Miracle-dz/UniFAR-FTUs huggingface dataset:
Causal Plot: Causal-Based Fault Diagnosis Method Based on Causal Analysis

Fault diagnosis is crucial for realizing safe process operation when a fault occurs. Multivariate statistical process control (MSPC) has widely been adopted for fault detection in real processes, and contribution plots based on MSPC are a well-known fault diagnosis method, but it does not always correctly diagnose the causes of faults. This study proposes a new fault diagnosis method based on the causality between process variables and a monitored index for fault detection, which is referred to as a causal plot. The proposed causal plot utilizes a linear non-Gaussian acyclic model (LiNGAM), which is a data-driven causal inference algorithm. LiNGAM estimates a causal structure only from data. In the proposed causal plot, the causality of a monitored index of fault detection methods, in addition to process variables, is estimated with LiNGAM when a fault is detected with the monitored index. The process variables having significant causal relationships with the monitored indexes are identified as causes of faults. In this study, the proposed causal plot was applied to fault diagnosis problems of a vinyl acetate monomer (VAM) manufacturing process. The application results showed that the proposed causal plot diagnosed appropriate causes of faults even when conventional contribution plots could not do the same. In addition, we discuss the effects of the presence of a recycle flow on fault diagnosis results based on the analysis result of the VAM process. The proposed causal plot contributes to realizing safe and efficient process operations.
No-boundary measure and preference for large e-foldings in multi-field inflation

The no-boundary wavefunction of quantum gravity usually assigns only very small probability to long periods of inflation. This was a reason to doubt about the no-boundary wavefunction to explain the observational universe. We study the no-boundary proposal in the context of multi-field inflation to see whether the number of fields changes the situation. For a simple model, we find that indeed the no-boundary wavefunction can give higher probability for sufficient inflation, but the number of fields involved Nf has to be very high, e.g., Nf ≃ m−2.
A SPECTROSCOPIC AND PHOTOMETRIC SURVEY OF NOVAE IN M31

We report the results of a multi-year spectroscopic and photometric survey of novae in M31 that resulted in a total of 53 spectra of 48 individual nova candidates. Two of these, M31N 1995-11e and M31N 2007-11g, were revealed to be long-period Mira variables, not novae. These data double the number of spectra extant for novae in M31 through the end of 2009 and bring to 91 the number of M31 novae with known spectroscopic classifications. We find that 75 novae (82%) are confirmed or likely members of the Fe ii spectroscopic class, with the remaining 16 novae (18%) belonging to the He/N (and related) classes. These numbers are consistent with those found for Galactic novae. We find no compelling evidence that spectroscopic class depends sensitively on spatial position or population within M31 (i.e., bulge versus disk), although the distribution for He/N systems appears slightly more extended than that for the Fe ii class. We confirm the existence of a correlation between speed class and ejection velocity (based on line width), as in the case of Galactic novae. Follow-up photometry allowed us to determine light-curve parameters for a total of 47 of the 91 novae with known spectroscopic class. We confirm that more luminous novae generally fade the fastest and that He/N novae are typically faster and brighter than their Fe ii counterparts. In addition, we find a weak dependence of nova speed class on position in M31, with the spatial distribution of the fastest novae being slightly more extended than that of slower novae.
THE PHYSICAL STRUCTURE OF PROTOPLANETARY DISKS: THE SERPENS CLUSTER COMPARED WITH OTHER REGIONS

Spectral energy distributions are presented for 94 young stars surrounded by disks in the Serpens Molecular Cloud, based on photometry and Spitzer/IRS spectra. Most of the stars have spectroscopically determined spectral types. Taking a distance to the cloud of 415 pc rather than 259 pc, the distribution of ages is shifted to lower values, in the 1–3 Myr range, with a tail up to 10 Myr. The mass distribution spans 0.2–1.2 M☉, with median mass of 0.7 M☉. The distribution of fractional disk luminosities in Serpens resembles that of the young Taurus Molecular Cloud, with most disks consistent with optically thick, passively irradiated disks in a variety of disk geometries (Ldisk/Lstar ∼ 0.1). In contrast, the distributions for the older Upper Scorpius and η Chamaeleontis clusters are dominated by optically thin lower luminosity disks (Ldisk/Lstar ∼ 0.02). This evolution in fractional disk luminosities is concurrent with that of disk fractions: with time disks become fainter and the disk fractions decrease. The actively accreting and non-accreting stars (based on Hα data) in Serpens show very similar distributions in fractional disk luminosities, differing only in the brighter tail dominated by strongly accreting stars. In contrast with a sample of Herbig Ae/Be stars, the T Tauri stars in Serpens do not have a clear separation in fractional disk luminosities for different disk geometries: both flared and flat disks present wider, overlapping distributions. This result is consistent with previous suggestions of a faster evolution for disks around Herbig Ae/Be stars. Furthermore, the results for the mineralogy of the dust in the disk surface (grain sizes, temperatures and crystallinity fractions, as derived from Spitzer/IRS spectra) do not show any correlation to either stellar and disk characteristics or mean cluster age in the 1–10 Myr range probed here. A possible explanation for the lack of correlation is that the processes affecting the dust within disks have short timescales, happening repeatedly, making it difficult to distinguish long-lasting evolutionary effects.
Galaxy assembly, stellar feedback and metal enrichment: the view from the Gaea model

