Miracle-dz/UniFAR-FTUs huggingface dataset:
Generalizations of the stochastic decomposition results for single server queues with vacations

In this paper we show that the sample path comparison used in Doshi [l] to prove the stochastic decomposition of the steady state waiting time for GI/G/1 queue with exhaustive service and multiple vacations can also be used to prove that this decomposition result is valid for more general (stationary) arrival and service processes. In addition, we use the same approach to show a similar decomposition result for the steady state virtual waiting time. The special case of semi-Markov arrival process and i.i. d. service times is analysed further and stronger results are obtained for that case: we show that there is a unique invariant waiting time (virtual waiting time) distribution which is the limiting distribution for any initial conditions. We also show that conditional distributions of the steady state waiting time and virtual waiting time (given the supplementary variables describing the state of the arrival process) have the stochastic decomposition property. Finally, the steady state queue length and th.
The magnetostatic surface‐wave propagation in a corrugated YIG slab

An analysis for the propagation characteristics of the magnetostatic surface waves in a YIG slab having periodically corrugated surfaces is presented. The Brillouin diagrams, close to the intersection point (ω,β) of m=0 and m=−1 space harmonics, are obtained for different strengths of modulation. Comparison between the magnetostatic surface waves and volume waves concerning the complex value of the propagation constant within the stop band is also discussed.
High-Order Solution of Viscoelastic Fluids Using the Discontinuous Galerkin Method

In this paper, the high-order solution of a viscoelastic fluid is investigated using the discontinuous Galerkin (DG) method. The Oldroyd-B model is used to describe the viscoelastic behavior of the fluid flow. The high-order accuracy of the applied DG method is verified for a Newtonian benchmark problem with an exact solution. Next, the same algorithm is utilized to solve the viscoelastic flow by separating the stress tensor into the stress due to the Newtonian solvent and the stress due to the solved viscoelastic polymers. The high-order accuracy of the solution for viscoelastic flow is demonstrated by solving the planar Poiseuille flow. Then, the planar contraction problem is simulated as a benchmark for the viscoelastic flow. The obtained results are in good agreement with the results in the literature for both creeping and inertial flow when high-order polynomials were used even on coarse meshes.
Optimal feature selection for classification of power quality disturbances using wavelet packet-based fuzzy k-nearest neighbour algorithm

The authors present an automatic classification of different power quality (PQ) disturbances using wavelet packet transform (WPT) and fuzzy k-nearest neighbour (FkNN) based classifier. The training data samples are generated using parametric models of the PQ disturbances. The features are extracted using some of the statistical measures on the WPT coefficients of the disturbance signal when decomposed upto the fourth level. These features are given to the fuzzy k-NN for effective classification. The genetic algorithm-based feature vector selection is done to ensure good classification accuracy by selecting 16 better features from all 96 features generated from the WPT coefficients. The necessity of selecting the best feature is to remove the redundant or irrelevant features, which may reduce the performance of the classification. It also reduces the computation time since it uses only 16 features instead of 96 features. The experimental analysis for the validation of the proposed algorithm is carried out in two stages. At the first stage, the sample data set is generated by varying the parameters in models in regular intervals and the proposed algorithm is applied to select the best features to obtain high accuracy. In the second stage, a new data set is generated by choosing the parameter values, which are not used in the first case and used to test the accuracy of the classifier with the same selected features as in stage one. The noisy and practical signals are also considered for the classification process to show the effectiveness of the proposed method.
Finite element model of laser-generated surface acoustic waves in coating-substrate system

The generation of ultrasound in coating-substrate systems subjected to laser beam illumination has been studied quantitatively by using the finite element method. Taking into account the temperature dependence of material properties, the transient temperature and temperature gradient field can be obtained in different coating-substrate systems. According to the thermoelastic theory, these temperature gradient fields are taken as bulk sources to generate ultrasound in coating-substrate systems. The typical surface acoustic waves (SAWs) in systems, a slow coating on a fast substrate and a fast coating on a slow substrate, are obtained. The influence of the propagation distance and the coating thickness on the SAWs is analyzed.
Ends of hyperbolic 3-manifolds

