Miracle-dz/UniFAR-FTUs huggingface dataset:
Dynamic Pricing with a Poisson Bandit Model

Abstract Suppose that one of two prices for the same product must be posted every day. Under each price, the demand function is described by a compound Poisson process with possibly unknown parameters. The objective is to sequentially post daily prices so as to maximize the total expected, possibly discounted gross revenue over a finite pricing horizon. To effectively balance between understanding the demand function and achieving economic revenues, we formulate the optimal pricing problem with a bandit model and characterize the solution by means of stochastic dynamic programming. When there is only one unknown demand function in the model, the optimal pricing decision is determined by a pricing index, whose limit is the Gittins index. These index values also demonstrate that it may be worth sacrificing some immediate payoff for the benefit of information gathering and better-informed decisions in the future. Moreover, the optimal stopping solution is derived and the myopic strategy is shown not to be optimal in general. When both demand functions are unknown, a version of the play-the-winner pricing rule is derived.
Relative Motion between Elliptic Orbits: Generalized Boundedness Conditions and Optimal Formationkeeping

Based on the concept of orbital commensurability, necessary and sufficient conditions are presented for bounded relative motion between any two spacecraft flying on elliptic Keplerian orbits. The proposed approach does not involve any simplifying assumptions regarding the relative dynamics but rather treats the general, nonlinear, eccentric relative motion problem. The methodology presented alleviates the difficulty in computing corrections to the linear equations of motion to account for nonlinearities and eccentricities. Instead of dealing with the local relative motion problem, the global relative motion problem is addressed by transforming the orbital resonance requirement into an energy-matching condition. The newly developed setup is then utilized to derive an optimal single-impulse formationkeeping maneuver based on relative state variables. The orbital elements interpretation of the optimal formationkeeping maneuver is also discussed.
Dynamic scaling for a competitive growth process: random deposition versus ballistic deposition

A random-ballistic deposition model where particles are aggregated according to the rules of ballistic deposition with probability p and following a random deposition process with probability 1-p, respectively, is proposed and studied. Based on extensive numerical simulations a dynamic scaling ansatz for the interface width W(L,t,p) as a function of lattice side L, time t and p is formulated. Three new exponents, which can be linked to the standard growth exponent of ballistic deposition by means of a new scaling relation, are identified.
Prediction of the compression pressure wave generated by a high-speed train entering a tunnel

The pressure history of the compression acoustic wave generated by a high-speed train tunnel entry is calculated in a finite element flow analysis. The generation of the pressure wave and its propagation into the tunnel is numerically simulated. To obtain an accurate prediction of the pressure gradient, a three-dimensional compressible transient finite element flow analysis with arbitrary Lagrangian–Eulerian (ALE) formulation is performed on a multi-domain parallel iterative solver. Also an alternative approximation method of predicting the pressure wave shape based on “v-wall” method is developed. The result of the numerical simulation is compared with that of the 1/50th-scale experimental test.
Diffusion approximation with polarization and resonance effects for the modelling of seismic waves in strongly scattering small-scale media

SUMMARY This paper presents an analytical study of the multiple scattering of seismic waves by a collection of randomly distributed point scatterers. The theory assumes that the energy envelopes are smooth, but does not require perturbations to be small, thereby allowing the modelling of strong, resonant scattering. The correlation tensor of seismic coda waves recorded at a threecomponent sensor is decomposed into a sum of eigenmodes of the elastodynamic multiple scattering(Bethe-Salpeter) equation. Forageneral moment tensor excitation, atotalnumber of four modes is necessary to describe the transport of seismic waves polarization. Their spatiotemporal dependence is given in closed analytical form. Two additional modes transporting exclusively shear polarizations may be excited by antisymmetric moment tensor sources only. The general solution converges towards an equipartition mixture of diffusing P and S waves which allows the retrieval of the local Green’s function from coda waves. The equipartition time is obtained analytically and the impact of absorption on Green’s function reconstruction is discussed. The process of depolarization of multiply scattered waves and the resulting loss of information is illustrated for various seismic sources. It is shown that coda waves may be used to characterize the source mechanism up to lapse times of the order of a few mean free times only. In the case of resonant scatterers, a formula for the diffusivity of seismic waves incorporating the effect of energy entrapment inside the scatterers is obtained. Application of the theory to high-contrast media demonstrates that coda waves are more sensitive to slow ratherthanfastvelocityanomaliesbyseveralordersofmagnitude.Resonantscatteringappears as an attractive physical phenomenon to explain the small values of the diffusion constant of seismic waves reported in volcanic areas.
Assessment of a Dual-Channel Array Spectrometer for Ground-Based Ozone Retrievals

