177,537 research outputs found

    Electroproduction of hadrons on nuclei at GeV energies

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    We investigate coherence length effects and hadron attenuation in lepton scattering off nuclei in the kinematic regime of the HERMES experiment. The elementary electron-nucleon interaction is described within the event generator PYTHIA while a full coupled-channel treatment of the final state interactions is included by means of a BUU transport model. The results of our calculations are in good agreement with the experimentally measured transparency ratio of incoherent rho0 electroproduction off Nitrogen and the multiplicity ratio R_M^h for charged hadrons, pions, kaons, protons and anti-protons in deep inelastic scattering off Nitrogen and Krypton targets.Comment: 17 pages, 4 figures. Proceedings of 2nd Int. Conf. on Nuclear and Particle Physics with CEBAF at Jefferson Lab, Dubrovnik, 26-31 May 2003, to be published in Fizika

    Expansion Aspect of Color Transparency on the Lattice

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    The opportunity to observe color transparency (CT) is determined by how rapidly a small-sized hadronic wave packet expands. Here we use SU(2) lattice gauge theory with Wilson fermions in the quenched approximation to investigate the expansion. The wave packet is modeled by a point hadronic source, often used as an interpolating field in lattice calculations. The procedure is to determine the Euclidean time (t), pion channel, Bethe-Salpeter amplitude Ψ(r,t)\Psi(r,t), and then evaluate b2(t)=d3rΨ(r,t)r2sin2θΨπ(r)b^2(t)=\int d^3 r \Psi(r,t) r^2 sin^2 \theta \Psi_{\pi}(r). This quantity represents the soft interaction of a small-sized wave packet with a pion. The time dependence of b2(t)b^2(t) is fit as a superposition of three states, which is found sufficient to reproduce a reduced size wave packet. Using this superposition allows us to make the analytic continuation required to study the wave packet expansion in real time. We find that the matrix elements of the soft interaction b^2\hat b^2 between the excited and ground state decrease rapidly with the energy of the excited state.Comment: 19 pages, latex, 4 figure

    ANALISIS PENGARUH PERILAKU PENGHINDARAN PAJAK TERHADAP NILAI PERUSAHAAN DENGAN TRANSPARANSI SEBAGAI VARIABEL MODERATING (Studi Empiris pada Perusahaan Manufaktur yang Terdaftar di Bursa Efek Indonesia Tahun 2010-2013)

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    The purpose of this research is to analyze the effect of tax avoidance behavior on firm value by considering transparancy as a moderating variable. Tax avoidance as an independen variable is measured by book-tax-difference (BTD) value. Firm value and agency cost as dependen variable are measured by Tobins q and STA value. Transparency as moderating variable measured by the ratio that takes intoitem contained in financial statements under the provisions of GCG self assessment int 2010. This research uses leverage as a control variabel. The sample of this research is manufacturing companies listed in Indonesia Stock Exchange during the period 2010-2013. The sampling method in this research is purposive sampling. The analysis techique in this study using multiple regression analysis. Overall, the results show that tax avoidance behavior has significant positive effects on the firm value. Tax avoidance has positive effects on the agency cost. And transparency can moderate the effect of tax avoidance on firm value

    Simple atomic quantum memory suitable for semiconductor quantum dot single photons

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    Quantum memories matched to single photon sources will form an important cornerstone of future quantum network technology. We demonstrate such a memory in warm Rb vapor with on-demand storage and retrieval, based on electromagnetically induced transparency. With an acceptance bandwidth of δf\delta f = 0.66~GHz the memory is suitable for single photons emitted by semiconductor quantum dots. In this regime, vapor cell memories offer an excellent compromise between storage efficiency, storage time, noise level, and experimental complexity, and atomic collisions have negligible influence on the optical coherences. Operation of the memory is demonstrated using attenuated laser pulses on the single photon level. For 50 ns storage time we measure ηe2e50ns=3.4(3)%\eta_{\textrm{e2e}}^{\textrm{50ns}} = 3.4(3)\% \emph{end-to-end efficiency} of the fiber-coupled memory, with an \emph{total intrinsic efficiency} ηint=17(3)%\eta_{\textrm{int}} = 17(3)\%. Straightforward technological improvements can boost the end-to-end-efficiency to ηe2e35%\eta_{\textrm{e2e}} \approx 35\%; beyond that increasing the optical depth and exploiting the Zeeman substructure of the atoms will allow such a memory to approach near unity efficiency. In the present memory, the unconditional readout noise level of 91039\cdot 10^{-3} photons is dominated by atomic fluorescence, and for input pulses containing on average μ1=0.27(4)\mu_{1}=0.27(4) photons the signal to noise level would be unity

