Miracle-dz/UniFAR-FTUs huggingface dataset:
The Effect of Combined Magnetic Geometries on Thermally Driven Winds. II. Dipolar, Quadrupolar, and Octupolar Topologies

During the lifetime of Sun-like or low-mass stars a significant amount of angular momentum is removed through magnetized stellar winds. This process is often assumed to be governed by the dipolar component of the magnetic field. However, observed magnetic fields can host strong quadrupolar and/or octupolar components, which may influence the resulting spin-down torque on the star. In Paper I, we used the MHD code PLUTO to compute steady-state solutions for stellar winds containing a mixture of dipole and quadrupole geometries. We showed the combined winds to be more complex than a simple sum of winds with these individual components. This work follows the same method as Paper I, including the octupole geometry, which not only increases the field complexity but also, more fundamentally, looks for the first time at combining the same symmetry family of fields, with the field polarity of the dipole and octupole geometries reversing over the equator (unlike the symmetric quadrupole). We show, as in Paper I, that the lowest-order component typically dominates the spin-down torque. Specifically, the dipole component is the most significant in governing the spin-down torque for mixed geometries and under most conditions for real stars. We present a general torque formulation that includes the effects of complex, mixed fields, which predicts the torque for all the simulations to within 20% precision, and the majority to within ≈5%. This can be used as an input for rotational evolution calculations in cases where the individual magnetic components are known.
Towards Accurate One-Stage Object Detection With AP-Loss

One-stage object detectors are trained by optimizing classification-loss and localization-loss simultaneously, with the former suffering much from extreme foreground-background class imbalance issue due to the large number of anchors. This paper alleviates this issue by proposing a novel framework to replace the classification task in one-stage detectors with a ranking task, and adopting the Average-Precision loss (AP-loss) for the ranking problem. Due to its non-differentiability and non-convexity, the AP-loss cannot be optimized directly. For this purpose, we develop a novel optimization algorithm, which seamlessly combines the error-driven update scheme in perceptron learning and backpropagation algorithm in deep networks. We verify good convergence property of the proposed algorithm theoretically and empirically. Experimental results demonstrate notable performance improvement in state-of-the-art one-stage detectors based on AP-loss over different kinds of classification-losses on various benchmarks, without changing the network architectures.
Research on the state of charge estimation method of lithium‐ion batteries based on novel limited memory multi‐innovation least squares method and SDE‐2‐RC equivalent model

Because of the common data redundancy phenomenon in the current least‐squares parameter identification algorithm and the complex offline parameter identification process, this research innovatively proposes a Limited Memory Multi‐Innovation Least Squares (LM‐MILS) ternary lithium‐ion battery (LIB) parameter identification algorithm that uses a limited set of data to estimate model parameters and attenuates the effects of old data. To improve the parameter fidelity of the equivalent circuit model (ECM) of the LIB, considering that the open‐circuit voltage of the lithium‐ion battery will gradually decrease with the self‐discharge when it is not in use, based on a large number of experiments, a model considering the self‐discharge of the LIB is constructed. The experimental results show that the self‐discharge effect‐2‐RC (SDE‐2‐RC) model can achieve higher accuracy in simulating the working state of the battery and the peak error of the simulated voltage is only 0.04342 V, and the accuracy can reach more than 98.966%. Using LM‐MILS and adaptive Kalman filtering algorithm (AEKF) for the state of charge (SOC) estimation, the results show that the algorithm has a fast convergence speed and strong tracking performance. The maximum SOC estimation errors in HPPC, DST, and BBDST three operating conditions are 0.00929, 0.01273, and 0.01002, respectively. The fluctuation range is small, and the maximum estimation error is less than 2%, which verifies that the improved parameter identification algorithm has good performance in improving the SOC estimation accuracy of LIB.
AI-enhanced Defense Against Ransomware Within the Organization's Architecture