One major problem of current theoretical models of galaxy formation is given by their inability to reproduce the apparently `anti-hierarchical' evolution of galaxy assembly: massive galaxies appear to be in place since $z\sim 3$, while a significant increase of the number densities of low mass galaxies is measured with decreasing redshift. In this work, we perform a systematic analysis of the influence of different stellar feedback schemes, carried out in the framework of GAEA, a new semi-analytic model of galaxy formation. It includes a self-consistent treatment for the timings of gas, metal and energy recycling, and for the chemical yields. We show this to be crucial to use observational measurements of the metallicity as independent and powerful constraints for the adopted feedback schemes. The observed trends can be reproduced in the framework of either a strong ejective or preventive feedback model. In the former case, the gas ejection rate must decrease significantly with cosmic time (as suggested by parametrizations of the cosmological `FIRE' simulations). Irrespective of the feedback scheme used, our successful models always imply that up to 60-70 per cent of the baryons reside in an `ejected' reservoir and are unavailable for cooling at high redshift. The same schemes predict physical properties of model galaxies (e.g. gas content, colour, age, and metallicity) that are in much better agreement with observational data than our fiducial model. The overall fraction of passive galaxies is found to be primarily determined by internal physical processes, with environment playing a secondary role.
The clustering of galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey: constraints on the time variation of fundamental constants from the large-scale two-point correlation function

We obtain constraints on the variation of the fundamental constants from the full shape of the redshift-space correlation function of a sample of luminous galaxies drawn from the Data Release 9 of the Baryonic Oscillations Spectroscopic Survey. We combine this information with data from recent CMB, BAO and H_0 measurements. We focus on possible variations of the fine structure constant \alpha and the electron mass m_e in the early universe, and study the degeneracies between these constants and other cosmological parameters, such as the dark energy equation of state parameter w_DE, the massive neutrinos fraction f_\nu, the effective number of relativistic species N_eff, and the primordial helium abundance Y_He. When only one of the fundamental constants is varied, our final bounds are \alpha / \alpha_0 = 0. 9957_{-0.0042}^{+0.0041} and m_e /(m_e)_0 = 1. 006_{-0.013}^{+0.014}. For their joint variation, our results are \alpha / \alpha_0 = 0. 9901_{-0.0054}^{+0.0055} and m_e /(m_e)_0 = 1.028 +/- 0.019. Although when m_e is allowed to vary our constraints on w_DE are consistent with a cosmological constant, when \alpha is treated as a free parameter we find w_DE = -1.20 +/- 0.13; more than 1 \sigma away from its standard value. When f_\nu and \alpha are allowed to vary simultaneously, we find f_\nu < 0.043 (95% CL), implying a limit of \sum m_\nu < 0.46 eV (95% CL), while for m_e variation, we obtain f_nu < 0.086 (95% CL), which implies \sum m_\nu < 1.1 eV (95% CL). When N_eff or Y_He are considered as free parameters, their simultaneous variation with \alpha provides constraints close to their standard values (when the H_0 prior is not included in the analysis), while when m_e is allowed to vary, their preferred values are significantly higher. In all cases, our results are consistent with no variations of \alpha or m_e at the 1 or 2 \sigma level.
Proposed security mechanism for preventing fake router advertisement attack in IPv6 link-local network

The design of router discovery (RD) is a trust mechanism to confirm the legitimacy of the host and router. Fake router advertisement (RA) attacks have been made possible by this RD protocol design defect. Studies show that the standard RD protocol is vulnerable to a fake RA attack where the host will be denied a valid gateway. To cope with this problem, several prevention techniques have been proposed in the past to secure the RD process. Nevertheless, these methods have a significant temporal complexity as well as other flaws, including the bootstrapping issue and hash collision attacks. Thus, the SecMac-secure router discovery (SecMac-SRD) technique, which requires reduced processing time and may thwart fake RA assaults, is proposed in this study as an improved secure RD mechanism. SecMac-SRD is built based on a UMAC hashing algorithm with ElGamal public key distribution cryptosystem that hides the RD message exchange in the IPv6 link-local network. Based on the obtained expected results display that the SecMac-SRD mechanism achieved less processing time compared to the existing secure RD mechanism and can resist fake RA attacks. The outcome of the expected results clearly proves that the SecMac-SRD mechanism effectively copes with the fake RA attacks during the RD process.
Bump formation in the runaway electron tail

