Miracle-dz/UniFAR-FTUs huggingface dataset:
Strong Calcium Emission Indicates that the Ultraviolet-flashing SN Ia 2019yvq Was the Result of a Sub-Chandrasekar-mass Double-detonation Explosion

We present nebular spectra of the Type Ia supernova (SN Ia) SN 2019yvq, which had a bright flash of blue and ultraviolet light after exploding, followed by a rise similar to other SNe Ia. Although SN 2019yvq displayed several other rare characteristics, such as persistent high ejecta velocity near peak brightness, it was not especially peculiar, and if the early “excess” emission were not observed, it would likely be included in cosmological samples. The excess flux can be explained by several different physical models linked to the details of the progenitor system and explosion mechanism. Each has unique predictions for the optically thin emission at late times. In our nebular spectra, we detect strong [Ca ii] λλ7291, 7324 and Ca near-IR triplet emission, consistent with a double-detonation explosion. We do not detect H, He, or [O i] emission, predictions for some single-degenerate progenitor systems and violent white dwarf mergers. The amount of swept-up H or He is <2.8 × 10−4 and 2.4 × 10−4 M⊙, respectively. Aside from strong Ca emission, the SN 2019yvq nebular spectrum is similar to those of typical SNe Ia with the same light-curve shape. Comparing to double-detonation models, we find that the Ca emission is consistent with a model with a total progenitor mass of 1.15 M⊙. However, we note that a lower progenitor mass better explains the early light-curve and peak luminosity. The unique properties of SN 2019yvq suggest that thick He-shell double detonations only account for of the total “normal” SN Ia rate. The SN 2019yvq is one of the best examples yet that multiple progenitor channels appear necessary to reproduce the full diversity of “normal” SNe Ia.
Equivalent conditions for simultaneous diagonalization via *-congruence of Hermitian matrices

This paper aims at giving some equivalent conditions for that a collection of finitely many of Hermitian matrices can be simultaneously diagonalizable via congruence (SDC) by a nonsingular matrix. It surprisingly turns out that one of such equivalent conditions applies the semidefinite programming (SDP), which leads to a practical usefulness. As a consequence, this certainly solves such SDC-problem for collections of real symmetric matrices listed in [J-B. Hiriart-Urruty, Potpourri of conjectures and open questions in nonlinear analysis and optimization, \textit{SIAM Review} 49(2), 2007]. Corresponding algorithms and illustrating examples by hand/coding are also presented.
Two-size probability-changing cluster algorithm

We propose a self-adapted Monte Carlo approach to automatically determine the critical temperature by simulating two systems with different sizes at the same temperature. The temperature is increased or decreased by checking the short-time average of the correlation ratios of the two system sizes. The critical temperature is achieved using the negative feedback mechanism, which can be regarded as an Ehrenfest model for diffusion with a central force. Moreover, the thermal average near the critical temperature can be calculated precisely. The proposed approach is a general method to treat second-order phase transition, first-order phase transition, and Berezinskii–Kosterlitz–Thouless transition on the equal footing.
Assessing spatial activity in captive feral ferrets, Mustela furo L. (Camivora: Mustelidae)

Abstract We observed eight male and five female feral ferrets (Mustela furo) directly and by video recording in an outdoor enclosure consisting of a 36 m2 arena and six dens and 13 tunnels. We determined the sizes of main ranges and core areas, the overlaps in areas and intensity of use, the patterns of use of dens and core areas, and the extent of temporal overlap between individuals. We assessed the effect of sex, grouping, density, social status and observation period on these spatial patterns. From May 1995 to December 1996, five social groups (two males, two females, one male with two females, two males with one female, and three males) were tested. The spatial patterns identified were consistent with previous studies of free‐ranging feral ferrets in New Zealand. Range sizes of males and females were similar. Dominant males had more temporal overlap with females than did subordinate males. There was less den sharing within sexes than between sexes. We conclude that intrasexual territoriality was demonstrated, and that the described methodology is an effective means of studying, in captivity, aspects of ferret social organisation and behaviour that are difficult to observe in free‐ranging animals.
A first look at the IP eXchange ecosystem

