Miracle-dz/UniFAR-FTUs huggingface dataset:
Boundary-layer-separation-driven vortex shedding beneath internal solitary waves of depression

Abstract We investigate global instability and vortex shedding in the separated laminar boundary layer beneath internal solitary waves (ISWs) of depression in a two-layer stratified fluid by performing high-resolution two-dimensional direct numerical simulations. The simulations were conducted with waves propagating over a flat bottom and shoaling over relatively mild $(S= 0. 05)$ and steep $(S= 0. 1)$ slopes. Over a flat bottom, the potential for vortex shedding is shown to be directly dependent on wave amplitude, for a particular stratification, owing to increase of the adverse pressure gradient ($\mathrm{d} P/ \mathrm{d} x\gt 0$ for leftward propagating waves) beneath the trailing edge of larger amplitude waves. The generated eddies can ascend from the bottom boundary to as high as 33 % of the total depth in two-dimensional simulations. Over sloping boundaries, global instability occurs beneath all waves as they steepen. For the slopes considered, vortex shedding begins before wave breaking and the vortices, shed from the bottom boundary, can reach the pycnocline, modifying the wave breaking mechanism. Combining the results over flat and sloping boundaries, a unified criterion for vortex shedding in arbitrary two-layer continuous stratifications is proposed, which depends on the momentum-thickness Reynolds number and the non-dimensionalized ISW-induced pressure gradient at the point of separation. The criterion is generalized to a form that may be readily computed from field data and compared to published laboratory experiments and field observations. During vortex shedding events, the bed shear stress, vertical velocity and near-bed Reynolds stress were elevated, in agreement with laboratory observations during re-suspension events, indicating that boundary layer instability is an important mechanism leading to sediment re-suspension.
Gotta Catch 'Em All: Using Concealed Trapdoors to Detect Adversarial Attacks on Neural Networks

Deep neural networks are vulnerable to adversarial attacks. Numerous efforts have focused on defenses that either try to patch `holes' in trained models or try to make it difficult or costly to compute adversarial examples exploiting these holes. In our work, we explore a counter-intuitive approach of constructing "adversarial trapdoors. Unlike prior works that try to patch or disguise vulnerable points in the manifold, we intentionally inject `trapdoors,' artificial weaknesses in the manifold that attract optimized perturbation into certain pre-embedded local optima. As a result, the adversarial generation functions naturally gravitate towards our trapdoors, producing adversarial examples that the model owner can recognize through a known neuron activation signature. In this paper, we introduce trapdoors and describe an implementation of trapdoors using similar strategies to backdoor/Trojan attacks. We show that by proactively injecting trapdoors into the models (and extracting their neuron activation signature), we can detect adversarial examples generated by the state of the art attacks (Projected Gradient Descent, Optimization based CW, and Elastic Net) with high detection success rate and negligible impact on normal inputs. These results also generalize across multiple classification domains (image recognition, face recognition and traffic sign recognition). We explore different properties of trapdoors, and discuss potential countermeasures (adaptive attacks) and mitigations.
A High-Resolution 21-CM Hydrogen-Line Survey of the Andromeda Nebula

A survey of 21-cm hydrogen-line radiation was made over the central 2° of the Andromeda Nebula (M31). The observations were obtained with a 20-channel receiver and the 300-foot radio telescope; at 21 cm the beam width of this telescope is 10', which corresponds to 2 kpc at the distance of M31. Among the results derived are: a map of the radial-velocity field, the rotation-curve, the total mass, and the distribution of the integrated brightness temperature. The radial-velocity map for M31 displays a striking diagonal symmetry—one pair of quadrants agrees quite well with predictions from a model based on a thin disk in pure rotation, while the other pair is in marked disagreement with such a model. An over-all expansion or contraction on a galactic scale cannot explain these features. The most direct explanation of the complex regions is in terms of bends at the ends of the hydrogen distribution similar to those found in our own Galaxy. The positions of loci of constant radial velocity near the minor axis require an additional mechanism for their explanation; a combination of expansion and contraction over various parts of M31 appears necessary. A rotation-curve was derived from data points in the “ordered” quadrants. The two halves of this rotation-curve are not symmetrical; this has been noted previously by Burke, Turner, and Tuve. The average total mass derived from the two quadrants as well as the mass computed from the combined (reflected) data is 3.1 X 10 üftO. The systemic radial velocity derived from the rotation-curve is —310 km/sec. A comparison is made between MayalPs optically derived radial velocities and the 21-cm data. There is qualitative agreement between his measures and the complex-region data. Over the region common to the present study, his measures are of emission regions confined exclusively to the complex regions. The integrated hydrogen distribution shows a clear ringlike shape of 10 kpc radius with a distinct minimum in the central regions of Andromeda. A comparison between the locations of the peak HI ridge line and the distribution of emission nebulae mapped by Baade and Arp shows good general agreement. The H i distribution is, however, shifted west by ^4' with respect to the concentrations of H n regions. This displacement could be attributed to uncertainties in the 300-foot telescope pointing corrections only by invoking the combined maximum errors in right ascension and declination. There is thus a high probability that there is a displacement in the plane of up to 1 kpc between the optical spiral features and the location of the peak hydrogen concentrations.
Detection of squamous carcinoma cells using gold nanoparticles