Ransomware is a type of revenue-generating tactic that cybercriminals utilize to improve their income. Businesses have spent billions of dollars recovering control of their resources, which may include confidential data, operational applications and models, financial transactions, and other information, as a result of malicious software. Ransomware can infiltrate a resource or device and restrict the owner from accessing or utilizing it. There are various obstacles that a business must overcome in order to avoid ransomware attacks. Traditional ransomware detection systems employ a static detection method in which a finite dataset is provided into the system and a logical check is performed to prevent ransomware attacks against the system. This was effective in the early stages of the internet, but the scenario of recent times is far more advanced, and as more and more cyber world contrivances have been analyzed, multiple gaps have been identified, to the benefit of ransomware attackers, who use these gaps to generate astronomically large sums of money. As a result, the suggested methodology aims to efficiently detect diverse patterns associated with various file formats by starting with their sources, data collecting, probabilistic identification of target devices, and deep learning classifier with intelligent detection. An organization can use the recommended approach to safeguard its data and prepare for future ransomware attacks by using it as a roadmap to lead them through their security efforts.
Can climate warming save Daphnia from parasites? Reduced parasite prevalence in Daphnia populations from artificially heated lakes

Climate warming might modify infection outcomes and it has been proposed that temperature increase will result in a “sicker world. ” We tested this hypothesis by comparing the prevalence of infection in a common freshwater host–parasite system (crustacean Daphnia infected with the ichthyosporean pathogen Caullerya mesnili) between five artificially heated lakes and four nearby non‐heated control lakes. The heated lakes, which receive warm water from two power plants, have experienced an elevation in water temperature of ca. 3–4°C for the last 60 yr. Analyses of 5 yr of field data revealed that Daphnia communities from heated lakes had lower parasite prevalence than communities from control sites. To disentangle a possible direct detrimental effect of elevated temperature on the parasite from differences in baseline levels of host resistance, we compared infection susceptibility between Daphnia clones isolated from heated and control lakes, under laboratory conditions at two different temperatures. Daphnia from heated lakes were less susceptible to infection than clones from control lakes, while experimental temperature did not affect infection outcome. The data did not confirm the “warmer hence sicker world” scenario. Instead, it seems that indirect effects of temperature elevation (via shifts in lake hydrology) may restrict its spread into heated lakes. Then, local adaptation to the host from control lakes further inhibits re‐establishment of the parasite from control to heated lakes. Our results underline the context‐dependency of the impact of temperature increase on host–parasite interactions.
ATMOSPHERIC COMPOSITION OF WEAK G BAND STARS: CNO AND Li ABUNDANCES

We determined the chemical composition of a large sample of weak G band stars—a rare class of G and K giants of intermediate mass with unusual abundances of C, N, and Li. We have observed 24 weak G band stars with the 2.7 m Harlan J. Smith Telescope at the McDonald Observatory and derived spectroscopic abundances for C, N, O, and Li, as well as for selected elements from Na–Eu. The results show that the atmospheres of weak G band stars are highly contaminated with CN-cycle products. The C underabundance is about a factor of 20 larger than for normal giants and the 12C/13C ratio approaches the CN-cycle equilibrium value. In addition to the striking CN-cycle signature the strong N overabundance may indicate the presence of partially ON-cycled material in the atmospheres of the weak G band stars. The exact mechanism responsible for the transport of the elements to the surface has yet to be identified but could be induced by rapid rotation of the main sequence progenitors of the stars. The unusually high Li abundances in some of the stars are an indicator for Li production by the Cameron–Fowler mechanism. A quantitative prediction of a weak G band star's Li abundance is complicated by the strong temperature sensitivity of the mechanism and its participants. In addition to the unusual abundances of CN-cycle elements and Li, we find an overabundance of Na that is in accordance with the NeNa chain running in parallel with the CN cycle. Apart from these peculiarities, the element abundances in a weak G band star's atmosphere are consistent with those of normal giants.
A double radio halo in the close pair of galaxy clusters Abell 399 and Abell 401

