Miracle-dz/UniFAR-FTUs huggingface dataset:
General open-system quantum evolution in terms of affine maps of the polarization vector

The operator-sum decomposition of a map from one density matrix to another has many applications in quantum information science. To this mapping there corresponds an affine map which provides a geometric description of the map of the density matrix in terms of the polarization vector representation. This has been thoroughly explored for qubits since the components of the polarization vector are measurable quantities (corresponding to expectation values of Hermitian operators) and also because it enables the description of map domains geometrically. Here we extend the operator-sum-affine-map correspondence to qudits, briefly discuss general properties of the map and the form for some particular cases, and provide several explicit results for qutrit maps. We use the affine map and a singular-value-like decomposition to find positivity constraints that provide a symmetry for small polarization vector magnitudes (states which are closer to the maximally mixed state), which is broken as the polarization vector increases in magnitude (a state becomes more pure). The dependence of this symmetry on the magnitude of the polarization vector implies the polar decomposition of the map cannot be used as it can for the qubit case. However, it still leads us to a connection between positivity and purity for generalmore » d-state systems. « less
Optimal Shakedown Design of Circular Plates

The optimal design of circular plates of elastic‐perfectly plastic material and subjected to variable repeated loads is studied according to the shakedown criterion. Two different types of design problem are formulated: one searches for the minimum volume design whose shakedown limit load is assigned; the other searches for the maximum shakedown limit load design whose volume is assigned. In both cases the design problem is formulated by means of a statical approach on the grounds of the shakedown lower‐bound theorem, and by means of a kinematical approach on the grounds of the shakedown upper‐bound theorem. The Euler‐Lagrange equations of these problems are found by a variational approach. The equivalence of the two types of design problem is proved and the design optimality condition is shown to constitute an extension to the shakedown context of the well‐known Drucker‐Prager‐Shield‐Rozvany theorem of optimal plastic design; namely, a modified unit cost is envisaged, the sum of the plate unit cost with .
Measurement of Thermo Physical Properties of Metallic Nanofluids for High Temperature Applications

This article presents the measurement of thermal conductivity and viscosity of nanofluids experimentally. Silver nanoparticles dispersed in water with volume concentrations of 0.3, 0.4, 0.6, 0.8, 0.9, and 1.2 vol% are used in the present study. A transient hot-wire apparatus is used for measuring the thermal conductivity of nanofluids and a Cannon-Fenske viscometer is used to measure the kinematic viscosity of nanofluids. The data are collected for temperatures ranging from 50 to 90°C. The results have shown an increase in the measured thermal conductivity and viscosity of nanofluids as the particle concentrations increase, and the values are higher than the values of the base liquids. The minimum enhancement of 27% for 0.3 vol% and a maximum enhancement of 115% for 1.2 vol% are observed at an average temperature of 70°C when compared with pure water for the same temperature. Further, the thermal conductivity of nanofluids increases with the increase in nanofluid temperatures and, conversely, the viscosity of nanofluids decreases with the increase in temperature of nanofluids. An experimental correlation is developed based on the experimental data for thermal conductivity and viscosity that relates the particle volume concentration and nanofluid temperature.
Excitation of the 2 3S state of helium by electron impact from threshold to 24 eV: measurements with the `magnetic angle changer'

The magnetic angle changer recently invented by Read and co-workers (Read F H and Channing J M 1996 Rev. Sci. Instrum. 67 2373) has been incorporated into an existing electron impact spectrometer. Both the inner and the outer solenoids consist of a single layer of self-supporting thin copper tubing, cooled by circulating water. This construction makes the solenoid nearly optically transparent, reducing the interference of the new device with the flow of sample gas - a feature important for measurements of absolute cross sections and for the operation of a supersonic free jet. The properties of the device are illustrated with measurements of the differential cross sections for the excitation of the 2 3 S state of helium by impact of electrons from threshold to 24 eV. Spectra are presented at the scattering angles of 0°, 45°, 90°, 135° and 180°, important for deriving integral cross sections, and 145°, 155° and 165°, revealing interesting details of the interference of narrow ridge resonances with background scattering at angles surrounding the deep minimum of the angular distribution at 22 eV.
A nomadic access mechanism for enabling dynamic video surveillance over IEEE 802.15.4 networks

IEEE 802.15. 4 networking technology is designed to be the common standard for integrating WSN applications in heterogeneous environments. However, applications considering mobile nodes along with strict temporal requirements, such as those required for video transmission, are an unexplored field for this technology. These applications involve different challenges and issues that the direct employment of the IEEE 802.15. 4 standard does not resolve. Therefore, in this paper a cross-layer mechanism consisting of application and medium access arbitration is presented, enabling the efficient connection and operation of mobile nodes together with the transmission of video flows. The proposed mechanism is evaluated via simulation and its feasibility checked by means of a first prototype. The study of power consumption is also taken into account and so are the quality of service parameters and the human quality perception of the received video stream. The results obtained are presented and further discussed.
Valence Bands and Core Levels of the Isoelectronic Series LiF, BeO, BN, and Graphite Studied by ESCA

