Miracle-dz/UniFAR-FTUs huggingface dataset:
The IC1396N proto-cluster at a scale of 250 AU

We investigate the mm-morphology of IC1396N with unprecedented spatial resolution to analyze its dust and molecular gas properties, and draw comparisons with objects of similar mass. We have carried out sensitive observations in the most extended configurations of the IRAM Plateau de Bure interferometer, to map the thermal dust emission at 3.3 and 1.3mm, and the emission from the $J$=13$_k\to12_k$ hyperfine transitions of methyl cyanide (CH$_3$CN). We unveil the existence of a sub-cluster of hot cores in IC1396N, distributed in a direction perpendicular to the emanating outflow. The cores are embedded in a common envelope of extended and diffuse dust emission. We find striking differences in the dust properties of the cores ($\beta\simeq$ 0) and the surrounding envelope ($\beta\simeq$ 1), very likely testifying to differences in the formation and processing of dust material. The CH$_3$CN emission peaks towards the most massive hot core and is marginally extended in the outflow direction.
Quadrature Rules for Regions Having Regular Hexagonal Symmetry

In this paper we investigate ${\text{D}}_6 $-quadrature rules for ${\text{D}}_6 $-regions. These are two-dimensional rules and regions which have the same symmetry as the regular hexagon. We derive a variant formulation of the standard moment fitting equations. By solving these we derive and list a set of quadrature rules for the hexagon of polynomial degree up to 15. In addition, using the same approach we have derived the corresponding rules for the circle and for two infinite regions, those having weight function $e^{ - r^2 } $ and $e^{ - r} $ respectively. A few of these rules, those which represent marginal improvements on similarly specified rules in Stroud (1971) are also listed.
Mechanism and Control of Cloud Cavitation

Generation mechanism of cloud cavitation on a hydrofoil section was investigated in a sequence of experiments through observation of cloud cavitation by high-speed video and high-speed photo as well as pressure measurements by pressure pick-ups and a hydrophone. The mechanism was also investigated by controlling cloud cavitation with an obstacle fitted on the foil surface. From the results of these experiments, it was found that the collapse of a sheet cavity is triggered by a re-entrant jet rushing from the trailing edge to the leading edge of the sheet cavity, and consequently, the sheet cavity is shed in the vicinity of its leading edge and thrown downstream as a cluster of bubbles called cloud cavity. In other words, the re-entrant jet gives rise to cloud cavitation. Moreover, cloud cavitation could be controlled effectively by a small obstacle placed on the foil. It resulted in reduction of foil drag and cavitation noise
On the diagonalizability of the Atkin U-operator for Drinfeld cusp forms

We study the diagonalizability of the Atkin $U$-operator acting on Drinfeld cusp forms for $\Gamma_1(t)$ and $\Gamma(t)$ using Teitelbaum's interpretation as harmonic cocycles. We prove $U$ is diagonalizable for small weights and explicitly compute the eigenvalues. We also formulate a conjecture, supported by numerical search and proofs in some special cases, about non diagonalizability of $U$ in even characteristic.
Stability and Controllability results for a Timoshenko system

In this paper, we study the indirect boundary stability and exact controllability of a one-dimensional Timoshenko system. In the first part of the paper, we consider the Timoshenko system with only one boundary fractional damping. We first show that the system is strongly stable but not uniformly stable. Hence, we look for a polynomial decay rate for smooth initial data. Using frequency domain arguments combined with the multiplier method, we prove that the energy decay rate depends on coefficients appearing in the PDE and on the order of the fractional damping. Moreover, under the equal speed propagation condition, we obtain the optimal polynomial energy decay rate. In the second part of this paper, we study the indirect boundary exact controllability of the Timoshenko system with mixed Dirichlet-Neumann boundary conditions and boundary control. Using non-harmonic analysis, we first establish a weak observability inequality, which depends on the ratio of the waves propagation speeds. Next, using the HUM method, we prove that the system is exactly controllable in appropriate spaces and that the control time can be small.
Modelling multivariate extreme value distributions

