Miracle-dz/UniFAR-FTUs huggingface dataset:
Model galactic coronae: Ionization structure and absorption-line spectra

We describe a general model for a gaseous galactic corona, and demonstrate that it is in harmony with a variety of observational and theoretical constraints. We then compute the ionization equilibria of H, He, C, N, O, Si, and S atoms in the corona and determine the strengths of resonance absorption lines arising therein. To this end, we obtain approximate cross sections for ionization of the heavy-element ions by photons of energy E/sub . gamma. /< or =100 eV.We use our results first to discuss the expected absorption spectrum of our Galaxy's corona. Subsequently, we discuss in detail the relevance of our computed equilibria to the suggestion that galactic coronae produce some redshift systems in quasar absorption spectra. Because our model coronae are not isothermal, the ionization structure existing along various lines of sight through them is not in accord with the concept of ''reasonable ionization equilibrium'': a concept assumed to be valid in most analyses of quasar spectra. However, our calculations indicate that typically one well-established redshift system in each quasar absorption spectrum could arise in the corona of an intervening galaxy. This is the number expected from statistical arguments if quasar redshifts are fully cosmological in origin. (AIP)
Delayed magnetic vortex core reversal

When switching the vortex core in a magnetic disc by a short excitation with an in-plane field, there is an initial global excitation of the magnetization due to a precession of the magnetization in the spatially homogeneous field. Then an energy transport from this global excitation towards the center of the disc takes place leading to a concentration of the energy close to the vortex core which suffices to switch the core. Because this transport requires time, there is a delay between the end of the excitation and the switching. This is demonstrated for switching by in-plane rotating GHz rf-bursts.
A complete sample of double-lobed radio quasars for VLBI tests of source models - Definition and statistics

A complete, flux-density-limited sample of double-lobed radio quasars is defined, with nuclei bright enough to be mapped with the Mark III VLBI system. It is shown that the statistics of linear size, nuclear strength, and curvature are consistent with the assumption of random source orientations and simple relativistic beaming in the nuclei. However, these statistics are also consistent with the effects of interaction between the beams and the surrounding medium. The distribution of jet velocities in the nuclei, as measured with VLBI, will provide a powerful test of physical theories of extragalactic radio sources. 131 refs.
Domain of validity of the equation for total integrated scatter (TIS)

The analytical expression for total integrated scatter (defined as diffuse reflectance divided by total reflectance) has been around for almost six decades TIS = 1 - exp[-(4π cosθi σ/λ)2]. Most surface scatter analysts now realize that the expression is ambiguous unless spatial frequency band-limits are specified for the rms roughness, σ, in the expression. However, there still exists uncertainty about the domain of validity of the expression with regard to both surface characteristics and incident angle. In this paper we will quantitatively illustrate this domain of validity for both Gaussian and fractal one-dimensional surfaces as determined by the rigorous integral equation method (method of moments) of electromagnetic theory. Two dimensional error maps will be used to illustrate the domain of validity as a function of surface characteristics and incident angle. Graphical illustrations comparing the TIS predictions of several approximate surface scatter theories will also be presented.
A new convergent point and distance modulus for the Hyades from radial velocities

The dynamics of the Hyades open star cluster is investigated analytically on the basis of the photoelectric radial velocities reported by Griffin et al. (1988). The methods used to determine the radial-velocity gradient, convergent point, and distance modulus are described, and the results are presented in tables and graphs and characterized in detail. Findings reported include convergent-point alpha = 98.2 + or - 1.1 deg and delta = 6.1 + or - 1.0 deg, space motion 48.0 + or - 0.27 km/s, distance to cluster center 45.4 + or - 2.1 pc, distance modulus 3.28 + or - 0.10, and cluster velocity dispersion 230 m/s.
Soft X-ray spectra of Seyfert 2 galaxies

The paper presents soft X-ray spectra of three Seyfert 2 galaxies obtained with the ROSAT PSPC. For two of these objects, NGC 5506 and MCG -5-23-16, most of the flux occurs at energies greater than 1 keV and probably represents a low-energy extension of the source seen at higher (greater than 2 keV) energies. The third source, Mrk 348, has very little flux in the ROSAT band, suggesting a photoelectric cutoff at energies above the ROSAT band, in agreement with Ginga observations. In all three galaxies, X-rays are detected at energies below these photoelectric cutoffs with flux above that expected from a model in which the source has the same spectral index as at higher energies (2-10 keV) and is covered by a uniform, cold, photoelectric absorber. This result indicates the presence of an additional component at soft energies, which is referred to as a 'soft excess'. The monochromatic flux of the soft excess measured at 1 keV is about 1-2 percent of the directly viewed hard X-ray continuum in all three galaxies.
Electromagnetic field near rail guns

