Miracle-dz/UniFAR-FTUs huggingface dataset:
A Green's function approach to analysing the effects of random synaptic background activity in a model neural network

The effect of randomly distributed synaptic background activity on the states of self-sustained firing in a model neural network with shunting is investigated. Using mean field theory, the steady state of the network is expressed in terms of an ensemble-averaged single-neuron Green's function. This Green's function is shown to satisfy a matrix equation identical in form to that found in the tight-binding-alloy model of excitations on a one-dimensional disordered lattice. The ensemble averaging is then performed using a coherent potential approximation thus allowing the steady-state firing rate of the network to be determined. The firing rate is found to decrease as the mean level of background activity across the network is increased; a uniform background (zero variance) leads to a greater reduction than a randomly distributed one (non-zero variance).
Resonances in piecewise potentials and Supersymmetric Quantum Mechanics (SUSY-QM) for the construction of optical potentials

A method to obtain the general solution of any constant piecewise potential is presented, this is achieved by means of the analysis of the transfer matrices in each cutoff. The resonance phenomenon together with the supersymmetric quantum mechanics technique allow us to construct a wide family of complex potentials which can be used as theoretical models for optical systems. The method is applied to the particular case for which the potential function has six cutoff points.
Material composition and structure design in PCVD silica-based single-mode fiber

Single mode fiber (SMF) has been used widely in local and access network since the early 1980's. Fiber loss reduction will accelerate the construction of various transmission systems with longer repeater spacing. It has been reported that the transmission loss in SMF increases due to residual stress, which is caused by viscosity mismatch between the core and cladding material. The idea of viscosity matching is to match the viscosity of core and cladding doping to minimize the viscosity difference on the cross-section of the fiber or preform. The dopant concentrations can be chosen so that the viscosity of core and the cladding are equal in ideal step index fiber. However, all the reported viscosity-matching design is based on single dopant, for example, only GeO2 is doped in the central core and only F in the cladding. In this paper, optical loss reduction through viscosity-matched design for the SMF with GeO2-F codoped silica core and cladding is described. The impact of viscosity-matching on optical loss of silica-based single-mode fiber has been investigated in detail theoretically and experimentally based on PCVD fiber. For PCVD optical fiber, F is introduced in core is to reduce the water peak. Single mode optical fiber with low attenuation fabricated by PCVD process can be gotten through viscosity-matching design between core and cladding. Viscosity-matching can reduce the sensitivity of attenuation to drawing tension. The model for estimating the viscosity matching has been deduced, which can not only be used for conventional SMF but also for the fiber with arbitrary index profile.
Analysis of Urban-Rural Canopy Using a Surface Heat Flux/Temperature Model

Abstract A one-dimensional numerical model, capable of simulating surface temperature and heat flux, is described in terms of the effective atmospheric and terrain variables. The two model parameters which are most responsible for the formation of important temperature variations in the horizontal over the urban-rural complex are the thermal inertia (thermal property) and moisture availability, the former being most responsible for shaping the nighttime temperature pattern while the latter has a greater effect during the day. The controlling substrate variables are not easily determinable by direct measurement over a surface consisting of an inhomogeneous agglomerate of elements. We present one method whereby surface temperature, a more readily obtainable quantity, can be used in conjunction with the surface model to determine by numerical or graphical inversion of the latter the effective values of moisture availability and thermal inertia and thereby provide a quantitative framework for analysis of a ro.
Effect of Duration on the Perception of Voicing

This paper describes an investigation of the effect of sound duration on the perception of a linguistic characteristic, the recognition of phonemes. A pair of single syllable words was selected which consisted of identical phoneme sequences, except for the final phoneme which was either the voiced or unvoiced version of the same articulation. Different versions of these words were synthesized with all possible combinations of four different vowel durations and five different final consonant durations. In all cases the sound wave corresponding to the final consonant was inharmonic and identical except for duration. These synthesized words were recorded and presented to a group of 33 listeners who had to judge whether they heard the final consonant as a voiced or as an unvoiced sound. The results clearly show that the relative durations of vowel and final consonant can be used as a cue for hearing the final sound as voiced or unvoiced. This demonstrates that, in certain circumstances, nonspectral characteri.
A comparison of quasi-continuous wave and broadband travel time techniques in the prediction of long-range reverberation

Previous work has shown that the general structure of deep ocean reverberation can be reasonably modeled using single-frequency propagation techniques. Recent results indicate that secondary, multipath influences can affect reverberation levels significantly. Primarily, these influences are observed in shadow regions of the primary, direct path ensonification. Temporal separation of these paths is required in order to distinguish these effects. This suggests that regions of the reverberation signal may not be well predicted by single-frequency quasi-cw (continuous wave) methods. In this paper, a quasi-cw method of predicting long-range reverberation is compared to an exact, two-way travel time technique. Each model assumes a simple, constant plane-wave scattering strength, thereby emphasizing the influence of propagation. Results from both models are compared to measured reverberation data from an ONR-SRP bottom reverberation experiment conducted near the Mid-Atlantic Ridge. It is shown that the single-fr.
Disclosure risks for microdata