SUMMARY Multivariate extreme value distributions arise as the limiting joint distribution of normalized componentwise maxima/minima. No parametric family exists for the depen- dence between the margins. This paper extends to more than two variables the models and results for the bivariate case obtained by Tawn (1988). Two new families of physically motivated parametric models for the dependence structure are presented and are illus- trated with an application to trivariate extreme sea level data. In the analysis of environmental extreme value data there is often need to study joint inter-site extreme behaviour: examples are joint flooding at various sea ports, or at various rain gauges. In this paper the class of multivariate extreme value distributions is considered. The marginal distributions are all extreme value distributions. Without loss of generality we follow Pickands's (1981) approach in transforming the margins to unit mean exponential distributions. The resulting class of p variable multivariate exponential distributions satisfies a strong stability relation. De Haan & Resnick (1977) and Pickands (1981) show that the resulting dependence structure is uniquely specified up to an arbitrary finite positive measure on p - 1 variables. Therefore, the bivariate dependence structure is univariate; only when p - 3, as considered here, does the problem become really multivari- ate. In addition, unlike in the multivariate normal distribution, the multivariate depen- dence structure is generally only restricted and not uniquely specified by the dependence structure of all possible pairs. Much has been written about the representations of multivariate extremes; see Resnick (1987) for a good review. On the other hand, models and estimation for such distributions have received little attention. These aspects are considered here. As no finite parametric family exists for the general dependence structure it must be modelled in some way. Thus true multivariate models are required. Using the most flexible bivariate model of Tawn (1988) as a basis, multivariate extensions are generated. A model derived in the discrete choice literature will also be introduced and extended. The resulting families of models are physically motivated, flexible and possess hierarchical properties.
Robust determination of thermal diffusivity values from periodic heating data

In this paper, an experimental technique dedicated to thermal diffusivity or thermal conductivity identification in isotropic and orthotropic materials is investigated. A method based on the analysis of thermal waves induced by periodic excitation in planar samples is proposed. Either frequency sweep at a single point in space or spatial fluctuations at a single frequency are considered. In such a context, in order to state both the accuracy and robustness of the data manipulation, a complete mathematical study is performed. Moreover, a sensitivity analysis allows us to implement an optimal strategy for the unknown parameter identification. Forward model and inverse problem are validated both on numerical simulation and known materials. Then, the presented experimental device developed is implemented for the analysis of orthotropic materials.
Unsteady separation in sharp fin-induced shock wave/turbulent boundary layer interaction at Mach 5

Fluctuating wall-pressure measurements are made in shock-wave/turbulent-boundary-layer interactions generated by sharp/unswept fins at angles of attack of 16, 18, 20, 22, 24, 26, and 28 degrees at Mach 5. The experiment was conducted under approximately adiabatic wall temperature conditions. The mean and rms pressure distributions can be collapsed in conical coordinates. The wall-pressure signal near separation is intermittent for all angles of attack (16-28 deg) and is qualitatively similar to that measured in unswept flows. However, the shock frequencies are higher - about 5 kHz compared to 0.5-1 kHz. Over the range of sweepbacks examined, from 25-55 deg, the spectral content of the fluctuating pressures does not change. Thus, the increase in separation-shock frequency from 1 to 5 kHz occurs at lower interaction sweepback and is not a continuous process with increasing sweepback. Power spectra at the position of maximum rms in the intermittent region for interactions in different incoming boundary layers have the same center frequency. The maximum rms in the intermittent region correlates with interaction sweepback, not with overall inviscid pressure rise.
The energy loss of energetic ions moving near a solid surface