The goal of this study is to use gold nanoparticle as a diagnostic agent to detect human squamous carcinoma cells. Gold nanoparticles were synthesized and the gold nanoparticle size was 34.3 ± 6.2 nm. Based on the over-expression of epidermal growth factor receptor (EGFR) biomarkers in squamous carcinoma cells, we hypothesized that EGFR could be a feasible biomarker with a target moiety for detection. We further modified polyclonal antibodies of EGFR on the surface of gold nanoparticles. We found selected squamous carcinoma cells can be selectively detected using EGFR antibody-modified gold nanoparticles via receptor-mediated endocytosis. Cell death was also examined to determine the survival status of squamous carcinoma cells with respect to gold nanoparticle treatment and EGFR polyclonal antibody modification.
Non-sticking drops

While the behaviour of large amounts of liquid is dictated by gravity, surface forces become dominant at small scales. They have for example the remarkable ability to make droplets stick to their substrates (even if they are inclined), which is a practical issue in many cases (windshields, window panes, greenhouses, or microfluidic devices). Here we describe how this problem can be overcome with super-hydrophobic materials. These materials are often developed thanks to micro-textures, which decorate a solid surface, and we describe the way such textures modify the wettability of that solid. We conclude by showing the unusual dynamics of drops in a super-hydrophobic situation.
An exponentially convergent adaptive sliding mode control of robot manipulators

Abstract A new robust adaptive algorithm for control of robot manipulators is proposed to account for a desired transient response with global exponential convergence of tracking errors without any persistent excitating assumption on the regressor. Its novelty lies in a new dynamic sliding surface that allows a systematic combination of adaptive control and variable structure control to yield a sliding mode inside an adaptive control loop. During sliding mode, parameter uncertainty appears in terms of known variables in such a manner that a new robust parameter estimator with enhanced stability properties is established. On the other hand, if the regressor meets the persistent exciting condition, the global uniform exponential stability of the equilibrium concerning the adaptive closed-loop error equation is easily established. The proposed controller from the VSS viewpoint relaxes the longstanding condition on a priori knowledge of the size of the parametric uncertainty to induce a sliding mode. On the o.
On bifurcations, voltage collapse and load modeling

This paper discusses the relation between bifurcations and power systems stability through a thorough analysis of several examples, to clarify some ideas regarding the usefulness and limitations of bifurcation theory in network studies and operation, particularly in voltage stability related issues. Different types of load models are used in a sample system to analyze their effect on system stability and bifurcation. Finally, the Ecuadorian National Interconnected System is used to depict and discuss the effect of load modeling in saddle-node bifurcation analysis of real power systems. >
Capacitated warehouse location model with risk pooling

In this article, we introduce the capacitated warehouse location model with risk pooling (CLMRP), which captures the interdependence between capacity issues and the inventory management at the warehouses. The CLMRP models a logistics system in which a single plant ships one type of product to a set of retailers, each with an uncertain demand. Warehouses serve as the direct intermediary between the plant and the retailers for the shipment of the product and also retain safety stock to provide appropriate service levels to the retailers. The CLMRP minimizes the sum of the fixed facility location, transportation, and inventory carrying costs. The model simultaneously determines warehouse locations, shipment sizes from the plant to the warehouses, the working inventory, and safety stock levels at the warehouses and the assignment of retailers to the warehouses. The costs at each warehouse exhibit initially economies of scale and then an exponential increase due to the capacity limitations. We show that this problem can be formulated as a nonlinear integer program in which the objective function is neither concave nor convex. A Lagrangian relaxation solution algorithm is proposed. The Lagrangian subproblem is also a nonlinear integer program. An efficient algorithm is developed for the linear relaxation of this subproblem. The Lagrangian relaxation algorithm provides near‐optimal solutions with reasonable computational requirements for large problem instances. © 2008 Wiley Periodicals, Inc. Naval Research Logistics, 2008
A CHARACTERISTIC‐LIKE METHOD FOR THERMALLY EXPANDABLE FLOW ON UNSTRUCTURED TRIANGULAR GRIDS

Finite-difference-like discretizations are developed for the time-dependent Navier-Stokes equations and the thermal energy equation on Delaunay triangulations of the flow domain. The flow is assumed to be thermally expandable ; that is, the density varies only with temperature. A characteristic-like (CL) method is used to discretize the temporal and convective terms. The dual variable method reduces the size of the discrete system by a factor of five.
An extended Navier-Stokes formulation for gas flows in the Knudsen layer near a wall