    Fuzzy modelling using a simplified rule base

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    Transparency and complexity are two major concerns of fuzzy rule-based systems. To improve accuracy and precision of the outputs, we need to increase the partitioning of the input space. However, this increases the number of rules exponentially, thereby increasing the complexity of the system and decreasing its transparency. The main factor behind these two issues is the conjunctive canonical form of the fuzzy rules. We present a novel method for replacing these rules with their singleton forms, and using aggregation operators to provide the mechanism for combining the crisp outputs

    On Timing Model Extraction and Hierarchical Statistical Timing Analysis

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    In this paper, we investigate the challenges to apply Statistical Static Timing Analysis (SSTA) in hierarchical design flow, where modules supplied by IP vendors are used to hide design details for IP protection and to reduce the complexity of design and verification. For the three basic circuit types, combinational, flip-flop-based and latch-controlled, we propose methods to extract timing models which contain interfacing as well as compressed internal constraints. Using these compact timing models the runtime of full-chip timing analysis can be reduced, while circuit details from IP vendors are not exposed. We also propose a method to reconstruct the correlation between modules during full-chip timing analysis. This correlation can not be incorporated into timing models because it depends on the layout of the corresponding modules in the chip. In addition, we investigate how to apply the extracted timing models with the reconstructed correlation to evaluate the performance of the complete design. Experiments demonstrate that using the extracted timing models and reconstructed correlation full-chip timing analysis can be several times faster than applying the flattened circuit directly, while the accuracy of statistical timing analysis is still well maintained

    Perceptual Copyright Protection Using Multiresolution Wavelet-Based Watermarking And Fuzzy Logic

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    In this paper, an efficiently DWT-based watermarking technique is proposed to embed signatures in images to attest the owner identification and discourage the unauthorized copying. This paper deals with a fuzzy inference filter to choose the larger entropy of coefficients to embed watermarks. Unlike most previous watermarking frameworks which embedded watermarks in the larger coefficients of inner coarser subbands, the proposed technique is based on utilizing a context model and fuzzy inference filter by embedding watermarks in the larger-entropy coefficients of coarser DWT subbands. The proposed approaches allow us to embed adaptive casting degree of watermarks for transparency and robustness to the general image-processing attacks such as smoothing, sharpening, and JPEG compression. The approach has no need the original host image to extract watermarks. Our schemes have been shown to provide very good results in both image transparency and robustness.Comment: 13 pages, 7 figure

    Transparency in Port-Hamiltonian-Based Telemanipulation

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    After stability, transparency is the major issue in the design of a telemanipulation system. In this paper, we exploit the behavioral approach in order to provide an index for the evaluation of transparency in port-Hamiltonian-based teleoperators. Furthermore, we provide a transparency analysis of packet switching scattering-based communication channels

    Transparent authentication methodology in electronic education

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    In the context of on-line assessment in e-learning, a problem arises when a student taking an exam may wish to cheat by handing over personal credentials to someone else to take their place in an exam, Another problem is that there is no method for signing digital content as it is being produced in a computerized environment. Our proposed solution is to digitally sign the participant’s work by embedding voice samples in the transcript paper at regular intervals. In this investigation, we have demonstrated that a transparent stenographic methodology will provide an innovative and practical solution for achieving continuous authentication in an online educational environment by successful insertion and extraction of audio digital signatures
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