In this paper a model is developed for assesing disclosure risks of a microdata set. It is an extension of the one presented in Bethlehem et al. (1988). It is used to calculate (an upper bound of) the risk that an investigator is able to reidentify at least one individual in an anonimyzed data set, and hence discloses some sensitive information about him. This risk is shown to depend on, among other things, two variables which can be controlled by the statistical office which is disseminating such a data set: the ‘coarseness’ of the key variables and the size of the data set. The model yields guidelines as to the usage of these two instruments to control the disclosure risk.
Affordances as part of the process of object identification in visual search

Annotation : Introduction. The study is aimed at studying the role of affordances in the representation of an object and the influence of motor programs on the process of visual search within the framework of the skipping search continuation paradigm (SPPP). A hypothesis was put forward about the occurrence of the effect of compatibility/congruence in the process of searching for real objects among distractors by running motor programs. Methods. The study involved 60 people from 18 to 30 years old, with normal or corrected vision, without disorders of the musculoskeletal system. The subjects had to search for target stimuli among the distractors, simultaneously performing a movement with a non-dominant hand, which could be congruent, not congruent, partially congruent to the target given by the word. Results. As a result of data analysis, there were no significant differences in accuracy and reaction time depending on the congruence of movement towards the search object in both groups. However, the effect of PPPP was observed in all groups, regardless of the congruence of movement towards the ob - ject. Discussion of the results. Since previous studies used the task of naming or categorization rather than visual search, a possible explanation for the results may be the following factors: the movement was performed by a non-dominant hand, the target stimulus was given by a word, irrelevant programs were launched, it was impossible to form an affordance situation due to the perception of objects with different from the target motor programs. Conclusion _ The study outlines the boundary of the position on the inclusion of functional knowledge in the representation of an object and the influence of the compatibility effect on the process of visual search. The launch of motor programs does not necessarily lead to a significant impact on the process of finding the target stimulus among distractors - there is a compatibility effect. Achieving a state of affordance is probably the key factor for the emergence of such an influence.
Model equations for long waves in nonlinear dispersive systems

Several topics are studied concerning mathematical models for the unidirectional propagation of long waves in systems that manifest nonlinear and dispersive effects of a particular but common kind. Most of the new material presented relates to the initial-value problem for the equation ut+ux+uux−uxxt=0,(a), whose solution u(x,t) is considered in a class of real nonperiodic functions defined for ࢤ∞ <x< ∞,t≥0. As an approximation derived for moderately long waves of small but finite amplitude in particular physical systems, this equation has the same formal justification as the Korteweg-de Vries equation ut+ux+uux−uxxx=0,(b) with which (a) is to be compared in various ways. It is contended that (a) is in important respects the preferable model, obviating certain problematical aspects of (b) and generally having more expedient mathematical properties. The paper divides into two parts where respectively the emphasis is on descriptive and on rigorous mathematics In §2 the origins and immediate properties of equations (a) and (b) are discussed in general terms, and the comparative shortcomings of (b) are reviewed. In the remainder of the paper (§§ 3,4) - which can be read independently Preceding discussion _ an exact theory of (a) is developed. In § 3 the existence of classical solutions is proved: and following our main result, theorem 1, several extensions and sidelights are presented. In § 4 solutions are shown to be unique, to depend continuously on their initial values, and also to depend continuously on forcing functions added to the right-hand side of (a). Thus the initial-value problem is confirmed to be classically well set in the Hadamard sense. In appendix 1 a generalization of (a) is considered, in which dispersive effects within a wide class are represented by an abstract pseudo-differential operator. The physical origins of such an equation are explained in the style of § 2, two examples are given deriving from definite physical problems, and an existence theory is outlined. In appendix 2 a technical fact used in § 3 is established.
Projection Methods for Monotone Variational Inequalities

In this paper, we study some new iterative methods for solving monotone variational inequalities by using the updating technique of the solution. It is shown that the convergence of the new methods requires the monotonicity and pseudomonotonicity of the operator. The new methods are very versatile and are easy to implement. The techniques include the splitting and extragradient methods as special cases.
Tetracyclic harmonic graphs

A graph G on n vertices v1, v2,. , vn is said to be harmonic if (d(v1),d(v2),. , d(vn))t is an eigenvector of its (0,1)-adjacency matrix where d(vi) is the degree ‚(= number of first neighbors) of the vertex Vi i = 1,2,. , n. Earlier all acyclic, unicyclic, bicyclic and tricyclic harmonic graphs were characterized. We now show that there are 2 regular and 18 non-regular connected tetracyclic harmonic graphs and determine their structures.
Effect of dew on aircraft-based passive microwave observations over an agricultural domain