Runaway electrons are generated in a magnetized plasma when the parallel electric field exceeds a critical value. For such electrons with energies typically reaching tens of MeV, the Abraham-Lorentz-Dirac (ALD) radiation force, in reaction to the synchrotron emission, is significant and can be the dominant process limiting the electron acceleration. The effect of the ALD-force on runaway electron dynamics in a homogeneous plasma is investigated using the relativistic finite-difference Fokker-Planck codes LUKE [Decker & Peysson, Report EUR-CEA-FC-1736, Euratom-CEA, (2004)] and CODE [Landreman et al, Comp. Phys. Comm. 185, 847 (2014)]. Under the action of the ALD force, we find that a bump is formed in the tail of the electron distribution function if the electric field is sufficiently large. We also observe that the energy of runaway electrons in the bump increases with the electric field amplitude, while the population increases with the bulk electron temperature. The presence of the bump divides the electron distribution into a runaway beam and a bulk population. This mechanism may give rise to beam-plasma types of instabilities that could in turn pump energy from runaway electrons and alter their confinement.
Dynamical randomness, information, and Landauer's principle

New concepts from nonequilibrium thermodynamics are used to show that Landauer's principle can be understood in terms of time asymmetry in the dynamical randomness generated by the physical process of the erasure of digital information. In this way, Landauer's principle is generalized, showing that the dissipation associated with the erasure of a sequence of bits produces entropy at the rate kBI per erased bit, where I is Shannon's information per bit.
Enhancing the yield of high-order harmonics with an array of gas jets

We report the experimental observation of an enhancement in the yield of high-order harmonics using an array of gas jets as the source medium. By comparing the experimental outcome for jet arrays of different spacings with the predicted harmonic intensity in the case of slit sources of equivalent lengths, we clearly show how the periodic modulation of the gas density can improve the harmonic yield. This behavior may be attributed to a quasi-phase-matching effect which increases the length of coherent harmonic buildup during propagation by partially counteracting the dephasing induced by free electrons.
EVIDENCE OF THERMONUCLEAR FLAME SPREADING ON NEUTRON STARS FROM BURST RISE OSCILLATIONS

Burst oscillations during the rising phases of thermonuclear X-ray bursts are usually believed to originate from flame spreading on the neutron star surface. However, the decrease of fractional oscillation amplitude with rise time, which provides a main observational support for the flame spreading model, have so far been reported from only a few bursts. Moreover, the non-detection and intermittent detections of rise oscillations from many bursts are not yet understood considering the flame spreading scenario. Here, we report the decreasing trend of fractional oscillation amplitude from an extensive analysis of a large sample of Rossi X-ray Timing Explorer Proportional Counter Array bursts from 10 neutron star low-mass X-ray binaries. This trend is 99.99% significant for the best case, which provides, to the best of our knowledge, by far the strongest evidence of such a trend. Moreover, it is important to note that an opposite trend is not found in any of the bursts. The concave shape of the fractional amplitude profiles for all the bursts suggests latitude-dependent flame speeds, possibly due to the effects of the Coriolis force. We also systematically study the roles of low fractional amplitude and low count rate for non-detection and intermittent detections of rise oscillations, and attempt to understand them within the flame spreading scenario. Our results support a weak turbulent viscosity for flame spreading, and imply that burst rise oscillations originate from an expanding hot spot, thus making these oscillations a more reliable tool to constrain the neutron star equations of state.
No-Signalling Is Equivalent To Free Choice of Measurements

No-Signalling is a fundamental constraint on the probabilistic predictions made by physical theories. It is usually justified in terms of the constraints imposed by special relativity. However, this justification is not as clear-cut as is usually supposed. We shall give a different perspective on this condition by showing an equivalence between No-Signalling and Lambda Independence, or "free choice of measurements", a condition on hidden-variable theories which is needed to make no-go theorems such as Bell's theorem non-trivial. More precisely, we shall show that a probability table describing measurement outcomes is No-Signalling if and only if it can be realized by a Lambda-Independent hidden-variable theory of a particular canonical form, in which the hidden variables correspond to non-contextual deterministic predictions of measurement outcomes. The key proviso which avoids contradiction with Bell's theorem is that we consider hidden-variable theories with signed probability measures over the hidden variables - i.e. negative probabilities. Negative probabilities have often been discussed in the literature on quantum mechanics. We use a result proved previously in "The Sheaf-theoretic Structure of Locality and Contextuality" by Abramsky and Brandenburger, which shows that they give rise to, and indeed characterize, the entire class of No-Signalling behaviours. In the present paper, we put this result in a broader context, which reveals the surprising consequence that the No-Signalling condition is equivalent to the apparently completely different notion of free choice of measurements.
Exploration of students’ information behaviour and experience of assignment completion process

