Miracle-dz/UniFAR-FTUs huggingface dataset:
Multi-port Pixel Antenna Optimization using Characteristic Mode Analysis and Sequential Feeding Port Search

An optimization approach for multi-port pixel antenna design using N-port characteristic mode analysis (CMA) and sequential feeding port selection is proposed. CMA is utilized to characterize the maximum number of independent or orthogonal resonant modes that can be formed in the limited space constrained by the size of the pixel antenna. Once the maximum number of orthogonal resonance modes is found sequential feeding port selection is proposed to find the optimum feed positions to independently excite each of the orthogonal resonance modes. The resulting design does not need additional complex feeding networks or impedance matching circuits, making the physical implementation of the design straightforward, compact and practical. Two examples are provided to verify the performance of the proposed approach, including a 3-port pixel antenna and a 4-port pixel antenna operating at 2.4 GHz. The performance of the optimized antennas is very good, and verifies the usefulness of the proposed approach.
A SUPER-SOLAR METALLICITY FOR THE PROGENITOR OF KEPLER'S SUPERNOVA

We have performed deep X-ray observations of the remnant of Kepler's supernova (SN 1604) as a Key Project of the Suzaku Observatory. Our main goal is to detect secondary Fe-peak elements in the supernova (SN) ejecta to gain insights into the Type Ia SN explosion mechanism and the nature of the progenitor. Here, we report our initial results. We made a conclusive detection of X-ray emission lines from highly ionized Mn, Cr, and Ni as well as Fe. The observed Mn-to-Cr line flux ratio is ∼0.60, ∼30% larger than that measured in Tycho's remnant. We estimate an Mn-to-Cr mass ratio of ∼0.77, which is strongly suggestive of a large neutron excess in the progenitor star before the onset of the thermonuclear runaway. The observed Ni-to-Fe line flux ratio (∼0.03) corresponds to a mass ratio of ∼0.06, which is generally consistent with the products of the explosive Si-burning regime in Type Ia explosion models, and rules out contamination from the products of neutron-rich nuclear statistical equilibrium in the shocked ejecta. Together with the previously suggested luminous nature of the explosion, these mass ratios provide strong evidence for a super-solar metallicity in the SN progenitor (∼3 Z☉). Kepler's SN was likely the thermonuclear explosion of a white dwarf formed in the recent past that must have exploded through a relatively prompt channel.
MHA-CNN: Aircraft Fine-Grained Recognition of Remote Sensing Image Based on Multiple Hierarchies Attention

Aircraft fine-grained recognition of remote sensing image is widely exploited in both military and civilian fields, which the similar physical structure and the changeable attitude between variable aircraft types makes this task challenge. Great progress has been made by proposal models based on convolutional neural network. However, previous works did not focus on local and multiple hierarchy features. In this paper, we propose a framework based on multiple hierarchy network and attention module for aircraft recognition. Compared to the existing methods, the extraction and enhancement of features proposed by us has been greatly improved. Remarkable results have been achieved on our dataset Aircraft-16 and the MTARSI dataset.
BBN And The CMB Constrain Light, Electromagnetically Coupled WIMPs

(Abridged) In the presence of a light WIMP ( 99% confidence. Allowing a light WIMP and Delta N_nu equivalent neutrinos together, the combined BBN and CMB data provide lower limits to the WIMP masses (> 0.5 - 5 MeV) that depend on the nature of the WIMP, favor m_chi ~8 MeV slightly over no WIMP, and loosen constraints on equivalent neutrinos, Delta N_nu = 0.65+0.46-0.35. While Delta N_nu = 0 is still disfavored at ~95% confidence with a light WIMP, Delta N_nu = 1 is now allowed.
50 Shades of Green—Angel Investing in Green Businesses