Aims. Radio halos are faint radio sources usually located at the center of merging clusters of galaxies. These diffuse radio sources are rare, having so far been found only in about 30 clusters of galaxies, suggesting that particular conditions are needed to form and maintain them. It is interesting to investigate the presence of radio halos in close pairs of interacting clusters in order to possibly clarify their origin in relation to the evolutionary state of the merger. In this work, we study the case of the close pair of galaxy clusters A399 and A401. Methods. A401 is already known to contain a faint radio halo, while a hint of diffuse emission in A399 has been suggested based on the NVSS. To confirm this possibility, we analyzed deeper Very Large Array observations at 1.4 GHz of this cluster. Results. We find that the central region of A399 is permeated by a diffuse low-surface brightness radio emission that we classify as a radio halo with a linear size of about 570 kpc and a central brightness of 0.3 μJy/arcsec 2 . Indeed, given their comparatively small projected distance of ~3 Mpc, the pair of galaxy clusters A401 and A399 can be considered as the first example of double radio halo system. The discovery of this double halo is extraordinary given the rarity of these radio sources in general and given that current X-ray data seem to suggest that the two clusters are still in a pre-merger state. Therefore, the origin of the double radio halo is likely to be attributed to the individual merging histories of each cluster separately, rather than to the result of a close encounter between the two systems.
Two new tests to the distance duality relation with galaxy clusters

The cosmic distance duality relation is a milestone of cosmology involving the luminosity and angular diameter distances. Any departure of the relation points to new physics or systematic errors in the observations, therefore tests of the relation are extremely important to build a consistent cosmological framework. Here, two new tests are proposed based on galaxy clusters observations (angular diameter distance and gas mass fraction) and H(z) measurements. By applying Gaussian Processes, a non-parametric method, we are able to derive constraints on departures of the relation where no evidence of deviation is found in both methods, reinforcing the cosmological and astrophysical hypotheses adopted so far.
Parcel-level mapping of apple orchard in smallholder agriculture areas based on feature-level fusion of VHR image and time-series images

ABSTRACT Accurate and reliable parcel-level apple orchard mapping is required for many precise agriculture application models, including planting suitability evaluation, standardized production, and personal agricultural operation loan approval. However, in hilly areas where smallholder management predominates, the highly fragmented and heterogeneous agricultural landscape means that fine parcel-level apple orchard mapping remains challenging. This paper proposes a parcel-level apple orchard mapping method based on feature-level spatiotemporal data fusion, which is suitable for hilly areas where smallholder management predominates. First, a hierarchical strategy that simulates human image cognition processing was used to extract redundant candidate parcels from a very high spatial resolution (VHR) image (Google Earth image with a spatial resolution of 0.6 m). Second, deep learning models, including a Depth-wise Asymmetric Bottleneck Network (DABNet) and long short-term memory (LSTM), were used to extract implicit spatial and time series features of the parcels. Third, the implicit features extracted by the deep learning models were formatted into meta-features, which then formed the feature space together with the morphological and geographical features of the parcel. Fourth, based on the constructed parcel feature space, a random forests (RF) model was used to classify candidate parcels. The experiment was carried out in the town of Guanli, southwest of Qixia city, Shandong Province, China: 21,123 apple orchard parcels were extracted from 31,235 candidate parcels. The overall accuracy (OA) of the parcel-level mapping result was 0.919. The parcel features were combined according to their types, and the performance of different feature combinations for parcel classification was further compared, demonstrating that the proposed meta-features had a stronger spatial information description capability than traditional features. Moreover, the mean decrease in the accuracy (MDA) index was used to evaluate the importance of each feature. And spatial-information-related meta-features were revealed to play the most important role in parcel classification. This method provides methodological references for parcel-level orchard mapping in hilly areas where smallholder management predominates and can be applied to improve the monitoring of orchards in such areas.
Security of networked control systems subject to deception attacks: a survey

