Miracle-dz/UniFAR-FTUs huggingface dataset:
Prominent ultraviolet emission lines from Type 1 Seyfert galaxies

IUE Explorer data with a 6-A resolution are reported for Ly-alpha, C IV 1550 A, C III semiforbidden line 1909 A, and Mg II 2800 A, as well as the continuum at 1450 A, for 20 Seyfert galaxies and one quasar. Good correlation is found between the continuum and the line fluxes, indicating that photoionization is the dominant heating mechanism for these active galactic nuclei. A combination of the data for Seyferts and high redshift quasars covering five orders of magnitude in continuum luminosity shows the lower luminosity objects to have higher equivalent widths for their emission lines, suggesting that the covering factor increases with decreasing luminosity.
A note on the approximate symmetry of Bregman distances

The Bregman distance $B_{\xi_x}(y,x)$, $\xi_x \in \partial J(y),$ associated to a convex sub-differentiable functional $J$ is known to be in general non-symmetric in its arguments $x$, $y$. In this note we address the question when Bregman distances can be bounded against each other when the arguments are switched, i.e., if some constant $C>0$ exists such that for all $x,y$ on a convex set $M$ it holds that $\frac{1}{C} B_{\xi_x}(y,x) \leq B_{\xi_y}(x,y) \leq C B_{\xi_x}(y,x). $ We state sufficient conditions for such an inequality and prove in particular that it holds for the $p$-powers of the $\ell_p$ and $L^p$-norms when $1 < p <\infty$.
νFν Spectra of Intense Short Gamma-Ray Bursts Peak at about 1 MeV

We compare the spectral parameter distributions of short- and long-duration gamma-ray bursts (GRBs) recorded by the PHEBUS experiment. Spectral parameters are those of standard photon models. They are derived from fits to fluence and peak flux spectra over a typical 0.1-17 MeV energy range. A striking result of this study is the significant difference between the Ep distributions of short and long GRBs, for both fluence and peak flux spectra. For long GRBs, the most probable value of Ep is seen to be ~0.4 MeV for fluence spectra and ~0.5 MeV for peak flux spectra. These values exceed those reported for BATSE by 0.2-0.3 MeV. At least in part, the reason for this is the larger proportion of hard events detected by PHEBUS above 0.1 MeV. However, for 30 long events common to both experiments, we find that the logarithmic mean of Ep values from 0.25 s peak flux spectra of PHEBUS is higher than that of BATSE by ~0.1 MeV with an increasing disagreement in Ep when the peak energy is greater than 0.4 MeV. Bright short bursts are found to have a peak energy at ~1 MeV on average for both fluence and peak flux spectra. We present evidence for an additional spectral break at about 0.2-0.3 MeV from the analysis of average spectra formed by combining the count-rate spectra of the 19 short PHEBUS events. This low-energy break might mistakenly be interpreted as the peak energy for those hard short events detected with poor statistics above a few hundred keV by experiments with limited high-energy sensitivity.
Augmented sensitivity of an IR-absorption gas sensor employing a metal hole array

We demonstrate the use of plasmonic extraordinary transmission at IR wavelengths for surface-enhanced infrared absorption (SEIRA) spectroscopy in gas sensing. Gas detection was performed through non-dispersive infrared (NDIR) absorption. The sensitivity of SF6 gas detection is increased around ∼27 times with metal hole array (MHA) microstructures placed on the gas cell mirrors, as compared with non-structured mirrors; an absorption change of 2% per 100 ppm was obtained on a standard commercial pyroelectric detector. Down-sizing of IR-sensors to a sub-1 mm gas cell width, delivering ∼ 40 nM (or 1 ppm) of SF6 sensitivity, can be foreseen with a simple source-detector setup.
First direct observation of self-imaging effect in active multimode-interference semiconductor laser diodes

