Miracle-dz/UniFAR-FTUs huggingface dataset:
Simple theoretical model for the temperature stability of InAs/GaAs self-assembled quantum dot lasers with different p-type modulation doping levels

We have developed a simple theoretical model to account for the effects of different p-doping levels on the temperature-dependent performance of InAs/GaAs self-assembled quantum dot (QD) lasers. An assumption of equal occupation probabilities among QDs has been applied for operating conditions near the lasing threshold. Theoretical results indicate that there is an optimum p-doping region, which can provide the lowest temperature dependence of lasing threshold at room temperature.
4H SiC betavoltaic powered temperature transducer

The change in open-circuit voltage of a 4H SiC p-n diode betavoltaic cell in response to temperature was used to sense temperature. A linear sensitivity of 2.7mV∕K was obtained from 24to86°C. This was achieved with only 2. 5μCi of active nickel-63 as the β source, giving a short circuit current of 21pA, a low-enough activity for civilian applications. The measured sensitivity of 2.7mV∕K was lower than the 5.5mV∕K predicted from the theory. The 28GΩ shunt resistance of the betavoltaic cell was used to explain the lower sensitivity.
Response of Auditory Neurons to Intensity Increments

Single units in the cochlear nuclei of anesthetized Mongolian gerbils were studied. Stimuli were tones at unit's best frequency and response firing rates were determined from PST histograms. The units under consideration typically showed an onset peak and decay to steady firing rate in response to 300‐msec tone bursts. The tone bursts served as pedestals upon which step intensity increments were placed. In response to the increments, units showed a jump in firing rate. The time of occurrence of the increment was varied relative to the onset of the pedestal. The maximum firing rate reached in response to the increment was found to be relatively independent of the time of occurrence of the increment. Thus, both the absolute and the relative change in firing rate caused by the increment increased as a function of time relative to the onset of the pedestal. The effect occurred over a wide range of increment and pedestal intensities and could not be attributed to saturation of firing rate. It may be related to the psychophysical ability to detect more easily intensity increments during, rather than at, the onset of tone pedestals.
Estimation of error rate in multiple group logistic discrimination. the approximate leaving-one-out method

We present an approximate leaving-one-out technique for estimating the error rate in logistic discrimination. The new measure is based on the one-step approximation of a(i), the maximum likelihood estimate of the parameter vector based on the sample without the ith case. Some inequalities between the resubstitution error rate, the approximate and exact leaving-one-out error rates for the multiple group logistic model are investigated. Monte-Carlo simulations assess the adequacy of the approximate leaving-one-out method as an estimate of the actual error rate. The usefulness of this approach is demonstrated by means of two medical examples.
MHD simulation for the interaction of an interplanetary shock with the Earth's magnetosphere

[1] The global BATS-R-US MHD code is used to simulate the interaction of a moderately strong interplanetary shock with the Earth's magnetosphere. The model predicts the propagation of a transmitted fast shock through the magnetosheath and magnetosphere and the reflection of this shock from the inner numerical boundary. The reflected fast shock propagates sunward through the dayside magnetosphere and magnetosheath. The passage of the transmitted shock causes the bow shock and magnetopause to move inward, while the passage of the reflected fast shock causes these boundaries to move outward, consistent with previously reported in situ observations. A supplementary study employing a one-dimensional MHD model addresses the interaction of the forward fast shock with the plasmapause. This study demonstrates that most of the energy associated with the fast shock energy penetrates into the plasmasphere. Consequently, the transmitted fast wave must reach the ionosphere, produce the well known sudden impulse signatures, and then be reflected due to the shielding effects of ionospheric currents. The predictions of the numerical simulations are consistent with observations of the dayside geosynchronous magnetic field.
The Subparsec-Scale Structure and Evolution of Centaurus A: The Nearest Active Radio Galaxy

