Miracle-dz/UniFAR-FTUs huggingface dataset:
SPARSE REPRESENTATION LEARNING OF DATA BY AUTOENCODERS WITH L 1 / 2 REGULARIZATION

Autoencoder networks have been demonstrated to be efficient for unsupervised learning of representation of images, documents and time series. Sparse representation can improve the interpretability of the input data and the generalization of a model by eliminating redundant features and extracting the latent structure of data. In this paper, we use L1/2 regularization method to enforce sparsity on the hidden representation of an autoencoder for achieving sparse representation of data. The performance of our approach in terms of unsupervised feature learning and supervised classification is assessed on the MNIST digit data set, the ORL face database and the Reuters-21578 text corpus. The results demonstrate that the proposed autoencoder can produce sparser representation and better reconstruction performance than the Sparse Autoencoder and the L1 regularization Autoencoder. The new representation is also illustrated to be useful for a deep network to improve the classification performance.
A Monte Carlo dose calculation tool for radiotherapy treatment planning

A Monte Carlo user code, MCDOSE, has been developed for radiotherapy treatment planning (RTP) dose calculations. MCDOSE is designed as a dose calculation module suitable for adaptation to host RTP systems. MCDOSE can be used for both conventional photon/electron beam calculation and intensity modulated radiotherapy (IMRT) treatment planning. MCDOSE uses a multiple-source model to reconstruct the treatment beam phase space. Based on Monte Carlo simulated or measured beam data acquired during commissioning, source-model parameters are adjusted through an automated procedure. Beam modifiers such as jaws, physical and dynamic wedges, compensators, blocks, electron cut-outs and bolus are simulated by MCDOSE together with a 3D rectilinear patient geometry model built from CT data. Dose distributions calculated using MCDOSE agreed well with those calculated by the EGS4/DOSXYZ code using different beam set-ups and beam modifiers. Heterogeneity correction factors for layered-lung or layered-bone phantoms as calculated by both codes were consistent with measured data to within 1%. The effect of energy cut-offs for particle transport was investigated. Variance reduction techniques were implemented in MCDOSE to achieve a speedup factor of 10–30 compared to DOSXYZ.
Cosmological radio emission induced by WIMP Dark Matter

We present a detailed analysis of the radio synchrotron emission induced by WIMP dark matter annihilations and decays in extragalactic halos. We compute intensity, angular correlation, and source counts and discuss the impact on the expected signals of dark matter clustering, as well as of other astrophysical uncertainties as magnetic fields and spatial diffusion. Bounds on dark matter microscopic properties are then derived, and, depending on the specific set of assumptions, they are competitive with constraints from other indirect dark matter searches. At GHz frequencies, dark matter sources can become a significant fraction of the total number of sources with brightness below the microJansky level. We show that, at this level of fluxes (which are within the reach of the next-generation radio surveys), properties of the faint edge of differential source counts, as well as angular correlation data, can become an important probe for WIMPs.
Forward problem solution of electromagnetic source imaging using a new BEM formulation with high-order elements

Representations of the active cell populations on the cortical surface via electric and magnetic measurements are known as electromagnetic source images (EMSIs) of the human brain. Numerical solution of the potential and magnetic fields for a given electrical source distribution in the human brain is an essential part of electromagnetic source imaging. In this study, the performance of the boundary element method (BEM) is explored with different surface element types. A new BEM formulation is derived that makes use of isoparametric linear, quadratic or cubic elements. The surface integration is performed with Gauss quadrature. The potential fields are solved assuming a concentric three-shell model of the human head for a tangential dipole at different locations. In order to achieve 2% accuracy in potential solutions, the number of quadratic elements is of the order of hundreds. However, with linear elements, this number is of the order of ten thousand. The relative difference measures (RDMs) are obtained for the numerical models that use different element types. The numerical models that employ quadratic and cubic element types provide superior performance over linear elements in terms of accuracy in solutions. Assuming a homogeneous sphere model of the head, the RDMs are also obtained for the three components (radial and tangential) of the magnetic fields. The RDMs obtained for the tangential fields are, in general, much higher than those obtained for the radial fields. Both quadratic and cubic elements provide superior performance compared with linear elements for a wide range of dipole locations.
Modelling the response of a tungsten oxide semiconductor as a gas sensor for the measurement of ozone