A networked control system (NCS), which integrates various physical components by utilising communication networks, is a complex intelligent control system with high flexibility and reliability. It has been widely applied in various areas, such as power grids, intelligent transportation, and smart manufacturing. However, compared with traditional control systems, NCSs expose more extra vulnerabilities with the openness of communication networks, leading to long-term concerns for the security of NCSs against cyber attacks. This paper gives a survey in detail on recent developments on the security of NCSs subject to deception attacks from the two domains of information technology (IT) and system control, respectively. First, several security incidents reported in recent years are reviewed and a couple of prevailing cyber attacks are analysed. Besides, the results on IT security with respect to the protection-detection-reaction model are summarised. Then, from the domain of system control, the security issues on attack design, attack detection, secure state estimation and resilient control are surveyed in depth. Furthermore, several novel security topics from the combination of IT and system control are also discussed. Finally, several future research directions are presented on this topic.
Efficiency bounds on thermoelectric transport in magnetic fields: The role of inelastic processes

We examine the efficiency of an effective two-terminal thermoelectric device under broken time-reversal symmetry. The setup is derived from a three-terminal thermoelectric device comprising a thermal terminal and two electronic contacts, under a magnetic field. We find that breaking time-reversal symmetry in the presence of the inelastic electron-phonon processes can significantly enhance the figure of merit for delivering electric power by supplying heat from a phonon bath, beyond the one for producing the electric power by investing thermal power from the electronic heat current. The efficiency of such a device is bounded by the non-negativity of the entropy production of the original three-terminal junction. The efficiency at maximal power can be quite close to the Carnot efficiency, but then the electric power vanishes.
Localization of four-dimensional super Yang-Mills theories compactified on Riemann surface

We consider the partition function of super Yang-Mills theories defined on $T^2 \times \Sigma_g$. This path integral can be computed by the localization. The one-loop determinant is evaluated by the elliptic genus. This elliptic genus gives trivial result in our calculation. As a result, we obtain a theory defined on the Riemann surface.
SAFARI: Searching Asteroids for Activity Revealing Indicators

Active asteroids behave dynamically like asteroids but display comet-like comae. These objects are poorly understood, with only about 30 identified to date. We have conducted one of the deepest systematic searches for asteroid activity by making use of deep images from the Dark Energy Camera (DECam) ideally suited to the task. We looked for activity indicators among 11,703 unique asteroids extracted from 35,640 images. We detected three previously identified active asteroids ((62412), (1) Ceres and (779) Nina), though only (62412) showed signs of activity. Our activity occurrence rate of 1 in 11,703 is consistent with the prevailing 1 in 10,000 activity occurrence rate estimate. Our proof of concept demonstrates (1) our novel informatics approach can locate active asteroids and (2) DECam data are well-suited to the search for active asteroids.
HUBBLE SPACE TELESCOPE OBSERVATIONS OF DUSTY FILAMENTS IN HERCULES A: EVIDENCE FOR ENTRAINMENT

We present U-, V-, and I-band images of the host galaxy of Hercules A (3C 348) obtained with HST/WFC3/UVIS. We find a network of dusty filaments which are more complex and extended than seen in earlier Hubble Space Telescope (HST) observations. The filaments are associated with a faint blue continuum light (possibly from young stars) and faint Hα emission. It seems likely that the cold gas and dust has been stripped from a companion galaxy now seen as a secondary nucleus. There are dusty filaments aligned with the base of the jets on both eastern and western sides of the galaxy. The morphology of the filaments is different on the two sides—the western filaments are fairly straight, while the eastern filaments are mainly in two loop-like structures. We suggest that despite the difference in morphologies, both sets of filaments have been entrained in a slow-moving boundary layer outside the relativistic flow. As suggested by Fabian et al., magnetic fields in the filaments may stabilize them against disruption. We consider a speculative scenario to explain the relation between the radio source and the shock and cavities in the hot intracluster medium seen in the Chandra data. We suggest that the radio source originally (∼60 Myr ago) propagated along a position angle of ∼35° where it created the shock and cavities. The radio source axis changed to its current orientation (∼100°) possibly due to a supermassive black hole merger and began its current epoch of activity about 20 Myr ago.
On the accretion process in a high-mass star forming region - A multitransitional THz Herschel-HIFI study of ammonia toward G34.26+0.15