The field in the neighborhood of an electromagnetic rail gun is computed for the case of constant current. The analysis centers on the Westinghouse EMACK launcher in which two rails of 2-m length carry a peak current of 2.1 MA, while a peak power of over 10 GW is delivered to the rails. Expressions are derived for electric field strength and magnetic flux density as functions of gun parameters. These formulas can be used to compute the electromagnetic pulse produced by a rail gun of any given characteristics. >
On The Expected Discounted Penalty function for Lévy Risk Processes

Abstract Dufresne et al. (1991) introduced a general risk model defined as the limit of compound Poisson processes. Such a model is either a compound Poisson process itself or a process with an infinite number of small jumps. Later, in a series of now classical papers, the joint distribution of the time of ruin, the surplus before ruin, and the deficit at ruin was studied (Gerber and Shiu 1997, 1998a, 1998b; Gerber and Landry 1998). These works use the classical and the perturbed risk models and hint that the results can be extended to gamma and inverse Gaussian risk processes. In this paper we work out this extension to a generalized risk model driven by a nondecreasing Lévy process. Unlike the classical case that models the individual claim size distribution and obtains from it the aggregate claims distribution, here the aggregate claims distribution is known in closed form. It is simply the one-dimensional distribution of a subordinator. Embedded in this wide family of risk models we find the gamma, inverse Gaussian, and generalized inverse Gaussian processes. Expressions for the Gerber-Shiu function are given in some of these special cases, and numerical illustrations are provided.
Ultra low power processor using perpendicular-STT-MRAM/SRAM based hybrid cache toward next generation normally-off computers

This paper presents novel processor architecture for HP-processor with MRAM/SRAM-based hybrid cache memory. By simulations of HP-processor using MTJs, it has been clarified that total power of the HP-processor using perpendicular-(p-)STT-MRAM [H. Yoda, et al., Current Appl. Phys. 10, e87 (2010)] can be reduced by 50.2% without any degradation of operation speed. This is the first report on effectively decreasing total power of HP-processors with no degradation of performance using magnetic memory. The presented architecture will be the first step to realize the next generation “normally-off computers. ”
A Multi‐dimensional Cognitive Analysis of Undergraduate Physics Students’ Understanding of Heat Conduction

This study proposes a multi‐dimensional approach to investigate, represent, and categorize students’ in‐depth understanding of complex physics concepts. Clinical interviews were conducted with 30 undergraduate physics students to probe their understanding of heat conduction. Based on the data analysis, six aspects of the participants’ responses were identified as nominal scales and designated as six dimensions in a multi‐axis (star) diagram to represent their in‐depth understanding of heat conduction. The results demonstrated a wide diversity of the participants’ in‐depth understanding of heat conduction. In addition, the proportions of participants’ naive ideas in the six dimensions were low, and many of them used some viable, sophisticated rules for explaining relevant phenomena of heat conduction. Furthermore, the patterns of the multi‐dimensional diagram illustrated that the participants who, across all dimensions, possessed scientifically accepted understanding performed better in the probes of their scientific explanations. This study also discusses the educational and instructional values of this multi‐dimensional analysis, and particularly highlights the importance of investigating students’ multi‐dimensional understanding to more fully account for the large variance in individual differences likely to be encountered in instructional settings.
Tunable VUV radiation generated by two-photon resonant frequency mixing in xenon

Efficient two-photon resonant frequency conversion of powerful pulsed dye laser radiation generates in Xe intense VUV light at \omega_{VUV} = 2\omega_{UV} - \omega_{D} . The frequency ω UV is tuned to the 5p-6p [ \frac{5}{2},2 ] two-photon resonance ( \lambda_{UV} = 255.9 nm). For dye laser radiation ω D at \lambda_{D} = 300-760 nm ω VUV is tunable in the spectral range of \lambda_{VUV} = 155-220 nm. The resonantly enhanced conversion efficiency is typically 0.05-0.2 percent; the generated VUV pulse power P_{VUV} = 0.5-1 kW. The experimental results provide detailed information on conversion limiting saturation phenomena and their dependence on the input power and the detuning of ω UV from the two-photon resonance.
An energy-based vector hysteresis model for ferromagnetic materials

Purpose – Proposes a new quasi‐static vector hysteresis model based on an energy approach, where dissipation is represented by a friction‐like force.Design/methodology/approach – The start point is the local energy balance of the ferromagnetic material. Dissipation is represented by a friction‐like force, which derives from a non‐differentiable convex functional. Several elementary hysteresis cells can be combined, in order to increase the number of free parameters in the model, and therefore improve the accuracy.Findings – A friction‐like force is a good way to represent magnetic dissipation at the macroscopic level. The proposed method is easy to implement and non‐differentiability amounts in this case to a simple “if” statement.Research limitations/implications – The next steps are the extension to dynamic hysteresis and the in‐depth analysis of the identification process, which is only sketched in this paper.Practical implications – This vector model, which is based on a reasonable phenomenological de.
Decision feedback equaliser design using support vector machines