AbstractThis study describes a dual-channel array spectrometer system designed to make high-frequency simultaneous spectral global irradiance and direct solar irradiance measurements covering the visible and ultraviolet wavelength ranges. The dual-channel nature of the instrument allows spectrally integrated quantities (e.g., erythema or vitamin D) to be calculated at a rate similar to broadband instruments while retrieving total column ozone (TCO) from the direct solar channel. The characterization and calibration of the instrument is discussed, with emphasis on temperature stabilization (<±0.01°C) and stray light removal. Focusing on the TCO retrieval from direct spectra, results are compared to a collocated Brewer spectrophotometer during the study period of May 2013–January 2014. Agreement for individual measurements made within 20 min of a reference Brewer direct sun observation on relatively clear example days is <1.5%. For all valid individual measurements, the study found an overall bias of 1.1 Do.
A note on atmospheric predictability

Using the method of Lorenz (1982), we have estimated the predictability of a recent version of the European Center for Medium-Range Weather Forecasting (ECMWF) model using two different estimates of the initial error corresponding to 6- and 24-hr forecast errors, respectively. For a 6-hr forecast error of the extratropical 500-hPa geopotential height field, a potential increase in forecast skill by more than 3 d is suggested, indicating a further increase in predictability by another 1.5 d compared to the use of a 24-hr forecast error. This is due to a smaller initial error and to an initial error reduction resulting in a smaller averaged growth rate for the whole 7-d forecast. A similar assessment for the tropics using the wind vector fields at 850 and 250 hPa suggests a huge potential improvement with a 7-d forecast providing the same skill as a 1-d forecast now. A contributing factor to the increase in the estimate of predictability is the apparent slow increase of error during the early part of the forecast.
Virtual alignment of x-ray cone-beam tomography system using two calibration aperture measurements

In cone-beam tomography, relatively small misalignment of the imaging system is geometrically magnified and may cause severe distortion of the reconstructed image. We describe a method for align- ment of a cone-beam tomography system built on an x-ray microfocus tube, an image intensifier, and a high-resolution CCD camera. To obtain geometrical parameters of system misalignment, we suggest measuring two 180-deg-opposed cone-beam radiographs of a specially manufac- tured calibration aperture. An advantage of the aperture over other cali- bration objects is that we can easily restore its idealized picture by ap- plying a certain threshold to the measured data. The method permits the lateral displacement vector and lateral tilt angle to be accurately found. Unlike other alignment methods, our approach enables virtual system alignment by using mathematical processing of the measured data, rather than moving the parts of the system. The virtually aligned system data are used for 3-D image reconstruction by a standard filtered back- projection algorithm. Experimental results demonstrate considerable im- provement of the image quality after applying the alignment method sug- gested. © 1999 Society of Photo-Optical Instrumentation Engineers. (S0091-3286(99)00802-8)
Semantic Representation of Flatness Based on ALC(R) and Mathematical Definition