Assignments play an important role in consolidating knowledge for university students. Understanding students’ information behaviour and experience in this type of work task, i.e., students’ assignments, would be beneficial to the design of learning platforms or search systems to better support effective and efficient information behaviour. A 37-day online observation of 14 university students in China, working on one assignment through client logging, combined with questionnaires and interviews were conducted in this study. This study used descriptive analysis to describe students’ information behaviour and experiences during the assignment completion processes at different stages. According to the proportion of efforts devoted to seeking information and working for the assignment in four evenly distributed periods, the students could be divided into four time-allocation types, namely 'Ninjas', 'Turtles', 'Time wasters' and 'Pursuers'. Different types of students had different information behaviour and experiences during assignment completion process. When applying Information Seeking Process model to analysis students’ information behaviour for the assignment completion, it is necessary to combine the time context and examine how each time allocation type of students would allocate their information seeking effort in task completion behaviour.
Evidence for dark matter modulation in CoGeNT

We investigate the question of whether the recent modulation signal claimed by CoGeNT is best explained by the dark matter (DM) hypothesis from a Bayesian model comparison perspective. We consider five phenomenological explanations for the data: no modulation signal, modulation due to DM, modulation due to DM compatible with the total CoGeNT rate, and a signal coming from other physics with a free phase but annual period, or with a free phase and a free period. In each scenario, we assign to the free parameters physically motivated priors. We find that while the DM models are weakly preferred to the no modulation model, but when compared to models where the modulation is due to other physics, the DM hypothesis is favoured with odds ranging from 185:1 to 560:1. This result is robust even when astrophysical uncertainties are taken into account and the impact of priors assessed. Interestingly, the odds for the DM model in which the modulation signal is compatible with the total rate against a DM model in which this prior is not implemented is only 5:8, in spite of the former's prediction of a modulation amplitude in the energy range 0.9 → 3.0 keVee that is significantly smaller than the value observed by CoGeNT. Classical hypothesis testing also rules out the null hypothesis of no modulation at the 1. 6σ to 2. 3σ level, depending on the details of the alternative. Lastly, we investigate whether anisotropic velocity distributions can help to mitigate the tension between the CoGeNT total and modulated rates, and find encouraging results.
Large pre-inflationary thermal density perturbations

In some versions of the theory of inflation, it is assumed that before inflation began the universe was in a Friedmann-Robertson-Walker (FRW) stage, with the energy density dominated by massless particles. The origin of the nearly scale-invariant density perturbations is quantum fluctuations in the inflaton field. Here we point out that under those conditions there would necessarily also be large thermally induced density perturbations. It is asserted that inflation would smooth out any pre-existing perturbations. But that argument relies on linear perturbation theory of the scalar modes, which would be rendered invalid because of the non-negligibility of the vector and tensor modes when the perturbation in the total density becomes large. Under those circumstances the original proof that inflation would have the desired smoothing effect no longer applies, {\it i.e.} for the theory to be robust an alternative (and hitherto unavailable) demonstration of the smoothing that takes account of these non-linear terms is necessary.
How general is the global density slope–anisotropy inequality?

Following the seminal result of An & Evans, known as the central density slope– anisotropy theorem, successive investigations unexpectedly revealed that the density slope–anisotropy inequality holds not only at the center, but at all radii in a very large class of spherical systems whenever the phase–space distribution function is positive. In this paper we derive a criterion that holds for all spherical systems in which the augmented density is a separable function of radius and potential: this new finding allows to unify all the previous results in a very elegant way, and opens the way for more general investigations. As a first application, we prove that the global density slope– anisotropy inequality is also satisfied by all the explored additional families of multi– component stellar systems. The present results, and the absence of known counter– examples, lead us to conjecture that the global density slope–anisotropy inequality could actually be a universal property of spherical systems with positive distribution function.
Revisiting the Fermi Surface in Density Functional Theory

The Fermi surface is an abstract object in the reciprocal space of a crystal lattice, enclosing the set of all those electronic band states that are filled according to the Pauli principle. Its topology is dictated by the underlying lattice structure and its volume is the carrier density in the material. The Fermi surface is central to predictions of thermal, electrical, magnetic, optical and superconducting properties in metallic systems. Density functional theory is a first-principles method used to estimate the occupied-band energies and, in particular, the isoenergetic Fermi surface. In this review we survey several key facts about Fermi surfaces in complex systems, where a proper theoretical understanding is still lacking. We address some critical difficulties.