Miracle-dz/UniFAR-FTUs huggingface dataset:
Long-wavelength MEMS tunable vertical-cavity surface-emitting lasers with high sidemode suppression

We present a micromechanically tunable long-wavelength vertical-cavity surface-emitting laser with a buried tunnel junction aperture and a stable half-symmetric cavity for full mode control. The conjunction of the active part ‘half-VCSEL’ and the curved MEMS-mirror in a two-chip assembly enables high output power singlemode emission exceeding 1 mW. Electrothermal actuation of the micromechanical chip allows us to extend the single wavelength performance to a continuously tunable, selectively wavelength-addressable spectrum of 28 nm. The concave curvature and the resulting long air-gap cavity are designed to favour the resonance of the fundamental mode, i.e. to match the phase front predicted by Gaussian beam theory corresponding to the aperture diameter of 10 µm. The spatial beam profile of the MEMS-VCSEL is measured in the far-field and compared with a conventional VCSEL with a fixed plane top mirror. The polarization is controlled by a dominating mirror asymmetry. High sidemode suppression over the whole tuning range with respect to both the transverse modes (>40 dB) and the polarization modes (>30 dB) is demonstrated.
Magnetically controllable nanofluid with tunable thermal conductivity and viscosity

We report the viscosity (η) and thermal conductivity (k) enhancement in a stable magnetic nanofluid containing particles size <10 nm as a function of volume fraction (vol %), shear rate, magnetic field, and time. Without field, the η enhancement of nanoparticle is much larger than that of k. In a nanofluid with 0.078 vol %, the k/η ratio is tunable from 0.725 to 2.35 by controlling the applied field. Our results show that magnetic nanofluids with tunable k/η ratio can be used as multifunctional “smart materials” for miniature cooling cum damping applications.
OPTIMAL UNAMBIGUOUS DISCRIMINATION OF TWO FINITE-DIMENSIONAL COHERENT STATES

An exact analytical solution to the optimal unambiguous state discrimination involving two finite-dimensional coherent states that occur with given prior probabilities is presented using the Lewenstein–Sanpera decomposition method. Furthermore, a numerical method is advised for efficient solving of the unambiguous state discrimination of the two finite-dimensional coherent states with the same dimensions. In this manner, it is shown that the maximum success rate for the unambiguous states discrimination of the two finite-dimensional coherent states with the arbitrary prior probability is decreased by increasing the dimensionality of the finite-dimensional coherent states. Also, the success rate for the unambiguous states discrimination of the two coherent states satisfies the upper bound proportional to the fidelity of the states for a given prior probability.
Fluctuation theory in continuous time

Our aim here is to give a survey of that part of continuous-time fluctuation theory which can be approached in terms of functionals of Lévy processes, our principal tools being Wiener-Hopf factorisation and local-time theory. Particular emphasis is given to one- and two-sided exit problems for spectrally negative and spectrally positive processes, and their applications to queues and dams. In addition, we give some weak-convergence theorems of heavy-traffic type, and some tail-estimates involving regular variation.
The Monge-Amp\`{e}re equation

We review recent advances in the numerical analysis of the Monge-Amp\`ere equation. Various computational techniques are discussed including wide-stencil finite difference schemes, two-scaled methods, finite element methods, and methods based on geometric considerations. Particular focus is the development of appropriate stability and consistency estimates which lead to rates of convergence of the discrete approximations. Finally we present numerical experiments which highlight each method for a variety of test problem with different levels of regularity.
The Influence of Entropy Waves on the Thermoacoustic Stability of a Model Combustor

