An Investigation of the Casimir Energy for a Fermion Coupled to the Sine-Gordon Soliton with Parity Decomposition

We consider a fermion chirally coupled to a prescribed pseudoscalar field in the form of the soliton of the sine-Gordon model and calculate and investigate the Casimir energy and all of the relevant quantities for each parity channel, separately. We present and use a simple prescription to construct the simultaneous eigenstates of the Hamiltonian and parity in the continua from the scattering states. We also use a prescription we had introduced earlier to calculate unique expressions for the phase shifts and check their consistency with both the weak and strong forms of the Levinson theorem. In the graphs of the total and parity decomposed Casimir energies as a function of the parameters of the pseudoscalar field distinctive deformations appear whenever a fermionic bound state energy level with definite parity crosses the line of zero energy. However, the latter graphs reveal some properties of the system which cannot be seen from the graph of the total Casimir energy. Finally we consider a system consisting of a valence fermion in the ground state and find that the most energetically favorable configuration is the one with a soliton of winding number one, and this conclusion does not hold for each parity, separately.Comment: 13 pages, 8 figure

Laboratory Generation and Physics of Propagation of Solitary Waves and Water Surface Depressions

Solitary waves and water surface depressions are generated using a piston-type wavemaker. Different aspects of their propagation including profile evolution, establishment rate, stability, and celerity are examined experimentally. Traditionally, solitary waves are generated in laboratory set-ups using a methodology developed by Goring (1979) that considers a wave of permanent form during the generation process. A New methodology for generation of solitary waves using piston-type wavemakers is proposed by considering the evolving nature of the wave during generation phase. The capability of the New methodology in generation of solitary waves is assessed by conducting a series of laboratory experiments in water depth, h, of 20 cm and for the dimensionless wave height, H/h, values (H - wave height) ranging from 0.3 to 0.6. Waves generated using the Goring methodology served as a benchmark to evaluate the performance of the New methodology in generating solitary waves. Recorded waveforms are compared with theoretical solutions in terms of various wave characteristics (e.g., wave height, profile shape, wave celerity). These comparisons revealed that the New methodology is capable of generating more accurate and rapidly-established solitary waves with less wave attenuation with distance compared to the Goring methodology. In the second part, water surface depressions are generated using the Goring methodology in water depths of 6, 10 and 30 cm and for the dimensionless trough amplitude, at/h, values (at - trough amplitude) ranging from 0.05 to 0.6. Generated water surface depressions are in good agreement with the aimed theoretical profile in the vicinity of the wave paddle. In all experiments, generated negative solitary wave-like depression wave rapidly deforms into a triangular-like depression wave followed by a series of oscillatory trailing waves. As the depression wave propagates, as a result of nonlinear and dispersive effects its amplitude attenuates, slope of the leading edge of the depression wave becomes gentler while its rear edge slope becomes steeper. The amplitudes of the oscillatory trailing waves increase initially as the depression propagates; then the amplitudes of the oscillatory trailing waves start attenuating with distance due to viscous and dispersive effects. Celerity of the depression wave increases with distance as the depression amplitude attenuates with distance, but it never reaches the celerity of long waves in deep waters. Based on the experimental data of the present study and those reported by Hammack and Segur (1978), three empirical equations are proposed to predict the profile shape of a depression (i.e. trough amplitude, frequency of the leading half, and slope of the rear edge) for a given propagation distance

Functional and Performance Analysis of Network-on-Chips Using Actor-based Modeling and Formal Verification

Network on Chip (NoC) has emerged as a promising architecture paradigmfor todays many-core systems. As complexity grows in NoCs, functional verificationand performance prediction in the early stages of the design process are suggestedas ways to reduce the fabrication cost. Formal methods have gained moreattention as alternative ways for analyzing NoC designs. In this paper we propose amethod to model different characteristics of the system, and also verify various functionaland performance properties by generating the full state space of the model fordifferent scenarios. We present a formal model for two-dimensional mesh GloballyAsynchronous Locally Synchronous (GALS) NoCs with four-phase handshakecommunication protocol, using the actor-based modeling language Rebeca. Functionaland timing behaviors, routing algorithm and communication protocol are capturedin the model. Deadlock freedom, message arrival, and end-to-end packet latencyare checked. In order to analyze large NoCs we propose a scalable approachbased on compositional verification for estimating maximum end-to-end packet latency.The compositional approach is specific for the XY-routing algorithm. Resultsof verification are compared and matched to simulation results of HSPICE using32nm technology

The Effect of Group Affiliation on Decisions to Pay Dividends in the Tehran Security Exchange

This study investigates the effect of group affiliation on decisions to pay dividends in the Tehran Security Exchange. Therefore, the relationship between policy dividends and factors such as information asymmetry, dependence on external financing (sources outside the institution) is checked.The research data is collected from 50 firms in the Tehran Security Exchange (TSE) during 2005-2013.The statistical technique is used to examine the assumption of multiple regressions. In order to examine the hypotheses, data is collected from the annual reports of the companies using official bulletins of the Tehran stock exchange, mainly, through Novin software, Tadbir Pardaz software, and stock sites such as www.rdis.ir. The results indicate that between the payment of dividends and the amount of capital and thus the dependence on external financing has a positive and significant relationship with information asymmetry. Keywords: Payment of dividends, Dependence on external financing, information asymmetry, The Tehran Security Exchang

A doxycycline-inducible urokinase receptor (uPAR) upregulates uPAR activities including resistance to anoikis in human prostate cancer cell lines

<p>Abstract</p> <p>Background</p> <p>The urokinase receptor (uPAR) mediates a diverse array of cellular processes including several events involved in prostate cancer metastasis. Many of these activities are initiated or enhanced by uPAR binding to its proteolytic ligand, urokinase (uPA). Our objective in this study was to generate and test an inducible lentiviral system capable of expressing uPAR and DsRed fluorescent protein in human prostate cancer cell lines.</p> <p>Results</p> <p>A DsRed-uPAR fusion construct was inserted into a lentiviral vector. Transduction of human prostate cancer cell lines with this virus and with a virus containing a reverse-tetracycline transactivator (rt-TA) resulted in a stable transgene which induced both uPAR and DsRed proteins in a dose-responsive fashion upon stimulation with doxycycline. Immunoblots and immunofluorescence studies indicated no detectable uPAR expression in non-induced prostate cancer cell lines. Cells with induced-uPAR demonstrated increased cellular adhesion to the matrix substrate vitronectin and increased net cell proliferation compared to uninduced cells. Finally, induced uPAR-expressing prostate cancer cells were resistant to anoikis over an extended time period when grown in suspension.</p> <p>Conclusion</p> <p>This doxycycline-inducible lentivirus system produces titerable levels of biologically active uPAR <it>in vitro</it>. This tool can be used to dissect cellular events following induction of uPAR in prostate cancer cells.</p

Intelligent GPS Spoofing Attack Detection in Power Grids

The GPS is vulnerable to GPS spoofing attack (GSA), which leads to disorder in time and position results of the GPS receiver. In power grids, phasor measurement units (PMUs) use GPS to build time-tagged measurements, so they are susceptible to this attack. As a result of this attack, sampling time and phase angle of the PMU measurements change. In this paper, a neural network GPS spoofing detection (NNGSD) with employing PMU data from the dynamic power system is presented to detect GSAs. Numerical results in different conditions show the real-time performance of the proposed detection method