The information of form tolerances in existing 3D CAD systems is just a kind of symbol and text which is lack of engineering semantic at present. Therefore, a reasonable explanation and Semantic representation of form tolerances has very important significance. In order to reduce the uncertainty and support the semantic interoperability in tolerance specification design, an approach for mathematical representation of flatness based on the Small Displacement Torsor (SDT) is proposed. Based on this, a representation of flatness using description logical language ALC(R) with concrete domain is proposed. Then flatness information is formalized using OWL, an ontology representation language devised by W3C, to be shared and interoperated between heterogeneous systems by building OWL ontology. At last, there is a practical example to verify the feasibility of this approach.
Collective d -wave exciton modes in the calculated Raman spectrum of Fe-based superconductors

Calculations of the pairing interaction in multi-band models of the Fe superconductors show that it is attractive in both the $A_{1g}$ (s-wave) and $B_{1g}$ (d-wave) channels. This raises the possibility that these materials may have collective excitonic modes. Here, assuming an s-wave groundstate, we investigate the d-wave collective excitonic mode and its coupling to the Raman scattering.
Isomorphisms between commutative Banach algebras with an application to rings of analytic functions

Chevalley and Kakutani showed that if DI and D2 are plane domains with no A#-removable boundary points, then they are conformally equivalent if and only if the rings B(Dί) and B(D2) of all bounded analytic functions on ΏI and D2l respectively, are algebraically isomorphic (cf. [5]). It is well known that two compact Hausdorff spaces are homeomorphic if and only if the Banach algebras of all real valued continuous functions on these spaces are isometric as Banach spaces, where the norm is defined by "sup" (the Theorem of Banach-Stone, cf. [1]), and also if and only if these Banach algebras are isomorphic as algebras (the Theorem of Gelfand-Kolmogoroίf, cf. [4]). If we define a norm in B(Dj) by "sup", then B(Dj) appear as Banach spaces with the unit (j = 1, 2). This suggests us an analogous question for the above mentioned rings of analytic functions: If B(Dι) and B(D2) are isometric as Banach spaces, are DI and D2 conformally equivalent? This question will be solved in general form as the main Theorem of this paper which will be stated in terms of Banach algebras, say, let B± (resp. B2) be a commutative Banach algebra with the unit satisfying a norm condition || x \\ = \\x\\ for all x^Bi (resp. B2), then BI and B2 are algebraically isomorphic if and only if they are isometric as Banach spaces. Then a Banach-Stone type theorem for analytic functions is a direct corollary of the main theorem. In the course of the proof, the representation theory of Banach algebras and the Krein-Milman's theorem which asserts that any weakly* compact convex subset of the conjugate space of a Banach space has sufficiently many extreme points, play naturally essential role. The author wishes to express his hearty thanks to Professor H. Umegaki, Mr. M. Takesaki and Professor M. Ozawa for their many suggestive discussions in presenting this paper.
Metal deep engraving with high average power femtosecond lasers

Deep engraving of 3D textures is a very demanding process for the creation of master tool e. g molds, forming tools or coining dies. As these masters are uses for reproduction of 3D patterns the materials for the tools are typically hard and brittle and thus difficult to machine. The new generation of industrial femtosecond lasers provides both high accuracy engraving results and high ablation rates at the same time. Operation at pulse energies of typically 40 μJ and repetition rates in the Mhz range the detrimental effect of heat accumulation has to be avoided. Therefore high scanning speeds are required to reduce the pulse overlap below 90%. As a consequence scan speeds in the range of 25-50 m/s a needed, which is beyond the capability of galvo scanners. In this paper we present results using a combination of a polygon scanner with a high average power femtosecond laser and compare this to results with conventional scanners. The effects of pulse energy and scan speed of the head on geometrical accuracy are discussed. The quality of the obtained structures is analyzed by means of 3D surface metrology microscope as well as SEM images.
Wage formation and employment in a cointegrated VAR model