Thermoacoustic instability can be a major problem for aero-engine combustors, particularly lean-premixed burners designed for low NOx emissions. The instability is caused by the interaction between unsteady heat release and acoustic waves within the combustion chamber. Unsteady combustion generates acoustic waves directly, as well as entropy fluctuations that are quiescent. The subsequent acceleration of these entropy waves at the combustor exit creates further acoustic waves known as indirect combustion noise. In this article, a thermoacoustic model is extended to study the effects of dissipation and dispersion of the entropy waves on the stability of the combustor. Four combustor configurations are discussed: a stable combustor that may be destabilized due to the presence of entropy noise, an unstable combustor that may be stabilized by indirect combustion acoustics, an unstable combustor that experiences a “mode switch” to oscillations at a different frequency, and a combustor that is driven to instability due to entropy waves but is not necessarily accompanied by an instability in the heat release. The different scenarios that may arise from the inclusion of entropy noise provide motivation for further work on the influence of entropy waves in combustors.
Equitable Decompositions of Graphs

We investigate connections between the symmetries (automorphisms) of a graph and its spectral properties. Whenever a graph has a symmetry, i.e. a nontrivial automorphism $\phi$, it is possible to use $\phi$ to decompose any matrix $M\in\mathbb{C}^{n \times n}$ appropriately associated with the graph. The result of this decomposition is a number of strictly smaller matrices whose collective eigenvalues are the same as the eigenvalues of the original matrix $M$. Some of the matrices that can be decomposed are the graph's adjaceny matrix, Laplacian matrix, etc. Because this decomposition has connections to the theory of equitable partitions it is referred to as an equitable decomposition. Since the graph structure of many real-world networks is quite large and has a high degree of symmetry, we discuss how equitable decompositions can be used to effectively bound both the network's spectral radius and spectral gap, which are associated with dynamic processes on the network. Moreover, we show that the techniques used to equitably decompose a graph can be used to bound the number of simple eigenvalues of undirected graphs, where we obtain sharp results of Petersdorf-Sachs type.
$\mathscr{B}$-free sets and dynamics

Let $B\subset \mathbb{N}$ and let $\eta\in \{0,1\}^\mathbb{Z}$ be the characteristic function of the set $F_B:=\mathbb{Z}\setminus\bigcup_{b}b\mathbb{Z}$ of B-free numbers. Consider $(S,X_\eta)$, where $X_\eta$ is the closure of the orbit of $\eta$ under the left shift S. When $B=\{p^2 : p\in P\}$, $(S,X_\eta)$ was studied by Sarnak. This case + some generalizations, including the case (*) of B infinite, coprime with $\sum_{b}1/b<\infty$, were discussed by several authors. For general B, contrary to (*), we may have $X_\eta\subsetneq X_B:=\{x\in \{0,1\}^\mathbb{Z} : |\text{supp }x\bmod b|\leq b-1 \forall_b\}$. Also, $X_\eta$ may not be hereditary (heredity means that if $x\in X$ and $y\leq x$ coordinatewise then $y\in X$). We show that $\eta$ is quasi-generic for a natural measure $\nu_\eta$. We solve the problem of proximality by showing first that $X_\eta$ has a unique minimal (Toeplitz) subsystem. Moreover B-free system is proximal iff B contains an infinite coprime set. B is taut when $\delta(F_B)<\delta(F_{B\setminus \{b\} })$ for each b. We give a characterization of taut B in terms of the support of $\nu_\eta$. Moreover, for any B there exists a taut B' with $\nu_\eta=\nu_{\eta'}$. For taut sets B,B', we have B=B' iff $X_B=X_{B'}$. For each B there is a taut B' with $\tilde{X}_{\eta'}\subset \tilde{X}_\eta$ and all invariant measures for $(S,\tilde{X}_\eta)$ live on $\tilde{X}_{\eta'}$. $(S,\tilde{X}_\eta)$ is shown to be intrinsically ergodic for all B. We give a description of all invariant measures for $(S,\tilde{X}_\eta)$. The topological entropies of $(S,\tilde{X}_\eta)$ and $(S,X_B)$ are both equal to $\overline{d}(F_B)$. We show that for a subclass of taut B-free systems proximality is the same as heredity. Finally, we give applications in number theory on gaps between consecutive B-free numbers. We apply our results to the set of abundant numbers.
X-ray flares in Orion low-mass stars