Let N = H3/F be a hyperbolic 3-manifold which is homeomorphic to the interior of a compact 3-manifold. We prove that N is geometrically tame. As a consequence, we prove that F's limit set L. is either the entire sphere at infinity or has measure zero. We also prove that N's geodesic flow is ergodic if and only if LF is the entire sphere at infinity. DEPARTMENT OF MATHEMATICS, STANFORD UNIVERSITY, STANFORD, CALIFORNIA 94305 Current address: Department of Mathematics, University of Michigan, Ann Arbor, Michigan 48109 E-mail address: dick.canary@math.lsa. umich.edu This content downloaded from 40.77. 167.14 on Wed, 15 Jun 2016 05:36:06 UTC All use subject to http://about.jstor. org/terms
The milliarcsecond polarization structure of six BL Lacertae objects

Milliarcsecond resolution total intensity and linear polarization maps at GHz are presented for the BL Lacertae objects 0235 + 164, 0454 + 844, 1749 + 096, 1823 + 568, and 2200 + 420 (BL Lac). Maps of 1807 + 698 (3C 371), which has in the past been classified either as a BL Lacertae object or an N galaxy, are also presented. Appreciable polarization structure is found in 0454 + 844, 1823 + 568, and BL Lac; in each the polarization position angle in the knots lies within about 10 deg of the structural direction of the VLBI jet, suggesting that plane perpendicular shock waves may be common in these objects. The polarization of 3C 371 is weak, and is quite atypical of BL Lacertae objects. Superluminal motion in 1823 + 568 is suggested. Similar comparison for 0454 + 844 over four epochs confirms proper motion at mu about 0.14 mas/yr. Systematic differences in the VLBI polarization structures of BL Lacertae objects and quasars rule out the possibility that a significant fraction of BL Lacertae objects are gravitationally microlensed quasars. 87 refs.
Characterization and recognition of partial 3-trees

Our interest in the class of k-trees and their partial graphs and subgraphs is motivated by some practical questions about the reliability of communication networks in the presence of constrained line- and site-failures, and about the complexity of queries in a data base system. We have found a set of confluent graph reductions such that any graph can be reduced to the empty graph if and only if it is a subgraph of a 3-tree. This set of reductions yields a polynomial time algorithm for deciding if a given graph is a partial 3-tree and for finding one of its embeddings in a 3-tree when such an embedding exists. Our result generalizes a previously known recognition algorithm for partial 2-trees (series-parallel graphs).
Hybrid simulation of the formation of a hot flow anomaly

Results are presented from two-dimensional hybrid simulations of the interaction of a supercritical quasi-perpendicular collisionless shock wave with current sheets embedded in the upstream flow. The current sheet normals are perpendicular to the shock normal. When the motional electric field is directed toward the discontinuity, the interaction leads to the generation of a region with high ion temperature, low magnetic field, and low density, which has many properties of a class of events variously referred to as active current sheets, hot diamagnetic cavities, or hot flow anomalies (HFAs). The simulations demonstrate that the HFA results from the interaction of ions reflected at the shock with the current sheet. The interaction does not involve an instability and is not caused by the collision of the current sheet and the shock but rather is a property of a shock with an embedded current sheet. The simulations suggest that the HFAs formed in this way are always attached to the shock and extend into both the upstream and downstream regions.
Application of a Lightning Data Assimilation Technique in the WRF-ARW Model at Cloud-Resolving Scales for the Tornado Outbreak of 24 May 2011

AbstractThis study presents the assimilation of total lightning data to help initiate convection at cloud-resolving scales within a numerical weather prediction model. The test case is the 24 May 2011 Oklahoma tornado outbreak, which was characterized by an exceptional synoptic/mesoscale setup for the development of long-lived supercells with large destructive tornadoes. In an attempt to reproduce the observed storms at a predetermined analysis time, total lightning data were assimilated into the Weather Research and Forecasting Model (WRF) and analyzed via a suite of simple numerical experiments. Lightning data assimilation forced deep, moist precipitating convection to occur in the model at roughly the locations and intensities of the observed storms as depicted by observations from the National Severe Storms Laboratory’s three-dimensional National Mosaic and Multisensor Quantitative Precipitation Estimation (QPE)—i.e., NMQ—radar reflectivity mosaic product. The nudging function for the total lightning .
CCD photometry of galactic open clusters - I. NGC 7790.

