Miracle-dz/UniFAR-FTUs huggingface dataset:
Special issue on “Petri Nets for system control and automation”

The rapid evolution of computing, communication, networking, and sensing technologies has brought about the proliferation of computer-integrated systems, mostly technological and often highly complex. These systems, indispensable for our modern life, include air traffic control systems, automated manufacturing systems, computer and communication networks, embedded and networked systems, and software systems. The challenges for the researchers and engineers are related to their design, planning, modeling, analysis, verification, control, scheduling, and implementation. Among a number of formalisms that are widely employed by academic and industrial communities, Petri nets are increasingly becoming one of the most important mathematical tools to meet the above challenges. For example, Petri nets have been widely used in the control and monitoring of automated manufacturing systems, supervisory control of discrete event systems and hybrid processes, deadlock resolution of resource allocation systems, real-time control of complex systems, system analysis and verification, performance evaluation, system biology, and even reliable computation. Many books dedicated to the area of Petri nets were published in the past two decades [1–14]. Significant tutorial and survey papers in the area of Petri nets include [15–22]. Although the last two decades have seen more and more significant contributions to the area, which are based on Petri net theory, many problems remain to be explored, discovered, and solved. The aim of this special issue is to collect the latest developments and achievements in systems control and automation areas using Petri nets. The papers included in the issue cover deadlock control at logical and time levels, the modeling and analysis of cluster tools in semiconductor and automated manufacturing systems, the process planning for wastewater treatment, fault diagnosis, and control implementation. We hope that our readers will benefit from and be motivated by reading this issue. Finally, the guest editors wish to thank Professor Li-Chen Fu, Editor-in-Chief of Asian Journal of Control for providing this precious opportunity, and all the authors and the reviewers for their contributions to this special issue.
Measuring consistency: spectrogram cross-correlation versus targeted acoustic parameters

Several recent studies indicate that the consistency of song or syllable repetitions signals male quality. However, the comparability and efficacy of different measurement methods is not known. Here, I compared two approaches to measuring the consistency of syllable repetitions within the trills of House Wren (Troglodytes aedon) songs. In the first approach, I calculated the coefficient of variation (CV) in standard time–frequency measurements within each trill. In the second approach, I used spectrogram cross-correlation (SPCC), which measures the maximum pixel-by-pixel similarity of two spectrograms. The two approaches gave correlated estimates of trill consistency, but SPCC was more strongly related to two putatively biologically relevant traits: specifically, SPCC differed more strongly between age classes, and more variation in SPCC could be attributed to individual differences. CV-based measures complemented SPCC measures by clarifying some of the specific acoustic features whose consistency changed with age. Although additional comparisons between measurement approaches would be useful to assess generality, it appears that researchers interested in song or trill consistency should consider using an SPCC, or a combined SPCC- and CV-based, approach.
Three‐Dimensional Dynamic Response of Twin Cavities due to Traveling Loads

An analytical procedure is proposed to determine the three-dimensional response of a multiple-cylindrical-cavity system deeply buried in a viscoelastic medium subjected to moving or seismic loading. The tunnels are treated in the local coordinate systems. The interaction between the tunnels is taken into account by a coordinate system transform. The accuracy of the coordinate transform has been investigated. A numerical study describes the dynamic through-soil interaction between a main tunnel and a service tunnel when the main tunnel is subjected to vehicles moving with constant velocity and applying pressure over rectangular areas. The effects of the Mach number of the traveling load, the space between the tunnels, and the vibration frequency of the traveling load are examined. The numerical results show that the through-soil interaction is important for the service tunnel when it is close to the main tunnel where vehicles travel at high speed.
Thermal remagnetization of Co 5 Sm magnets

Co 5 Sm magnets that are partly or fully demagnetized at room temperature regain some of their magnetization on heating. This phenomenon of thermal remagnetization, which is of importance in several applications, has been characterized as a function of prior treatment, magnet shape, temperature, and thermal cycling. A demagnetization-remagnetization pretreatment is found to provide stabilization against the effect. Domain studies by the Kerr effect demonstrate that thermal remagnetization in Co 5 Sm results from reduction of microscopic magnetostatic energy by domain rearrangement. Because of different domain behavior, precipitation-hardened cobalt-rare earth magnets exhibit little or no thermal remagnetization.
Grain growth, densification, and gyromagnetic properties of LiZnTi ferrites with H3BO3-Bi2O3-SiO2-ZnO glass addition