[Abridged] Our aim is to explore the gas dynamics and the accretion process in the early phase of high-mass star formation. The inward motion of molecular gas in the massive star forming region G34.26+0.15 is investigated by using high-resolution profiles of seven transitions of ammonia at THz frequencies observed with Herschel-HIFI. The shapes and intensities of these lines are interpreted in terms of radiative transfer models of a spherical, collapsing molecular envelope. An accelerated Lambda Iteration (ALI) method is used to compute the models. The seven ammonia lines show mixed absorption and emission with inverse P-Cygni-type profiles that suggest infall onto the central source. A trend toward absorption at increasingly higher velocities for higher excitation transitions is clearly seen in the line profiles. The $J = 3\leftarrow2$ lines show only very weak emission, so these absorption profiles can be used directly to analyze the inward motion of the gas. This is the first time a multitransitional study of spectrally resolved rotational ammonia lines has been used for this purpose. Broad emission is, in addition, mixed with the absorption in the $1_0-0_0$ ortho-NH$_3$ line, possibly tracing a molecular outflow from the star forming region. The best-fitting ALI model reproduces the continuum fluxes and line profiles, but slightly underpredicts the emission and absorption depth in the ground-state ortho line $1_0-0_0$. The derived ortho-to-para ratio is approximately 0.5 throughout the infalling cloud core similar to recent findings for translucent clouds in sight lines toward W31C and W49N. We find evidence of two gas components moving inwards toward the central region with constant velocities: 2.7 and 5.3 km$\,$s$^{-1}$, relative to the source systemic velocity. The inferred mass accretion rates derived are sufficient to overcome the expected radiation pressure from G34.26+0.15.
Gamma-ray emission from proton-proton interactions in hot accretion flows

We present a model of gamma-ray emission through neutral pion production and decay in two-temperature accretion flows around supermassive black holes. We refine previous studies of such a hadronic gamma-ray emission by taking into account (1) relativistic effects in the photon transfer and (2) absorption of gamma-ray photons in the radiation field of the flow. We use a fully general relativistic description of both the radiative and hydrodynamic processes, which allows us to study the dependence on the black hole spin. The spin value strongly affects the gamma-ray emissivity within similar to 10 gravitational radii. The central regions of flows with the total luminosities L less than or similar to 10(- 3) of the Eddington luminosity (L-Edd) are mostly transparent to photons with energies below 10 GeV, permitting investigation of the effects of space-time metric. For such L, an observational upper limit on the gamma-ray (0.1-10 GeV) to X-ray (2-10 keV) luminosity ratio of L0.1-10 GeV/L2-10 keV < 0.1 can rule out rapid rotation of the black hole; on the other hand, a measurement of L0.1-10 GeV/L2-10 keV similar to 0.1 cannot be regarded as the evidence of rapid rotation, as such a ratio can also result from a flat radial profile of gamma-ray emissivity (which would occur for non-thermal acceleration of protons in the whole body of the flow). At L greater than or similar to 10(- 2)L(Edd), the gamma-ray emission from the innermost region is strongly absorbed and the observed gamma-rays do not carry information on the value of a. We note that if the X-ray emission observed in Centaurus A comes from an accretion flow, the hadronic gamma-ray emission from the flow should contribute significantly to the MeV/GeV emission observed from the core of this object, unless it contains a slowly rotating black hole and protons in the flow are thermal.