A systematic study of the energy loss by energetic ions moving near a solid surface has been made. Special emphasis is placed on the case of an ion moving with velocity less than that of electrons in the solid. A clear distinction is made between contributions to energy loss from the excitation of collective states and particle-hole pairs. At large distances from the surface the authors show that the contribution of collective excitation always dominates that from particle-hole excitation.
Estimating Latent Variable Systems When Specification is Uncertain: Generalized Component Analysis and the Eliminant Method

Abstract This article argues that, to relieve the specification difficulties that frequently accompany latent variable models, a first application should in most cases employ an estimator that makes no assumption about the nature of the unobservables. The two possibilities are generalized component analysis, with the unobservables treated as incidental parameters; and the eliminant method, where they are removed by transformation of the model before estimation. It is shown that these are equivalent, whichever transformation is used, but that the latter has substantial practical advantages.
A COUNTEREXAMPLE TO A CONJECTURE OF LARMAN AND ROGERS ON SETS AVOIDING DISTANCE 1

For $n \geq 2$ we construct a measurable subset of the unit ball in $\mathbb{R}^n$ that does not contain pairs of points at distance 1 and whose volume is greater than $(1/2)^n$ times the volume of the ball. This disproves a conjecture of Larman and Rogers from 1972.
Matroid-minor Hopf algebra: a cancellation-free antipode formula and other applications of sign-reversing involutions

In this paper, we give a cancellation-free antipode formula for the matroid-minor Hopf algebra. We then explore applications of this formula. For example, the cancellation-free formula expresses the antipode of uniform matroids as a sum over certain ordered set partitions. We also prove that all matroids over any hyperfield (in the sense of Baker and Bowler) have cancellation-free antipode formulas; furthermore, the cancellations in the antipode are independent of the hyperfield structure and only depend on the underlying matroid.
Metamaterial fishnet structure formed from nanoimprint lithography

We report on the fabrication and characterisation of fishnet structures of various dimensions on a polymer layer. The fabrication process causes metal-dielectric-metal rectangular pillars to be compressed to the bottom of fishnet structures. The metamaterial structures are fabricated using nanoimprint lithography, allowing large areas to be patterned quickly and good reproducibility through multiple use of the nanoimprint stamp. A tri-layer comprising of silver (Ag) and magnesium fluoride (MgF2) was deposited on a thick polymer layer, in this instance PMMA, before being directly imprinted by a stamp. When the metal-dielectric layered pillars are imprinted to a sufficient depth in the PMMA below the fishnet, distinct resonance peaks can be measured at both visible and near-infrared frequencies. The precise wavelength of the resonant peak at near-infrared and its Q-factor can be changed by altering the physical dimensions and number of metal and dielectric layers of the fishnet respectively. The response viewed at visible frequencies is due to the pillars that sit in the PMMA, below the fishnet. Silver and magnesium fluoride layers that comprise the suppressed pillars are crushed during the imprinting process but still allow for light to be transmitted. Despite imprinting directly into multiple metal and dielectric layers, high quality structures are observed with a minimum feature size as low as 200 nm. Resonance peaks are measured experimentally in reflectance using an FTIR spectrometer with a calcium fluoride (CaF2) beam-splitter and a visible wavelength range spectrometer with a silicon (Si) detector.
2D collisional-radiative model for non-uniform argon plasmas: with or without ‘escape factor’

Collisional-radiative models for excited rare-gas atoms in low-temperature plasmas are a widely investigated topic. When these plasmas are optically thick, an ‘escape factor’ is introduced into the models to account for the reabsorption of photons (so-called radiation trapping process). This factor is usually obtained assuming a uniform density profile of the excited species; however, such an assumption is often not satisfied in a bounded plasma. This article reports for the first time a self-consistent collisional-radiative model without using an ad hoc ‘escape factor’ for excited Ar atoms in the 2p states (in Paschen’s notation). Rather, the rate balance equations—i.e. the radiation transfer equations—of the 2p states are numerically solved to yield the actual density profiles. The predictions of this self-consistent model and a model based on the escape factor concept are compared with spatially-resolved emission measurements in a low-pressure inductive Ar plasma. The self-consistent model agrees well with the experiment but the ‘escape factor’ model shows considerable deviations. By the comparative analysis the limitations and shortcomings of the escape factor concept as adopted in a significant number of works are revealed.
Finite-size effects on the QCD phase diagram