LiZnTi (Li0.43Zn0.27Ti0.13Fe2.17O4) ferrites doped with 0.35 wt. %–1.5 wt. % H3BO3-Bi2O3-SiO2-ZnO (BBSZ) were synthesized through a low temperature ceramic sintering process. The grain growth of LiZnTi ferrites was discussed by using the liquid phase sintering mechanism. BBSZ promoted grain growth via liquid phase sintering, and the optimum addition of BBSZ could reduce porosity of the sample. Meanwhile, selected parameters including saturation induction (BS), coercivity (HC) and ferromagnetic resonance line width (ΔH) were measured as functions of doping content, and their relationships with ferrite porosity and microstructure were also discussed. The LiZnTi ferrite samples containing x = 0.5, 0.65, and 0.8 sintered at 920 °C, 900 °C, and 880 °C, respectively, exhibited high BS and low ΔH values at 9.3 GHz. The addition of proper content of BBSZ can not only improve BS but also reduce HC and ferromagnetic resonance line width (ΔH) by low temperature (∼900 °C) liquid phase sintering.
Active Galactic Nuclei Unification and the X-Ray Background

Active galactic nuclei (AGNs) unification, which implies a large number of obscured AGNs, can explain the optical, infrared, and X-ray content of deep multiwavelength surveys. Here we show that the same model also successfully explains the spectral shape and intensity of the X-ray background. The simplest possible unified model assumes a constant ratio of obscured to unobscured AGNs, independent of redshift or luminosity. With almost no free parameters, the predicted X-ray background agrees remarkably well with observations. Both the observed properties of deep AGN samples and the X-ray background can be explained by the same model without invoking a different evolution for obscured and unobscured AGNs. Recent observational evidence shows that the ratio of obscured to unobscured AGNs may depend on luminosity. An AGN unification model that allows for such a dependence also fits the X-ray background spectrum, and the predicted number counts in the 2-10 keV X-ray band are in good agreement with observations. We present predictions for the source counts in hard X-rays (10-100 keV), which indicate that future missions such as the Black Hole Finder probe will observe thousands of heavily obscured AGNs.
The anharmonic route to chaos: kneading theory

The kneading theory for maps which model the anharmonic route to chaos is developed. The authors show that the transition to chaos in a range of problems is via a sequence of period-doubling and homoclinic bifurcations, and that this route to chaos is robust in the sense that if a family of differential equations undergoes this transition to chaos, then so do sufficiently close families. The sequence of bifurcations generates orbits of period (pn), n>or=1, related by pn+1=2pn+(-1)nk which exist for maps on the boundary of chaos.
Shading of holographic reconstructed image by two-dimensional amplitude modulation of zone plates

We propose a technique to shade reconstructed images of electronic holography. Our technique modifies the zone plate technique, which represents a three-dimensional object as an aggregate of object points and zone plates, which generate object points, are summed to calculate a hologram. Our technique is based on the Phong reflection model developed for computer graphics, which assumes that light reflected from an object consists of three components: diffuse, specular, and ambient reflection light. Among these components, only the specular component depends on the position of the camera (or the eye). A holographic reconstructed image changes depending on the viewing direction. Therefore, the specular component changes for different viewing directions. Because light modulated by a zone plate converges to an object point, we assumed that light is redirected differently at each point on the zone plate. Therefore, two-dimensional amplitude modulation of the zone plate would generate an object point that emits light with different intensities in different directions. The proposed two-dimensional amplitude modulation comprises variable and constant modulations: the former one controls the specular component and the latter one controls the diffuse and ambient components. We experimentally verified the proposed technique.
On the Validity of Babinet's Principle for Fraunhofer Diffraction

Some misconceptions concerning Babinet's principle are pointed out. The Fraunhofer diffraction patterns of complementary screens are not similar unless the detail in the screens obeys certain conditions, which are not easily fulfilled. Some examples of the diffraction patterns of complementary screens are given, illustrating the extent to which Babinet's principle is valid in practice. A way in which the principle can be used to give the diffraction patterns of three-dimensional crystal-structure models is indicated.
Scattering of electromagnetic waves on a system of coupling high-Q dielectric resonators

I investigate an eigenoscillation problem of a coupling dielectric resonator (DR) system, which arrangement in a regular line. Eigenfunction orthogonality conditions is given. Solution of the scattering problem by N DR was by eigenoscillations superposition. Obtained results are used to investigate scattering parameters of the cylindrical form DR configurations placed side-by-side, and two-layer spherical resonators in a rectangular waveguide.
Integration of segmental and tonal information in speech perception: A cross‐linguistic study