The subparsec-scale structure of Cen A is complex, consisting of a bright jet and a fainter counterjet. The bright jet contains components that have subluminal speeds of approximately 0.1c and undergo irregular episodes of rapid internal evolution. The rapid evolution sometimes observed could be interpreted as evidence for an underlying jet flow much faster (>0.45c) than observed from the proper motion of components (∼0.1c). Considering the large-scale morphology of the source, the motions and temporal variations in the jet, and the detection of a counterjet, we conclude that the axis of the Cen A jet lies between ∼50° and ∼80° to our line of sight. We find that the estimated times of component ejection from the compact core are reasonably coincident with enhancements in hard X-ray intensity and 22 GHz flux density. In the context of the radio galaxy population, Cen A is a low-luminosity FR I–type source and in general has the properties observed in other FR I radio galaxies. Overall, the observations of Cen A presented here, and from other investigations, are consistent with the idea that sources with an FR I appearance are not aligned with our line of sight and have relativistic flow on the subparsec scale. The apparently subluminal subparsec-scale jet components are interpreted as being slow patterns on the relativistic flow.
Transport of energy by ultraintense laser-generated electrons in nail-wire targets

Nail-wire targets (20 μm diameter copper wires with 80 μm hemispherical head) were used to investigate energy transport by relativistic fast electrons generated in intense laser-plasma interactions. The targets were irradiated using the 300 J, 1 ps, and 2×1020 W⋅cm−2 Vulcan laser at the Rutherford Appleton Laboratory. A spherically bent crystal imager, a highly ordered pyrolytic graphite spectrometer, and single photon counting charge-coupled device gave absolute Cu Kα measurements. Results show a concentration of energy deposition in the head and an approximately exponential fall-off along the wire with about 60 μm 1/e decay length due to resistive inhibition. The coupling efficiency to the wire was 3.3±1.7% with an average hot electron temperature of 620±125 keV. Extreme ultraviolet images (68 and 256 eV) indicate additional heating of a thin surface layer of the wire. Modeling using the hybrid E-PLAS code has been compared with the experimental data, showing evidence of resistive heating, magnetic trap.
BAYESIAN METHODS AND MAXIMUM ENTROPY FOR ILL-POSED INVERSE PROBLEMS

In this paper, we study linear inverse problems where some generalized moments of an unknown positive measure are observed. We introduce a new construction, called the maximum entropy on the mean method (MEM), which relies on a suitable sequence of finite-dimensional discretized inverse problems. Its advantage is threefold: It allows us to interpret all usual deterministic methods as Bayesian methods; it gives a very convenient way of taking into account prior information; it also leads to new criteria for the existence question concerning the linear inverse problem which will be a starting point for the investigation of superresolution phenomena. The key tool in this work is the large deviations property of some discrete random measure connected with the reconstruction procedure.
Error and sensitivity analysis of stochastic approximation algorithms for linear system identification

Propagation of errors in identifying constant coefficient parameters of a discrete time linear system, using stochastic approximation algorithms, is investigated. Error and sensitivity analysis algorithms are derived for the cases when there is structural modeling error as well as when the a priori statistics of identified parameters, and plant and measurement noise, are incorrectly specified. The error and sensitivity analysis algorithms are useful as a design tool to better specify appropriate identification algorithms for actual implementation. The error and sensitivity analysis algorithms are applied to several examples including identification of eight predictor coefficients for adaptive digitized speech transmission.
Characteristics of radio transmitter fingerprints

In this paper, the characteristics of radio transmitter fingerprints will be examined by analyzing both the amplitude and phase information obtained from complex envelope recordings of transmitter turn‐on transients. The interest in the analysis of such transients is related to the identification of malfunctioning or illegally operated radio transmitters in support of radio spectrum management practices. Of the 28 VHF radios considered in this study, many were found to produce fingerprints having uniquely distinctive features which could be used for identification purposes. Unfortunately, some of these radios were found to have fingerprints that were virtually indistinguishable from each other, making the identification process more difficult, if not impossible. Details of the equipment, analyses, and data collection procedures will be presented along with a discussion of the experimental results. The merits of this technique over others currently in use will also be presented.
Representations of polycyclic groups

