Miracle-dz/UniFAR-FTUs huggingface dataset:
A positive interest rate model with sticky barrier

This paper proposes an efficient model for the term structure of interest rates when the interest rate takes very small values. We make the following choices: (i) we model the short-term interest rate, (ii) we assume that once the interest rate reaches zero, it stays there and we have to wait for a random time until the rate is reinitialized to a (possibly random) strictly positive value. This setting ensures that all term rates are strictly positive. Our objective is to provide a simple method to price zero-coupon bonds. A basic statistical study of the data at hand indeed suggests a switch to a different mode of behaviour when we get to a low level of interest rates. We introduce a variable for the time already spent at 0 (during the last stay) and derive the pricing equation for the bond. We then solve this partial integro-differential equation (PIDE) on its entire domain using a finite difference method (Cranck–Nicholson scheme), a method of characteristics and a fixed point algorithm. Resulting yield curves can exhibit many different shapes, including the S shape observed on the recent Japanese market.
Accelerated unconditionally stable FDTD scheme with modified operators

Purpose – The locally one-dimensional (LOD) finite-difference time-domain (FDTD) method features unconditional stability, yet its low accuracy in time can potentially become detrimental. Regarding the improvement of the method’s reliability, existing solutions introduce high-order spatial operators, which nevertheless cannot deal with the augmented temporal errors. The purpose of the paper is to describe a systematic procedure that enables the efficient implementation of extended spatial stencils in the context of the LOD-FDTD scheme, capable of reducing the combined space-time flaws without additional computational cost. Design/methodology/approach – To accomplish the goal, the authors introduce spatial derivative approximations in parametric form, and then construct error formulae from the update equations, once they are represented as a one-stage process. The unknown operators are determined with the aid of two error-minimization procedures, which equally suppress errors both in space and time. Further.
Applications of a femtocomb laser optically filtered by stimulated Brillouin scattering in an optical fiber

A frequency comb is the optical spectrum formed by a train of optical pulses and comprises a series of equally spaced spectral lines. Ytterbium and Erbium based fiber lasers can produce frequency combs in the region of 1.0 and 1.5 μm respectively. The frequency comb based on an Erbium doped fiber is especially interesting because it emission is centered in the spectral region of optical fiber communications. In this work we use a frequency comb based on an Erbium doped fiber optically filtered by stimulated Brillouin scattering in an optical fiber to generate optical reference frequency in the regions of optical fiber telecommunications and microwaves. The study of the stability of the isolated tooth are performed, resulting two orders of magnitude better than the stability of the pump laser used. This result is the calibration of telecommunication wavelength meters. Also, we analyze some applications based on the Brillouin filtering technique.
A Matrix Completion Based Spectrum Prediction Scheme under Incomplete Data

Spectrum prediction is a technology to estimate the channel status by mining and using the correlation of the spectrum data. Using a reliable prediction scheme, the performance of opportunity spectrum access can be more effective. However, the traditional study on the spectrum prediction methods only use the correlation of the historical data in time domain, and on the basis of the spectrum historical data is complete. In reality, the historical data are often incomplete. The reality calls for a deeper understanding of the correlation of current spectrum data. In this paper, we present a correlation study, with data collected by measure both on the time domain and spectrum domain. Main findings include that the channel status information has correlation not only in the time domain, but also in the spectrum domain. We then exploit such time and spectrum correlation to develop a matrix completion based spectrum prediction scheme under the incomplete data that can predict channel availability based on past observations with considerable accuracy.
Minimum-error quantum distinguishability bounds from matrix monotone functions: A comment on “Two-sided estimates of minimum-error distinguishability of mixed quantum states via generalized Holevo–Curlander bounds” [J. Math. Phys. 50, 032106 (2009)]