Entrepreneurs will play a critical role in developing the technological solutions to achieve a successful transition to net carbon zero. Their ability to develop these innovations into market ready products requires access to finance. Angels play a critical role in financing the start of the entrepreneurial pipeline. However, their actual and potential role investing in green/clean businesses is not considered in either the business angel or socially responsible investment literatures. This article addresses this omission. It asks what motivates business angels to invest in green/clean tech businesses and how the weight of green/clean tech in their portfolios impacts the motivations to invest in this sector. Based on interviews with 65 investors, we show that the motivation of business angels for investing in green/clean tech opportunities differs according to the proportion of their investment portfolio that comprises green/clean tech investments. Those angels who invested solely in green/clean tech gave a higher weighting to economic motivations and lower weightings to Altruistic and Hedonistic motivations. Angels with less exposure to green/clean tech in their portfolios gave a higher weighting to Altruistic motivations and had lower weightings for economic and hedonistic motivations. Our findings have implications for policy-makers and to green entrepreneurs.
Estimating f_NL and g_NL from Massive High-Redshift Galaxy Clusters

There are observations of at least 14 high-redshift massive galaxy clusters, which have an extremely small probability with a purely Gaussian initial curvature perturbation. Here we revisit the estimation of the contribution of non-Gaussianities to the cluster mass function and point out serious problems that have resulted from the application of the mass function out of the range of its validity. We remedy the situation and show that the values of fNL previously claimed to completely reconcile (i.e. at ~ 100% confidence) the existence of the clusters with ΛCDM are unphysically small. However, for WMAP cosmology and at 95% confidence, we arrive at the limit fNL411, which is similar to previous estimates. We also explore the possibility of a large gNL as the reason for the observed excess of the massive galaxy clusters. This scenario, gNL > 2 × 106, appears to be in more agreement with CMB and LSS limits for the non-Gaussianity parameters and could also provide an explanation for the overabundance of large voids in the early universe.
Connecting the dots: distribution grid investments to power the energy transition

In early 2021, Eurelectric releases a landmark study on distribution grid investment needs at the EU level by 2030, conducted by Monitor Deloitte in partnership with E.DSO, entitled ‘Connecting the dots’, see also here: https://www.eurelectric. org/connecting-the-dots/
Inflation via Gravitino Condensation in Dynamically Broken Supergravity

Gravitino-condensate-induced inflation via the super-Higgs effect is a UV-motivated scenario for both inflating the early universe and breaking local supersymmetry dynamically, entirely independent of any coupling to external matter. As an added benefit, this also removes the (as of yet unobserved) massless Goldstino associated to global supersymmetry breaking from the particle spectrum. In this review we detail the pertinent properties and outline previously hidden details of the various steps required in this context in order to make contact with current inflationary phenomenology. The class of models of SUGRA we use to exemplify our approach are minimal four-dimensional N=1 supergravity and conformal extensions thereof (with broken conformal symmetry). Therein, the gravitino condensate itself can play the role of the inflaton, however the requirement of slow-roll necessitates unnaturally large values of the wave-function renormalisation. Nevertheless, there is an alternative scenario that may provide Starobinsky-type inflation, occurring in the broken-SUGRA phase around the non-trivial minima of the gravitino-condensate effective potential. In this scenario higher curvature corrections to the effective action, crucial for the onset of an inflationary phase, arise as a result of integrating out massive quantum gravitino fields in the path integral. The latter scenario is compatible with Planck satellite phenomenology but not with BICEP2 data.
Efficient Use of Interferometric Coherence for Improvement in Classification of Urban and Tall Vegetation with SAR Data

Classification of synthetic aperture radar data has been attempted by researchers in the past for several years, with varying degrees of success. One of the most challenging problem in such classifications is the segregation of urban (built-up region) and tall vegetation (TV). This is due to lack of difference in their scattering power. Therefore, an attempt has been made to improve urban and TV classification accuracy by exploring the use of Sentinel-1 interferometric coherence images as an additional feature along with other popularly used scattering features. A convolutional neural network (CNN) is trained on these features to obtain a good accuracy for classifying urban, TV and other classes. Obtained results are analyzed in both visual and quantitative ways. It is observed that when interferometric coherence images are added as an additional input feature in the CNN, producer and user accuracy for the urban and TV are improved from 15 to 25%, and overall accuracy(OA) is reached from 72.5% to 79.3%. Results oabtained with the CNN model is also compared with the traditional machine learning models such as support vector machine(SVM) and k-nearest neighbors(KNN). CNN over performes with 79.3% OA, followed by KNN with 66% OA while the performance of SVM is the worst among them all with 60% OA.
Suppressing structure formation at dwarf galaxy scales and below: late kinetic decoupling as a compelling alternative to warm dark matter