The core lines and valence bands of LiF, BeO, BN and graphite have been studied by the ESCA technique. The energy differences between inner levels and valence bands are compared with X-ray transition energies. The changes in binding energy for the Bels level when going from metal to oxide and fluoride are compared with X-ray spectroscopic data and with a study of the disintegration constant in electron capture of 7Be in the same compounds.
A condition number scaling policy for stability robustness analysis

The condition number of the process transfer function G(s) has been proposed and used as an indicator of the inherent controllability of a process even though it is a scale-dependent quantity. A rapid suboptimal scaling policy known as G-balancing is developed for the case of the l2 norm where the condition number is the ratio of the largest to the smallest singular value of G(s). For 2 × 2 systems, G-balancing gives the same optimal scaling as an available analytical solution. The higher order examples given compare the results of G-balancing with the known analytic results for l2 norm optimal scaling.
Estimation by polynomial splines with variable selection in additive Cox models

In this article, we consider penalized variable selection in additive Cox models based on (group) smoothly clipped absolute deviation penalty and hence widen the scope of applicability of penalized variable selection to semiparametric models for censored data. We demonstrate the asymptotic consistency in model selection and convergence rate in estimation. Our simulation study emphasizes comparison of several different criteria for tuning parameter selection and also compares two appropriate definitions of the degrees of freedom in additive models.
Stratospheric Wave-Mean Flow Feedbacks and Sudden Stratospheric Warmings in a Simple Model Forced by Upward Wave Activity Flux

AbstractA classic result of studying stratospheric wave–mean flow interactions presented by Holton and Mass is that, for constant incoming wave forcing (at a notional tropopause), a vacillating stratospheric response may ensue. Simple models, such as the Holton–Mass model, typically prescribe the incoming wave forcing in terms of geopotential perturbation, which is not a proxy for upward wave activity flux. Here, the authors reformulate the Holton–Mass model such that incoming upward wave activity flux is prescribed. The Holton–Mass model contains a positive wave–mean flow feedback whereby wave forcing decelerates the mean flow, allowing enhanced wave propagation, which then further decelerates the mean flow, etc., until the mean flow no longer supports wave propagation. By specifying incoming wave activity flux, this feedback is constrained to the model interior. Bistability—where the zonal wind may exist at one of two distinct steady states for a given incoming wave forcing—is maintained in this reformu.
Number theoretic transforms of periodic structures and their applications

The properties of the Fermat number transforms of periodic data are investigated and it is shown they have regular structures with many zero-valued elements. Expressions are derived for the maximum number of nonzero elements related to the data row and column periods. Examples are given and applications suggested for image compression and data storage. It is also shown that the effects of defects as small as a single pixel in the image data produce effects upon the FNT, completely altering its regular structure. Applications for this result are suggested to the detection of errors in maskmaking for integrated circuit design and defect detection in industrial inspection.
Conductivity of nanometer-sized ion tracks in diamond-like carbon films

Amorphous diamond-like carbon films were irradiated with high-energy heavy ions like 1 GeV uranium or 340 MeV gold. The large energy deposition along the ion track leads to a transformation of the material from insulating diamond-like to conducting graphite-like carbon. The ion tracks form thin straight channels (nanowires) with a diameter of approximately 8 nm and a conductivity of the order of 1–10 S/cm. The conductivity in the tracks is up to eight orders of magnitude larger than in the surrounding material. The surface topography and the conduction properties of these channels were studied with an atomic force microscope.
Second-law-based thermoeconomic optimization of two-phase heat exchangers

This paper presents a closed-form analytical method for the second-law-based thermoeconomic optimization of two-phase heat exchangers used as condensers or evaporators. The concept of internal economy as a means of estimating the economic value of entropy generated (due to finite temperature difference heat transfer and pressure drops) has been proposed, thus permitting the engineer to trade the cost of entropy generation in the heat exchanger against its capital expenditure. Results are presented in terms of the optimum heat exchanger area as a function of the exit/inlet temperature ratio of the coolant, unit cost of energy dissipated, and the optimum overall heat transfer coefficient. The total heat transfer resistance represented by (1/U = C1 + C2 Re{sup {minus}n}) in the present analysis is patterned after Wilson (1915) which accommodates the complexities associated with the determination of the two-phase heat transfer coefficient and the buildup of surface scaling resistances. The analysis of a water-cooled condenser and an air-cooled evaporator is presented with supporting numerical examples which are based on the thermoeconomic optimization procedure of this paper.
Mathematical modelling of the atmospheric aerosol transfer with coagulation taken into account