Matrix monotonicity is used to obtain upper bounds on minimum-error distinguishability of arbitrary ensembles of mixed quantum states. This generalizes one direction of a two-sided bound recently obtained by the author [J. Tyson, J. Math. Phys. 50, 032106 (2009)]. It is shown that the previously obtained special case has unique properties.
Vortex Shedding of an Airfoil at Low Reynolds Numbers

Characteristics of airfoil wake vortices in low Reynolds number flows are investigated. The focus of this investigation is the effect of Reynolds number and airfoil thickness on the shedding frequency of these coherent structures. Experiments were conducted on a NACA 0018 airfoil at an angle of attack of 10° for a range of chord Reynolds numbers from 30,000 to 200,000. The experimental conditions were selected to investigate both laminar boundary-layer separation without reattachment and separation-bubble formation as well as to enable a comparison with data from previous studies. The results show that vortex shedding occurs in the airfoil wake for both flow regimes investigated. The dimensionless wake vortex shedding frequency is shown to vary linearly with Reynolds number; however, the slope of the linear fit depends on the shear-layer behavior. When an increase in Reynolds number results in shear-layer reattachment on the upper surface of the airfoil, the wake shedding frequency increases significantly, and the vortical structures become less coherent. The present results are compared with those available for NACA 0012 and NACA 0025 profiles as well as selected bluff bodies. The comparison demonstrates a similar dependence of the dimensionless frequency on the Reynolds number. In the absence of shear-layer reattachment on the upper surface, airfoil wake vortex shedding resembles that of a bluff body; however, the results show a more pronounced effect of the Reynolds number on the Strouhal number for airfoils. Using a frequency scaling based on a characteristic wake length, the data for two different airfoil profiles are shown to collapse on to a universal Strouhal number of approximately 0.18.
Particle-in-cell simulation of two stream instability in the non-extensive statistics

We have performed extensive one dimensional particle-in-cell (PIC) simulations to explore generation of electrostatic waves driven by two-stream instability (TSI) that arises due to the interaction between two symmetric counterstreaming electron beams. The electron beams are considered to be cold, collisionless and magnetic-field-free in the presence of neutralizing background of static ions. Here, electrons are described by the non-extensive q -distributions of the Tsallis statistics. Results shows that the electron holes structures are different for various q values such that: (i) for q > 1 cavitation of electron holes are more visible and the excited waves were more strong (ii) for q q = 0.5 the holes are not distinguishable. Furthermore, time development of the velocity root-mean-square (VRMS) of electrons for different q-values demonstrate that the maximum energy conversion is increased upon increasing the non-extensivity parameter q up to the values q > 1. The normalized total energy history for a arbitrary entropic index q = 1.5, approves the energy conserving in our PIC simulation.
DYNAMICS OF TRANSITION TO ENHANCED CONFINEMENT IN REVERSED MAGNETIC SHEAR DISCHARGES

A simple model of the transition to enhanced confinement in reversed shear discharges is presented. The proposed transition mechanism relies on a synergism between electric field shear suppression of turbulence aided by reduced curvature drive due to magnetic shear reversal or reduction. Profile structure and transport barrier propagation dynamics are predicted. A novel analytical theory for the time evolution of the barrier foot-point location is presented. The model predicts that the transition threshold has favorable dependence on pretransition temperature ratio $({T}_{i}{/T}_{e})$, in-out asymmetry in the $E\ifmmode\times\else\texttimes\fi{}B$ shearing rate (i.e., lower for larger Shafranov shift), density profile peakedness, and unfavorable scaling with density. Optimal confinement occurs in discharges where deposition is peaked within the magnetic shear reversal radius.
Development of multi-hierarchy simulation model with non-uniform space grids for collisionless driven reconnection