Warm dark matter cosmologies have been widely studied as an alternative to the cold dark matter paradigm, the characteristic feature being a suppression of structure formation on small cosmological scales. A very similar situation occurs if standard cold dark matter particles are kept in local thermal equilibrium with a, possibly dark, relativistic species until the universe has cooled down to keV temperatures. We perform a systematic phenomenological study of this possibility, and classify all minimal models containing dark matter and an arbitrary radiation component that allow such a late kinetic decoupling. We recover explicit cases recently discussed in the literature and identify new classes of examples that are very interesting from a model-building point of view. In some of these models dark matter is inevitably self-interacting, which is remarkable in view of recent observational support for this possibility. Hence, dark matter models featuring late kinetic decoupling have the potential not only to alleviate the missing satellites problem but also to address other problems of the cosmological concordance model on small scales, in particular the cusp-core and too-big-too-fail problems, in some cases without invoking any additional input.
MATCHING THE SPECTRAL ENERGY DISTRIBUTION AND p-MODE OSCILLATION FREQUENCIES OF THE RAPIDLY ROTATING DELTA SCUTI STAR α OPHIUCHI WITH A TWO-DIMENSIONAL ROTATING STELLAR MODEL

Spectral energy distributions are computed using two-dimensional (2D) rotating stellar models and non-LTE plane-parallel model atmospheres. A rotating, 2D stellar model has been found that matches the observed ultraviolet and visible spectrum of α Oph. The SED match occurs for the interferometrically deduced surface shape and inclination, and is different from the SED produced by spherical models. The p-mode oscillation frequencies in which the latitudinal variation is modeled by a linear combination of eight Legendre polynomials were computed for this model. The five highest and seven of the nine highest amplitude modes show agreement between computed axisymmetric, equatorially symmetric mode frequencies and the mode frequencies observed by the Microvariability and Oscillations of Stars satellite (MOST) to within the observational error. Including nonaxisymmetric modes up through |m| = 2, and allowing for the possibility that the eight lowest amplitude modes could be produced by modes that are not equatorially symmetric, matches for 24 out of the 35 MOST modes to within the observational error and another eight modes to within twice the observational error. The remaining three observed modes can be fitted within 4.2 times the observational error, but even these may be fitted to within the observational error if the criteria for computed modes are expanded.
Spatial Distribution of Abundance Patterns in the Starburst Galaxy NGC 3079 Revealed with Chandra and Suzaku

We performed simultaneous spectral analysis of 26.6 ksec of Chandra and 102.3 ksec of Suzaku X-ray data of the starburst galaxy NGC 3079. The spectra are extracted from four regions: 0.5' (2.25 kpc) circle, an inner 0.5'-1' (2.25--4.5 kpc) ring, and an outer 1'-2' (4.5--9 kpc) ring from Chandra, and 4' (18 kpc) circle from Suzaku, all centered on the nucleus. Fitting with thermal plasma models yields interstellar medium (ISM) temperatures of 0.65+0.05-0.04, 0.45+0.07-0.06, and 0.24+0.03-0.02 keV in the three regions, respectively. The combination of Chandra's high angular resolution and Suzaku's good spectral sensitivity enable us to spatially resolve and measure the abundances of the metals O, Ne, Mg, and Fe within the hot ISM. In particular, the abundance patterns of O/Fe, Ne/Fe, Mg/Fe, and Si/Fe in the central regions (<4.5 kpc) are consistent with the expectations from Supernovae (SN) II synthesis. On the other hand, the pattern in the region beyond 4.5 kpc is closer to solar. The central regions are also where copious polycyclic aromatic hydrocarbon infrared emission related to recent starburst activity is known to occur. This suggests that we are seeing starburst-related SN II metal enrichment in the hot X-ray--emitting nuclear ISM. The spatial extent of the SN II--like abundance patterns is consistent with NGC 3079 being in a relatively-early phase of starburst activity.
Contamination from a nearby star cannot explain the anomalous transmission spectrum of the ultrashort period giant planet WASP-103 b