Context. X-ray flares are common phenomena in pre-main sequence stars. Their analysis gives insights into the physics at work in young stellar coronae. The Orion Nebula Cluster offers a unique opportunity to study large samples of young low mass stars. This work is part of the Chandra Orion Ultradeep project (COUP), an ∼10 day long X-ray observation of the Orion Nebula Cluster (ONC). Aims. Our main goal is to statistically characterize the flare-like variability of 165 low mass (0.1–0.3 M� ) ONC members in order to test and constrain the physical scenario in which flares explain all the observed emission. Methods. We adopt a maximum likelihood piece-wise representation of the observed X-ray light curves and detect flares by taking into account both the amplitude and time derivative of the count-rate. We then derive the frequency and energy distribution of the flares. Results. The high energy tail of the energy distribution of flares is well described by a power-law with index ∼2.2. We test the hypothesis that light curves are built entirely by overlapping flares with a single power law energy distribution. We constrain the parameters of this simple model for every single light curve. The analysis of synthetic light curves obtained from the model indicates a good agreement with the observed data. Comparing low mass stars with stars in the mass interval (0.9–1.2 M� ), we establish that, at ∼1 Myr, low mass and solar mass stars of similar X-ray luminosity have very similar flare frequencies. Conclusions. Our observational results are consistent with the following model/scenario: the light curves are entirely built by overlapping flares with a power-law intensity distribution; the intense flares are individually detected, while the weak ones merge and form a pseudo-quiescent level, which we indicate as the characteristic level.
Eradication confirmation of mice from Antipodes Island and subsequent terrestrial bird recovery

Antipodes Island is part of New Zealand’s World Heritage subantarctic region and hosts special biodiversity values and significant species endemism. Invasive house mice were the only introduced mammal and detrimentally impacted invertebrate and native bird communities. Eradication of mice from Antipodes Island was undertaken in 2016 and confirmed in 2018. We present the monitoring used to confirm eradication of mice and the ecological outcomes measured over the 6 years since the eradication. Result monitoring for confirmation applied a simple regime to search for mice following a delay of two mouse breeding seasons since baiting was completed. Outcome monitoring targeted endemic land bird taxa for possible changes due to operational impacts and ecological recovery following eradication of mice. The operation had no longterm negative impacts and endemic land bird taxa have recovered quickly from variable levels of non-target mortality. Estimates of abundance of Antipodes Island snipe, Antipodes Island pipit and Reischek’s parakeet showed strong long-term positive response to mouse eradication.
Global Temporal Difference Network for Action Recognition

Temporal modeling still remains as a challenge for action recognition. Most existing temporal models focus on learning local variation between neighbor frames. There exists obvious deviations between local and global variations, such as subtle and notable motion variations. In this paper, we propose a global temporal difference module for action recognition, which consists of two sub-modules, i.e., a global aggregation module and a global difference module. These two sub-modules cooperate following the idea of using prior knowledge from the global view (i.e., global motion variation) to guide local learning at each moment. In the global aggregation module, the global prior knowledge is learned by aggregating the visual feature sequence of video into a global vector. In the global difference module, we prepare the difference vector sequence of video by subtracting each local vector from the global vector. Our method performs as a contextual guidance with a global view. The sequential dependency between these difference vectors is exploited with a channel-wise self-attention operation. Finally, the difference vectors at each timestamp are further used to enhance the semantics of the original local features. The enhanced features endow the action recognition has less deviation to understand the variation in the video globally. We instantiate the global temporal difference module into the ResNet block to form a global temporal difference network (GTDNet). Exhaustive experiments are conducted and our method achieves competitive performance at small FLOPs on Something-Something V1 & V2 and Kinetics-400.
Clinical outcome of intravitreal gentamicin injection for the treatment of end-stage glaucoma in five rabbits (eight eyes)