A combined model of the atmosphere hydrothermodynamics and the pollutant transport is described. The atmospheric pollution processes are considered having regard to the aerosol coagulation. The coagulation is allowed for by the Smolukhovsky equation. To transform the equation into the form solvable numerically, we divide the mass range of particles involved in coagulation into fractions on a logarithmic scale. This allows us to describe a wide range of masses by using a small number of equations without any loss in accuracy. The coagulation kernels are taken close to reality, which allows us to take into consideration the change-over from one collision regime to another (free molecular, transition and diffuse regimes). Implementation of the numerical model and discussion of numerical experiments are presented as well. The atmospheric aerosols (small particles suspended in the air) were known for more than a hundred years, but only in the last decade their role in global atmospheric processes stimulated their thorough investigation. By now the atmospheric aerosols are known to affect the weather and climate on our planet, the radiation and energy balances of the atmosphere, the precipitation and cloud formation processes. Though the natural aerosols account for about 90% of the total aerosol mass, the important role of the anthropogenic aerosols becomes more and more clear, since the remaining 10% of the anthropogenic aerosols possesses anomalous physical and chemical properties and can induce and transform many chemical processes in the atmosphere. On the one hand, these processes supply the atmosphere with contaminations causing smog, global geophysical phenomena, acid rains, elc. , on the other hand, they can provide efficient mechanisms for removing the anthropogenic pollution from the atmosphere. As a rule, the atmospheric pollutants are polydispersive, hence to model their dynamics numerically one needs to consider two main mechanisms: (1) the transport and diffusion of pollutants and (2) the changes of the aerosol concentration and disperse composition due to such kinetic processes as condensation, coagulation, nucleation, precipitation, etc. As these processes take place in the turbulent atmosphere, the problem of the aerosol dynamics must be solved using the hydrodynamic models. This allows one to reproduce the space and temporal variations in the fields of meteoelements and in the turbulent characteristics of the atmosphere. Some physical mechanisms of the aerosol formation are being intensively investigated in recent years. A wide range of problems is discussed in the Proceedings of the International Conference on Atmospheric Aerosols [2]. However, these papers are practically devoid of complex models which simultaneously allow for the aerosol transfer, transformation, origin and destruction processes taking place in the conditions of the atmospheric circulation. It is obvious that nowadays the development of such models is of great importance, since they allow one to describe precisely the aerosol dynamics in the atmosphere.
A CO Survey toward Starless Cores

A CO survey is undertaken toward about 80% of the starless cores in the Lee & Myers catalog that can be observed in the northern hemisphere to investigate their general observational properties such as line width and intensity, from which one can deduce their environmental physical conditions. The peak 12CO intensity implies a kinetic temperature close to 10 K, as is already known, but for some of the cores the kinetic temperature is much higher than 10 K, suggesting either that they are not really starless or that they are externally heated. We derive the ratios of peak intensities and line widths for the pairs of 12CO and 13CO lines and find a value of ∼1.7 for both. The linear correlations between them are most likely to be due to clumpy structure. These data are also compared with data sets of CS 2-1 and N2H+ 1-0 lines tracing high-density regions. It is found that the peak intensity and line width of 13CO are roughly correlated with those of CS, suggesting that the outer envelope is kinematically related to the inner dense core. Confirming that the 12CO lines seldom exhibit deep self-reversal features, whereas this is not unusual for the CS lines, we propose a heuristic model where the outer part is clumpy, but the inner part has a rather smooth density profile, with a uniform temperature and mean density decreasing outward. We apply three-dimensional radiative transfer calculations to this simple model, demonstrating that the essential observational features of the starless cores are successfully reproduced.
X-Ray Observations of BL Lacertae during the 1997 Outburst and Association with Quasar-like Characteristics

This paper reports on the X-ray emission from BL Lacertae during its 1997 July outburst as observed with the Rossi X-Ray Timing Explorer (RXTE), compares the RXTE data with previous measurements, and interprets the overall electromagnetic emission in the context of the currently popular theoretical models. The source is bright and variable, with the 2-10 keV flux approximately 2-3.5 times higher than measured in 1995 November by ASCA. The spectrum is also harder, with power-law energy indices of ~0.4-0.6, compared with ~0.9 in 1995 November. Both in the optical band, where BL Lacertae now shows broad emission lines, and in the X-ray band, where the spectrum is hard, the overall electromagnetic distribution of BL Lacertae is similar to that observed in blazars associated with quasars rather than to that seen in the more common high-energy peaked BL Lac-type objects. We argue that the high-energy (X-ray and γ-ray) emission from BL Lacertae consists of two spectral components: X-rays are produced by Comptonization of synchrotron radiation, while the γ-rays are produced by Comptonization of the broad emission line flux.
Spectroscopic characteristics and laser performance of Tm:CaYAlO4 crystal