The behaviour of gas-sensitive resistors based on WO3 towards small concentrations of ozone in air can be understood with a simple model involving the reaction of ozone with surface oxygen vacancies. This model has been validated by comparison with experimental results for the effects of varying oxygen partial pressure on the ozone response. A complete description of the behaviour of devices constructed by printing WO3 as porous layers onto an impermeable substrate requires consideration of the effects of the microstructure of such a device upon its response. A very simple series-parallel equivalent circuit model captures the effects and allows a simple interpretation of the sensor behaviour, including the quadratic limiting steady state resistance response to ozone and the effects of variation of device thickness. An important fact that allows WO3 to be used at rather high temperatures as an effective ozone sensor is that ozone does not decompose at any discernible rate on the oxide surface. Saturation of the oxide surface at ambient temperature with water vapour inhibits the ozone response when the sensor is subsequently heated. The effect can be removed by heating at sufficiently high temperature. Water vapour also gives a high-temperature sensor response, but appears to act at sites different to those that mediate the response to ozone.
Measuring the elastic modulus of ex vivo small tissue samples

Over the past decade, several methods have been proposed to image tissue elasticity based on imaging methods collectively called elastography. While progress in developing these systems has been rapid, the basic understanding of tissue properties to interpret elastography images is generally lacking. To address this limitation, we developed a system to measure the Young's modulus of small soft tissue specimens. This system was designed to accommodate biological soft tissue constraints such as sample size, geometry imperfection and heterogeneity. The measurement technique consists of indenting an unconfined small block of tissue while measuring the resulting force. We show that the measured force–displacement slope of such a geometry can be transformed to the tissue Young's modulus via a conversion factor related to the sample's geometry and boundary conditions using finite element analysis. We also demonstrate another measurement technique for tissue elasticity based on quasi-static magnetic resonance elastography in which a tissue specimen encased in a gelatine–agarose block undergoes cyclical compression with resulting displacements measured using a phase contrast MRI technique. The tissue Young's modulus is then reconstructed from the measured displacements using an inversion technique. Finally, preliminary elasticity measurement results of various breast tissues are presented and discussed. For more information on this article, see medicalphysicsweb.org
Comments on the vacuum energy decay

The instability of vacuum energy in de Sitter space as discussed recently by Polyakov is argued to be a generic feature when external gravitational fields are present. It is related to the existence of forbidden (by momentum conservation) decays derived in some detail by Bros, Epstein and Moschella. Some calculations are discussed in a conformally invariant setting, and a flat space model is presented.
Quantum fluctuations of coupled dark solitons in a trapped Bose–Einstein condensate

We examine the quantum fluctuations associated with the Bogoliubov quasiparticle vacuum of coupled dark solitons in a quasi-one-dimensional Bose–Einstein condensate. We show that the quantum fluctuations appear in the form of incoherent atoms strongly concentrated near the notches. We identify a finite number of collective modes that are responsible for such quantum phenomena. These collective modes describe the particle-like oscillations of coupled dark solitons.
Space–time relationship in continuously moving table method for large FOV peripheral contrast-enhanced magnetic resonance angiography

Data acquisition using a continuously moving table approach is a method capable of generating large field-of-view (FOV) 3D MR angiograms. However, in order to obtain venous contamination-free contrast-enhanced (CE) MR angiograms in the lower limbs, one of the major challenges is to acquire all necessary k-space data during the restricted arterial phase of the contrast agent. Preliminary investigation on the space–time relationship of continuously acquired peripheral angiography is performed in this work. Deterministic and stochastic undersampled hybrid-space (x, ky, kz) acquisitions are simulated for large FOV peripheral runoff studies. Initial results show the possibility of acquiring isotropic large FOV images of the entire peripheral vascular system. An optimal trade-off between the spatial and temporal sampling properties was found that produced a high-spatial resolution peripheral CE-MR angiogram. The deterministic sampling pattern was capable of reconstructing the global structure of the peripheral arterial tree and showed slightly better global quantitative results than stochastic patterns. Optimal stochastic sampling patterns, on the other hand, enhanced small vessels and had more favourable local quantitative results. These simulations demonstrate the complex spatial–temporal relationship when sampling large FOV peripheral runoff studies. They also suggest that more investigation is required to maximize image quality as a function of hybrid-space coverage, acquisition repetition time and sampling pattern parameters.
Model Construction and Optimization of Wall Climbing Robot Oriented Electro-adhesion Array

A novel electro-adhesion technology is presented for deficiency of existing adhesion methods. The mechanism of electro-adhesion is analyzed and the structure of planar combed interdigitated electrode array for climbing robots usage is presented based on the characteristics of climbing robot usage. With regard to the presented structure, the adhesion force output model is constructed with finite element analysis tool. The quantum particle swarm algorithm (QPSO) is used to optimize the parameters of the adhesion array for the maximal adhesion force output. The shape of electrode is also designed with regard to the force layout and dielectric characteristics of the whole array. With MEMS tech, a testing sample is designed and generated. In order to validate the effectiveness of electro-adhesion method, experiments were performed based on different substrates (concrete wall, glass and wood) and a single tracked climbing robot based on electro-adhesion caterpillar is designed. Experimental data and performance of the designed robot indicate effectiveness and advantage of the depicted method which can provide stable and robust adhesion foe climbing robot.
High Gain Power Generation Based On Hybrid Renewable Energy for AC Load Application