Background: Glaucoma is a painful and blinding condition that occurs in many species, including rabbits. When medication is no longer effective in maintaining intraocular pressure (IOP), enucleation is the recognized treatment for rabbits with end-stage glaucoma. However, this procedure carries risks relating to the procedure and the anesthesia. Aim: The aim of this retrospective study was to report the efficacy of intravitreal gentamicin injection in controlling IOP in blind eyes of rabbits with end-stage glaucoma. Ocular and non-ocular complications were retrospectively assessed. Methods: Medical record review was performed to identify five client-owned rabbits (eight eyes) that were treated by intravitreal injection of 6–20 mg of gentamicin per eye (median 7.18 mg/kg) for chronic, end-stage glaucoma. Treatment was unilateral in two and bilateral in three rabbits. IOP control was assessed via rebound tonometry readings performed approximately 2 weeks, 1 month, 3 months, and 6 months after injection. Total follow-up was between 313 and 1,111 days. Ocular complications were recorded and systemic health was estimated by the owner-answered questionnaire and changes in body weight. Results: IOP was <25 mmHg in 87.5% of eyes 3 months post-injection. The most common ocular complications were cataracts (62.5%), anterior uveitis (25%), retinal detachment (12.5%), and corneal erosion (12.5%). There were no behavioral or body weight changes suggestive of systemic complications. Conclusion: 87.5% of rabbit eyes treated with intravitreal gentamicin had controlled IOP 3 months after injection. All eyes were blind at the time of injection. Ocular side effects were common. Investigation of the safety and systemic effects of intravitreal gentamicin injection is required; however, no overt complications were identified in treated rabbits in this study.
Coherence functions of plane and spherical waves in a turbulent medium with the von Karman spectrum of medium inhomogeneities

This paper deals with line-of-sight sound propagation in a medium with the von Karman spectra of temperature and medium velocity fluctuations. The mean sound field, the coherence functions of plane and spherical waves and their coherence radii in such a medium are calculated analytically and numerically. It is found that the temperature and medium velocity contributions to these statistical moments of a sound field may differ significantly. The coherence functions of plane and spherical waves for the von Karman spectrum of medium inhomogeneities have been compared with those for the Kolmogorov and Gaussian spectra. The latter two spectra have been used widely in theories of sound propagation in random media. It is shown that, in limiting cases, the coherence functions calculated for the von Karman spectrum coincide with those calculated for the Kolmogorov and Gaussian spectra. This result supports the use of the Gaussian spectrum in theories of sound propagation in random media.
Carbon pseudospheres and the BTZ black hole

I ﬁrst recall the uses of Dirac materials as table top realizations of high energy physics scenarios. Then I point to a speciﬁc system that might reproduce a massless BTZ black hole, where the key role is played by hyperbolic carbon pseudospheres. Finally some considerations are oﬀered on the possibility to realize rotating black holes, along with some comments on the future of the whole analog gravity enterprise.
On the Acceleration of the Coupled-Integral-Equations Technique and Its Application To Multistub E-Plane Discontinuities

A technique to accelerate the numerical solution of scattering from multiple waveguide discontinuities by the Coupled-Integral-Equations Technique (CIET) is presented. The sums appearing in the numerical solution of the integral equations are computed at an initial frequency point and then used to accelerate the analysis at subsequent frequency points. Only few, typically 2 to 3, terms are needed to reach convergence for all structures investigated. Basis functions which include the edge conditions are used to guarantee numerical efficiency. A special routine to take advantage of the sparsity of the matrix relating the expansion coefficients to the incident excitation is also used. The method is applied to determine the scattering from rectangular waveguide E-plane discontinuities as well as multistub E-plane structures. Results from this work are compared to measurement and to those from the Mode-Matching Technique (MMT) to demonstrate its superiority.
Magnetic proximity effect and spin-orbital texture at the Bi 2 Se 3 /EuS interface