We discuss the finite-size effects on the chiral phase transition in QCD. We employ the Nambu-Jona-Lasinio model and calculate the thermodynamic potential in the mean-field approximation. Finite-size effects on the thermodynamic potential are taken into account by employing the multiple reflection expansion. The critical temperature is lowered and the order of the phase transition is changed form first to second as the size of the system of interest is reduced.
Shape invariance and equivalence relations for pseudo-Wronskians of Laguerre and Jacobi polynomials

In a previous paper we derived equivalence relations for pseudo-Wronskian determinants of Hermite polynomials. In this paper we obtain the analogous result for Laguerre and Jacobi polynomials. The equivalence formulas are richer in this case since rational Darboux transformations can be defined for four families of seed functions, as opposed to only two families in the Hermite case. The pseudo-Wronskian determinants of Laguerre and Jacobi type will thus depend on two Maya diagrams, while Hermite pseudo-Wronskians depend on just one Maya diagram. We show that these equivalence relations can be interpreted as the general transcription of shape invariance and specific discrete symmetries acting on the parameters of the isotonic oscillator and Darboux–Pöschl–Teller potential.
H I superclouds in the inner Galaxy

Atomic hydrogen clouds in the Weaver-Williams 21 cm survey are found in the vicinity of the largest molecular cloud complexes in the first Galactic quadrant. The atomic masses are estimated in several ways, including a new method where the clouds are assumed to be composed of cool clumps immersed in a warm interclump medium. The clouds are found to contain between a million and 40 million solar masses of atoms at an average density of about 9/cu cm. They appear gravitationally bound, their molecular mass fractions decrease from 70 percent to 5 percent with increasing distance from the Galactic center, and they are located in the spiral arms. The importance of these clouds for the large-scale distributions of interstellar mass, molecular fraction, and star formation is discussed. 103 references.
Investigation of Copper Scratches and Void Defects after Chemical Mechanical Polishing

In semiconductor metallization processes, copper metal is widely used for interconnection lines due to its low resistivity. However, various defects, such as scratches and voids, are usually formed after chemical mechanical polishing (CMP), which influences manufacturing yield because the copper metal is soft and easily corroded. In this study, our results indicate that defect formation is related to the properties of electroplated copper films. By increasing the plating current densities, the number of void defects increases while the number of scratch defects decreases after CMP. It is suggested that the increase in void defects with plating current densities is due to the increase in film tensile stress, while the decrease in scratch defects results from an increase in film hardness.
Optimization of the sizing and the energy management for a hybrid fuel cell vehicle including fuel cell dynamics and durability constraints

L'hydrogene a travers de l'utilisation des piles a combustible (PAC), est de plus en plus considere comme une option energetique possible au secteur des transports grâce a ces caracteristiques fonctionnelles. Cependant, la technologie liee a la mise en œuvre de vehicules alimentes par une pile a combustible n'a pas encore atteint le niveau de maturite requis. Ainsi, ce travail propose de traiter certaines de ces limitations qui existent encore. Plus precisement, trois themes representent les objectifs de ce travail : Le dimensionnement optimal des elements presents dans un vehicule hybride a pile a combustible. La gestion d'energie optimale pour les applications en temps reel et integrant les contraintes dynamiques du systeme PAC. Inclusion de la durabilite de la pile a combustible dans la gestion d'energie du vehicule. Le premier theme est aborde a travers l'elaboration d'une methodologie de dimensionnement adapte a un vehicule hybride a la pile a combustible. Dans une approche systematique, le dimensionnement propose combine les exigences de performance presente dans les specifications techniques du vehicule, les algorithmes d'optimisation, l'analyse de la mobilite de la population et la viabilite economique de la conception. Le deuxieme objectif etabli a ete developpe a l'aide d'une approche d'optimisation de la repartition de puissance entre la batterie et le systeme PAC. Par l'adoption d'une methode d'optimisation globale combinee a une strategie de commande predictive et l'inclusion de la dynamique du systeme PAC, un algorithme de gestion d'energie pour des applications de temps reel a ete concu. Enfin, la durabilite de la pile a combustible a ete incluse dans ce travail par l'integration de sa dynamique de degradation dans le probleme d'optimisation lie a la gestion d'energie. Cette dynamique represente une contrainte a prendre en consideration lors de la repartition de puissance entre le systeme PAC et la batterie.
Formal Verification of the WirelessHART Protocol - Verifying Old and Finding New Attacks