We report the first direct observation of the self-imaging effect in active multimode-interference semiconductor laser diodes (MMI-SLDs). Interference patterns inside laser diode waveguides were obtained by using the electroluminescence (EL) method. To the best of our knowledge, this result is the first direct observation of the self-imaging effect in self-photon-emitting active waveguides such as laser diodes. The observed EL pattern confirms the adequateness of the design of the higher light output-aimed MMI-SLDs.
Intra-cavity absorber photocurrent characteristics of a quantum dot laser emitting on two emission-states: experiment and simulation

In this contribution we investigate both experimentally and by simulations a quantum dot absorber of a two-section quantum dot laser as an intra-cavity photodiode with a focus on the photo-generated absorber current. The escape of the photo-generated ES carrier sweep-out from the absorber can be controlled by variably biasing the absorber either with a variable external resistor in resistor Self-electro-optic-effect device (resistor-SEED) configuration or by applying a reverse bias. This escape is directly observable in the absorber photocurrent. In the resistor-SEED regime where the absorber is operated in so-called photoconductive mode, a steep increase in photocurrent is observed when the ES joins the GS emission and is attributed to increased losses, as reported recently. In contrast, GS emission and a low photocurrent in the resistor-SEED regime corresponds to a large carrier occupation probability corresponding to a reduced escape. In reverse bias operation, sole ES emission is observed together with a shallow increase in photocurrent with increasing reverse bias, in analogy to the p-n photodiode characteristics. By joining both resulting photocurrent regimes, the respective contributions of carrier capture and escape in the absorber to the averaged photocurrent is identified by numerical simulations. The obtained numerical results are in excellent qualitative agreement with the experiment.
Facial Expression Recognition Based on Multi-Channel Fusion of Gabor Features

This paper presents a facial expression recognition algorithm based on multi-channel integration of Gabor feature. First, a Gabor wavelet filter extracts facial features with 5 scales and 8 orientations, and then transform the 40 channels into 13 channels according to the maximum rule presented in this paper. Second, we reduce the dimension of expression features by the method of PCA+LDA. At last, expression features are classified using the nearest neighbor method. The experiments involve two databases and show that the proposed algorithm can recognize facial expression in high rate.
Light-emitting thin films of glassy forming organic compounds containing 2-tert-butyl-6-methyl-4H-pyran-4-ylidene

Low molecular mass organic compounds which make thin films from volatile organic solutions would be great benefit in future organic light emitting systems. Two most important advantages could be mentioned. First - the repetition of synthesis of small molecules is better than for polymers. Second - wet casting methods could be used. In this work we are presenting optical, electroluminescence and amplified spontaneous emission properties of four original glassy forming compounds containing 2-tert-butyl-6-methyl-4H-pyran-4-ylidene fragment as backbone of the molecule. They has the same N,N-dialkylamino electron donating group with incorporated bulky trityloxy ethyl groups. The difference of these compounds is in electron acceptor group. One has 1H-indene-1,3(2H)-dione group, second has pyrimidine-2,4,6(1H,3H,5H)-trione group, third has malononitrile group and fourth has 2-ethyl-2-cyanoacetate. Absorption maximum of the compounds is between 420 and 500 nm and is red shifted from weaker acceptor group to stronger one. The electroluminescence efficiency for simple device ITO/PEDOT:PSS/Organic compound/BaF/Al is low. For the best one with malononitrile group it was 0.13 cd/A and 0.036 lm/W. It could be increased by optimising the sample geometry or adding addition layers for charge carrier transport and exciton blocking. But nevertheless the use of these compounds in organic light emitting devices in neat films is unlikely. Attached bulky trityloxy ethyl groups and tert-butyl group decrease interaction between the molecules thus allowing to obtain amplified spontaneous emission in neat thin films for all investigated compounds.
An Inventory System with Periodic Regular Review and Flexible Emergency Review