Gas flows in the Knudsen layer adjacent to a solid wall cannot be described by the classical Navier-Stokes constitution in general, and high-order models such as the Burnett and super-Burnett models encounter many difficulties in practical applications. In the present work we propose an extended Navier-Stokes constitution in which the effect of the collisions between the gas molecules and bounded walls is incorporated. With this model, it is found that the flow behaviors in the Knudsen layer can be effectively captured.
Using a Light DBSCAN Algorithm for Visual Surveillance of Crowded Traffic Scenes

ABSTRACT Behaviour analysis in visual surveillance has become a very active issue for the computer vision research community, particularly when crowded scenes are concerned. In this perspective, motion analysis and tracking is challenging due to significant visual ambiguities which incite to look into more alternative solutions. In this work, we introduce a new framework for recognizing various motion patterns, extracting abnormal behaviours, and tracking them over crowded traffic scenes. The proposed approach exploits a novel density-based clustering method and highlights three traffic density levels. It performs in two modes: an “offline” mode for motion patterns learning and modelling, and an “online” mode for distinguishing irregular motions and tracking them separately. We developed a light density-based clustering technique to “online” cluster motion vectors, produced by optical flow, and compare them with motion pattern models previously defined. Non-identified clusters are treated as suspicious and tracked over the scene. To evaluate and validate our work, experiment results are discussed and compared with the most recent approaches.
Collapsing and adsorbing polygons

The adsorption transition in the phase diagram of a self-interacting lattice polygon is examined. The polygon has a nearest-neighbour contact fugacity and the interaction between the polygon and an impenetrable wall is modelled by a visit fugacity which is conjugate to the number of vertices of the polygon incident with the wall. The partition function of this model is Z C.y;z/D P v;cp C.v;c/y v z c , where p C.v;c/ is the number of polygons with c nearest- neighbour contacts, v visits to the wall, and n edges (and counted up to translations parallel to the wall). The limiting free energy of this model is F C.y;z/ D limn! 1 1 logZ C.y;z/, and it is known to be a non-analytic function of y for each z 1 for all z2.0;1/.
Simplement, seulement, malheureusement, heureusement

Les adverbes seulement, simplement, malheureusement et heureusement se pretent en francais contemporain a des emplois ou ils commutent avec mais. Dans un premier temps, nous montrons a l’aide d’une serie de tests syntaxiques que, dans les contextes "oppositifs", seulement et simplement se rapprochent plus de mais que malheureusement et heureusement. Ces donnees plaident en faveur de l’idee que seulement et simplement, tout en n’etant pas des conjonctions a part entiere, sont plus grammaticalises que malheureusement et heureusement, qui demeurent des adverbes evaluatifs. Ces hypotheses sont ensuite etoffees et discutees a partir des donnees obtenues sur un corpus de 100 emplois de chacun de ces adverbes dans la presse actuelle.
Vocal tract dimensions obtained from magnetic resonance images

Serial magnetic resonance images (MRIs) of the vocal tract were obtained from two speakers of English during steady‐state productions of nine isolated vowels including the four point vowels. Vowels were sustained for about 2.5 min, interrupted only by inhalations. Maintenance of a stable configuration was aided by a head positioner and by constantly hearing the target vowel. Images were obtained in the transaxial, and also in the sagittal and coronal planes for the four point vowels. Images representing 0.5‐ to 0.8‐cm slice thickness were obtained at 0.5‐cm intervals. Computer‐assisted tracings of the boundaries of the vocal tract were used to construct a three‐dimensional digital model of the airway. Using methods from the Haskins articulatory synthesizer, vocal‐tract area functions were derived and vowels were resynthesized. Analysis of the first three formants showed good agreement with the subjects' original productions. Data on the relationship between the sagittal dimensions and the cross‐sectional .
Evaluation of oxygen saturation using a heart simulator

We evaluate the degree of oxygen saturation for several explicit wavelengths in the spectral interval from 650 to 1050 nm (therapeutic window). We analyze the effect of selecting a particular wavelength pair to calculate oxygen saturation considering the known absorption specific coefficients of oxy- and deoxy-hemoglobin. Also, we design a heart simulator to determine the most useful wavelength couple for oxygen saturation for all wavelengths in the therapeutic window. We present a selection map to facilitate wavelength choice. Furthermore, we examine the random noise sensitivity of the trans-illuminated irradiance. This information will be used to determine accurately the illumination sources for NIR spectroscopy and oximetry.
Cell density-dependent increase in the level of protease-resistant prion protein in prion-infected Neuro 2 a mouse neuroblastoma cells