The conventional decision feedback equaliser (DFE) that employs a linear combination of channel observations and past decisions is considered. The design of this class of DFE is to construct a hyperplane that separates the different signal classes. It is well known that the popular minimum mean square error (MMSE) design is generally not the optimal minimum bit error rate (MBER) solution. A strategy is proposed for designing the DFE based on support vector machines (SVMs). The SVM design achieves asymptotically the MBER solution and is superior in performance to the usual MMSE solution. Unlike the exact MBER solution, this SVM solution can be computed very efficiently.
Modeling and implementation of a fiber-based quartz-enhanced photoacoustic spectroscopy system

A compact fiber-based quartz-enhanced photoacoustic spectroscopy system requiring no extra optical lens has been developed for the detection of acetylene. The system is based on a common fiber or an axicon fiber to conduct the light. Experimental results show comparable detection sensitivity to that of tapered fiber-based photoacoustic spectroscopy systems. The system is easy to adjust and has low insertion loss and is thus well suited for small portable sensor applications in the future. A numerical model based on actual beam profiles was furthermore developed as part of the study to investigate the optimal positions of the fibers and to verify the experimental results.
LUMINOSITIES OF SX PHOENICIS, LARGE-AMPLITUDE DELTA SCUTI, AND RR LYRAE STARS

Strömgren uvbyβ photometry of SX Phoenicis and large-amplitude δ Scuti variables is analyzed to determine the mean temperatures, metal abundances, and surface gravities of the stars. The mean temperatures and fundamental periods are used in conjunction with the pulsation equation and stellar models to derive masses, radii, surface gravities, and Mbol of the variables. The stars exhibit a period-luminosity relation. With the aid of Hipparcos trigonometric parallaxes the zero-point of the Mv, p is set. We find Mv = -3.725 log P - 1.933. This P-L relation is utilized to find the M-v values of RR Lyrae stars or horizontal-branch stars in globular clusters and the Carina galaxy-objects that contain both SX Phe, and RR Lyrae variables, or horizontal-branch stars. The Mv values of the metal-poor RR Lyrae stars are found to be consistent with Mv [Fe/H] calibrations derived by Sandage (1993) and by McNamara (1997) from revised Baade- Wesselink Mv values. At [Fe/H] = -1.9 Mv is 0.42. Feast and Catchpole (1997) suggestion that Mv = 0.25 at [Fe/H] = -1.9 for RR Lyrae is discussed. This Mv value is too luminous because it makes the (Teff) of RR Lyraes too high-well off any (Teff) = f (color index) calibration.
Survival and spatial fidelity of moufl on (Ovis gmelini): A Bayesian analysis of an age-dependent capture-recapture model

We study the influence of age and sex on survival and spatial fidelity of moufl on (Ovis gmelini) in the Caroux-Espinouse massif. Survival and movement probabilities are estimated through a Bayesian analysis of an age-dependent capture-recapture model. Prior information is based on external data, namely on radio-tracked animals. Recapture rates differed between age, sexes, and areas. Whatever the area, survival of males and females less than 5 years old was high and decreased for older animals, particularly males. Female spatial fidelity was high; males were as faithful as females to their capture area in their first 2 years of life but gradually used distinct areas in two successive years as they were getting older.
A Second Law Based Unstructured Finite Volume Procedure for Generalized Flow Simulation

An unstructured finite volume procedure has been developed for steady and transient thermo-fluid dynamic analysis of fluid systems and components. The procedure is applicable for a flow network consisting of pipes and various fittings where flow is assumed to be one dimensional. It can also be used to simulate flow in a component by modeling a multi-dimensional flow using the same numerical scheme. The flow domain is discretized into a number of interconnected control volumes located arbitrarily in space. The conservation equations for each control volume account for the transport of mass, momentum and entropy from the neighboring control volumes. In addition, they also include the sources of each conserved variable and time dependent terms. The source term of entropy equation contains entropy generation due to heat transfer and fluid friction. Thermodynamic properties are computed from the equation of state of a real fluid. The system of equations is solved by a hybrid numerical method which is a combination of simultaneous Newton-Raphson and successive substitution schemes. The paper also describes the application and verification of the procedure by comparing its predictions with the analytical and numerical solution of several benchmark problems.
Optimal control of current switching angles for high‐speed SRM drive