This study presents the distributed energy source based current fed inverter has generated high voltage with less passive elements. The hybrid renewable energy generation such as solar and wind has used. The single stage power generation based switched inverter has combined characteristics of both impedance source inverter and switched boost inverter. In conventional voltage source inverter has less boost ability and high electromagnetic noise immunity to the modified current fed inverter circuit. The single diode photovoltaic model and wind-based energy generation have fed into current fed switched inverter for improving high gain and high power factor. The maximum power point tracking such as incremental conductance algorithm has fast-tracking of solar power and generates continuous power to the inverter circuit. 12V solar power and wind power is designed for dc power production, and the output of dc link capacitor is 118V using current fed switched inverter. The current fed switched inverter is designed and implemented in MATLAB/Simulink environment.
1983 observations of the eclipsing nucleus of the bipolar planetary nebula NGC 2346

IUE data are presented of the eclipsing nucleus of NGC 2346 obtained at 3 phases of the 1983 observing season. At phi 0.02, a highly asymmetric C IV emission line is seen, but the He II line has a gaussian profile with a slight suggestion of an inverse P Cygni character. The stellar continuum in the 1200 to 1950 A region and high excitation emission lines argue for a hot subdwarf component in the binary nucleus.
Wireless power collection using radio frequency identification system

A wireless power collection (WPC) system is proposed to harvest excess electromagnetic energies in space that are reflected and not received by target antennas. The radio frequency identification (RFID) system was utilized to demonstrate WPC. The power was transmitted between the reader and tags, and the rectenna (rectified antenna) was used to collect energy in our WPC system. The rectenna includes ultra‐high frequency RFID tags. When the distance between the rectenna and the reader was 10 cm, the maximum voltages of a single rectenna and four rectennas in series were measured to be nearly 1.5 and 5.7 V, respectively. This WPC system can be used to supply power to charge batteries or other electronic products. A WPC tree consisted of four sets of rectenna arrays provided a charging current of ∼0.203 mA to a set of four AAA NiMH batteries.
Grid based linear neutrino perturbations in cosmological N-body simulations

We present a novel, fast and precise method for including the effect of light neutrinos in cosmological N-body simulations. The effect of the neutrino component is included by using the linear theory neutrino perturbations in the calculation of the gravitational potential in the N-body simulation. By comparing this new method with the full non-linear evolution first presented in [1], where the neutrino component was treated as particles, we find that the new method calculates the matter power spectrum with an accuracy better than 1% for ∑mν ≲ 0.5 eV at z = 0. This error scales approximately as (∑mν)2, making the new linear neutrino method extremely accurate for a total neutrino mass in the range 0.05−0.3 eV. At z = 1 the error is below 0.3% for ∑mν ≲ 0.5 eV and becomes negligible at higher redshifts. This new method is computationally much more efficient than representing the neutrino component by N-body particles.
Laboratory experiments on the transition to MHD dynamos

We present observations of a mechanically forced liquid-metal dynamo experiment and review international efforts in this field. As the magnetic Reynolds number is increased, our measurements show lengthening of the decay time of pulsed magnetic fields. These measurements quantify the approach to magnetic field self-generation. While an external field is applied, large fluctuations occur in the magnetic response of the system. We analyse these fluctuations to characterize the liquid-metal velocity field. This analysis suggests that turbulence strongly influences the approach to self-generation in a forced liquid-metal flow.
Phytochemical Constituents in Leaves and Callus of Ficus deltoidea Jack var. Kunstleri (King) Corner

Qualitative and quantitative analysis of phytochemical constituents was done on leaves and leaf’s callus of Ficus deltoidea Jack var. kunstleri (King) Corner. Tannins, phlobatannins, saponins, flavonoids, steroids, terpenoids, alkaloids, anthraquinones and polyphenols were present in the leaves and callus cultured on Murashige and Skoog (1962) media supplemented with 0.8 mg/L 2,4-D + 0.7 mg/L Kinetin (KIN). Meanwhile, cardiac glycosides only exist in the leaves but not in the callus tissue. Quantitative analysis showed that alkaloids, saponins, phenols, flavonoids and tannins exist in both samples but in lower amounts for the callus tissue. The significance of the phytochemical constituents with respect to the role of this plant in traditional medicine treatment and the future prospect for callus in the production of secondary metabolites is discussed. doi: 10.14456/WJST.2015. 86
FDTD calculations of the whole-body averaged SAR in an anatomically realistic voxel model of the human body from 1 MHz to 1 GHz

