8,709 research outputs found

    From Anti-equilibrium to The Socialist System and Beyond

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    This essay attempts to understand János Kornai’s works from a political economy perspective. It argues that Kornai has significantly contributed to the formation of a new paradigm of political economy. The main endeavor of Kornai has been the combination of analytical concepts of economics with the empirical description of real economies. After a certain period of theoretical experimentation János Kornai formulated his research program that can be called the shortage economy explanation of the socialist system. The Economics of Shortage and The Socialist System have created a new theoretical paradigm in a framework in which it has become possible to establish a connection between the analytical and empirical, universal and historical aspects of the theory studying the socialist system as a real economic entity. János Kornai has built his analysis of the socialist system on the primary role of politics in the creation of economic institutions. In his present work on capitalism he has extended this thesis to the capitalist system. This seems to be an important contribution of his to a new political economy paradigm that is just in the process of formation

    Balanced modified systematic sampling in the presence of linear trend

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    In the presence of linear trend, linear systematic sampling (LSS) is less efficient than stratified random sampling (STR) and more efficient than simple random sampling (SRS). Consequently, some authors have proposed modifications to the LSS design, which have shown to yield optimal results under certain conditions. In this paper, a further modified design, termed as balanced modified systematic sampling (BMSS), is proposed. BMSS is compared to various well-known modified LSS designs as well as LSS, SRS and STR. If half the sample size is an even integer, then BMSS is optimal. To obtain linear trend free sampling results for the other cases of the sample size, a BMSS with end corrections (BMSSEC) estimator is constructed. The results in this paper suggest that the proposed estimator performs better than all other estimators for odd sample sizes and even sampling intervals. Moreover, the proposed estimator is competitive for all other cases

    Effect of long-range Coulomb interaction on shot-noise suppression in ballistic transport

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    We present a microscopic analysis of shot-noise suppression due to long-range Coulomb interaction in semiconductor devices under ballistic transport conditions. An ensemble Monte Carlo simulator self-consistently coupled with a Poisson solver is used for the calculations. A wide range of injection-rate densities leading to different degrees of suppression is investigated. A sharp tendency of noise suppression at increasing injection densities is found to scale with a dimensionless Debye length related to the importance of space-charge effects in the structure.Comment: RevTex, 4 pages, 4 figures, minor correction

    A comparative study of multiple imputation and subset correspondence analysis in dealing with missing data

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    Methods: Multiple imputation and subset correspondence analysis are applied to a set of child asthma data that is mainly categorical and suffers from non-response. Differences in the methods and in the outcomes they produce are studied. In addition, the inclusion of interactions in a subset correspondence analysis is illustrated. Results: Despite the vast differences in the two approaches, they yielded similar results in the identification of genetic, environmental and socio-economic factors that affect childhood asthma. A number of exposure related variables were found to be associated with the greater severity of asthma. It was also found that a finer distinction between the asthma severity levels and their associations with factors was possible with a subset correspondence analysis, compared to the multiple imputation approach. Conclusions: Both multiple imputation and subset correspondence analysis were able to identify several factors associated with childhood asthma while at the same time successfully managing the missing data. This offers the researcher a choice to select the method that best suits his/her study

    Heat and Mass Transport in Heat Pipe Wick Structures

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    Anovel experimental approach is developed for characterizing the performance of heat pipe wick structures. This approach simulates the actual operation of wick structures in a heat pipe. Open, partially submerged, sintered copper wicks of varying pore size are studied under the partially saturated conditions found in normal heat pipe operation. A vertical wick orientation, where the capillary lift is in opposition to gravity, is selected to test the wicks under the most demanding conditions. Mass transport measurements of the working fluid, in addition to the temperature field, are obtained for the porous wicks under the action of a discrete heat source (evaporator) mounted on one end. The working fluid, supplied from a condenser pool, evaporates from the wick surface primarily in the evaporator region and is condensed and collected into a container separate from the pool, to yield mass flow rates. Thus the liquid-pumping capability of the wick, coupled with flow impedance, is measured as a function of applied heat flux. Repeatable results with low uncertainty are obtained.Acareful analysis of the transport paths for heat and mass transfer in the wick structure confirms that mass transfer due to vaporization of the working fluid is the largest contributor to heat dissipation from the wick. The expected and measured values of evaporation rate are in good agreement. Results are also presented in terms of overall effective conductance based on measured temperatures