The IPX Network interconnects about 800 Mobile Network Operators (MNOs) worldwide and a range of other service providers (such as cloud and content providers). It forms the core that enables global data roaming while supporting emerging applications, from VoLTE and video streaming to IoT verticals. This paper presents the first characterization of this, so-far opaque, IPX ecosystem and a first-of-its-kind in-depth analysis of an IPX Provider (IPX-P). The IPX Network is a private network formed by a small set of tightly interconnected IPX-Ps. We analyze an operational dataset from a large IPX-P that includes BGP data as well as statistics from signaling. We shed light on the structure of the IPX Network as well as on the temporal, structural and geographic features of the IPX traffic. Our results are a first step in understanding the IPX Network at its core, key to fully understand the global mobile Internet.
Resource-rational Task Decomposition to Minimize Planning Costs

People often plan hierarchically. That is, rather than planning over a monolithic representation of a task, they decompose the task into simpler subtasks and then plan to accomplish those. Although much work explores how people decompose tasks, there is less analysis of why people decompose tasks in the way they do. Here, we address this question by formalizing task decomposition as a resource-rational representation problem. Specifically, we propose that people decompose tasks in a manner that facilitates efficient use of limited cognitive resources given the structure of the environment and their own planning algorithms. Using this model, we replicate several existing findings. Our account provides a normative explanation for how people identify subtasks as well as a framework for studying how people reason, plan, and act using resource-rational representations.
Conservation of the Biodiversity of Brazil's Inland Waters

Abstract: In terms of biodiversity, Brazilian inland waters are of enormous global significance for Algae (25% of the world's species), Porifera (Demospongiae, 33%), Rotifera (25%), Cladocera (Branchiopoda, 20%), and fishes (21%). Threatened freshwater species include 44 species of invertebrates (mostly Porifera) and 134 fishes (mostly Cyprinodontiformes, Rivulidae), primarily distributed in south and southeastern Brazil. Reasons for the declines in biodiversity in Brazilian inland waters include pollution and eutrophication, siltation, impoundments and flood control, fisheries, and species introductions. These problems are more conspicuous in the more‐developed regions. The majority of protected areas in Brazil have been created for terrestrial fauna and flora, but they also protect significant water bodies and wetlands. As a result, although very poorly documented, these areas are of great importance for aquatic species. A major and pressing challenge is the assessment of the freshwater biodiversity in protected areas and surveys to better understand the diversity and geography of freshwater species in Brazil. The concept of umbrella species (e.g., certain migratory fishes) would be beneficial for the protection of aquatic biodiversity and habitats. The conservation and improved management of river corridors and associated floodplains and the maintenance of their hydrological integrity is fundamental to preserving Brazil's freshwater biodiversity and the health of its aquatic resources.
Photoinhibition of Photosynthesis Induced by Visible Light

INTRODUCTION . PHOTOINHIBITION FROM EXPOSURE TO A HIGH PFD WITHOUT ADDITIONAL STRESS . Aquatic Plants . Shade Plants . Sun Plants. Damage to Photosynthesis Caused by an Excessive PFD . PHOTOINHIBITION INDUCED BY INTERACTION BETWEEN LIGHT AND OTHER ENVIRONMENTAL STRESS FACTORS .
Survey of 3 rd generation cephalosporin genes in multi- resistant Salmonella serotypes from septic poultry and an asymptomatic healthy pig from Nigeria

Occurrence and spread of Salmonella genes encoding AmpC and extended-spectrum beta-lactamases (ESBL) is a major public health problem worldwide. These genes have been identified in Salmonella serotypes all over the world yet there is paucity of reports on these genes in Nigeria, despite the phenotypic evidence of resistance to beta-lactam drugs. The current work used a multiplex PCR to identify beta-lactam resistance genes in five Nigerian-origin Salmonella isolates exhibiting resistance to third-generation cephalosporins. The isolates included four strains isolated from septic poultry (two strains of Salmonella enterica serotype Kentucky and two strains of presumptive S. enterica serotype Pullorum) and one S. enterica serotype Give isolated from one of two hundred asymptomatic pigs. The predominant genes found in these Nigeria serotypes include: TEM, SHV, GES, OXA-2, ACCM, FOX, ECBM and DHAM. The presence of these plasmid-borne genes underscores the potential health risk of antibiotic resistance transfer from food animals to human in Nigeria because third-generation cephalosporin drugs are still the drug of choice in treating life-threatening systemic infections in Nigeria. Key words:
Cost of quantum entanglement simplified