We analyze a discrete time inventory model with two supply modes. Regular orders are placed periodically and arrive after a deterministic lead time. Emergency orders, characterized by a shorter deterministic lead time but higher purchase costs, can be placed in case of imminent stock-outs. We propose and analyze flexible order-up-to policies with emergency orders that arrive one, two, . , up to some fixed number of time units before a regular order arrives. Based on an approximate cost model, we develop two sets of approximate explicit optimality conditions. The first set of conditions are rather complicated, but simulation shows that they do lead to near-optimal policies in most cases. The second set of conditions are very simple and seem more practical, but they only lead to a near-optimal policy if there are enough emergency supply opportunities in a review period to prevent most backorders.
Solving multi-resource allocation and location problems in disaster management through linear programming

In this paper we propose a new efficient linear programming based approach for multi-resource allocation and location problems in disaster management. Such problems require an integer solution and therefore, in most cases, the computations rely on integer and mixed-integer linear programming solvers. In general, these solvers can not handle large scaled problem. In this paper we demonstrate that there exists a large class of disaster management problems whose exact solutions can be obtained by applying the simplex method (linear programming). The results of numerical experiments are provided. Another important contribution of this paper is related to general cluster analysis and allocation. Namely, we demonstrate that the classical $k$-medoid clustering method can be implemented using linear programming techniques (simplex method) without relying on integer solvers.
Admissible Consensus of Multi‐Agent Singular Systems

Consensus problems are studied for both continuous‐time and discrete‐time multi‐agent singular systems with time‐invariant and directed communication topologies. Under restricted system equivalence of singular agents, sufficient and necessary conditions are obtained for admissible consensus ability with static protocols, which are based on both the relative information of the dynamic states and the absolute information of the static states. For a network of continuous‐time singular systems, the existence of admissible consensualization can be cast into strong stabilizability of the agent dynamics. Once discrete‐time multi‐agent singular systems satisfy the condition of reaching nontrivial final consensus states, strong stabilizability is a sufficient condition to achieve admissible consensualization. Two algorithms are proposed to construct two protocols, which are based on a linear matrix inequality and a modified Riccati equation, respectively. Finally, the algorithms are illustrated by two simulation examples.
COMPLEMENT PLOTS: ANALYZING OPPOSITES REVEALS MANDALA-LIKE PATTERNS IN HUMAN HEART BEATS

A highly regular two dimensional pattern is found in apparently chaotic time series of human heart beats. Complement plots are created by calculating the sine and cosine of each term of a time series, plotting them in the XY plane, and drawing a chord between successive points to represent transitions. In time series of R to R interval in the electrocardiogram, these chords generate a pattern of concentric rings. The pattern is absent in some psychotics, stressing the importance of psychological modulation of cardiac action. Similar patterns were detected in a few empirical time series, including some economic data. No such patterns obtain with random series, Brownian random walks, pink noise, chaotic series, or simple periodic series. The mandate pattern of concentric rings can be observed in integer series generated by a random walk with variable integer steps (greater than 2 and less than 13) that models the composition of quantic action and variation. They also obtain with integer biotic series generated by the process equation Ai+1 = Ai+g * sin Ai; that models bipolar feedback, pointing to the vital dialectic of complementary opposites. Sine and cosine, paradigmatic of complementary opposite, provide a tool to analyze the dynamic of opposites in time series. The data support the view that heart rate variation represents a biotic pattern generated by the opposing actions of the sympathetic and parasympathetic nerves as part of integrative neuropsychological processes.
Dust acoustic solitary waves and double layers in a dusty plasma with an arbitrary streaming ion beam

The effects of variable dust charge, dust temperature and an arbitrary streaming ion beam on small amplitude dust acoustic waves are investigated. It is found that both compressive and rarefactive solitons as well as double layers exist. There exists a critical ion beam velocity below which the ion beam is unable to generate solitons. Korteweg–de Vries (KdV) equations with third and fourth-order nonlinearity at the critical values are derived and the properties of dust acoustic solitary waves are discussed. In the vicinity of the critical values, KdV-type with mixed nonlinearity is obtained. The quite dense positive ion, the dust temperature, the ion beam density, mass ratio and temperature govern the existence of dust acoustic waves. The findings of this investigation may be useful in understanding laboratory plasma phenomena and astrophysical situations.
Towards a unified framework for high and low frequency return volatility modeling