A multi-hierarchy simulation model aimed at magnetic reconnection studies has been developed, in which macroscopic and microscopic physics are solved self-consistently and simultaneously. In this work, the previous multi-hierarchy model by these authors is extended to a more realistic one with non-uniform space grids. Based on the domain decomposition method, the multi-hierarchy model consists of three parts: a magnetohydrodynamics algorithm to express the macroscopic global dynamics, a particle-in-cell algorithm to describe the microscopic kinetic physics, and an interface algorithm to interlock macro and micro hierarchies. For its verification, plasma flow injection is simulated in this multi-hierarchy model and it is confirmed that the interlocking method can describe the correct physics. Furthermore, this model is applied to collisionless driven reconnection in an open system. Magnetic reconnection is found to occur in a micro hierarchy by injecting plasma from a macro hierarchy.
The Formation of Protostellar Disks. III. The Influence of Gravitationally Induced Angular Momentum Transport on Disk Structure and Appearance

Hydrodynamical two-dimensional calculations are presented for the evolution of collapsing, rotating protostars, including the effects of radiative acceleration and angular momentum transport. The initial cloud is assumed to be a uniformly rotating centrally condensed sphere with ρ ∝ r-2. Results are presented for masses of 1, 2, and 10 M☉, over times comparable to protostellar lifetimes. The calculations show how a warm, quasi-hydrostatic disk surrounding a central unresolved core forms, grows in mass and size, and accretes onto the central object. As a result of the accretion of material from the parent cloud, the disk is encased in one or two accretion shock fronts, located several scale heights above the equatorial plane. During accretion, the disks grow radially due to the effects of angular momentum transport, which according to our model arises from tidally induced gravitational torques. In this manner, quasi-static disks in excess of several thousand AU in radius can be produced. Accretion onto the central object slows down, however, and rather long timescales (M/ ≳ 107 yr) are reached while an appreciable fraction of the total mass (≈35%) is still in the disk. In order to further reduce the disk mass on a shorter timescale, processes not considered here must be invoked. Alternatively, if the initially selected angular momentum is significantly lower, smaller disk sizes would result. Frequency-dependent radiative transfer calculations at selected ages, including the effects of scattered radiation in the infrared and optical spectral regimes, show how the continuum spectra of the structure depend on the disk's orientation and age and how the observed isophotal contours vary with wavelength and viewing angle. Because of the strong dependence on viewing angle, continuum spectra alone should not be used to estimate the evolutionary stage of development of these objects. The infrared flux at ~10 μm can vary by orders of magnitude between pole-on and edge-on views, and the inferred total bolometric luminosity will vary by up to a factor of ≳30 as a function of viewing angle during much of the lifetime of accreting circumstellar disks. We conclude that near- and mid-infrared searches for disks will be strongly biased toward pole-on orientations because of this "flashlight" effect.
A novel method for uncertainty evaluation of roundness errors based on geometrical product specification

Roundness of circular and cylindrical parts can greatly affect assembly accuracy. It is essential to establish a proper method for evaluation roundness error to ensure achieving accurate assessment. According to the evaluation principle of roundness error and the uncertainty theory, a novel method for the uncertainty evaluation of roundness errors is proposed based on the new generation geometrical product specification (GPS). Under the condition of minimum zone, the mathematical model of roundness error and the optimal objective function were developed. Particle Swarm Optimization (PSO) algorithm was used to search for the optimal solution of roundness error. The uncertainties of each of coefficients which influenced the roundness error and of transfer coefficient were calculated in order to get the uncertainty of roundness error. The evaluation results accord with requirements of new generation GPS standard and indicate that this method can assure the integrity and veracity of evaluation.
An integral formulation for eddy current analyses in axisymmetric configurations

A method for solving problems of electromagnetic field diffusion in axisymmetric configurations with linear conducting media is presented. The approach, which is based on lumped-parameter circuit modeling, has a number of theoretical and practical advantages in comparison with other methods currently used, particularly in dealing with problems where the coupling between the magnet system and the external feed network is important. The authors describe in detail the analytical basis and the numerical approach of the method and present its most interesting aspects together with a discussion on a number of critical problems faced during numerical implementation. In order to show the method's capabilities and performance, some numerical results are given. >
Magnetic leverage effects in amorphous SmCo/CoAlZr heterostructures

