Rotational Symmetry of Classical Orbits, Arbitrary Quantization of Angular Momentum and the Role of Gauge Field in Two-Dimensional Space

We study the quantum-classical correspondence in terms of coherent wave functions of a charged particle in two-dimensional central-scalar-potentials as well as the gauge field of a magnetic flux in the sense that the probability clouds of wave functions are well localized on classical orbits. For both closed and open classical orbits, the non-integer angular-momentum quantization with the level-space of angular momentum being greater or less than $\hbar$ is determined uniquely by the same rotational symmetry of classical orbits and probability clouds of coherent wave functions, which is not necessarily $2\pi$-periodic. The gauge potential of a magnetic flux impenetrable to the particle cannot change the quantization rule but is able to shift the spectrum of canonical angular momentum by a flux-dependent value, which results in a common topological phase for all wave functions in the given model. The quantum mechanical model of anyon proposed by Wilczek (Phys. Rev. Lette. 48, 1144) becomes a special case of the arbitrary-quantization.Comment: 6 pages, 5 figure

Two-electron QED corrections in helium-like ions

The calculation of two-electron QED energy shifts in helium-like ions is discussed in order to correct a number of errors and misunderstandings which have appeared in the literature. New results are presented for the terms involving (r12-3) in the ground and low-lying excited states for ions up to Z=10. A detailed comparison is made with the high-precision measurement by Martin (1984) and a calculation by Hata (1984) for the 1s2p 1P1-1s2p 3P1 transition of helium

Perturbative Calculation of the Adiabatic Geometric Phase and Particle in a Well with Moving Walls

We use the Rayleigh-Schr\"odinger perturbation theory to calculate the corrections to the adiabatic geometric phase due to a perturbation of the Hamiltonian. We show that these corrections are at least of second order in the perturbation parameter. As an application of our general results we address the problem of the adiabatic geometric phase for a one-dimensional particle which is confined to an infinite square well with moving walls.Comment: Plain Latex, accepted for publication in J. Phys. A: Math. Ge

Comparison of Frequentist and Bayesian Meta-Analysis Models for Assessing the Efficacy of Decision Support Systems in Reducing Fungal Disease Incidence

Diseases of fruit and foliage caused by fungi and oomycetes are generally controlled by the application of fungicides. The use of decision support systems (DSSs) may assist to optimize fungicide programs to enhance application on the basis of risk associated with disease outbreak. Case-by-case evaluations demonstrated the performance of DSSs for disease control, but an overall assessment of the efficacy of DSSs is lacking. A literature review was conducted to synthesize the results of 67 experiments assessing DSSs. Disease incidence data were obtained from published peer-reviewed field trials comparing untreated controls, calendar-based and DSS-based fungicide programs. Two meta-analysis generic models, a “fixed-effects” vs. a “random-effects” model within the framework of generalized linear models were evaluated to assess the efficacy of DSSs in reducing incidence. All models were fit using both frequentist and Bayesian estimation procedures and the results compared. Model including random effects showed better performance in terms of AIC or DIC and goodness of fit. In general, the frequentist and Bayesian approaches produced similar results. Odds ratio and incidence ratio values showed that calendar-based and DSS-based fungicide programs considerably reduced disease incidence compared to the untreated control. Moreover, calendar-based and DSS-based programs provided similar reductions in disease incidence, further supporting the efficacy of DSSs

Diagnostic Application for Development of Custom ATCA Carrier Board for LLRF

The Advanced Telecommunications Computing Architecture (ATCA) standard describes a powerful and efficient platform. With multiple integrated solutions like redundancies and intelligent control mechanisms this technology is characterized with reliability estimated at the level of 99.99999 percent. These features make the standard perfect for use in projects like the Free Electron Laser in Hamburg (FLASH) and the X-ray Free Electron Laser (X-FEL) in order to help them meet the requirements of high availability and reliability. The ATCA standard incorporates advanced control systems defined in the Intelligent Platform Management Interface (IPMI) specification as one of the key elements. The entire ATCA implementation retains its functionality as long as the IPMI remains operational. The complexity level of the application increases, which results in preparing it to run and debugging being more difficult to perform. At the same time, only scrupulous elimination of any kind of possible deficiencies can enable the ATCA implementation to offer the desired level of reliability. Thus, diagnostics become crucial, which creates a need for additional tools performing these tasks during the preparations of both hardware and software for the ATCA application. The paper presents application aiding in development of the prototype Carrier Board by enabling the user of external PC station to perform diagnostic and control activities over the Board. It helps in examining all its components at the stage of running the Board, as well as in further operation analysis

Quantum Dynamics in a Time-dependent Hard-Wall Spherical Trap

Exact solution of the Schr\"{o}dinger equation is given for a particle inside a hard sphere whose wall is moving with a constant velocity. Numerical computations are presented for both contracting and expanding spheres. The propagator is constructed and compared with the propagator of a particle in an infinite square well with one wall in uniform motion.Comment: 6 pages, 4 figures, Accepted by Europhys. Let

User Profile and Workload Analysis for Local Area Networks

Performance analysis tools for computer networks need accurate and comprehensive estimates of user workload. An approach is presented that estimates network impact for a wide variety of end user types and applications that are typical on local area networks. Fourteen user types and nine generic application types are defined, and data is collected to determine the average network bandwidth needed to accommodate the output of individual and aggregate user/application combinations. Workload is estimated using a combination of data obtained from live test experiments, and data collected from the literature. Finally, the implementation of this data in a highly interactive network modeling tool (NetMod) is illustrated with screen images generated during tool execution.http://deepblue.lib.umich.edu/bitstream/2027.42/107870/1/citi-tr-90-3.pd