La photometrie CCD est presentee pour 607 etoiles dans l'amas ouvert NGC 2243. Le diagramme magnitude-couleur resultant etablit la presence d'une fraction de binaires jusqu'a 30 % de la population totale. Les abondances chimiques, le rougissement, le module de distance, et l'âge sont ensuite determines.
A Large-Scale CO Survey of the Galactic Center

We present high-resolution CO images of the Galactic center region taken with the 2 × 2 focal-plane array receiver mounted on the 45 m telescope of Nobeyama Radio Observatory. We have collected about 44,00012C16O (J = 1-0) spectra and over 13,00013C16O (J = 1-0) spectra with a 34'' (1.4 pc) grid spacing. The 12CO mapping area is roughly -1. °5 ≤ l ≤ +3. °4 and -0. °6 ≤ b ≤ +0. °6, which covers almost the full extent of the molecular gas concentration in the Galactic center. These CO images demonstrate extremely complex distribution and kinematics of molecular gas in the Galactic center. While its large-scale behavior can be attributed to the well-known coherent features, bright CO emission arises from a number of compact (d ≤ 10 pc) clouds with large velocity widths (ΔV ≥ 30 km s-1). The small-scale structure of molecular gas is characterized by filaments, arcs, and shells. The boisterous molecular gas kinematics there may be a result of violent release of kinetic energy by a number of supernova explosions and/or Wolf-Rayet stellar winds.
Search-Guided Sampling to Reduce Uncertainty of Minimum Deviation Zone Estimation

Integrating computational tasks in coordinate metrology and its effect on the inspection’s uncertainty is studied. It is shown that implementation of an integrated inspection system is crucial to reduce the uncertainty in minimum deviation zone (MDZ) estimation. An integrated inspection system based on the iterative search procedure and online MDZ estimation is presented. The search procedure uses the Parzen Windows technique to estimate the probability density function of the geometric deviations between the actual and substitute surfaces. The computed probability density function is used to recognize the critical points in the MDZ estimation and to identify portions of the surface that require further iterative measurements until the desired level of convergence is achieved. Reduction of the uncertainty in the MDZ estimation using the developed search method compared to the MDZ estimations using the traditional sampling methods is demonstrated by presenting experiments including both actual and virtual inspection data. The proposed search method can be used for assessing any geometric deviations when no prior assumptions about the fundamental form and distribution of the underlying manufacturing errors are required. The search method can be used to inspect and evaluate both primitive geometric features and complicated sculptured surfaces. Implementation of this method reduces inspection cost as well as the cost of rejecting good parts or accepting bad parts. DOI: 10.1115/1.2798114
EM Algorithm-Based Likelihood Estimation for Some Cure Rate Models

In the recent work of Rodrigues et al. (2009), a flexible cure rate survival model was developed by assuming the number of competing causes of the event of interest to follow the Conway-Maxwell Poisson distribution. This model includes as special cases some of the well-known cure rate models discussed in the literature. As the data obtained from cancer clinical trials are often subject to right censoring, the expectation maximization (EM) algorithm can be used as a powerful and efficient tool for the estimation of the model parameters based on right censored data. In this paper, the cure rate model developed by Rodrigues et al. (2009) is considered and assuming the time-to-event to follow the exponential distribution, exact likelihood inference is developed based on the EM algorithm. The inverse of the observed information matrix is used to compute the standard errors of the maximum likelihood estimates (MLEs). An extensive Monte Carlo simulation study is performed to illustrate the method of inference developed here. Finally, the proposed methodology is illustrated with real data on cutaneous melanoma.
Fast Time Analysis of Intermittent Point-to-Plane Corona in Air I. The Positive Point Burst Pulse Corona