    Correcting the extended-source calibration for the <i>Herschel</i>-SPIRE Fourier-transform spectrometer

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    We describe an update to the Herschel-Spectral and Photometric Imaging Receiver (SPIRE) Fourier-transform spectrometer (FTS) calibration for extended sources, which incorporates a correction for the frequency-dependent far-field feedhorn efficiency, ηff. This significant correction affects all FTS extended-source calibrated spectra in sparse or mapping mode, regardless of the spectral resolution. Line fluxes and continuum levels are underestimated by factors of 1.3–2 in thespectrometer long wavelength band (447–1018 GHz; 671–294 μm) and 1.4–1.5 in the spectrometer short wavelength band (944–1568 GHz; 318–191 μm). The correction was implemented in the FTS pipeline version 14.1 and has also been described in the SPIRE Handbook since 2017 February. Studies based on extended-source calibrated spectra produced prior to this pipeline version should be critically reconsidered using the current products available in the Herschel Science Archive. Once the extended-source calibrated spectra are corrected for ηff, the synthetic photometry and the broad-band intensities from SPIRE photometer maps agree within 2–4 per cent – similar levels to the comparison of point-source calibrated spectra and photometry from point-source calibrated maps. The two calibration schemes for the FTS are now self-consistent: the conversion between the corrected extended-source and point-source calibrated spectra can be achieved with the beam solid angle and a gain correction that accounts for the diffraction loss

    Methyl methanesulfonate (MMS) produces heat-labile DNA damage but no detectable in vivo DNA double-strand breaks

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    Homologous recombination (HR) deficient cells are sensitive to methyl methanesulfonate (MMS). HR is usually involved in the repair of DNA double-strand breaks (DSBs) in Saccharomyces cerevisiae implying that MMS somehow induces DSBs in vivo. Indeed there is evidence, based on pulsed-field gel electrophoresis (PFGE), that MMS causes DNA fragmentation. However, the mechanism through which MMS induces DSBs has not been demonstrated. Here, we show that DNA fragmentation following MMS treatment, and detected by PFGE is not the consequence of production of cellular DSBs. Instead, DSBs seen following MMS treatment are produced during sample preparation where heat-labile methylated DNA is converted into DSBs. Furthermore, we show that the repair of MMS-induced heat-labile damage requires the base excision repair protein XRCC1, and is independent of HR in both S.cerevisiae and mammalian cells. We speculate that the reason for recombination-deficient cells being sensitive to MMS is due to the role of HR in repair of MMS-induced stalled replication forks, rather than for repair of cellular DSBs or heat-labile damage

    Definitive spectroscopic determination of the transverse interactions responsible for the magnetic quantum tunneling in Mn12-acetate

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    We present detailed angle-dependent single crystal electron paramagnetic resonance (EPR) data for field rotations in the hard plane of the S=10 single molecule magnet Mn12-acetate. A clear four-fold variation in the resonance positions may be attributed to an intrinsic fourth order transverse anisotropy (O44). Meanwhile, a four-fold variation of the EPR lineshapes confirms a recently proposed model wherein disorder associated with the acetic acid of crystallization induces a locally varying quadratic (rhombic) transverse anisotropy (O22). These findings explain most aspects of the magnetic quantum tunneling observed in Mn12-acetate.Comment: 7 pages, including figures, accepted for publication in Phys. Rev. Let

    Outlook Economic Conference, 2019 : Preparing for the future

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    A PowerPoint presentation from the UNC Wilmington annual OUTLOOK conference, delivered October 10, 2019. This conference is the region's premier forum for economic activity and forecasts. The first part titled "The U.S. economy: Losing its legs? was given by Dr. Thomas D. Simpson of UNCW and the second part titled "The regional outlook: When the sun is out, don't forget to smile" given by Dr. Adam T. Jones of UNCW
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