• Title, Summary, Keyword: constant-sign

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Performance Comparisons of some nonparametric detectors (몇가지 비모수 검파기의 성능 비교)

  • 김홍길;송익호;장태주;배진수
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • pp.9-15
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    • 1996
  • In this paper, we propose a new detector based on the median-shift sign. We call it the median-shift sign (MSS) detector, which is an extension of the classical sign detector. We first analyze the problem of detecting a dc signal in noise of known probability density function (pdf). The MSS detector with the optimum median-shift value, the optimum MSS detector, performs better than the sign detector in Gaussian noise: it has the best performance among the detectors compared in Laplacian and Cauchy noise. It is shown that the MSS detectors with constant median-shift values are nearly equal to the optimum MSS detector. We also analyze the problem of detecting a dc signal when only partial information is available on the noise. The MSS detectors with constant median-shift values are almost equal to the sign detector in Gaussian noise: they perform better than the sign and Wilcoxon detectors for most signal ranges in Laplacian and Cauchy noise.

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CONSTANT-SIGN SOLUTIONS OF p-LAPLACIAN TYPE OPERATORS ON TIME SCALES VIA VARIATIONAL METHODS

  • Zhang, Li;Ge, Weigao
    • Bulletin of the Korean Mathematical Society
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    • v.49 no.6
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    • pp.1131-1145
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    • 2012
  • The purpose of this paper is to use an appropriate variational framework to discuss the boundary value problem with p-Laplacian type operators $$\{({\alpha}(t,x^{\Delta}(t)))^{\Delta}-a(t){\phi}_p(x^{\sigma}(t))+f({\sigma}(t),x^{\sigma}(t))=0,\;{\Delta}-a.e.\;t{\in}I\\x^{\sigma}(0)=0,\\{\beta}_1x^{\sigma}(1)+{\beta}_2x^{\Delta}({\sigma}(1))=0,$$ where ${\beta}_1$, ${\beta}_2$ > 0, $I=[0,1]^{k^2}$, ${\alpha}({\cdot},x({\cdot}))$ is an operator of $p$-Laplacian type, $\mathbb{T}$ is a time scale. Some sufficient conditions for the existence of constant-sign solutions are obtained.

A Theoretical Study on the Space Signal of Facade (파사드의 공간적 사인성에 관한 이론적 고찰)

  • 송인호;신수길
    • Archives of design research
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    • v.13 no.3
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    • pp.261-270
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    • 2000
  • In general, sign is the way of communication directing human beings with their daily activities particularly in urban circumstances. And sign planning is designing and installing signboards systematically in urban environment. Generally, the range of application in space sign is pretty wide, and it may safely be say that the attractiveness of the city image is considerably decided upon the sign system. The subject of this study investigates the meaning and the role of sign system applying on human environment, and disirable design direction cope with the constant change of city space. The present study doesn't specifically deals with the basic function of signboards only, but with the problems and solution corresponding with sign system as structual element in city environment.

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Sign-Extension Overhead Reduction by Propagated-Carry Selection (전파캐리의 선택에 의한 부호확장 오버헤드의 감소)

  • 조경주;김명순;유경주;정진균
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.27 no.6C
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    • pp.632-639
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    • 2002
  • To reduce the area and power consumption in constant coefficient multiplications, the constant coefficient can be encoded using canonic signed digit(CSD) representation. When the partial product terms are added depending on the nonzero bit(1 or -1) positions in the CSD-encoded multiplier, all sign bits are properly extended before the addition takes place. In this paper, to reduce the overhead due to sign extension, a new method is proposed based on the fact that carry propagation in the sign extension part can be controlled such that a desired input bit can be propagated as a carry. Also, a fixed-width multiplier design method suitable for CSD multiplication is proposed. As an application, 43-tap filbert transformer for SSB/BPSK-DS/CDMA is implemented. It is shown that, about 16∼28% adders can be saved by the proposed method compared with the conventional methods.

TRIPLE SOLUTIONS FOR THREE-ORDER PERIODIC BOUNDARY VALUE PROBLEMS WITH SIGN CHANGING NONLINEARITY

  • Tan, Huixuan;Feng, Hanying;Feng, Xingfang;Du, Yatao
    • Journal of applied mathematics & informatics
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    • v.32 no.1_2
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    • pp.75-82
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    • 2014
  • In this paper, we consider the periodic boundary value problem with sign changing nonlinearity $$u^{{\prime}{\prime}{\prime}}+{\rho}^3u=f(t,u),\;t{\in}[0,2{\pi}]$$, subject to the boundary value conditions: $$u^{(i)}(0)=u^{(i)}(2{\pi}),\;i=0,1,2$$, where ${\rho}{\in}(o,{\frac{1}{\sqrt{3}}})$ is a positive constant and f(t, u) is a continuous function. Using Leggett-Williams fixed point theorem, we provide sufficient conditions for the existence of at least three positive solutions to the above boundary value problem. The interesting point is the nonlinear term f may change sign.

ZORA DFT Calculation of $^{11}$B Electric Field Gradient Tensor for Lithium Borates

  • Woo, Ae-Ja;Wasylishen, Roderick E.
    • Journal of the Korean Magnetic Resonance Society
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    • v.8 no.2
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    • pp.70-76
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    • 2004
  • ZORA-DFT calculations of $^{11}$B EFG (electric field gradient) tensors for lithium borates, LiB$_3O_5$ (LBO) and Li$_2B_4O_7$ (LTB), were performed. The calculated values of 11B quadrupole coupling constant and asymmetry parameter are in good agreement with the experimental values. The sign of the quadrupole coupling constant for the tetrahedral boron site was deduced from the distortion from the ideal tetrahedral symmetry.

