Miracle-dz/UniFAR-FTUs huggingface dataset:
ETPS-MAC: Energy Traffic Priority Scheduling-based QoS-aware MAC protocol for hierarchical WSNs

ABSTRACT The evolution of the wireless sensor network (WSN) in recent years has reached its greatest heights and applications are increasing day by day, one such application is Smart Monitoring Systems (SMSs) which is in vision of implementation in every urban and rural areas. The implementation of WSN architecture in SMS needs an intelligent scheduling mechanism that efficiently handles the dynamic traffic load without sacrificing the energy efficiency of network. This paper presents a centralized TDMA scheduling based medium access control (MAC) protocol, called Energy Traffic Priority Scheduling MAC (ETPS-MAC) that accommodates variable traffic load while maintaining Quality-of-Service (QoS) assurance in hierarchical WSNs. The ETPS-MAC protocol employs priority scheduling algorithm which considers two factors for assigning priority, the energy factor and the traffic load factor to avoid packet buffering and maintains minimum data packet delay in case of high traffic load. Moreover, a novel rank-based clustering mechanism in FPS-QMAC protocol prolongs the network lifetime by minimizing the distance between the cluster head (CH) and the base station (BS). Both analytical and simulation models demonstrate the superiority of the ETPS-MAC protocol in terms of energy consumption, transmission delay, data throughput and message complexity when compared with the existing TDMA based MAC protocols.
Multiwavelength Absolute Phase Retrieval from Noisy Diffractive Patterns: Wavelength Multiplexing Algorithm

We study the problem of multiwavelength absolute phase retrieval from noisy diffraction patterns. The system is lensless with multiwavelength coherent input light beams and random phase masks applied for wavefront modulation. The light beams are formed by light sources radiating all wavelengths simultaneously. A sensor equipped by a Color Filter Array (CFA) is used for spectral measurement registration. The developed algorithm targeted on optimal phase retrieval from noisy observations is based on maximum likelihood technique. The algorithm is specified for Poissonian and Gaussian noise distributions. One of the key elements of the algorithm is an original sparse modeling of the multiwavelength complex-valued wavefronts based on the complex-domain block-matching 3D filtering. Presented numerical experiments are restricted to noisy Poissonian observations. They demonstrate that the developed algorithm leads to effective solutions explicitly using the sparsity for noise suppression and enabling accurate reconstruction of absolute phase of high-dynamic range.
Behaviour of a spin-½ particle around a charged black hole

The Dirac equation is separable in curved spacetime and its solution has been found for both spherically and axially symmetric geometry. However, most work on this subject has been done without considering the charge of the black hole. Here we consider the spherically symmetric charged black-hole background, namely the Reissner-Nordström black hole. Due to the presence of the charge of the black-hole, charge-charge interaction will be important for the case of an incoming charged particle (e.g. an electron, proton, etc). Therefore, both gravitational and electromagnetic gauge fields should be introduced. Naturally the behaviour of the particle will be changed from that in the Schwarzschild geometry. We compare both the solutions. In the case of a Reissner-Nordström black hole there is a possibility of super-radiance unlike in the Schwarzschild case. We also check this branch of the solution.
The first law of black hole physics for a class of nonlinear matter models

The discovery of new black hole solutions and other surprises prompted the authors to study the following topics related to stationary black holes for nonlinear matter models, such as Yang-Mills fields or general sigma models: (i) the staticity problem for non-rotating stationary black holes, (ii) the circularity and Frobenius conditions for rotating black holes and (iii) the first law of black hole physics. Definitive and satisfactory results concerning these issues are derived for arbitrary minimally coupled scalar field (nonlinear sigma) models. For general Yang-Mills theories they show that, contrary to the Abelian case, the proof of the circularity theorem requires additional assumptions on the Yang-Mills field tensor. Concerning the first law, they derive an expression for the variation of the mass, involving only global quantities and surface terms. This relation generalizes the Bardeen-Carter-Hawking formula to black hole solutions of Einstein-Yang-Mills theories with arbitrary gauge groups.
Underwater rays