This paper uses a general equilibrium, monopolistic competition model of wage bargaining between trade unions and firms to derive two steady state relations which are estimated within a cointegrated VAR framework using quarterly Danish data. The first coin-tegrating relation is the marginal productivity condition for labour, derived from profit max-imization of firms who face a downward sloping demand curve for their product. The sec-ond cointegrating relation is a real wage relation, derived from the bargaining between trade unions and firms over wages, in the right-to-manage manner. The theoretical model is not rejected and the model displays parameter constancy throughout the estimation period and is able to forecast out-of-sample.
Deduction and Demonstration of an Urban Planning Model Based on “CAS” Theory

“The city can be regarded as a complex system based on CAS theory. The study has extracted five characteristic elements of CAS theory, i.e. concentration, identification, nonlinearity, stream and diversity, and concluded three parameters of “preference”(P), “input” (threshold) (I) and “total associated cost” (T) through analogical deduction, having constructed a self-adaptive urban planning model based on CAS theory and demonstrated issues on “scale and configuration” of a city.
Perceptually optimized pyramid coding for efficient progressive image transmission

The progressive transmission of digital images is an important field of interactive image communications over low-bandwidth channels. An effective progressive transmission system should be able to build up images with highest possible fidelity at every stage of transmission, so that a viewer can respond to the received image as quickly as possible. In this paper, a perceptually tuned progressive image transmission scheme based on removing just-noticeable distortion (JND) from the image in pyramid form is presented. The JND profile is derived from the analysis of local properties of image signals. According to the sensitivity of human visual perception to spatial frequency, a distortion allocation algorithm is developed to find the associated JND profile of each pyramid level to sift out perceptually significant signals and determining their quantizer stepsizes. Simulation results show that images reconstructed by the proposed coding schemes can be perceptually more pleasing than those reconstructed by the JPEG progressive decoder at earlier stages of transmission.
A probabilistic approach to intermittency

We present an original approach which allows us to investigate the statistical properties of a non-uniformly hyperbolic map on the interval. Based on a stochastic approximation of the deterministic map, this method essentially gives the optimal polynomial bound for the decay of correlations, the degree depending on the order of the tangency at the neutral fixed point.
The outbursts of symbiotic novae

We discuss possible conditions under which thermonuclear burning episodes in the hydrogen-rich envelopes of accreting white dwarfs give rise to outbursts similar in nature to those observed in the symbiotic stars AG Peg, RT Ser, RR Tel, AS 239, V1016 Cyg, V1329 Cyg, and HM Sge. In principle, thermonuclear runaways involving low-luminosity white dwarfs accreting matter at low rates produce configurations that evolve into A--F supergiants at maximum visual light and which resemble the outbursts of RR Tel, RT Ser, and AG peg. Very weak, nondegenerage hydrogen shell flashes on white dwarfs accreting matter at high rates (M> or approx. =10/sup -8/ M/sub sun/ yr/sup -1/) do not produce cool supergiants at maximum, and may explain the outbursts in V1016 Cyg, V1329 Cyg, and HM Sge. The low accretion rates demanded for systems developing strong hydrogen shell flashes on low-luminsoity white dwarfs are not compatible with observations of ''normal'' quiescent symbiotic stars. The extremely slow outbursts of symbiotic novae appear to be typical of accreting white dwarfs in wide binaries, which suggests that the outbursts of classical novae may be accelerated by the interaction of the expanding white dwarf envelope with its close binary companion.
Progress toward a video-rate, passive millimeter-wave imager for brownout mitigation

Currently, brownout is the single largest contributor to military rotary-wing losses. Millimeter-wave radiation penetrates these dust clouds effectively, thus millimeter-wave imaging could provide pilots with valuable situational awareness during hover, takeoff, and landing operations. Herein, we detail efforts towards a passive, video-rate imager for use as a brownout mitigation tool. The imager presented herein uses a distributed-aperture, optically-upconverted architecture that provides real-time, video-rate imagery with minimal size and weight. Specifically, we detail phenomenology measurements in brownout environments, show developments in enabling component technologies, and present results from a 30-element aperiodic array imager that has recently been fabricated.
MAGNETOCARDIOGRAMS TAKEN INSIDE A SHIELDED ROOM WITH A SUPERCONDUCTING POINT‐CONTACT MAGNETOMETER