Although magnetic heterostructures are the basis of many magnetic technologies, the mechanisms involved in magnetization reversals in such structures are not fully understood, especially in amorphous multilayers. Here, we report on the SmCo/CoAlZr system and exploit resonant magnetic x-ray scattering to probe the element specific magnetization reversals. When combined into a tri-layer structure, two different switching fields and reversal mechanisms are observed for the Sm and Co sub-lattices. We argue that the decoupling of the sub-lattices arises from the local distribution of atomic species within the amorphous matrix leading to a strong magnetic leverage effect and exchange pinning. The decoupling arises due to strong interactions between regions of high Co density which span the interface. The relatively sparse interactions between Sm and Co induce a localized pinning of the Co-rich areas, resulting in an exchange bias in minor loops and an enhanced coercivity.
A Fast Direct Solver for a Class of 3-D Elliptic Partial Differential Equation with Variable Coefficient

We propose a direct solver for the three-dimensional Poisson equation with a variable coefﬁcient, and an algorithm to directly solve the associated sparse linear systems that exploits the sparsity pattern of the coefﬁcient matrix. Introducing some appropriate ﬁnite difference operators, we derive a second-order scheme for the solver, and then two suitable high-order compact schemes are also discussed. For a cube containing N nodes, the solver requires O ( N 3/2 log 2 N ) arithmetic operations and O ( N log N ) memory to store the necessary information. Its efﬁciency is illustrated with examples, and the numerical results are analysed.
From Automatic Metaphor Processing in Spanish to a Multilingual Perspective: Annotation, Systems, and Evaluation

There is very few work on Natural Language Processing (NLP) to automatically deal with the metaphorical use in Spanish and those developed so far rely on unsupervised approaches, which obtain a significantly lower performance than supervised systems developed for English. The main reason is the lack of a corpus with wide coverage and large size compared to English resources with metaphor annotations. This thesis project aims to collect and label the first corpus with sufficient magnitude to be able to develop NLP systems for the automatic processing of metaphor in Spanish. Thus, this thesis will analyze the linguistic metaphor present in everyday language from a corpus-based perspective. In order to achieve this purpose, a corpus of wide coverage of texts in Spanish will be gathered and annotated by means of appropriate guidelines. Idiosyncrasies of each language will be taken into account during the application of these guidelines, establishing new annotation criteria when necessary. The corpus will serve as a foundation for the development of metaphor processing systems in Spanish, both in detection and interpretation. Additionally, this thesis will also explore multilingual approaches for both tasks. Finally, an extrinsic evaluation will be considered to analyse the impact metaphor on final NLP tasks such as Machine Translation, Sentiment Analysis, Fact-checking and Hoax detection, as well as opinion mining and argumentative discourse generation.
Families of Reed-Muller canonical forms

The existence of a large number of Reed-Muller canonical forms for switching functions is demonstrated and it is shown that these can be arranged in a nested hierarchy of families with increasing size and decreasing general structure. Many of these forms can be derived, and their weights evaluated for particular functions, by employing recursively defined incidence matrices operating on an extended form of truth vector. The more useful forms are also characterized by their being realizable using a modular circuit tree involving combinations of 1-variable sub-modules.
EMPIRICAL ASSESSMENTS OF AIC PROCEDURE FOR MODEL SELECTION IN FACTOR ANALYSIS

Application of AIC to the number of factors problem in maximum likelihood factor analysis was investigated. Analysis of some empirical data sets suggested that nonconvergent cases and improper solutions require special considerations. Monte Carlo experiment showed that selecting the model minimizing the value of AIC with proper solution is quite satisfactory. However, there remains a requirement on sample size corresponding to the model characteristics such as communalities so that the occurrence of nonconvergent cases and improper solutions may be suppressed when the extracted number of factors is equal to the true one.
The results of the first photonuclear reaction performed in Turkey: the zinc example