Connected industrial control systems open up many possibilities for increased efficiency and control but also bring drawbacks. Attacks against connected industrial control systems have highlighted the need for rigorous security analysis of every part of the systems. In this paper, we report a careful scrutiny of the security of the WirelessHART protocol. A literature study points at the need for a formal verification of the protocol. We have modeled Wireless-HART using the state-of-the-art formal verification tool Tamarin and tested the claimed security properties. Our analysis has verified the existence of all previously published attacks. In addition we have shown a new type of attack that enable an insider attacker to maliciously re-key devices in the system, effectively performing a denial of service attack on large parts of the system. Our analysis has demonstrated that WirelessHART is secure as long as no device in the network has been compromised. If an attacker can get a foothold in the network it can launch several types of attacks to compromise the network further.
Bayesian approach for Rician non-local means denoising in MR images

Abstract In this paper, we present an advanced algorithm for Rician noise reduction based on the combination of Bayesian estimation method, maximum a posteriori (MAP) and non-local mean (NLM) filtering. This algorithm is called the non-local MAP (NL-MAP) method. Our method constructs a proper prior for the unknown parameters, which is more realistic in describing actual beliefs about parameters. Moreover, we use observations, which proved to have statistically identical neighborhoods by statistical hypothesis test, in an NL neighborhood of a certain pixel to estimate its true noise free signal. We demonstrate that NL-MAP performs better than the NLM and non-local maximum likelihood estimation (NL-MLE) methods in terms of quantitative measures, especially in low signal-to-noise ratio (SNR) images; however, the NLM performs worst compared to other methods. On the other hand, NL-MAP performs well even when the SNR is high. The NL-MAP and NL-MLE methods also perform visually at a similar level, both better than the NLM method; however, the NL-MAP method performs better than the NL-MLE method through detailed comparisons with different criterion measures.
Thermal evolution of neutron stars with internal frictional heating

It has been suggested that the frictional interaction of neutron superfluids with normal matter in the inner crust of neutron stars dissipates rotational energy of superfluids and generates heat. Incorporating of general formula of internal heating into the detailed numerical codes of thermal evolution, we examine the effects of the internal heating on thermal evolution of neutron stars. We find that when a very stiff equation of state is used, it takes as long as ∼2×10 4 yr for the interior of a neutron star to reach the isothermal state, even if a strong heat source is placed in a thin layer of the inner crust
A NOTE ON DERIVABILITY CONDITIONS

Abstract We investigate relationships between versions of derivability conditions for provability predicates. We show several implications and non-implications between the conditions, and we discuss unprovability of consistency statements induced by derivability conditions. First, we classify already known versions of the second incompleteness theorem, and exhibit some new sets of conditions which are sufficient for unprovability of Hilbert–Bernays’ consistency statement. Secondly, we improve Buchholz’s schematic proof of provable $\Sigma_1$ -completeness. Then among other things, we show that Hilbert–Bernays’ conditions and Löb’s conditions are mutually incomparable. We also show that neither Hilbert–Bernays’ conditions nor Löb’s conditions accomplish Gödel’s original statement of the second incompleteness theorem.