Light beams in wavy unclear water, also called underwater rays, and caustic networks of light formed at the bottom of shallow water are two faces of a single phenomenon. Derivation of the caustic using only simple geometry, Snell's law and simple derivatives accounts for observations such as the existence of the caustic network on vertical walls, the splitting of the networks, the underwater rays and the intensity of a light profile in different depth regimes. As the phenomenon presented is easily observed in nature but rather poorly understood, its explanation may strengthen students' awareness of the connection between physics and everyday life. The explanation of the phenomenon presented is appropriate for undergraduate courses of optics within physics.
Chip mounting and interconnection in multi-chip modules for space applications

The objective of this study is to develop processing knowledge and technology of three-dimensional multi-chip modules for space applications. The aim is to test the reliability as well as to optimize the different process steps. Bisbenzocyclobuthene (BCB) was chosen as the interdielectric material as it fulfills the requirements for space qualification and process compatibility. Integrated circuit chips have been mounted recessed in silicon using BCB as glue. Metal interconnects of thin-film aluminum are isolated with spin-on deposited BCB as an interlayer dielectric (ILD). Two layers of BCB, total thickness 30 µm, are needed to achieve chip edge step coverage. Via interconnections, minimum dimensions 100×100 µm2 have successfully been patterned in a 30 µm thick BCB layer. Measuring I-V characteristics has validated the connections.
Femtosecond spectroscopy in semiconductors: a key to coherences, correlations and quantum kinetics

The application of femtosecond spectroscopy to the study of ultrafast dynamics in semiconductor materials and nanostructures is reviewed with particular emphasis on the physics that can be learned from it. Excitation with ultrashort optical pulses in general results in the creation of coherent superpositions and correlated many-particle states. The review comprises a discussion of the dynamics of this correlated many-body system during and after pulsed excitation as well as its analysis by means of refined measurements and advanced theories. After an introduction of basic concepts—such as coherence, correlation and quantum kinetics—a brief overview of the most important experimental techniques and theoretical approaches is given. The remainder of this paper is devoted to specific results selected in order to highlight how femtosecond spectroscopy gives access to the physics of coherences, correlations and quantum kinetics involving charge, spin and lattice degrees of freedom. First examples deal with the dynamics of basic laser-induced coherences that can be observed, e.g. in quantum beat spectroscopy, in coherent control measurements or in experiments using few-cycle pulses. The phenomena discussed here are basic in the sense that they can be understood to a large extent on the mean-field level of the theory. Nevertheless, already on this level it is found that semiconductors behave substantially differently from atomic systems. Subsequent sections report on the occurrence of coherences and correlations beyond the mean-field level that are mediated either by carrier–phonon or carrier–carrier interactions. The corresponding analysis gives deep insight into fundamental issues such as the energy–time uncertainty, pure dephasing in quantum dot structures, the role of two-pair or even higher correlations and the build-up of screening. Finally results are presented concerning the ultrafast dynamics of resonantly coupled excitations, where a combination of different interaction mechanisms is involved in forming new types of correlations. Examples are coupled plasmon–phonon and Bloch–phonon oscillations. The results reviewed in this paper clearly reveal the central role of many-particle correlations and coherences for the ultrafast dynamics of dense semiconductor systems. Both the presence of strong correlation effects and the formation of coherences in a genuine many-particle system have important implications for the controllability of optical signals from this class of materials, which is of utmost importance for applications in present-day and future optoelectronic devices.
Study of the expansion characteristics of a pulsed plasma jet in air