The planet in the WASP-103 system is an excellent candidate for transmission spectroscopy because of its large radius and high temperature. Application of this technique found a variation of radius with wavelength which was far too strong to be explained by scattering processes in the planetary atmosphere. A faint nearby star was subsequently detected, whose contamination of the transit light curves might explain this anomaly. We present a reanalysis of published data in order to characterize the faint star and assess its effect on the measured transmission spectrum. The faint star has a mass of 0.72 +/- 0.08 M-aS (TM) and is almost certainly gravitationally bound to the planetary system. We find that its effect on the measured physical properties of the planet and host star is small, amounting to a planetary radius larger by 0.6 sigma and planetary density smaller by 0.8 sigma. Its influence on the measured transmission spectrum is much greater: the spectrum now has a minimum around 760 nm and opacity rises to both bluer and redder wavelengths. It is a poor match to theoretical spectra and the spectral slope remains too strong for Rayleigh scattering. The existence of the faint nearby star cannot therefore explain the measured spectral properties of this hot and inflated planet. We advocate further observations of the system, both with high spatial resolution in order to improve the measured properties of the faint star, and with higher spectral resolution to confirm the anomalous transmission spectrum of the planet.
Pulsar Timing Arrays and Gravity Tests in the Radiative Regime

In this paper, we focus on testing gravity theories in the radiative regime using pulsar timing array observations. After reviewing current techniques to measure the dispersion and alternative polarization of gravitational waves, we extend the framework to the most general situations, where the combinations of a massive graviton and alternative polarization modes are considered. The atlas of the Hellings-Downs functions is completed by the new calculations for these dispersive alternative polarization modes. We find that each mode and corresponding graviton mass introduce characteristic features in the Hellings-Downs function. Thus, in principal, we can not only detect each polarization mode, measure the corresponding graviton mass, but also discriminate the different scenarios. In this way, we can test gravity theories in the radiative regime in a generalized fashion, and such method is a direct experiment, where one can address the gauge symmetry of the gravity theories in their linearised limits. Although current pulsar timing still lacks enough stable pulsars and sensitivity for such practices, we expect that future telescopes with larger collecting area could make such experiments be feasible.
An Investigation of the Use of Simplified IRT Models for Scaling and Equating the TOEFL Test. TOEFL Technical Report TR-2.

The purpose of this study was to explore the use of two alternative item response theory estimation models in the scaling and equating of TOEFL – a modified one-parameter model (M1PL) and a modified two-parameter model (M2PL) – and to compare item scaling and test equating results based on these two alternative models with results based on the three-parameter model (3PL) that is currently being used to scale and equate the TOEFL. The study employed a design in which a typical TOEFL equating was simulated using artificial data. The simulated equatings were compared in terms of correlations between estimated and generating parameters, model-data fit, and concordance of simulated score conversions with conversions based on the generating parameters. The results of the study clearly indicated that the 3PL model performed better than the M1PL and M2PL models on the basis of each of the evaluation criteria. There was also evidence that the M2PL model performed better than the M1PL model, particularly in terms of model-data fit and in the weighted root mean square difference statistics used to evaluate the simulated score conversions. The results of the study also indicated that discrepancies between score conversions based on the M1PL and M2PL model and those based on the 3PL model tended to occur at the lower and upper ends of the score scales. Finally, the results of the study for the 3PL model indicated that while correlations between item parameter estimates and generating parameters tended to be affected by sample size, neither the quality of model-data fit nor the quality of simulated equatings appeared to be sensitive to the different sample sizes used in the study.
Electron correlation in the FeSe superconductor studied by bulk-sensitive photoemission spectroscopy