Techniques for fast oscilloscopic analysis of intermittent point‐to‐plane coronas in air are described. Such analysis shows the positive point burst pulse corona to consist of an initial pulse followed by secondary pulses at varying time intervals. The duration of both pulses is less than 10−7 second, the initial pulses having from 1 to 2×107 ions and the secondaries from 1 to 5×106 ions depending on the voltage. Time intervals between pulses range from the clearing time of ions across the gap (milliseconds) to random intervals as short as 2 microseconds for secondary pulses well above threshold. Thus, in analogy to Geiger counter terminology dead times run from 2 microseconds up, and clearing times are in the order of milliseconds corresponding to local clearing of space charge near the point for secondaries, and removal of massive space charge from the low field region of the gap. A complete sequence of events from threshold to steady corona is analyzed, and indicates the predominance of self‐counting through negative ion formation in air.
Convergence of functional k-nearest neighbor regression estimate with functional responses

: Let ( X 1 ,Y 1 ) ,. , ( X n ,Y n ) be independent and identically dis- tributed random elements taking values in F ×H , where F is a semi-metric space and H is a separable Hilbert space. We investigate the rates of strong (almost sure) convergence of the k-nearest neighbor estimate. We give two convergence results assuming a ﬁnite moment condition and exponential tail condition on the noises respectively, with the latter requiring less stringent conditions on k for convergence.
Comparison between Low-Flash and Non-Lightning-Producing Convective Areas within a Mature Mesoscale Convective System

AbstractTwo small multicellular convective areas within a larger mesoscale convective system that occurred on 20 June 2004 were examined to assess vertical motion, radar reflectivity, and dual-polarimetric signatures between flash and non-flash-producing convection. Both of the convective areas had similar life cycles and general structures. Yet, one case produced two flashes, one of which may have been a cloud-to-ground flash, while the other convective area produced no flashes. The non-lightning-producing case had a higher peak reflectivity up to 6 km. Hence, if a reflectivity-based threshold were used as a precursor to lightning, it would have yielded misleading results. The peak upward motion in the mixed-phase region for both cases was 8 m s−1 or less. However, the lightning-producing storm contained a wider region where the updraft exceeded 5 m s−1. Consistent with the broader updraft region, the lightning-producing case exhibited a distinct graupel signature over a broader region than the non-light.
Measurements of D A for a Large QSO Sample and Determination of Evolution of Lyman-Alpha Clouds

We have measured D A , the mean relative depression of quasar continuum between Lyα and Lyβ emission, for a large sample of quasars. We have carried out the measurements by simply adding the Lyα lines (excluding the lines in identified systems) together. The big advantage of this approach over the conventional method is that the continuum is fitted locally by employing high S/N and relatively high resolution spectra, and this leads to a more reliable estimate of the continuum level in the Lyα forest region. Also, the contamination of D A by metal lines is easily removed. Extending the method proposed by Zuo (1993) and Lu & Zuo (1993), we have determined γ int , the intrinsic evolutionary rate exponent of Lyα forest lines
An Insight Into The Modeling of Short-Pulse Laser Transport Through A Participating Medium

Thermal radiation is a time-dependent process in the analysis of a short-pulse laser irradiation. The numerical modeling of the radiative phenomenon considers a finite number of intensity directions over a spherical space. Thus, in time-dependent radiative transfer problems, radiative intensities take different times to reach a particular location in the medium, and accordingly, collectively they remain available for durations different than the laser pulse width. The present work proposes that the above aspect be taken into account in the analysis of transient radiative transfer problems. To validate this concept, transport of a short square-pulse laser in a plane-parallel participating medium is studied. It is found that the magnitude of the transmittance signals differ for higher values of the extinction coefficient and also that the signals remain available for a longer duration. Reflectance signals are found to be less affected.
DIFFUSIVE SHOCK ACCELERATION OF HIGH-ENERGY CHARGED PARTICLES AT FAST INTERPLANETARY SHOCKS: A PARAMETER SURVEY