Quantum entanglement is a key physical resource in quantum information processing that allows for performing basic quantum tasks such as teleportation and quantum key distribution, which are impossible in the classical world. Ever since the rise of quantum information theory, it has been an open problem to quantify entanglement in an information-theoretically meaningful way. In particular, every previously defined entanglement measure bearing a precise information-theoretic meaning is not known to be efficiently computable, or if it is efficiently computable, then it is not known to have a precise information-theoretic meaning. In this Letter, we meet this challenge by introducing an entanglement measure that has a precise information-theoretic meaning as the exact cost required to prepare an entangled state when two distant parties are allowed to perform quantum operations that completely preserve the positivity of the partial transpose. Additionally, this entanglement measure is efficiently computable by means of a semidefinite program, and it bears a number of useful properties such as additivity and faithfulness. Our results bring key insights into the fundamental entanglement structure of arbitrary quantum states, and they can be used directly to assess and quantify the entanglement produced in quantum-physical experiments.
Determinants of some special matrices over commutative finite chain rings

Abstract Circulant matrices over finite fields and over commutative finite chain rings have been of interest due to their nice algebraic structures and wide applications. In many cases, such matrices over rings have a closed connection with diagonal matrices over their extension rings. In this paper, the determinants of diagonal and circulant matrices over commutative finite chain rings R with residue field 𝔽q are studied. The number of n × n diagonal matrices over R of determinant a is determined for all elements a in R and for all positive integers n. Subsequently, the enumeration of nonsingular n × n circulant matrices over R of determinant a is given for all units a in R and all positive integers n such that gcd(n, q) = 1. In some cases, the number of singular n × n circulant matrices over R with a fixed determinant is determined through the link between the rings of circulant matrices and diagonal matrices. As applications, a brief discussion on the determinants of diagonal and circulant matrices over commutative finite principal ideal rings is given. Finally, some open problems and conjectures are posted
A Comparative Study of Multilateration Methods for Single-Source Localization in Distributed Audio

—In this article we analyze the state-of-the-art in multilateration - the family of localization methods enabled by the range difference observations. These methods are computationally efﬁcient, signal-independent, and ﬂexible with regards to the number of sensing nodes and their spatial arrangement. However, the multilateration problem does not admit a closed-form solution in the general case, and the localization performance is conditioned on the accuracy of range difference estimates. For that reason, we consider a simpliﬁed use case where multiple distributed microphones capture the signal coming from a near ﬁeld sound source, and discuss their robustness to the estimation errors. In addition to surveying the relevant bibliography, we present the results of a small-scale benchmark of few “main-stream” multilateration algorithms, based on an in-house Room Impulse Response dataset.
Rigidity of Compact Fuchsian Manifolds with Convex Boundary

A compact Fuchsian manifold with boundary is a hyperbolic 3-manifold homeomorphic to $S_g \times [0; 1]$ such that the boundary component $S_g \times \{ 0\}$ is geodesic. We prove that a compact Fuchsian manifold with convex boundary is uniquely determined by the induced path metric on $S_g \times \{1\}$. We do not put further restrictions on the boundary except convexity.
The Ionized- and Cool-gas Content of the BR1202−0725 System as Seen by MUSE and ALMA