In the background of electrothermal-chemical (ETC) emission, an investigation has been conducted on the characteristics of a freely expanding pulsed plasma jet in air. The evolutionary process of the plasma jet is experimentally investigated using a piezoelectric pressure sensor and a digital high-speed video system. The variation relation in the extended volume, axial displacement and radial displacement of the pulsed plasma jet in atmosphere with time under different discharge voltages and jet breaking pressures is obtained. Based on experiments, a two-dimensional axisymmetric unsteady model is established to analyze the characteristics of the two-phase interface and the variation of flow-field parameters resulting from a pulsed plasma jet into air at a pressure of 1.5–3.5 MPa under three nozzle diameters (3 mm, 4 mm and 5 mm, respectively). The images of the plasma jet reveal a changing shape process, from a quasi-ellipsoid to a conical head and an elongated cylindrical tail. The axial displacement of the jet is always larger than that along the radial direction. The extended volume reveals a single peak distribution with time. Compared to the experiment, the numerical simulation agrees well with the experimental data. The parameters of the jet field mutate at the nozzle exit with a decrease in the parameter pulse near the nozzle, and become more and more gradual and close to environmental parameters. Increasing the injection pressure and nozzle diameter can increase the parameters of the flow field such as the expansion volume of the pulsed plasma jet, the size of the Mach disk and the pressure. In addition, the turbulent mixing in the expansion process is also enhanced.
Degenerate equations of monotone type: Lavrent'ev phenomenon and attainability problems

A non-linear monotone equation with degenerate weight function is considered. In the general case the smooth functions are not dense in the corresponding weighted Sobolev space , which leads to a non-uniqueness of a particular kind. Taking for the energy space either itself or its subspace equal to the closure of the smooth functions one obtains at least two uniquely soluble problems. In addition, there exist infinitely many weak solutions distinct from the - and -solutions. The problem of approximability or attainability is considered: which solutions of the original equation can be obtained as limits of solutions of the equations with suitable non-degenerate weights? It is shown that the - and the -solutions are attainable; in both cases a regular approximation algorithm is described. Bibliography: 14 titles.
If it’s pinched it’s a memristor

This paper presents an in-depth review of the memristor from a rigorous circuit-theoretic perspective, independent of the material the device is made of. From an experimental perspective, a memristor is best defined as any two-terminal device that exhibits a pinched hysteresis loop in the voltage–current plane when driven by any periodic voltage or current signal that elicits a periodic response of the same frequency. This definition greatly broadens the scope of memristive devices to encompass even non-semiconductor devices, both organic and inorganic, from many unrelated disciplines, including biology, botany, brain science, etc. For pedagogical reasons, the broad terrain of memristors is partitioned into three classes of increasing generality, dubbed Ideal Memristors, Generic Memristors, and Extended Memristors. Each class is distinguished from the others via unique fingerprints and signatures. This paper clarifies many confusing issues, such as non-volatility, dc V–I curves, high-frequency v–i curves, local activity, as well as nonlinear dynamical and bifurcation phenomena that are the hallmarks of memristive devices. Above all, this paper addresses several fundamental issues and questions that many memristor researchers do not comprehend but are afraid to ask.
A PENTA-BAND PRINTED MONOPOLE ANTENNA FOR MIMO APPLICATIONS

An E-shaped printed monopole antenna with loaded resonant elements suitable for pentaband multi-input multi-output (MIMO) application is proposed. The simple E-shaped monopole antenna results in a single resonance, and by loading the vertical arm of the antenna with narrow slots and stubs, a multi-band antenna can be obtained. The slots so placed on the antenna create L-shaped resonance paths which are multiples of λg/4, and stubs resonate at λg/4. The antenna is designed for operation over the UMTS, WiMAX and WLAN frequencies 2.1, 2.5, 3.5, 5.2, 5.8 GHz. A two element array of such antennas with close spacing of λg/15 is suitable for MIMO application. The array has low mutual coupling, low envelope correlation, high efficiency and good radiation patterns over all five frequency bands. Simulation and measurement results are compared and discussed.
Development, assessment and optimisation of meat systems for the aging consumer through processing and packaging modification