L. Auslander [1] has recently shown that every polycyclic group' has a faithful representation in GL(n, Z) for some n, thus solving a problem of P. Hall [2]. His proof involves considerable knowledge of the theory of Lie groups. Since the result obtained is purely algebraic, it is of interest to find a purely algebraic proof of it. It struck me that the proof of Ado's theorem [5] could be adapted to this purpose and I will show here that this is indeed the case. I would like to thank J. Thompson and J. Alperin for calling this problem to my attention. Recall that a matrix (aij) is called uni-triangular if aij = 0 for j <i and aii = i for all i. These form a nilpotent subgroup Tn(Z) of GL(n, Z).
Dynamic estimation of number of clusters in data sets

A new method for estimating during clustering the number of clusters in data sets is proposed. The cluster validity index, Bcrit, takes the homogeneity in each cluster into account and is connected to the geometrical properties of the data set. Bcrit represents the combination of two validity indices. Comparisons between Bcrit and six cluster validity indices, conducted on real data sets, are presented.
Polarization of Astronomical Maser Radiation. II. Polarization Modes and Unsaturated Growth

Maser polarization is analyzed in the limit of overlapping Zeeman components (gν B Δν D , where gν B is the Zeeman splitting and Δν D is the Doppler width). All the discrepancies among the conflicting conclusions of previous studies that identified maser polarizations in this limit are fully resolved. In the case of m-independent pumping, proper application of the eigenvalue technique of Goldreich, Seeley, & Swan shows that the polarization eigenvectors are the same for saturated and unsaturated masers and are independent of spin for pure spin states, in agreement with the results of the first paper in this series. Stable eigenvectors correspond to the peak of the polarization mode distribution of self-amplified radiation at any degree of saturation
A FAST CARTESIAN SCHEME FOR UNSTEADY HEAT DIFFUSION ON IRREGULAR DOMAINS

A numerical integration method is presented for the treatment of transient heat conduction problems. A Cartesian formulation is developed that is suitable for the treatment of irregular domains under general boundary conditions. The qualities of the scheme are demonstrated, in terms of both accuracy and computational efficiency, by comparison with analytical and numerical solutions. Results for the basic two-dimensional annular geometry show that the method has nearly second-order accuracy in space and time, at least in simple cases. Finally, a complex multiconnected domain is considered, to test the method performance under more severe conditions, including the presence of multiple length scales. The numerical experiment demonstrates that the numerical scheme is efficient, stable, and convergent.
Ambient‐Noise Directivity Measurements

Measurements have been made from which the vertical directivity of ambient sea noise near the ocean bottom in water 14 500 ft deep has been computed. A vertical linear array of 40 hydrophones was used, with delay lines, to form 28 beams in directions from horizontal to vertically upward. Measurements were made at four fixed frequencies, 200, 400, 750, and 1500 cps, in a variety of weather conditions. The directional distribution of the noise is shown as a function of angle for three sea states at each frequency. It is found that at low sea state the noise distribution has a peak in the horizontal direction. As the sea state increases, the vertical and near‐vertical contributions increase more rapidly than do the horizontal contributions.
The relationship between the body mass index and the subcutaneous adipose tissue

Objectives: The aim of the study was to investigate the relationship between the body mass index and ultrasound-measured subcutaneous adipose tissue (SCAT) thickness, in order to propose an alternative non-invasive and inexpensive method to measure the subcutaneous fat. We also evaluated the liver size and the existence of hepatosteatosis, and investigated whether there was a relationship between liver measurements and body mass index (BMI), and the SCAT measurements. Methods: Height, weight, arm SCAT, umbilical SCAT, thigh SCAT, umbilical preperitoneal fat (PPF) and craniocaudal liver size of 72 volunteers were measured and liver parenchymal echogenicity was evaluated with ultrasound. Correlations between BMI and the SCAT, the PPF, and liver measurements were evaluated statistically. Results: BMI was mostly well correlated with umbilical SCAT (r=0.650, p<0.001). The arm SCAT (r=0.549, p<0.001) and the thigh SCAT (r=0.470, p£0.001) followed it. The umbilical PPF was only correlated with the umbilical SCAT. There was no relationship between arm, or thigh SCAT values and existence of hepatosteatosis, but existence of hepatosteatosis was related with umbilical SCAT (p=0.008), and umbilical PPF (p=0.009) values. Conclusion: As an alternative method to skinfold measurement, SCAT measurement with ultrasound can be used to evaluate body fat status.
The role of high-frequency cues for spatial hearing in rooms