Abstract. Microwave remote sensing can provide reliable measurements of surface soil moisture. However, some land surface conditions can have a perturbing influence on soil moisture retrievals. In the soil moisture experiments in 2005 (SMEX05), we attempted to contribute to the understanding of the effect of dew using concurrent ground and aircraft observations. Early morning flights were conducted with an airborne microwave radiometer from June 19 to July 2, 2005, in Iowa, USA over an agricultural domain. Results of the experiment indicated that dew had a small but measurable effect on the observed 10.7-GHz brightness temperatures. The results indicate that the H-pol emissivity increased 0.015 to 0.04 for the corn sites, 0.014 to 0.02 for soybean, and 0.01 for forest sites as dew evaporated. These results suggest that the presence of dew decreases X-band land surface emissivity slightly and the effect of dew varies with vegetation types. Our findings are consistent with other works in the literature that has found that the effect of dew depends on both the type of vegetation and the wavelength of observation, but further studies should be conducted to verify this hypothesis.
Polarization Reversal in Tri‐Glycine Fluoberyllate and Tri‐Glycine Sulfate Single Crystals

Time and field dependence of switching current at room temperature was studied for tri‐glycine fluoberyllate as well as for tri‐glycine sulfate. It is shown that the theory describing polarization reversal in BaTiO3 c‐domain crystals based on observed time and field dependence of polarization P=f(E,t) developed by the authors is applicable. Activation field α and mobility μ appearing in the basic equation were determined for tri‐glycine fluoberyllate (TGFB) as well as for tri‐glycine sulfate (TGS). For both materials, α, as well as μ was found to be independent of crystal thickness indicating that no skin properties are involved. The value of α for TGFB and TGS is lower by a factor of at least 2.5 and 3, respectively, than for BaTiO3. Compared to values for BaTiO3, the value of μ for TGFB and TGS is lower for thick crystals and higher for relatively thin crystals (δ<8×10−3 cm). Switching conductivity for both materials is given. Both TGFB and TGS were investigated under various pulsed conditions and no fa.
The influence of vortical structures on the thermal fields of jets

In this investigation we explore the effect of unsteady vortical structures on the adiabatic wall temperature distribution in an impinging jet. Treating first the simpler case of a free jet, we introduce a conceptual model for the separation of the total temperature, appealing to the dynamics of particle pathlines and vortex rings in the jet. The presence of a region of higher total temperature on the inside of the jet and a region of lower total temperature toward the jet periphery, predicted by the model, exhibits good agreement with the experimental data taken at high subsonic Mach number. The results from a numerical simulation further confirm the theoretical expectations. Through a similar argument, we show that when a thermally insulated flat plate is inserted into the jet, the wall temperature distribution is modified by the presence of secondary vortical structures, which are induced near, and swept over, the plate surface. When the plate is near the jet nozzle, a region of lower wall temperature, attributable to these additional vortices, is observed in the experimental data. When the plate is further from the nozzle, no secondary vortices are formed and no region of lowered wall temperature is measured. Self-sustaining acoustic resonance, when it occurs, is found to alter significantly this picture of the wall temperature distribution. Although the scope of this work is limited to free and impinging jets, this present topic, along with the previously reported mechanism of the Eckert–Weise effect, exemplifies the wider family of problems in which unsteady vortical structure strongly affects the wall temperature and heat transfer.
Perbaikan Citra dengan Menggunakan Metode Histogram Equalization

Abstrak Kerangka umum perbaikan citra berdasarkan histogram equalization telah banyak digunakan peneliti terutama untuk meningkatkan kontras citra. Namun dengan metode ini menghasilkan nilai kontras yang berlebihan sehingga menampilkan bentuk yang tidak alami serta munculnya cacat visual. Dalam tulisan ini kami menggunakan metode yang disebut Probability Distribution Histogram Equalization (PDHE). Mula-mula citra dihitung nilai Probability Density Function (PDF) hasil yang didapat untuk mencari nilai Cumulative Distribution Function (CDF). Selanjutnya hasil yang didapatkan digunakan untuk nilai acuan dalam alih ragam point-wise citra keabuan. Evaluasi ujicoba yang telah dilakukan, nilai optimal keluaran citra hasil histogram equalization dengan menggunakan ukuran window [35 35] dengan SNR = 1.52 dan waktu proses yang dibutuhkan 3.067741 detik. Metode ini menghasilkan keluaran citra yang lebih baik secara visual bila dibandingkan dengan metode histogram equalization klasik. Sebagai pembanding, diperlihatkan hasil histogram dan tampilan citra dengan metode spesifikasi histogram dan metode lokal histogram.
Transverse ion energization and low-frequency plasma waves in the mid-altitude auroral zone: A case study