We investigate a magnetic proximity effect on Dirac surface states of topological insulator (TI) induced by a Bi$_2$Se$_3$/EuS interface, using density-functional theory (DFT) and a low-energy effective model, motivated by a recent experimental realization of the interface. We consider a thin ferromagnetic insulator EuS film stacked on top of Bi$_2$Se$_3$(111) slabs of three or five quintuple layers (QLs) with the magnetization of EuS normal to the interface ($z$ axis), which breaks both time-reversal and inversion symmetry. It is found that a charge transfer and surface relaxation makes the Dirac cones electron-doped. For both 3 and 5 QLs, the top-surface Dirac cone has an energy gap of 9 meV, while the bottom surface Dirac cone remains gapless. This feature is due to the short-ranged induced magnetic moment of the EuS film. For the 5 QLs, an additional Dirac cone with an energy gap of 2 meV is formed right below the bottom-surface Dirac point, while for 3 QLs, there is no additional Dirac cone. We also examine the spin-orbital texture of the Dirac surface states with broken inversion symmetry, using DFT and the effective model. We find that the $p_z$ orbital is coupled to the $z$ component of the spin moment in the opposite sign to the $p_x$ and $p_y$ orbitals. The $p_z$ and radial $p$ orbitals are coupled to the in-plane spin texture in the opposite handedness to the tangential $p$ orbital. The result obtained from the effective model agrees with our DFT calculations. The calculated spin-orbital texture may be tested from spin-polarized angle-resolved photoemission spectroscopy.
Cornus: Atomic Commit for a Cloud DBMS with Storage Disaggregation

Two-phase commit (2PC) is widely used in distributed databases to ensure atomicity of distributed transactions. Conventional 2PC was originally designed for the shared-nothing architecture and has two limitations: long latency due to two eager log writes on the critical path, and blocking of progress when a coordinator fails. Modern cloud-native databases are moving to a storage disaggregation architecture where storage is a shared highly-available service. Our key observation is that disaggregated storage enables protocol innovations that can address both the long-latency and blocking problems. We develop Cornus, an optimized 2PC protocol to achieve this goal. The only extra functionality Cornus requires is an atomic compare-and-swap capability in the storage layer, which many existing storage services already support. We present Cornus in detail and show how it addresses the two limitations. We also deploy it on real storage services including Azure Blob Storage and Redis. Empirical evaluations show that Cornus can achieve up to 1.9X latency reduction over conventional 2PC.
Mixed Variational Formulation and Mixed-Hybrid Discretization of the Transport Equation

We introduce a new variational formulation of the transport equation based on a mixed form of the transport equation. We prove some theoretical results about existence and uniqueness of the solution of this abstract problem by using desirable functional spaces. We then apply a mixed and hybrid finite element method to discretize the transport equation by introducing appropriate basis functions. We present some numerical results to illustrate the efficiency of our method.
Unlabelled Gibbs partitions

Abstract We study random composite structures considered up to symmetry that are sampled according to weights on the inner and outer structures. This model may be viewed as an unlabelled version of Gibbs partitions and encompasses multisets of weighted combinatorial objects. We describe a general setting characterized by the formation of a giant component. The collection of small fragments is shown to converge in total variation toward a limit object following a Pólya–Boltzmann distribution.
Mean field games with common noise

A theory of existence and uniqueness is developed for general stochastic differential mean field games with common noise. The concepts of strong and weak solutions are introduced in analogy with the theory of stochastic differential equations, and existence of weak solutions for mean field games is shown to hold under very general assumptions. Examples and counter-examples are provided to enlighten the underpinnings of the existence theory. Finally, an analog of the famous result of Yamada and Watanabe is derived, and it is used to prove existence and uniqueness of a strong solution under additional assumptions.
Printing Defects Detection Based on Two-Times Difference Image Method

With an aim at printing quality on-line detection, a method based on two-times difference image algorithm was proposed. Firstly, a standard template image and a gray threshold value image were calculated by using statistical methods. Secondly, an abnormal spots image was obtained through two-times difference image of the detection image, the standard template image and gray threshold value image. Lastly, the defects can be detected by analysis of connected region of the abnormal spots image. The results demonstrated that the problems of false detection and omission detection due to edge of image can be solved effectively, and the detection accuracy can be improved through this method.