We present Multi Unit Spectroscopic Explorer (MUSE) observations of the gas-rich major merger BR1202−0725 at z ∼ 4.7, which constitutes one of the most overdense fields known in the early universe. We utilize these data in conjunction with existing Atacama Large Millimeter/submillimeter Array (ALMA) observations to compare and contrast the spatially resolved ionized- and cool-gas content of this system, which hosts a quasar (QSO), a submillimeter galaxy (SMG), the two known optical companion Lyα emitters (“LAE 1” and “LAE 2”), and an additional companion discovered in this work “LAE 3” just 5″ to the north of the QSO. We find that QSO BR1202−0725 exhibits a large Lyα halo, covering ≈55 pkpc on-sky at surface-brightness levels of SB ≥ 1 × 10−17 erg s−1 cm−2 arcsec−2. In contrast, the SMG, of similar far-infrared luminosity and star formation rate (SFR), does not exhibit such a Lyα halo. The QSO’s halo exhibits high velocity widths (∼1000 km s−1) but the gas motion is to some extent kinematically coupled with the previously observed [C ii] bridge between the QSO and the SMG. We note that the object known in the literature as LAE 2 shows no local peak of Lyα emission, rather, its profile is more consistent with being part of the QSO’s extended Lyα halo. The properties of LAE 3 are typical of high-redshift LAEs; we measure FLyα(LAE 3) = 0.24 ± 0.03 × 10−16 erg s−1 cm−2, corresponding to SFRLyα ≈ 5.0 ± 0.5 M⊙ yr−1. The velocity width is Δv(LAE 3) ≈ 400 km s−1, and the equivalent width is EW0( Å, consistent with star formation being the primary driver of Lyα emission. We also note a coherent absorption feature at ∼−400 km s−1 in spectra from at least three objects; the QSO, LAE 1, and LAE 2, which could imply the presence of an expanding neutral gas shell with an extent of at least 24 pkpc.
mmFall: Fall Detection Using 4-D mmWave Radar and a Hybrid Variational RNN AutoEncoder

Elderly fall prevention and detection becomes extremely crucial with the fast aging population globally. In this article, we propose mmFall, a novel fall detection system, which comprises 1) the emerging millimeter-wave (mmWave) radar sensor to collect the human body’s point cloud along with the body centroid and 2) a hybrid variational recurrent neural network (RNN) autoencoder (HVRAE) to compute the anomaly level of the body motion based on the acquired point cloud. A fall is detected when the spike in anomaly level and the drop in centroid height occur simultaneously. The mmWave radar sensor offers privacy-compliance and high sensitivity to motion, over the traditional sensing modalities. However, 1) randomness in radar point cloud and 2) difficulties in fall collection/labeling in the traditional supervised fall detection approaches are the two major challenges. To overcome the randomness in radar data, the proposed HVRAE uses variational inference, a generative approach rather than a discriminative approach, to infer the posterior probability of the body’s latent motion state every frame, followed by a RNN to summarize the temporal features over multiple frames. Moreover, to circumvent the difficulties in fall data collection/labeling, the HVRAE is built upon an autoencoder architecture in a semisupervised approach, which is only trained on the normal activities of daily living (ADL). In the inference stage, the HVRAE will generate a spike in the anomaly level once an abnormal motion, such as fall, occurs. During the experiment,1 we implemented the HVRAE along with two other baselines, and tested on the data set collected in an apartment. The receiver operating characteristic (ROC) curve indicates that our proposed model outperforms baselines and achieves 98% detection out of 50 falls at the expense of just 2 false alarms. Note to Practitioners—Traditional nonwearable fall detection approaches typically make use of a vision-based sensor, such as camera, to monitor and detect fall using a classifier that is trained in a supervised fashion on the collected fall and nonfall data. However, several problems render these methods impractical. First, camera-based monitoring may trigger privacy concerns. Second, fall data collection using human subjects is difficult and costly, not to mention the impossible ask of the elderly repeating simulated falls for data collection. In this article, we propose a new fall detection approach to overcome these problems 1) using a palm-size mmWave radar sensor to monitor the elderly, that is highly sensitive to motion while protecting privacy and 2) using a semisupervised anomaly detection approach to circumvent the fall data collection. Further hardware engineering and more training data from people with different body figures could make the proposed fall detection solution even more practical.
Inductive Reachability Witnesses

