{\ge}1$ under the condition that the underlying measure only satisfies some growth condition, where the kernels of $Calder\acute{o}n-Zygmund$ operators only satisfy the standard size condition and some $H\ddot{o}rmander$ type regularity condition, and $Osc_{exp}L^{\gamma}({\mu})$ are the spaces of Orlicz type satisfying that $Osc_{exp}L^{\gamma}({\mu})$ = RBMO(${\mu}$) if ${\gamma}$ = 1 and $Osc_{exp}L^{\gamma}({\mu}){\subset}RBMO({\mu})$ if ${\gamma}$ > 1.

[ $L^p$ ] NORM INEQUALITIES FOR AREA FUNCTIONS WITH APPROACH REGIONS

  • Suh, Choon-Serk
    • East Asian mathematical journal
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    • 제21권1호
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    • pp.41-48
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    • 2005
  • In this paper we first introduce a space of homogeneous type X, and then consider a kind of generalized upper half-space $X{\times}(0,\;\infty)$. We are mainly considered with inequalities for the $L^p$ norms of area functions associated with approach regions in $X{\times}(0,\;\infty)$.

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On the Study for the Simultaneous Test

  • Park, Hyo-Il
    • Communications for Statistical Applications and Methods
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    • 제20권4호
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    • pp.241-246
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    • 2013
  • In this study, we propose a nonparametric simultaneous test procedure for the location translation and scale parameters. We consider the Wilcoxon rank sum test for the location translation parameter and the Mood test for the scale parameter with the quadratic and maximal types of combining functions. Then we derive the limiting null distributions of the combining functions. We illustrate our procedure with an example and compare efficiency by obtaining the empirical powers through a simulation study. Finally, we discuss some interesting features related to the nonparametric simultaneous tests.

THE CORONA THEOREM FOR BOUNDED FUNCTIONS IN DIRICHLET SPACE

  • Nah, Young-Chae
    • 충청수학회지
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    • 제10권1호
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    • pp.141-146
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    • 1997
  • In this paper we prove that the corona theorem for the algebra $H^{\infty}(D){\cap}D(D)$. That is, we prove that $\mathcal{M}{\setminus}{\overline{D}}$ is an empty set where $\mathcal{M}$ is the maximal ideal space of the given algebra.

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Effects of Modified Cervical Exercise on Respiratory Functions in Smartphone Users with Forward Head Posture

  • Kong, Yong-Soo;Kim, Yu-Mi;Shim, Je-Myung
    • The Journal of Korean Physical Therapy
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    • 제28권5호
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    • pp.292-296
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    • 2016
  • Purpose: This study was conducted to investigate the effects of modified cervical exercise on respiratory functions in smartphone users with forward head posture. Methods: Thirty-three smartphone users with forward head posture participated in this study. Subjects were divided into three groups that performed modified cervical exercise one time a day (A group), two times a day (B group), and three times a day (C group). All subjects performed the exercise for four weeks, during which time respiratory functions were measured. Results: There were significant differences in respiratory functions such as forced vital capacity, forced expiratory volume at one second, and maximal voluntary ventilation in the C group after four weeks (p<0.05). Moreover, the forced vital capacity differed among groups, and the post hoc test revealed a significant difference between A group and C group (p<0.05). Conclusion: The results of this study confirmed that modified cervical exercise improved respiratory functions in smartphone users with forward head posture. These findings indicate that smartphone users with forward head posture should perform modified cervical exercise to build correct posture and respiratory functions.

주파수 영역 등화기를 사용하는 단일 반송파 전송 시스템을 위한 저 전력 전송 기법 (Low Power Transmission Technique for Single-Carrier Modulation with Frequency Domain Equalization)

  • 정혁구
    • 전기학회논문지P
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    • 제66권4호
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    • pp.247-251
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    • 2017
  • This paper proposes a low power transmission technique for single-carrier modulation with frequency domain equalization. As time domain signals and frequency domain signals have unique corresponding functions, inserting zeros after each symbol causes a repetition in other domain, so maximal ratio combining technique using repetitive transmission can be applied in the frequency domain. In this paper, we configure transmit signals to insert zeros after each symbols for single-carrier modulation with frequency domain equalization and maximal ratio receive combining block in the receiver structures, propose a structure for transmitter and receiver and show that its performance is better than the traditional algorithm by simulations.