This paper provides a selective summary of recent work that has documented the usefulness of high‐frequency, intraday return series in exploring issues related to the more commonly studied daily or lower‐frequency returns. We show that careful modeling of intraday data helps resolve puzzles and shed light on controversies in the extant volatility literature that are difficult to address with daily data. Among other things, we provide evidence on the interaction between market microstructure features in the data and the prevalence of strong volatility persistence, the source of significant day‐of‐the‐week effect in daily returns, the apparent poor forecast performance of daily volatility models, and the origin of long‐memory characteristics in daily return volatility series.
Livelihood Sustainability of Herder Households in North Tibet, China

The livelihood sustainability of rural residents has attracted a great deal of attention across the globe, especially in remote mountain areas. In this study, we interviewed 696 householders who were randomly selected from ‘Changtang’ (also called ‘North Tibet’), Tibetan Autonomous Region, China. Under the sustainable livelihood index (SLI) framework, we evaluated the livelihood sustainability of herder households and examined the differences between low- and high-sustainability groups. Our findings revealed the following: (1) The livelihood sustainability of all herder households was generally low; low-sustainability households accounted for 87.07% of the samples. (2) Social, human, and physical capitals accounted for 81.6% of the variance in the SLI of herder households. Less physical capital was the main reason for a lower SLI. (3) Compared with high-SLI households, low-SLI families were characterized by having a higher dependency on natural resources, fewer fixed assets, weaker personal ability, and less participation in social organizations. Moreover, low-sustainability households were more vulnerable to medical expenses. Our study suggests that policymakers should pay closer attention to skills training, promote livelihood diversification, and strengthen social capital security. These actions are recommended for global poverty reduction and to promote the United Nations’ Sustainable Development Goals.
Transformation of MHD modes near magnetic separatrix surfaces

The linear propagation of magnetosonic and of shear Alfven waves is considered in a magnetic configuration with an X-line and a parallel (along the X-line) magnetic field B/sup ///. The two modes are decoupled both in the limits of zero and of infinite B/sup ///, whereas for finite B/sup /// they transform one into the other. The spatial structure of the current densities induced by this transformation is examined in the small and in the large B/sup /// limit. In both limits the induced currents exhibit, either at the separatrices or at the X-line, singular structures which can be associated with the formation of current sheets.
Attack SureThing! Offensive security assessment of a location certiﬁcation system

—The SureThing project is developing a location certiﬁcation framework that can prevent location spooﬁng on Location Based Services (LBS). The current prototypes using the framework allow to issue and verify location certiﬁcates using mobile devices in a variety of use cases, including the CROSS smart tourism application. Despite the best efforts of designers, a system cannot be said to be truly secure and robust until it has experienced attacks from skilled and motivated attackers. With that in mind, we performed an offensive security assessment of CROSS, composed a smart tourism mobile application that issues location certiﬁcates and a server with a publicly exposed interface on the Internet. Our assessment involved exercising offensive security techniques, in the form of vulnerability assessment and penetration testing. We used generic tools, from different vantage points in the network, always in the perspective of an attacker. We present the tools and the techniques that were used to attack the server of the CROSS system, along with the our ﬁndings and the procedures taken to harden the server after the detection of vulnerabilities. Our security assessment included the use of ﬁve different tools. Using them, we were able to ﬁnd a previously unknown vulnerability that allowed unauthorized writes to the database of the server. We also prepared all the necessary materials, allowing the same offensive approach to be replicated by organizing future offensive security tournaments, so that the same attacks can be reproduced in a gamiﬁed environment allowing for the future discovery of new attacks.
The Polarization Lidar Technique for Cloud Research: A Review and Current Assessment