In this work, we consider the fundamental problem of reachability analysis over imperative programs with real variables. The reachability property requires that a program can reach certain target states during its execution. Previous works that tackle reachability analysis are either unable to handle programs consisting of general loops (e.g. symbolic execution), or lack completeness guarantees (e.g. abstract interpretation), or are not automated (e.g. incorrectness logic/reverse Hoare logic). In contrast, we propose a novel approach for reachability analysis that can handle general programs, is (semi-)complete, and can be entirely automated for a wide family of programs. Our approach extends techniques from both invariant generation and ranking-function synthesis to reachability analysis through the notion of (Universal) Inductive Reachability Witnesses (IRWs/UIRWs). While traditional invariant generation uses over-approximations of reachable states, we consider the natural dual problem of under-approximating the set of program states that can reach a target state. We then apply an argument similar to ranking functions to ensure that all states in our under-approximation can indeed reach the target set in finitely many steps.
Derivation of OTFS Modulation From First Principles

Orthogonal Time Frequency Space (OTFS) modulation has been recently proposed to be robust to channel induced Doppler shift in high mobility wireless communication systems. However, to the best of our knowledge, none of the prior works on OTFS have derived it from first principles. In this paper, using the ZAK representation of time-domain (TD) signals, we rigorously derive an orthonormal basis of approximately time and bandwidth limited signals which are also localized in the delay-Doppler (DD) domain. We then consider DD domain modulation based on this orthonormal basis, and derive OTFS modulation. We show that irrespective of the amount of Doppler shift, the received DD domain basis signals are localized in a small interval of size roughly equal to the inverse time duration along the Doppler domain and of size roughly equal to the inverse bandwidth along the delay domain (time duration refers to the length of the time-interval where the TD transmit signal has been limited). With sufficiently large time duration and bandwidth, there is little interference between information symbols modulated on different basis signals, which allows for joint DD domain equalization of all information symbols. This explains the inherent robustness of DD domain modulation to channel induced Doppler shift when compared with Orthogonal Frequency Division Multiplexing (OFDM).
Online Optimization with Barzilai-Borwein Quasi-Newton Method

This paper considers the online case for the Barzilai-Borwein quasi-Newton method and presents a regret analysis. To solve online convex optimization problems, sequential decisions are made at each time-step using some algorithm of choice. We use a greedy online gradient algorithm based on Barzilai-Borwein (BB) step sizes and show that the regret obtained from our algorithm is sublinear in time and that the average regret approaches zero. Analysis is presented for the two forms of the Barzilai-Borwein step sizes.
Blackbody-cavity Ideal Solar Absorbers

Spectrally selective solar absorbers (SSAs), harvesting sunlight into heat, are the key to the concentrated solar thermal systems. Current SSAs' designs using photonic crystals, metamaterials, or cermets are either cost-inefficient or have limited applicability due to complicated nanofabrication methods and poor thermal stability at high temperatures. We present a scalable-manufactured blackbody cavity solar absorber design with nearly ideal properties. The unity solar absorptivity and nearly zero infrared emissivity allow for a stagnation temperature of 880C under 10 suns. The performance surpasses those state-of-the-art SSAs manufactured by nanofabrication methods. This design relies on traditional fabricating methods, such as machining, casting, and polishing. This makes it easy for large-scale industrial applications, and the "blackbody cavity" feature enables its fast-integration to existing concentrated solar thermal systems.
Changes in the Odor-Active Compounds in Vitis labruscana Cv. Concord during Growth and Development

Three compounds important to the characteristic flavor (American character) of Vitis labruscana Bailey cv. Concord grapes (o-aminoacetophenone, methylfuraneol, and methyl anthranilate) were quantified in both berries and leaves before and after veraison (the onset of color formation in fruit). β-Damascenone, a compound important to the flavor of most grapes, and its hydrolyzable precursors (including glycosides) were also measured. The compounds with American character were detected only after veraison and only in the berries, where they increased rapidly after veraison. However, β-damascenone and its hydrolyzable precursors were detected in the leaf and berry tissue during the entire season