A point‐contact (SQUID) magnetometer was used inside a shielded room to record the magnetic field of the human heart, without noise‐averaging. The resulting magnetocardiograms, with the peak signal at about 3 × 10−7 G had a noise level of about 1 × 10−9 G (rms, per root cycle). They approach good medical electrocardiograms in clarity, and are an order‐of‐magnitude improvement in sensitivity over previous magnetic detectors of the heart. These results suggest new medical uses for this magnetometer.
Terahertz beam generation by femtosecond optical pulses in electro‐optic materials

We have observed subpicosecond pulses having terahertz bandwidths generated from electro‐optic materials by using femtosecond optical pulses. The time‐resolved radiation signal clearly indicates that the terahertz radiation comes from the regions within the coherence length near the surfaces of electro‐optic materials under the phase‐mismatched condition. When the high‐energy femtosecond laser pulses are used, this method provides a new way to generate large amplitude broad bandwidth terahertz radiation efficiently.
Optimum Shape Design for Unsteady Three-Dimensional Viscous Flows Using a Nonlinear Frequency-Domain Method

Thispaperpresentsanadjointmethodfortheoptimumshapedesignofunsteadythree-dimensionalviscous flows. The goal is to develop a set of discrete unsteady adjoint equations and the corresponding boundary condition for the nonlinear frequency-domain method. First, this paper presents the complete formulation of the time-dependent optimal design problem. Second, we present the nonlinear frequency-domain adjoint equations for threedimensional viscous transonic flows. Third, we present results that demonstrate the application of the theory to a three-dimensional wing.
Software as a service approach to sensor simulation software deployment

Traditionally, military simulation has been problem domain specific. Executing an exercise currently requires multiple simulation software providers to specialize, deploy, and configure their respective implementations, integrate the collection of software to achieve a specific system behavior, and then execute for the purpose at hand. This approach leads to rigid system integrations which require simulation expertise for each deployment due to changes in location, hardware, and software. Our alternative is Software as a Service (SaaS) predicated on the virtualization of Night Vision Electronic Sensors (NVESD) sensor simulations as an exemplary case. Management middleware elements layer self provisioning, configuration, and integration services onto the virtualized sensors to present a system of services at run time. Given an Infrastructure as a Service (IaaS) environment, enabled and managed system of simulations yields a durable SaaS delivery without requiring user simulation expertise. Persistent SaaS simulations would provide on demand availability to connected users, decrease integration costs and timelines, and benefit the domain community from immediate deployment of lessons learned.
Determination of the translational order parameter for smectic liquid crystals using small-angle neutron scattering

A simple method to determine the translational order parameter of a smectic liquid crystal is presented. It is based on a measurement of the absolute intensity of the first-order layer reflection from an unaligned (powder) sample using small-angle neutron scattering. The Lorentz factor and molecular form factor are used to derive the order parameter from the intensity. The method is demonstrated for 4-octyl-4'-cyanobiphenyl (8CB), using two different isotopomers which give a consistent translational order parameter value of 0.5 in the smectic A phase.
Uniformly bound-growing network models and their spanning trees

To understand the dynamical phenomena of networks, one must know the global properties of networks as well as the local properties such as the degree distribution. So, researching topological structures of complex networks is important and catches many researchers' attention. A class of bound growing network models (BGN-models) has been defined in this article. We determine some properties of the bound growing network models, such as scale-free, power law distribution, degree cumulative distribution. Since thousands of Autonomous Systems (ASes) and networks have more leaves, we provide an algorithm for finding spanning trees having maximum leaves (ML-spanning trees) in the BGN-models, and determine some important properties of ML-spanning trees as well as apply ML-spanning trees to determine balanced and dominating sets in BGN-models.