4,529 research outputs found

    Algebraic, geometric, and stochastic aspects of genetic operators

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    Genetic algorithms for function optimization employ genetic operators patterned after those observed in search strategies employed in natural adaptation. Two of these operators, crossover and inversion, are interpreted in terms of their algebraic and geometric properties. Stochastic models of the operators are developed which are employed in Monte Carlo simulations of their behavior

    HB 481 - Heartbeat Bill

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    The Act adds an unborn child with a detectable human heartbeat to the definition of a natural person and includes such unborn child in state population counts. The Act defines abortion, prescribes when abortions may be performed, provides exceptions to abortion performance limitations, establishes requirements for performing an abortion, and provides for a right of action, damages, and affirmative defenses. The Act permits alimony and child support payments starting when an unborn child has a detectable human heartbeat. Parents have the right to recover the full value of a child’s life when a detectable human heartbeat exists. The Act requires that women seeking an abortion be advised that a detectable human heartbeat exists, provides for certain notices to the woman, and repeals certain penalties. The Act requires physicians who perform abortions to determine the presence of a detectable human heartbeat before performing an abortion and requires physicians to report certain information concerning such abortions. The Act considers an unborn child with a detectable human heartbeat a dependent minor for income tax purposes. The Act also provides for legislative findings and provides standing to intervene and defend constitutional challenges to the Act. The Act provides a short title, provides for severability of claims, provides an effective date, and repeals conflicting laws

    Magnetic and Metal-Insulator Transitions in beta-Na0.5CoO2 and gamma-K0.5CoO2 -NMR and Neutron Diffraction Studies-

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    Co-oxides beta-Na0.5CoO2 and gamma-K0.5CoO2 have been prepared by the Na de-intercalation from alpha-NaCoO2 and by the floating-zone method, respectively. It has been found that successive phase transitions take place at temperatures Tc1 and Tc2 in both systems. The appearance of the internal magnetic field at Tc1 with decreasing temperature T indicates that the antiferromagnetic order exists at T < Tc1, as in gamma-Na0.5CoO2. For beta-Na0.5CoO2, the transition temperatures and the NMR parameters determined from the data taken for magnetically ordered state are similar to those of gamma-Na0.5CoO2, indicating that the difference of the stacking ways of the CoO2 layers between these systems do not significantly affect their physical properties. For gamma-K0.5CoO2, the quantitative difference of the physical quantities are found from those of beta- and gamma-Na0.5CoO2. The difference between the values of Tci (i = 1 and 2) of these systems might be explained by considering the distance between CoO2 layers.Comment: 8 pages, 14 figures, 1 Tabl

    Optical evidence for the proximity to a spin-density-wave metallic state in Na0.7_{0.7}CoO2_2

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    We present the optical properties of \na single crystals, measured over a broad spectral range as a function of temperature (TT). The capability to cover the energy range from the far-infrared up to the ultraviolet allows us to perform reliable Kramers-Kronig transformation, in order to obtain the absorption spectrum (i.e., the complex optical conductivity). To the complex optical conductivity we apply the generalized Drude model, extracting the frequency dependence of the scattering rate (Γ\Gamma) and effective mass (mm^*) of the itinerant charge carriers. We find that Γ(ω)ω\Gamma(\omega)\sim \omega at low temperatures and for ω>T\omega > T. This suggests that \na is at the verge of a spin-density-wave metallic phase

    Pressure effects in the triangular layered cobaltites NaxCoO2

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    We have measured transport properties as a function of temperature and pressure up to 30GPa in the NaxCoO2 system. For the x=0.5 sample the transition temperature at 53K increases with pressure, while paradoxically the sample passes from an insulating to a metallic ground state. A similar transition is observed in the x=0.31 sample under pressure. Compression on the x=0.75 sample transforms the sample from a metallic to an insulating state. We discuss our results in terms of interactions between band structure effects and Na+ order.Comment: 18 pages, 5 figure

    Retrofit of water network with regeneration using water pinch analysis

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    This paper presents the development of a new systematic technique for the retrofit of water network with regeneration based on water pinch analysis. The procedure consists of two parts: retrofit targeting and design for a water network with regeneration unit(s). In the targeting stage, retrofit targets (utility savings and capital investment) were determined for a range of process parameters (total flowrate and/or outlet concentration of the regeneration unit) to obtain a savings versus investment curve. Next, the existing water network was re-designed to meet the chosen targets. A case study on paper making process was used to demonstrate the new methodology
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