We present results from numerical simulations of the acceleration of solar energetic particles (SEPs) associated with strong, fast, and radially propagating interplanetary shocks. We focus on the phase of the SEP event at the time of the shock passage at 1 AU, which is when the peak intensity at energies below a few MeV is the highest. The shocks in our study start between 2 and 10 solar radii and propagate beyond 1 AU. We study the effect of various shock and particle input parameters, such as the spatial diffusion coefficient, shock speed, solar wind speed, initial location of the shock, and shock deceleration rate, on the total integrated differential intensity, I, of SEPs with kinetic energies > 10 MeV. I is the integral over energy of the differential intensity spectrum at the time of the shock passage at 1 AU. We find that relatively small changes in the parameters can lead to significant event-to-event changes in I. For example, a factor of 2 increase in the diffusion coefficient at a given energy and spatial location, can lead to a decrease in I by as much as a factor of 50. This may help explain why there are fewer large SEP events seen during the current solar maximum compared to previous maxima. It is known that the magnitude of the interplanetary magnetic field is noticeably weaker this solar cycle than it was in the previous cycle and this will naturally lead to a somewhat larger diffusion coefficient of SEPs.
Numerical Investigation of Conjugate Heat Transfer to Supercritical CO2 in a Vertical Tube-in-Tube Heat Exchanger

Conjugate heat transfer to supercritical CO2 in a vertical tube-in-tube heat exchanger was numerically investigated. The results demonstrate that most models considered are able to reproduce the heat transfer processes qualitatively, and the Abe, Kondoh, and Nagano model shows optimal agreement with the experimental data. The influences of hot fluid mass flux and temperature of the shell side, supercritical fluid mass flux of the tube side, flow direction, and pipe diameter on conjugate heat transfer were investigated based on velocity and turbulence fields. It is concluded that hot fluid mass flux and temperature of the shell side significantly affect heat transfer of the tube side. Mixed convection is the main heat transfer mechanism for the supercritical CO2 conjugate heat transfer process when the inner diameter of the tube is greater than 1 mm. In addition, density variation is highly significant for heat transfer of supercritical CO2 while high viscosity hinders the distortion of the flow field and reduces deterioration in heat transfer.
Passage time moments for multidimensional diffusions

Let τ r denote the hitting time of B(0:r) for a multidimensional diffusion process. We give verifiable criteria for finiteness/infiniteness of As an application we exhibit classes of diffusion processes which are recurrent but is infinite for all p > 0, |x| > r > 0; this includes the two-dimensional Brownian motion and the reflecting Brownian motion in a wedge with a certain parameter α = 0.
Quantized feedback control for linear uncertain systems

This paper studies robust control problems under the setting of quantized feedback. We consider both the static and dynamic logarithmic quantizers. In the static quantization case, the quantizer has an infinite number of levels, and the design problem is to find the minimal quantization density required to achieve a given control objective. In the dynamic quantization case, the problem is to minimize the number of quantization levels to achieve a given control objective. We present a number of results for different controller‐quantizer configurations. These results are developed using the so‐called sector bound approach for quantized feedback control, which was initiated by the authors previously for systems without uncertainties. Copyright © 2009 John Wiley & Sons, Ltd.
Magnetic properties of Co50−xNixMn25Al25 alloys with B2 structure

Magnetic properties of the B2 phase in Co50−xNixMn25Al25 alloys were investigated. Spontaneous magnetization Ms measured at 4.2 K increases linearly with increasing x in the region of x ≤ 30 in accordance with following the generalized Slater-Pauling (GSP) line. However, Ms abruptly decreases with increasing x and deviates from the GSP line in the Ni-rich region of x > 30, suggesting a drastic change in the density of states at the Fermi energy. The Curie temperature TC decreases monotonically with increasing x and significantly decreases in the region of x > 30. Antiferromagnetic evidence is clearly observed at x > 45, and the Neel temperature TN increases with increasing x, in reaching the value of the B2 phase in Ni2MnAl.