The transport of ions from the ionosphere to the magnetosphere requires that ions acquire significant energy in directions both transverse and parallel to the magnetic field. There is a considerable body of experimental evidence that shows that transverse energization occurs over a wide range of altitudes on auroral field lines. Many recent analytical and simulation studies have addressed the microphysics involved in transverse ion energization. There are, however, remarkably few published high-resolution plasma and plasma wave observations obtained in the mid-altitude auroral region available to compare with the analytical and simulation studies. Several hundred hours of high-resolution plasma data obtained from the Dynamics Explorer 1 satellite have been surveyed. A wide variety of plasma environments that are difficult to simply characterize were found. We present here a comprehensive set of high-sensitivity, high-resolution plasma wave, ion, and magnetometer data obtained from an evening auroral zone crossing at r/R/sub E/approx.3. The total density, thermal structure, and composition of the plasma in this representative interval varied rapidly, as did the character (mode) of low-frequency plasma waves observed. We did not find an unambiguous particle and wave signature of local transverse ion energization, but we did frequently find intervals where local transverse ion heatingmore » was consistent with the observations. We also found a downward flowing ion distribution that occurred simultaneously with a region of intense plasma wave emissions primarily below the lower hybrid resonance frequency. copyright American Geophysical Union 1988« less
Electrically tunable defects in metallic single-walled carbon nanotubes

A defect whose electron transmission probability can be controlled by electric field is intentionally created on a metallic single-walled carbon nanotube (SWCNT) with a voltage pulse from a tip of an atomic force microscope (AFM). Localized characteristics of the created defect are elucidated with local electrical property measurements using an AFM. The result demonstrates that conductance of a metallic SWCNT can be modulated by electric field such as from a back gate with the introduction of a local defect.
Superconvergent recovery of gradients on subdomains from piecewise linear finite-element approximations

Engineers have been aware for some time of the phenomenon of superconvergence, whereby there exist (stress) points at which the accuracy of a finite-element solution is superior to that of the approximation generally. This phenomenon has been treated in recent years by mathematicians who have proved, for certain two-dimensional secondorder elliptic problems, superconvergent error estimates for retrieved finite-element derivatives. These results have demanded high global regularity of the solutions of the bondary value problems. In this present article cut-off functions are used to prove similar superconvergence results over interior subdomains. This allows superconvergence estimates to be derived for problems with solutions of low global regularity, particularly those involving singularities.
ON SEMIPARAMETRIC REGRESSION WITH O'SULLIVAN PENALIZED SPLINES

An exposition on the use of O'Sullivan penalized splines in contemporary semiparametric regression, including mixed model and Bayesian formulations, is presented. O'Sullivan penalized splines are similar to P‐splines, but have the advantage of being a direct generalization of smoothing splines. Exact expressions for the O'Sullivan penalty matrix are obtained. Comparisons between the two types of splines reveal that O'Sullivan penalized splines more closely mimic the natural boundary behaviour of smoothing splines. Implementation in modern computing environments such as Matlab, r and bugs is discussed.
Numerical study of educed coherent structures in the near-wall region of a particle-laden channel flow

The interaction of small heavy solid particles with turbulence near the wall of a vertical downward channel flow is investigated by using direct numerical simulation (DNS) and Lagrangian particle tracking. The interest is focused on the effect of the particles on the near-wall coherent structures obtained by conditional sampling of DNS results of a particle-laden turbulent channel flow. The coherent structures are detected from instantaneous flow fields by using the vortex definition of Jeong and Hussain [J. Fluid Mech. 285, 69 (1995)]. The Reynolds number of the particle-free flow is Reτ≈180 based on the friction velocity and the wall half distance. The particle response time is 200 wall units and the average mass and volume fractions φm=0.5 and φv=6.8×10−5, respectively. The particle diameter is smaller than the Kolmogorov length scale and the grid spacing, the latter being small enough to adequately resolve the smaller fluid flow scales. The feedback effect of the particles on the carrier phase is take.
Dislocation density reduction in multicrystalline silicon via cyclic annealing

Manufacturing processes to reduce dislocation densities in multicrystalline silicon (mc‐Si) solar cells could reduce the cost of photovoltaics by increasing cell efficiency with minimum additional process complexity. The present work investigates how cyclically varying temperature (stress) in mc‐Si blocks can lead to dislocation‐density reduction. Cyclic annealing is found to be more effective at activating immobile dislocations than isothermal annealing. Once immobile dislocations are activated, however, they are hypothesized to impede density reduction of mobile dislocations by accelerating multiplication of overall dislocations. Thus, a combined process of thermal cycling and isothermal annealing is found to provide a maximum dislocation density reduction of ∼70%, with 12 h of static annealing followed by 12 h of cyclic annealing.