The ability to attend to a sound source of interest while ignoring competing sounds is vital to navigating everyday acoustic scenes. Commonly, this ability depends on the ability to focus on a sound source using acoustic spatial cues, particularly interaural time differences (ITDs) and interaural level differences (ILDs). Based on past studies of localization in anechoic settings, low-frequency ITDs have been thought to dominate perception of source location. However, reverberant environments differentially degrade ITDs and ILDs, which may affect their relative influence on localization. Moreover, a recent study suggests that ILDs play a bigger role on spatial perception in reverberant settings than in anechoic settings. Here, in a series of localization and spatial attention experiments using high-pass, low-pass and broadband sounds, we tested the hypothesis that high-frequency ILD and envelope ITD cues are important for spatial judgments in reverberant rooms. We also measured the brainstem frequency fol.
No species loss, but pronounced species turnover in grasslands in the Northern Alps over 25 years

Abstract The abandonment of marginally productive habitats and the intensification of land use on productive sites have caused transformative changes in vegetation composition in Central Europe. In this study, after 25 years we resurveyed a total of 145 grassland relevés from the mid‐1990s in a grassland‐dominated valley of the Northern Alps of Upper Austria. We studied changes in richness and composition, and related these to underlying drivers. We found that the average species number in plots increased from 46 in the first survey period to 49 in the second one. Median species richness across sites significantly increased from 1995 to 2020 for Festuco‐Brometea (55–61 species) and Galio‐Urticetea (24–32 species), but did not show any significant change for the other classes. Further, we recorded substantial species turnover, with winners consisting mostly of species that prefer nutrient‐rich sites, while losers were predominantly species of nutrient‐poor sites. In particular, using Ellenberg Indicator Values for calculating community indices, we found an indication for ongoing eutrophication in vegetation types of nutrient‐poor vegetation classes ( Festuco‐Brometea and Calluno‐Ulicetea ), and in wet habitats ( Scheuchzerio‐Caricetea fuscae). Community indices of wet habitats also showed clear signs of becoming more mesic. Thermophilization of community indices was evident across several vegetation classes. Further, alien species that were very rare in the mid‐1990s became more abundant in the resurveyed plots, although the level of invasion is still low. Finally, community values for nutrients of plots that are located in a protected area that has been established in 2014 did not increase significantly, while this was the case in plots outside the protected area, indicating that the management of the protected area has positive effects in halting eutrophication. We conclude that despite overall species richness changing only moderately between both surveys, substantial changes in community composition toward more nitrophilic and thermophilic conditions occurred.
The X-ray absorption spectrum of Vela X-1

Exosat observations of the massive X-ray binary Vela X-1 are spectrally analyzed. The absorbing column density shows erratic factor of 10 increases up to 5 x 10 to the 23rd H/sq cm that can occur at any orbital phase and last from minutes to many hours. These variations occur on top of a base level of absorption that increases from 3 x 10 to the 22nd H/sq cm to 15 x 10 to the 22nd H/sq cm from orbital phase about 0.2 to 0.85. It is suggested that these changes are due to intermittent formation of a tenuous accretion disk around the neutron star. The X-ray spectra show a low-energy excess above that expected from cold photoelectric absorption. The character of this excess depends on orbital phase and two different modifications to the simple absorption model are required. 24 refs.
A fiber laser pumped dual-wavelength mid-infrared optical parametric oscillator based on aperiodically poled magnesium oxide doped lithium niobate