We have investigated the electronic structures of recently discovered superconductor FeSe by soft-x-ray and hard-x-ray photoemission spectroscopy with high bulk sensitivity. The large Fe 3d spectral weight is located in the vicinity of the Fermi level (EF), which is demonstrated to be a coherent quasi-particle peak. Compared with the results of the band structure calculation with local-density approximation, Fe 3d band narrowing and the energy shift of the band toward EF are found, suggesting an importance of the electron correlation effect in FeSe. The self energy correction provides the larger mass enhancement value (Z^-1=3.6) than in Fe-As superconductors and enables us to separate a incoherent part from the spectrum. These features are quite consistent with the results of recent dynamical mean-field calculations, in which the incoherent part is attributed to the lower Hubbard band.
Energy-Efficient Dual-Node-Upset-Recoverable 12T SRAM for Low-Power Aerospace Applications

With technology scaling, transistor sizing, as well as the distance between them, is decreasing rapidly, thereby reducing the critical charge of sensitive nodes. This reduction makes SRAM cells, used for aerospace applications, more susceptible to radiation as it can cause single-event upsets (SEUs) and also single-event multi-node upsets (SEMNUs). This article presents an energy-efficient dual-node-upsetrecoverable 12T SRAM cell for low-power aerospace applications, EDP12T, in 65-nm CMOS technology. The proposed cell mitigates SEUs as well as SEMNUs. To judge the relative performance of EDP12T, a comparative study is made between it and other radiation-hardened cells, RHM12T, QUCCE12T, QUATRO12T, RHD12T, SRRD12T, RHPD12T, RSP14T, LWS14T, SAR14T, and S8P4N16T. EDP12T can recover from SEUs injected at all the sensitive nodes and SEMNUs that have occurred at its internal node-pair. In addition, EDP12T also exhibits better write performance than most of the comparison cells. Among all the cells for comparison, EDP12T dissipates the lowest hold power, except RHM12T. In addition to these, it consumes the least energy during write mode and also consumes lower energy than most of the comparison cells during read mode. It also exhibits 1.08×/ 1.17×/ 1.37×/ 1.56×/ 2.32× higher read stability than S8P4N16T/ RHPD12T/ QUCCE12T/ QUATRO12T/ LWS14T. All these aforementioned improvements are obtained by the proposed cell while consuming 1.03×/ 1.06×/ 1.07×/ 1.08×/ 1.14×/ 1.43× lower area than SAR14T/ RHD12T/ S8P4N16T/ RSP14T/ LWS14T/ RHPD12T. However, these advantages come with a slight penalty in read delay.
A Bibliometric Review And Analysis of Modis Land Surface Temperature Data Application In Africa

The Moderate Resolution Imaging Spectroradiometer (MODIS) has become one of the widely used sensors to acquire continuous land surface temperature (LST) over large areas. However, despite the progress in the use of MODIS LST data globally, Africa still lags in the number of publications that utilized the data in research. The data extraction and analysis were done using bibliometric analysis in R statistical software. A total of 59 articles that used MODIS LST data in Africa were generated. The results indicated a steady rise in publication since 2006. China was the most contributing country to publications and Remote Sensing was the most active journal. MODIS was the most common word used in the generated publications. This study is vital in showing improvements in the application of MODIS LST data in Africa which provides information and encourages researchers to use new and unique models that can assist in global warming mitigation.
Equidistribution of zeros of random holomorphic sections

We study asymptotic distribution of zeros of random holomorphic sections of high powers of positive line bundles defined over projective homogenous manifolds. We work with a wide class of distributions that includes real and complex Gaussians. As a special case, we obtain asymptotic zero distribution of multivariate complex polynomials given by linear combinations of orthogonal polynomials with i.i. d. random coefficients. Namely, we prove that normalized zero measures of m i.i. d random polynomials, orthonormalized on a regular compact set $K\subset \Bbb{C}^m,$ are almost surely asymptotic to the equilibrium measure of $K$.