For speakers of a tone language, a close functional association exists between segmental structure and F0 contour (i.e., tone) in speech because both dimensions are needed to identify words. Using the speeded classification paradigm, which does not require lexical access, the hypothesis that segmental and tonal dimensions are perceptually more strongly integrated for speakers of a tone language (Mandarin Chinese) than for speakers of a nontone language (English) was examined. In four classification tasks, requiring attention to one dimension (either segmental or tonal) of CV syllables while ignoring the other, both subject groups showed strong interference from orthogonal variation in the unattended dimension. The Chinese subjects showed significantly more interference than the English subjects in only one of the four tasks (vowel classification with irrelevant tonal variation). These findings thus provide only weak evidence of differences between Chinese and English speakers in the perceptual integrality.
Measurements of mean velocity profiles in a hydrocyclone using laser doppler anemometry

A quantitative study of the axial and tangential components of the mean velocity in a 3″-hydrocyclone using laser doppler anemometry has revealed multiple reverse flows in the vortex core. Flow visualization by dye injection shows that these flows are coherent over a significant portion of the hydrocyclone and that little radial mixing occurs between these secondary flows and the outer helical flow. A 2:1 contraction in the vortex finder plays an important role in causing four distinct simultaneous countercurrent flows in the conical section of the hydrocyclone.
The honey bee colony as a superorganism.

In an essay titled "The Architecture of Complexity," the economist Herbert A. Simon (1962) presented a parable about two watchmakers. Although both craftsmen built fine watches and both received frequent calls from cus tomers placing orders, one, Horn, grew richer while the other, Tempus, became poorer and eventually lost his shop. This difference was traced to different methods used in assembling the watches, which in both cases consisted of 1,000 parts. Tempus's procedure was such that if he had a watch partially assembled and then had to put it down? to take an order, for example? it fell apart and had to be reassembled from scratch. Hora's watches were no less complex than those of Tempus but were designed so that he could put together stable subassemblies of about ten parts each. Ten of the subassemblies
On functional relations between the Mordell–Tornheim double zeta functions and the Riemann zeta function

Abstract In this paper, we give certain analytic functional relations between the Mordell–Tornheim double zeta functions and the Riemann zeta function. These can be regarded as continuous generalizations of the known discrete relations between the Mordell–Tornheim double zeta values and the Riemann zeta values at positive integers discovered in the 1950's.
On the equations of landscape formation

This paper starts by establishing a list of the main physical and empirical laws that have been proposed for modeling landscape evolution. Then it proposes a detailed mathematical discussion of several classic landscape evolution models. This discussion permits to distinguish a priori laws from a posteriori laws governing landscape evolution. While the first kind of law relies on physical principles, the second kind stems from the observation of actual stable landscapes. It emerges from the analysis of several models that the a posteriori laws are often used to create hybrid models combining fundamental physical laws with empirical modeling. Such models can be valid near equilibrium. Nevertheless, this situation is not satisfactory from a mathematical standpoint. One would like to be able to deduce the a posteriori laws from a mathematical analysis, or at the very least to observe them from numerical simulations using only a priori physical laws. Such a mathematical and numerical research programme is sketched here. We propose a minimal landscape model coping with the main features of all models. This model singles out three spatially distributed scalar state variables, namely the landscape elevation, the water elevation, and the sediment concentration in water. These state variables are linked by three partial differential equations coping with the three main features identified in the literature as the main phenomena shaping a landscape: erosion, sedimentation and creep, and respecting conservation laws for water and sediment. Based on these equations, the first numerical simulations confirm that valley formation and drainage network formation can be simulated on virgin artificial landscapes. A first surprising result seems to emerge from these simulations: the valley spacing depends not only on a relation between the creep and erosion parameters, but is also strongly influenced by the sedimentation rate and by the rainfall intensity. The conjectured mathematical instability and non-uniqueness of landscape evolution is
Performance and results of the NAOS visible wavefront sensor