Purpose – The purpose of this paper is to propose a method of optimal control of current commutation of switched reluctance motor drive.Design/methodology/approach – The problem of optimal current commutation control is solved by off‐line selection of switching‐on and switching‐off angles. Selection of optimal values of angles is provided on computer model of the drive with help of particle swarm optimisation method. The optimal angle values are detected as functions of phase current and rotor speed. These calculated optimal values are stored in microcomputer control system memory in form of two‐input look‐up tables. The results are validated on laboratory set up.Findings – Three different criteria of optimal control, which are taken into account: the maximum electromagnetic torque for given reference current, the maximum ratio of electromagnetic torque to root mean square value of phase current and the minimum electromagnetic torque ripples, gave a good results validated by simulation and experimental in.
Statistical Properties of Random Interface System

StatisticaJ properties of binary phase system with semi-macroscopic random interfaces are studied. Singularity and symmetry of the correlation function are discussed in the case of smooth interface. Characteristic length scales,are defined by using the interface statistics. The existence of the equivalent sphere system is shown for the non-spherical irregular droplet. The irregularity of simple droplets is characterized by an inequality related to the topological invariant. It is shown that statistically self­ complementary, smooth system is mutually percolating. As a statistical foundation of the random interface problem, the relations to the theory of excursion set of random field are discussed. The expression of area density of the boundary set is obtained for the Gaussian field in Euclidean space with arbitrary dimension d. The cross-over phenomena in the spinodal decomposition process is also discussed using the statistical analyses on the interface.
The design of a slot array in nonradiating dielectric waveguide, part II: Experiment

Measurement procedures for obtaining the self-impedance of an isolated inclined radiating slot in the metal wall of a nonradiating dielectric (NRD) waveguide are discussed. The design procedure for an antenna array fed by NRD-waveguide and making use of this information is described. As an example, the design, construction and evaluation of a ten-element input-matched broadside linear array is described.
A location-routing-inventory model for designing multisource distribution networks

This article studies a ternary-integration problem that incorporates location, inventory and routing decisions in designing a multisource distribution network. The objective of the problem is to minimize the total cost of location, routing and inventory. A mixed-integer programming formulation is first presented, and then a three-phase heuristic is developed to solve large-sized instances of the problem. The numerical study indicates that the proposed heuristic is both effective and efficient.
Design of a gonio-spectro-photometer for optical characterization of gonio-apparent materials

Gonio-apparent surfaces, characterized by large variations in optical properties with small variations in detection or illuminating directions, have a huge appeal for industrial product for aesthetic reasons. This work is dedicated to the design of a gonio-spectrophotometer (OptiMines goniometer) adequate for analyzing the light reflecting behavior of these challenging surface aspects. Such optical characterizations are useful data for realistic rendering of such surfaces in computer graphics but also for new product development and quality control in industrial manufacturing. To reach the four degrees of freedom necessary to cover the entire reflecting hemisphere, the designed geometrical setup favors movements of the sample so that illuminating and detection arms only carry one degree of freedom each. Having only one degree of freedom on each optical arm enables an easy installation of precise optical systems that leads to a very high directional accuracy for small arm dimensions. High directional accuracy is essential for fine analysis of gonio-apparent surfaces in order to prevent signal averaging with out-of-direction beam, in particular when the property change is abrupt. The analysis of both diffuse and gonio-apparent materials demonstrates the performance in surface metrology provided by this new device.
The numerical solution of A'Q+QA = -C

A rapidly convergent algorithm is given which will solve A'Q + QA = -C for Q when A is a stable matrix. The algorithm proposed requires only 4n^{2} words of memory (for large n ) and converges in approximately 17n^{3} \mu s where μ is the multiplication time of the computer and n is the order of the matrix A .
Monochromator for the synchrotron radiation beamline X-MOSS at ELETTRA

The optical configuration of the monochromator for the new beamline X-MOSS at the ELETTRA synchrotron ring is described. The requirements for this instrument are to collect a 3 mrad X 2 mrad aperture beam produced by a bending magnet in the 3 - 1400 eV energy range; the energy resolution has to be 3000 or better over the whole range, with a focused beam of the order of 10 - 50 micrometer. The designed monochromator, presently under construction, is a slitless four grazing incidence optical elements: the first element is a one-meter paraboloidal mirror in sagittal focusing, then there is a plane mirror-plane grating dispersion system and finally a second one-meter paraboloidal mirror, also used in sagittal focusing. The latter focuses the radiation on the monochromator exit slit. This monochromator design is not limited by a defined working curve: in this way it is possible to select the preferred operational parameters, to optimize either the flux or the resolution or the high order rejection. The monochromatic beam is finally sent on the sample under examination by an ellipsoidal refocusing mirror.