Title Development, assessment and optimisation of meat systems for the aging consumer through processing and packaging modification Author(s) Conroy, Paula M. Publication date 2018 Original citation Conroy, P. M. 2018. Development, assessment and optimisation of meat systems for the aging consumer through processing and packaging modification. PhD Thesis, University College Cork. Type of publication Doctoral thesis Rights © 2018, Paula M. Conroy. http://creativecommons.org/licenses/by-nc-nd/3.0/
Average Distribution of Ionic Charges and Ionizability for the Au Plasma System

Using relativistic multi-configuration Dirac-Fock theory, we calculate the transition data of 3dj-nfj' (n = 5,6,7) for the M-shell from an Ni-like Au ion to an As-like Au ion using the GRASP programme with the core-polarization, quantum electrodynamical effect and Breit correction. Based on the present calculation results and the experiment of the Xingguang-II laser facilities, the average distribution of ionic charge and the ionizability have been derived. The average ionization degree of Au plasma Z* is 49.06±0.5, which is comparable with the result of the Lawrence Livermore National Laboratory.
Chiral splitting and world-sheet gravitinos in higher-derivative string amplitudes

We report on progress made in the construction of higher-derivative superinvariants for type-II theories in ten dimensions. The string amplitude calculations required for this analysis exhibit interesting features which have received little attention in the literature so far. We discuss two examples from a forthcoming publication: the construction of the (HNS)2 R3 terms and the fermionic completion of the ϵϵR4 terms. We show that a correct answer requires very careful treatment of the chiral splitting theorem, implies unexpected new relations between fermionic correlators, and most interestingly, necessitates the use of world-sheet gravitino zero modes in the string vertex operators. In addition we compare the relation of our results to the predictions of the linear scalar superfield of the type-IIB theory.
Intelligent pattern recognition of SLM machine energy data

Selective Laser Melting (SLM) is an additive manufacturing process, in which the research has been increasing over the past few years to meet customer-specific requirements. Different parameters from the process and the machine components have been monitored in order to obtain vital information such as productivity of the machine and quality of the manufactured workpiece. The monitoring of parameters related to energy is also realized, but the utilisation of such data is usually performed for determining basic information, for instance, from energy consumption. By applying machine learning algorithms on these data, it is possible to identify not only the steps of the manufacturing process, but also its behaviour patterns. Along with these algorithms, evidences regarding the conditions of components and anomalies can be detected in the acquired data. The results can be used to point out the process errors and component faults and can be adopted to analyse the energy efficiency of the SLM process by comparing energy consumption of one single layer during the manufacturing of different components. Moreover, the state of the manufacturing process and the machine can be determined automatically and applied to predict failures in order to launch appropriate counter measures.
Magnetism and electronic structure of hcp Gd and the Gd(0001) surface

We investigate hcp Gd and the Gd(0001) surface on the basis of density functional theory. The localized 4f states of Gd, which represent a challenge for first-principles theory, are treated in four different models, employing consistently the full-potential linearized augmented plane-wave method. Our results support previous findings that within the local density approximation (LDA) or generalized gradient approximation (GGA) the itinerancy of the 4f states is overestimated. In particular, the large density of states at the Fermi energy due to the minority 4f electrons is unphysical, and our results show that this is the origin of the incorrect prediction of the antiferromagnetic ground state for hcp Gd by many LDA and GGA calculations. We show that different models of removing these states from the region close to the Fermi energy, for example the treatment of the 4f electrons as localized core electrons or by using the LDA + U formalism, lead to the prediction of the correct ferromagnetic ground state for the bulk and a ferromagnetically coupled (0001) surface layer. With these models ground-state properties such as the magnetic moment and structural parameters can be determined in good agreement with experiment. The energetic positions of the surface states of the Gd(0001) surface are compared with experimental data.
Dynamic DC-link Voltage Adjustment for Electric Vehicles Considering the Cross Saturation Effects