Abstract The development of the polarization lidar field over the past two decades is reviewed, and the current cloud-research capabilities and limitations are evaluated. Relying on fundamental scattering principles governing the interaction of polarized laser light with distinctly shaped hydrometers, this remote-sensing technique has contributed to our knowledge of the composition and structure of a variety of cloud types. For example, polarization lidar is a key component of current climate-research programs to characterize the properties of cirrus clouds, and is an integral part of multiple remote-sensor studies of mixed-phase cloud systems, such as winter mountain storms. Although unambiguous cloud-phase discrimination and the identification of some ice particle types and orientations are demonstrated capabilities, recent theoretical approaches involving ice crystal ray-tracing and cloud microphysical model simulations are, promising to increase the utility of the technique. New results simulating the.
Estimating the Short-Run Income Elasticity of Demand for Electricity by Using Cross-Sectional Categorized Data

Abstract This study uses the 1980 energy application survey conducted by Ontario Hydro to estimate a short-run or conditional demand for electricity model. Two-step inference procedures are developed to take account of the special nature of the data in which the income variable is recorded in categorical form. Comparisons of short-run income elasticities with other studies, using the complete information of income variable, are also made.
Robustness of Standard Confidence Intervals for Location Parameters Under Departure from Normality

Let X i = θ + σZ i , where Z i are i.i. d. from a distribution F, and -∞ 0 are unknown parameters. If F is N(0,1), a standard confidence interval for the unknown mean θ is the t-interval X± t α/2 s/? n. The question of conservatism of this interval under nonnormality is considered by evaluating the infimum of its coverage probability when F belongs to a suitably chosen class of distributions F. Some rather surprising phenomena show up. For F={all symmetric unimodal distributions} it is found that, for high nominal coverage intervals, the minimum coverage is attained at U[-1,1] distribution, and the t-interval is quite conservative. However, for intervals with low or moderate nominal coverages (t α/2 < 1), it is proved that the infimum coverage is zero, thus indicating drastic sensitivity to nonnormality. This phenomenon carries over to more general families of distributions. Our results also relate to robustness of the P-value corresponding to the t-statistic when the underlying distribution is nonnormal.
1. Regression Analysis of Multivariate Binary Response Variables Using Rasch-Type Models and Finite-Mixture Methods

A model is considered for the regression analysis of multivariate binary data such as repeated-measures data (for example, panel data) or multiple-indicators with measures of some underlying characteristic such as attitude or ability (for example, surveys or tests). The model is related to the usual Rasch model, the usual latent-class model, and other familiar models such as logistic regression. In addition to a regression specification, the model includes parameters that describe heterogeneity not accounted for by the predictors. In contrast to most other approaches, a nonparametric specification of the latent mixing distribution is used, leading to a formulation based on scaled latent classes. We examine the relationship between this model and several other models, give a tractable formulation of the likelihood function and likelihood equations, present an algorithm for maximum-likelihood estimation, and analyze marginal and conditional latent structures. The approach is illustrated with longitudinal data from the German Socioeconomic Panel.
THE SPECTRUM OF THE NEBULOSITY AROUND THE SYMBIOTIC LONG-PERIOD VARIABNLE, R AQR.

Multichannel spectrophotometric and SIT spectrograph data are reported for the symbiotic star R Agr, and the physical parameters that describe the emission nebulosity are established. The reddening is 0.67 in (B-V), an electron temperature near 11,000 K is derived, and an electron density between 300,000 and 5,000,000 is found on the star position. A small enhancement of helium and a substantial enhancement of nitrogen are observed; the ratios of Ne III and S III to O III are nearly normal. Attention is also given to physical dimensions for the system, and the expansion velocity is estimated at about 30 km/s. In addition, it is argued that R Aqr may be a single star with a magnetically active region.