SINGULAR INNER FUNCTIONS OF $L^{1}-TYPE$

  • Izuchi, Keiji;Niwa, Norio
    • 대한수학회지
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    • 제36권4호
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    • pp.787-811
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    • 1999
  • Let M be the maximal ideal space of the Banach algebra $H^{\infty}$ of bounded analytic functions on the open unit disc $\triangle$. For a positive singular measure ${\mu}\;on\;{\partial\triangle},\;let\;{L_{+}}^1(\mu)$ be the set of measures v with $0\;{\leq}\;{\nu}\;{\ll}\;{\mu}\;and\;{{\psi}_{\nu}}$ the associated singular inner functions. Let $R(\mu)\;and\;R_0(\mu)$ be the union sets of $\{$\mid$\psiv$\mid$\;<\;1\}\;and\;\{$\mid${\psi}_{\nu}$\mid$\;<\;0\}\;in\;M\;{\setminus}\;{\triangle},\;{\nu}\;\in\;{L_{+}}^1(\mu)$, respectively. It is proved that if $S(\mu)\;=\;{\partial\triangle}$, where $S(\mu)$ is the closed support set of $\mu$, then $R(\mu)\;=\;R0(\mu)\;=\;M{\setminus}({\triangle}\;{\cup}\;M(L^{\infty}(\partial\triangle)))$ is generated by $H^{\infty}\;and\;\overline{\psi_{\nu}},\;{\nu}\;{\in}\;{L_1}^{+}(\mu)$. It is proved that %d{\theta}(S(\mu))\;=\;0$ if and only if there exists as Blaschke product b with zeros $\{Zn\}_n$ such that $R(\mu)\;{\subset}\;{$\mid$b$\mid$\;<\;1}\;and\;S(\mu)$ coincides with the set of cluster points of $\{Zn\}_n$. While, we proved that $\mu$ is a sum of finitely many point measure such that $R(\mu)\;{\subset}\;\{$\mid${\psi}_{\lambda}$\mid$\;<\;1}\;and\;S(\lambda)\;=\;S(\mu)$. Also it is studied conditions on \mu for which $R(\mu)\;=\;R0(\mu)$.

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노멕스 허니콤 구조 직물을 적용한 소방관용 특수방화복 개발 및 이의 보호 쾌적 성능평가 (Development of Firefighters' Personal Protective Clothing with Nomex Honeycomb Fabric and its Protective and Comfort Evaluation)

  • 정재연;구본준;김도형;권민재;강성욱;최정윤;이주영
    • 한국의류산업학회지
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    • 제21권5호
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    • pp.606-617
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    • 2019
  • The present study newly developed a firefighters' protective jacket and pants using a Nomex honeycomb structured layer (HPC) in cases of being exposed to flashover or flameover. This study evaluated the protective and comfort functions of an HPC compared to the current KFI firefighters' protective clothing (FPC). The results are as follows. First, thermal protective performance (TPP) of fabric layers was 2.75 times greater for HPC than FPC at $125kW/m^2$. Second, the predicted second and third degree burn areas were smaller for HPC than FPC when using a flame manikin. Third, thermal insulation using a thermal manikin was 0.2 clo greater for HPC than FPC. Fourth, there were no marked differences in maximal performance, mobility, and microclimate temperature/humidity between FPC and HPC through human wear trials. The thermal insulation of HPC was higher than that of FPC; however, any negative effect of HPC thermal insulation on the comfort functions for firefighters was not found. In conclusion, the newly-developed HPC provided more protection in reducing burn injuries from $125kW/m^2$, while no negative impact on maximal performance, mobility and thermal comfort functions of firefighters, which is appropriate for quick-evasive tactics at the flashover, flameover or back draft fires.

ON THE SEPARATING IDEALS OF SOME VECTOR-VALUED GROUP ALGEBRAS

  • Garimella, Ramesh V.
    • 대한수학회보
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    • 제36권4호
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    • pp.737-746
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    • 1999
  • For a locally compact Abelian group G, and a commutative Banach algebra B, let $L^1$(G, B) be the Banach algebra of all Bochner integrable functions. We show that if G is noncompact and B is a semiprime Banach algebras in which every minimal prime ideal is cnotained in a regular maximal ideal, then $L^1$(G, B) contains no nontrivial separating idal. As a consequence we deduce some automatic continuity results for $L^1$(G, B).

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