The demands of remarkable reliability and high power density of traction systems are becoming more and more rigorous. The conflicting requirements imposed on the control strategy are higher accuracy and higher efficiency over the whole speed range. However, parameter variations caused by the cross coupling and magnetic saturation effect (omitted from the cross saturation effects in the following) are usually neglected in conventional control strategies, which could reduce the control precision. In order to fully consider the influence of parameter changes on the motor control and derive an approach that could realize the maximum efficiency during the whole speed range, this paper proposes a dynamic DC-link voltage adjustment strategy considering the cross coupling and magnetic saturation effects. The strategy can be categorized into three parts. Firstly, the torque request is transformed to the optimal current reference signal. Secondly, the differences between the setpoint and the real-time feedback signals of torque and voltage can be applied in the linearized function in the did,q coordinate. The solution guides the current vector into the optimal direction under the current and voltage limits to ensure the safety and reliability of the motor. Finally, last, the bus voltage can be modified according to the asked terminal voltage. A 10 kW prototype which instrumented a bidirectional DC-DC converter to regulating the bus voltage has been studied. The simulation and experiment results verify that the proposed control strategy can reduce the inverter losses in low speed region by offering the low bus voltage and track the actual maximum torque control trace more accurately, meanwhile, the flux weakening region can be delayed in high speed region by applying a high bus voltage. It helps the motor realize the high utilization rate of the DC-link voltage and guarantees the system reliability and robustness.
Mechanical properties of steel fiber reinforced recycled aggregate concrete

This study experimentally investigates the mechanical properties of steel fiber reinforced recycled aggregate concrete (SFRRAC). The smaller strength and ductility of recycled aggregate concrete (RAC), compared to those of natural aggregate concrete (NAC), have restricted its use to mainly non‐structural applications in the construction industry. Such limitations in the mechanical behavior of RAC can be overcome by adding industrial steel fiber (SF). In this study, the split‐tensile strength, the compressive strength, the toughness under compression and the elastic modulus for 25 SFRRAC mixes are experimentally investigated. These 25 mixes were prepared from combinations of five different volume fractions of SF, 0, 0.3, 0.5, 0.7 and 1.0% and five different replacement proportions of natural aggregates (NA) by recycled aggregate (RA), 0, 30, 50, 70 and 100%. From experiments, it was observed that the split‐tensile strength, the compressive strength and the elastic modulus of SFRRAC mixes decreased with RA content; the split‐tensile strength and the toughness under compression increased with SF content. However, there was no clear correlation observed between the SF content and the compressive strength or the elastic modulus. Regression models were established based on the RA and SF contents in the SFRRAC mixes to predict their split‐tensile strength, compressive strength and elastic modulus.
The detection of surface vibrations from interior acoustical pressure

We consider the problem of detecting the source of acoustical noise inside the cabin of a midsize aircraft from measurements of the acoustical pressure field inside the cabin. Mathematically this field satisfies the Helmholtz equation. In this paper we consider the three-dimensional case. We show that any regular solution of this equation admits a unique representation by a single-layer potential, so that the problem is equivalent to the solution of a linear integral equation of the first kind. We study uniqueness of reconstruction and obtain a sharp stability estimate and convergence rates for some regularization algorithms when the domain is a sphere. We have developed a boundary element code to solve the integral equation. We report numerical results with this code applied to three geometries: a sphere, a cylinder with spherical endcaps and a cylinder with a floor modelling the interior of an aircraft cabin. The exact test solution is given by a point source exterior to the surfaces with about 1% random noise added. Regularization methods using the truncated singular value decomposition with generalized cross validation and the conjugate gradient (cg) method with a stopping rule due to Hanke and Raus are compared. An interesting feature of the three-dimensional problem is the relative insensitivity of the optimal regularization parameter (number of iterations) for the cg method to the wavenumber and the multiplicity of the singular values of the integral operator.