The spectroscopic characteristics of Tm:CaYAlO4 crystal were studied. Continuous wave laser operation at 2 μm was achieved with a 6 at. % Tm:CaYAlO4 (Tm:CYA) crystal pumped by a fiber-coupled laser diode. The laser emits a maximum output power of 4.3 W with a slope efficiency as high as 46.7%. In addition, a wavelength tuning experiment on Tm:CYA crystal was performed showing the Tm:CYA laser could be continuously tuned from 1861 to 2046 nm using an intracavity CaF2 prism, suggesting the potential of this crystal for ultrashort pulse generation by mode-locking.
Large core Yb-doped optical fiber through vapor phase doping technique

Rare earth (RE) doped optical fibers have shown tremendous progress for producing high power fiber lasers for industrial, medical and strategic applications. However, fabrication of large core, high Yb-doped fiber is still a challenge through conventional process due to poor repeatability and limitation regarding core size. This paper presents successful fabrication of Yb-doped fibers through vapor phase doping technique. Preform fabrication was carried out using a specially constructed MCVD system containing High Temperature Vapor Delivery Unit with sublimators for Al and Yb precursors. The novelty of the present work lies in deposition of Al2O3 and Yb2O3 in vapor phase simultaneously with silica during formation of sintered core layer which result in uniform dopants distribution in the preform. The fibers exhibited lasing efficiency of 76% with low ‘photodarkening effect’.
A Precoding Scheme Based Game Theory for Cooperative MIMO System

This paper considers a tradeoff between maximizing the user’s signal interference noise ratio and minimizing interference leakage in preprocessing for multi-cell MIMO system. A sub-optimal precodingalgorithm based on game theory is proposed to deal with it. A game-based algorithm mathematics model is constructed and interference pricing function is also introduced in the solution to the precoding vector by Lagrange equation. Implement step of the proposed algorithm is also summarized in the paper. Finally in simulation the proposed algorithm is compared with conventional algorithms and convergence of utility function is also discussed. The simulation results show that the proposed algorithm provide improvement over existing schemes.
High-volume manufacturing equipment and processing for directed self-assembly applications

Directed Self-Assembly (DSA) is one of the most promising technologies for scaling feature sizes to 16 nm and below. Both line/space and hole patterns can be created with various block copolymer morphologies, and these materials allow for molecular-level control of the feature shapes—exactly the characteristics that are required for creating high fidelity lithographic patterns. Over the past five years, the industry has been addressing the technical challenges of maturing this technology by addressing concerns such as pattern defectivity, materials specifications, design layout, and tool requirements. Though the learning curve has been steep, DSA has made significant progress toward implementation in high-volume manufacturing. Tokyo Electron has been focused on the best methods of achieving high-fidelity patterns using DSA processing. Unlike other technologies where optics and photons drive the formation of patterns, DSA relies on surface interactions and polymer thermodynamics to determine the final pattern shapes. These phenomena, in turn, are controlled by the processing that occurs on clean-tracks, etchers, and cleaning systems, and so a host of new technology has been developed to facilitate DSA. In this paper we will discuss the processes and hardware that are emerging as critical enablers for DSA implementation, and we will also demonstrate the kinds of high fidelity patterns typical of mainstream DSA integrations.
Arbitrary Lagrangian-Eulerian Numerical Prediction for Local Scour Caused by Turbulent Flows

A numerical prediction method has been developed for local scour on a sand bed due to turbulent flows on the basis of the arbitrary Lagrangian? Eulerian formulation, in which three-dimensional body-fitted coordinates are properly generated for the sand bed profile unsteadily deformed by the flows. The curvilinear coordinates are generated with reasonable accuracy by means of cubic spline interpolations. The equations for momentum, turbulent quantities, and sand concentration are discretized in a Lagrangian scheme so as to preserve second-order accuracy with respect to time and space. The convection of the variables are evaluated with third-order accuracy, taking account of the velocity of the grid point caused by ALE formulation. On the other hand, the sand bed profiles are predicted with the continuity equation for sand by evaluating the total flux consisting of the bed and suspended loads caused by the tractive and convective forces of the turbulent flows. This prediction method is applied to the results of a three-dimensional local scour experiment. From the comparison with the experimental results, it is verified that the sand bed profiles are satisfactorily predicted and that the predicted results are largely improved compared with those based on the Eulerian coordinate system.