The NAOS adaptive optics system was installed in December 2001 on the Nasmyth focus of the ESO VLT. It includes two wavefront sensors: one is working at IR wavelength analysis and the other at visible wavelengths. This paper describes the NAOS Visible Wave Front Sensor based on a Shack-Hartman principle and its performances as measured on the sky. This wavefront sensor includes within a continuous flow liquid nitrogen cryostat: 1) a low noise fast readout CCD camera controlled by the ESO new generation CCD system FIERA using a fast frame rate EEV/Marconi CCD-50 focal plane array. This 128×128 pixels focal plane array has a readout noise of 3 e- at 50 kilopixel/sec/port. FIERA provides remotely controlled readout modes with optional binning, windowing and flexible integration time. 2) two remotely exchangeable micro-lens arrays (14×14 and 7×7 micro-lenses) cooled at the CCD temperature ( -100 °C) within the cryostat. The CCD array is directly located in the micro lenses focal plane at a few millimeters apart without relay optics. 3) Additional opto-mechanical functions are also provided (atmospheric dispersion compensator, flux level control, field of view limitation). On sky performances of the wavefront sensor are presented. Adaptive Optics corrections was obtained with a reference star as faint as a visible magnitude 17 with a band-path of 40 Hz in close loop.
Hierarchical image encryption based on cascaded iterative phase retrieval algorithm in the Fresnel domain

A novel hierarchical image encryption system based on cascaded multiple-phase retrieval by an iterative Fresnel-transform algorithm is proposed. In this method a series of phase masks cascaded in free space is employed to retrieve different target hidden images in their corresponding hierarchical levels. It can realize different levels of accessibility to the secret data for different authority levels with the same system, and the higher level authority can get access to more hidden images. This approach can achieve fast convergence and high quality of the recovered images without any recognizable cross-talk noise or distortion, and the security level of this system is further enhanced by the use of a series of supplemental keys such as the orders of cascaded phase masks and the geometrical parameters in addition to all the iterated phase masks as principal keys. The feasibility of this method and its unique features are verified and analysed by computer simulations.
Fiber chromatic dispersion measurement with improved measurement range based on chirped intensity modulation

A novel method for accurately measuring chromatic dispersion of optical fibers is proposed based on the use of chirped intensity-modulated signals. Unlike the conventional method, the proposed method utilizes the configurable transfer function of optical fibers caused by the residual chirp of intensity modulation, which not only eliminates the chirp error but also improves the measurement range through adjusting the chirp parameter of the intensity modulator. Our method is applicable for measuring both the magnitude and sign of chromatic dispersion of optical fibers or other dispersive devices at different operating wavelengths by using a vector network analyzer.
Estimation of Regression Coefficients When Some Regressors are not Always Observed

Abstract In applied problems it is common to specify a model for the conditional mean of a response given a set of regressors. A subset of the regressors may be missing for some study subjects either by design or happenstance. In this article we propose a new class of semiparametric estimators, based on inverse probability weighted estimating equations, that are consistent for parameter vector α0 of the conditional mean model when the data are missing at random in the sense of Rubin and the missingness probabilities are either known or can be parametrically modeled. We show that the asymptotic variance of the optimal estimator in our class attains the semiparametric variance bound for the model by first showing that our estimation problem is a special case of the general problem of parameter estimation in an arbitrary semiparametric model in which the data are missing at random and the probability of observing complete data is bounded away from 0, and then deriving a representation for the efficient score.
Bifurcation analysis of a free boundary problem modelling tumour growth under the action of inhibitors

In this paper we investigate non-radial stationary solutions of a free boundary problem modelling tumour growth under the action of inhibitors. The model consists of two elliptic equations describing the concentration of nutrients and inhibitors, respectively, and a Stokes equation for the velocity of tumour cells and internal pressure. The ratio μ/γ of the proliferation rate μ and the cell-to-cell adhesiveness γ plays the role of the bifurcation parameter. We prove that in certain situations there exists a positive sequence such that for each (μ/γ)n(n even ⩾n*) there exist non-radial stationary solutions bifurcating from the radial stationary solution, while in the other situations there exists at most a finite number of bifurcation points. This is a remarkable difference from the corresponding inhibitor-free model where there always exist infinitely many branches of non-radial stationary bifurcation solutions. Our analysis also indicates that inhibitor supply may lower the ability of tumour invasion, and even make the tumour unaggressive and stable.
coherent generation of VLF hiss

VLF hiss is proposed to result from convective beam amplification of incoherent Cerenkov whistler radiation by the beam of precipitating auroral electrons. The beam amplification mechanism is investigated by using the lowest-order WKB wave kinetic equation and linear growth rates. It is shown that incoherent Cerenkov radiation cannot produce strong VLF hiss without beam amplification and that the beam amplification mechanism can account for the observed bandwidth and power fluxes of strong VLF hiss when the electron gyrofrequency is less than the electron plasma frequency. The theory is not adequate for high frequencies when the electron plasma frequency is less than the electron gyrofrequency, because nonlinear processes are important for frequencies near the plasma frequency. (AIP)