This paper presents finite-difference time-domain (FDTD) calculations of the whole-body averaged SAR in an anatomically realistic voxel model of the human body. This model, NORMAN, consists of million voxels, of 2 mm dimension in the adult phantom, segmented into 37 tissue types. SAR values are presented for an adult phantom and for scaled 10, 5 and 1 year old models, grounded and isolated in air from 1 MHz to 1 GHz for plane wave exposure. External electric field values corresponding to a whole-body averaged SAR of are also presented.
Testing Lorentz invariance of dark matter

We study the possibility to constrain deviations from Lorentz invariance in dark matter (DM) with cosmological observations. Breaking of Lorentz invariance generically introduces new light gravitational degrees of freedom, which we represent through a dynamical timelike vector field. If DM does not obey Lorentz invariance, it couples to this vector field. We find that this coupling affects the inertial mass of small DM halos which no longer satisfy the equivalence principle. For large enough lumps of DM we identify a (chameleon) mechanism that restores the inertial mass to its standard value. As a consequence, the dynamics of gravitational clustering are modified. Two prominent effects are a scale dependent enhancement in the growth of large scale structure and a scale dependent bias between DM and baryon density perturbations. The comparison with the measured linear matter power spectrum in principle allows to bound the departure from Lorentz invariance of DM at the per cent level.
Feasibility Studies on a Stand-Alone Hybrid Wind-Diesel System for Fish Farming Applications

This thesis aims to explore feasibility related to implementing a Hybrid Wind-Diesel System for an offshore fish farm. The primary motivation behind this is to exploit the excellent wind resources along the Norwegian coast in order to reduce CO2 emissions related to the operation of diesel generators (DGs). Thus, instead of diesel as the only source of electrical power, the hybrid system will utilise a wind turbine and battery system to reduce the diesel generator’s operating time as much as possible. Additionally, excessive wind energy from the wind turbine could be used to run auxiliary equipment on the farm, such as oxygen production, washers for lice removal and freshwater production. As a starting point, the thesis provides a clear and perspicuous overview of conventional offshore fish farms and Hybrid Wind-Diesel Systems in general. This constitutes the basis for building a suitable model from fundamental blocks in the MATLAB®/Simulink environment. The purpose is assessing the system’s dynamic performance when exposed to disturbances. Figure 1 displays the system layout schematic. M Battery System Diesel Generator Wind Turbine and Generator Back-to-back Converter Three-phase Transformer
Electron-impact excitation of Rydberg and valence electronic states of nitric oxide: II. Integral cross sections

Integral cross sections (ICSs) for the excitation of 18 excited electronic states, and four composite excited electronic states, in nitric oxide (NO) have been determined for incident electron energies of 15, 20, 30, 40 and 50 eV. These ICSs were derived by extrapolating the respective measured differential cross sections (M J Brunger et al 2000 J. Phys. B: At. Mol. Opt. Phys. 33 783) to 0° and 180° and by performing the appropriate integration. Comparison of the present ICSs with the results of those determined in earlier optical emission measurements, and from theoretical calculations is made. At each incident energy considered, the current ICSs are also summed along with the corresponding elastic and rovibrational excitation ICSs from B Mojarrabi et al (1995 J. Phys. B: At. Mol. Opt. Phys. 28 487) and the ionization cross sections from Rapp and Englander-Golden (1965 J. Chem. Phys. 43 1464), to derive an estimate of the grand total cross sections (GTSs) for e- + NO scattering. The GTSs derived in this manner are compared with the results from independent linear transmission experiments and are found to be entirely consistent with them. The present excited electronic state ICS, and those for elastic and rovibrational excitation from Mojarrabi et al , appear to represent the first set of self-consistent cross sections for electron impact scattering from NO.
Maximum entropy spectral analy-sis and autoregressive decomposition

The duality between the maximum entropy method (MEM) of spectral analysis and the autoregressive (AR) representation of the data allows the application of recent advances in AR analysis to MEM in an attempt to obviate some shortcomings in this method of spectral decomposition. Specifically, this paper investigates the work of Akaike (1969a, b) on a criterion for choosing the length of the required prediction error filter and compares two methods of determining the filter coefficients. Recent work by Kromer (1970) on asymptotic properties of the AR spectral estimator is also of importance. Some preliminary results of the splitting of the normal modes of the earth are presented as an illustration of the application of MEM to geophysics.