We report a fiber laser pumped dual-wavelength mid-infrared optical parameter oscillator (OPO) based on an aperiodic optical superlattice (AOS) structure. An aperiodically poled MgO-doped lithium niobate wafer was designed and fabricated as the nonlinear crystal for the OPO. Using a linearly polarized pulsed Yb fiber laser at 1.064 μm as the pump source, mid-infrared emissions at 3.3 and 3.8 μm were obtained simultaneously from the OPO. The total output power at the idler wavelengths of 3.3 and 3.8 μm reached 3.07 W under the maximum pump power of 27 W. The pump-to-idler conversion efficiency was 11.4% with a ratio of about 1.2:1 for 3.3 μm and 3.8 μm.
Perceived Social Support and Alcohol Consumption during Adolescence: A Path-Analysis with Internalizing and Externalizing Behaviour Problems

ABSTRACT The aim of the current study was to investigate the relationship between adolescents’ social support, their internalising and externalising behaviour problems, and their alcohol consumption. Adolescents attending Grade 7–10 (N = 329), answered questionnaires regarding their perceived social support (from parents, teachers, classmates, and friends), internalising (emotional and peer problems) and externalising behaviour problems (hyperactivity and conduct problems), and alcohol consumption (monthly frequency of consumption, beverage consumption on the weekend, and problematic consumption). Building a structural equation model, we found negative associations between parent support and all internalising and externalising behaviour problem scales. Furthermore, social support from classmates was negatively associated with the internalising behaviour problem scales. In turn, peer problems were negatively associated with alcohol consumption, and conduct problems were positively associated with alcohol consumption. Both parent and teacher support had a direct effect on alcohol consumption, and parent support also had an indirect effect via behaviour problems. The findings highlight the importance of parents and teachers for alcohol consumption during adolescence.
EXPLORING THE AUSTRALIAN PUBLIC'S RESPONSE TO HYDROGEN

Over the past three years there has been a rapid increase in discussions across the different levels of Australia’s governments about the role that hydrogen might play in helping the world transition to a low carbon future. While those working in the energy industry are aware of the opportunities and challenges that lay ahead, the general public is less engaged. However, we know from the introduction of previous technologies that public attitudes towards technologies, including whether they view them to be safe, can severely impact overall acceptance. Understanding how the public perceives hydrogen, both for domestic and export use and the potential benefits it brings to Australia is critical for the industry to progress. In this paper we present the initial findings of a national survey of the Australian public conducted in March 2021, which builds on the results of a previous survey conducted in 2018. The 2021 respondents were drawn from all Australian states and territories ( n =3,020), and quotas were used to ensure adequate representation of age groups and gender. Overall, the respondents have favorable views about using hydrogen for energy in Australia, with caveats about production-related environmental impacts and issues such as safety. While there has been a slight increase in support for hydrogen as a possible solution for energy and environmental challenges since the 2018 survey, the effect size is very small. This suggests that while hydrogen discussions have increased at a policy level, little has been done to improve public understanding of hydrogen in the last 3 years. Evidence-based public communication strategies will be needed as the Australian hydrogen industry continues to develop and gain more widespread media attention.
Phyllanthus debilis : A poorly investigated plant with antidiabetic effects

- Phyllanthus debilis ( Ela pitawakka in Sinhala) whole plant is used as a remedy for diabetes mellitus. However, scientific evidence available on its therapeutic effects is very limited. The aim of this review was to focus on the limited scientific literature available on the antidiabetic effects, phytochemicals and safety of P. debilis . According to the reported findings, P. debilis has demonstrated evidence to support its hypoglycemic effects, glycation and glycation induced cross-link inhibitory effects and antioxidant effects that are known to minimize diabetic complications. Additionally, anti-inflammatory effects, anticancer effects, antihepatotoxic effects and some phytochemicals present in P. debilis have been revealed. More investigations on P. debilis need to be carried out.