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Propagation Constant and Material constants of Metamaterials (Metamaterial의 전파 상수 및 물질 상수)

  • Lee, Dong-Hyun;Kim, Jae-Hee;Park, Wee-Sang
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.45 no.8
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    • pp.69-74
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    • 2008
  • The propagation constant, which is defined for a double-positive (DPS) material of positive permittivity (${\varepsilon}'$) and permeability (${\mu}'$), is extended and derived for an epsilon-negative (ENG) material (${\varepsilon}'<0,\;{\mu}'>0$), a mu-negative (MNG) material (${\varepsilon}'>0,\;{\mu}'<0$), and a double-negative (DNG) material (${\varepsilon}'<0,\;{\mu}'<0$). By investigating how the permittivity loss (${\varepsilon}"$) and permeability loss (${\mu}"$) terms affect the propagation constant, we determine that the wave in the materials propagates as a right-handed (RH) triad or a left-handed (LH) triad. Regardless of the magnitudes of ${\varepsilon}"$ and ${\mu}"$, DPS and DNG materials become RH and LH media, respectively. However, ENG and MNG materials possess unusual characteristics that both materials become a RH medium when the sign of (${\varepsilon}'{\mu}"+{\varepsilon}"{\mu}'$) is positive and they become a LH medium when the sign is negative.

Kinetics and Mechanism of the Anilinolysis of Bis(aryl) Chlorophosphates in Acetonitrile

  • Barai, Hasi Rani;Lee, Hai-Whang
    • Bulletin of the Korean Chemical Society
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    • v.32 no.6
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    • pp.1939-1944
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    • 2011
  • The nucleophilic substitution reactions of bis(Y-aryl) chlorophosphates (1) with substituted anilines and deuterated anilines are investigated kinetically in acetonitrile at 35.0 $^{\circ}C$. The kinetic results of 1 are compared with those of Y-aryl phenyl chlorophosphates (2). The substrate 1 has one more identical substituent Y compared to substrate 2. The cross-interaction between Y and Y, due to additional substituent Y, is significant enough to result in the change of the sign of cross-interaction constant (CIC) from negative ${\rho}_{XY}$ = -1.31 (2) to positive ${\rho}_{XY}$ = +1.91 (1), indicating the change of reaction mechanism from a concerted $S_N2$ (2) to a stepwise mechanism with a rate-limiting leaving group departure from the intermediate (1). The deuterium kinetic isotope effects (DKIEs) involving deuterated anilines ($XC_6H_4ND_2$) show secondary inverse, $k_H/k_D$ = 0.61-0.87. The DKIEs invariably increase as substituent X changes from electron-donating to electron-withdrawing, while invariably decrease as substituent Y changes from electron-donating to electron-withdrawing. A stepwise mechanism with a rate-limiting bond breaking involving a predominant backside attack is proposed on the basis of positive sign of ${\rho}_{XY}$ and secondary inverse DKIEs.

Launch Stage Thermal Analysis on a Mass Varying Satellite Box by Analytical Solutions (해석해를 이용한 질량변화가 있는 위성 부품에 대한 발사시 열해석)

  • Choi, Joon-Min;Kim, Hui-Kyung;Hyun, Bum-Seok
    • Proceedings of the KSME Conference
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    • pp.163-168
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    • 2003
  • Analytical approach is applied to predict temperature of satellite box under worst hot condition from fairing jettison to separation. The box is tried to solve analytically which is exposed to known environmental heating condition and has internal heating and irradiation to space. For a single thermal mass, governing equation for temperature is simplified to 1st order ordinary differential equation(ODE) by several assumptions. Two cases are considered. The one is for constant mass box and the other is for mass-varying box. Each case has three different analytical solution by sign of constant term in ODE. One analytical solution for constant mass is applied to physical launch stage condition. It is concluded that the present analytical method can be used to quick predict the temperature of a satellite box and check whether a satellite is safe against space environment during launch stage.

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The Change of the Vital Sign by the Variables of Stimulated Areas in Interferential Current Treatment (간섭 전류 치료의 자극부위에 따른 활력징후의 변화)

  • Park, Young-Han
    • Journal of Korean Physical Therapy Science
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    • v.16 no.3
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    • pp.1-9
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    • 2009
  • Background: The purpose of this study is to have examined the influence on the blood circulation by comparing the differences between stimulating the sympathetic ganglion and the muscle group among the stimulation variables in interferential current stimulation. Method: The object of the study is the twenties(M=8, F=12), who are in great condition and have no pathological report for the blood circulation influence. The intensity of the inferential current stimulation is the medium degree, 100 bps constant current, which is the comfort and degree to confirm the muscle contraction. The areas stimulated are the stellate ganglion area in the seventh cervical vertebrae and the forearm muscle area. Results: We have made sure that there is no change in blood pressure and pulse and that the change in the skin temperature occurred highly. Conclusion: In considering the change of the blood circulation in case of stimulation area by the inferential current stimulation, we have seen that stimulating the sympathetic ganglion area is more effective than stimulating muscle area directly.

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