We have investigated the decays of several zinc isotopes produced by photonuclear reactions, which were induced by bremsstrahlung photon beams from a clinical e-linac. A photon beam of 18 MeV endpoint energy was directed at a target consisting of primarily zinc isotopes in their natural abundances. Subsequently, the induced decays of unstable zinc isotopes were measured with an HPGe detector twice, once shortly after irradiation and once on the following day. Decays of Zn-63, Zn-65, Zn-69m, and Cu-67 were measured and fitted. In addition, the gamma energy levels of the daughters of these decays were measured with good accuracy. All of the measurements were consistent with established data within error bars.
Reachability of positive 2D fractional linear systems

Two new classes of positive two-dimensional (2D) fractional linear systems are introduced in this work. Two definitions of fractional differences of 2D function are proposed. The solutions of fractional 2D state equations of the linear systems are given. The classical Cayley–Hamilton theorem is extended to 2D fractional systems. The necessary and sufficient conditions for the positivity of 2D fractional systems are established. The notion of reachability is introduced for the positive fractional systems and the necessary and sufficient conditions for the reachability are established. The considerations are illustrated with numerical examples.
Development of a dual‐beam intersection technique for microwave breakdown plasma spectroscopy and detection of air compositions

A dual‐beam intersection apparatus for microwave breakdown plasma spectroscopy (MBS) has been developed and tested for real‐time, simultaneous, and in situ monitoring of the trace gases in the air. The dual microwave beams, which are supplied by a 9.4G Hz pulse magnetron (feed power: 0–80 kW, pulse width: 5 μs, pulse repetition frequency: 10 Hz) using a power divider, are focused and superposed on a center of a reaction chamber through two dielectric lenses. The superposed electric field brings about the gaseous breakdown phenomena on the focusing point, where the photons emitted from the proper gas components can be detected and assigned using two‐dimensional wavelength/time‐resolved photoemission spectroscopy. The preliminary experiment has demonstrated that the emission intensities of breakdown plasma strongly depended on the phase difference between two microwave beams. Also, almost all the plasma spectra of the dual‐beam system were more intensified than that of the single‐beam system developed previously by us, and the relative continuum background decreased remarkably as well. For the 81 ppm of CCl2F2 gas mixed with the model atmosphere, the Cl atomic line of 837.6 nm (4p4D − 4s4P5/2) could clearly be detected at room temperature in total pressure of 10Torr. Present experiments have proved that the beam controllability of the dual‐beam system is superior to that of the single‐beam system to realize the appropriate breakdown conditions.
Leakage Resilient (cid:96) -more Extractable Hash and Applications to Non-Malleable Cryptography

(cid:96) -more extractable hash functions were introduced by Ki-ayias et al. (CCS ’16) as a strengthening of extractable hash functions by Goldwasser et al. (Eprint ’11) and Bitansky et al. (ITCS ’12, Eprint ’14). In this work, we deﬁne and study an even stronger notion of leakage-resilient (cid:96) -more extractable hash functions, and instantiate the notion under the same assumptions used by Kiayias et al. and Bitansky et al. In addition, we prove that any hash function that can be modeled as a Random Oracle (RO) is leakage resilient (cid:96) -more extractable, while it is however, not extractable according to the deﬁnition by Goldwasser et al. and Bitansky et al., showing a separation of the notions. We show that this tool has many interesting applications to non-malleable cryptography. Particularly, we can derive eﬃcient, continuously non-malleable, leakage-resilient codes against split-state attackers (TCC ’14), both in the CRS and the RO model. Additionally, we can obtain succinct non-interactive non-malleable commitments both in the CRS and the RO model, satisfying a stronger deﬁnition than the prior ones by Crescenzo et al. (STOC ’98), and Pass and Rosen (STOC ’05), in the sense that the simulator does not require access to the original message, while the attacker’s auxiliary input is allowed to depend on it.