Received 28 August 2009 Accepted 6 October 2009 Cells persistently infected with prions continuously produce protease-resistant prion protein (PrPres). Here, we show that the PrP-res level in prion-infected Neuro2a (N2a) neuroblastoma cells decreased to 50 % of their initial level over the first 48 h and then recovered by 96 h after seeding. The level of cellular prion protein (PrP) also appeared to fluctuate, but did not influence the fluctuation of the PrP-res level. Prion-infected N2a cells, co-cultured with a higher number of prion-unsusceptible cells, had twice as much PrP-res as those cultured without unsusceptible cells, suggesting that cell density influences the fluctuation of PrP-res as. Direct cell-to-cell contact between cells, rather than soluble factors, was involved in the cell density-dependent increase in the PrP-res level. The cholesterol content, which is known to influence PrP-res formation, also changed depending on cell density. Our data suggest that alterations in cellular microenvironments controlled by cell density influence PrP-res formation.
The Ising and anisotropy phase transitions of the periodic XY model in a transverse field

It is found that, for a periodic XY chain, the competition between periodicity and anisotropy gives rise to more than one phase-transition point at some parameter region. In this paper, the phase diagram of a period-two XY model in a transverse field is discussed. Two phase transitions, the Ising and anisotropy transitions, driven by the anisotropy parameter γ, are studied by singularities of the order parameters, the ground-state energy and the quantum entanglement. These two transitions are of second order and their traits are discussed.
Continuously operated (Al,Ga)As double‐heterostructure lasers with 70 °C lifetimes as long as two years

Lifetimes longer than two years, and decreases in light output power less than 15% at constant current after one year, both at 70 °C, are reported for selected continuously operated double‐heterostructure (Al,Ga)As lasers. Also, a median 70 °C lasing lifetime of 4500 h is reported for 100 lasers chosen randomly from 10 slices. This median lifetime is thought to correspond to 3.0×105 h (34 yr) of continuous operation had the devices been operated at 22 °C. The corresponding mean time to failure is 1.3×106 h (≳100 yr).
Another characterization of the Hardy space with non doubling measures

Let μ be a Radon measure on ℝd which may be non doubling, and let H 1(μ) be the Hardy space associated with μ introduced by Tolsa. In this paper, a new atomic characterization of H 1(μ) is established. Some applications of this characterization are also given. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ground-State Energy of a High-Density Electron Gas

The terms of $O({r}_{s}\mathrm{ln}{r}_{s})$ and $O({r}_{s})$ in the expansion of the ground-state energy of the high-density electron gas are studied in this paper. The value of the coefficient of ${r}_{s}\mathrm{ln}{r}_{s}$ is evaluated, and it is found to differ from the value obtained by DuBois. The result of the present calculation for the energy per electron is $E=2.21{{r}_{s}}^{\ensuremath{-}2}\ensuremath{-}0.916{{r}_{s}}^{\ensuremath{-}1}+0.0622\mathrm{ln}{r}_{s}\ensuremath{-}0.096+0.018{r}_{s}\mathrm{ln}{r}_{s}+({{E}_{3}}^{\ensuremath{'}}\ensuremath{-}0.036){r}_{s}+O({{r}_{s}}^{2}\mathrm{ln}{r}_{s}),$ where ${{E}_{3}}^{\ensuremath{'}}$ is a sum of twelve dimensional integrals. Although ${{E}_{3}}^{\ensuremath{'}}$ has not been evaluated it is shown with the aid of the virial theorem that no reasonable value of ${{E}_{3}}^{\ensuremath{'}}$ can make the series expansion rapidly convergent beyond ${r}_{s}\ensuremath{\sim}1$. Under the rather arbitrary assumption that ${{E}_{3}}^{\ensuremath{'}}{r}_{s}$ as well as higher order terms can be neglected below ${r}_{s}=1$, an interpolation between the present result and the low-density expansion is carried out, and values of the correlation energy in the region of metallic densities are estimated.
Enhanced thermoelectric performance in PbTe-based superlattice structures from reduction of lattice thermal conductivity

We have fabricated two-dimensional n-type PbTe∕PbTe0.75Se0. 25 structures using an evaporation process. In optimized films exhibiting a high-quality superlattice structure, a significant reduction in lattice thermal conductivity has been experimentally measured. The reduction would indicate enhanced thermoelectric device performance compared to standard PbTeSe alloys given that the electrical components, specifically, the Seebeck coefficient and electrical resistivity, were not observed to deteriorate from bulk values. The analysis of these films shows continuous layers with a true two-dimensional superlattice structure, as opposed to the PbTe∕PbSe system that exhibits zero-dimensional structures from self-assembly. The room-temperature measurement of cross-plane figure-of-merit in a n-type PbTe∕PbTe0.75Se0. 25 device structure by the transient method has been combined with temperature-dependent measurements of in-plane resistivity and Seebeck coefficient to yield evidence of enhanced thermoelectric perform.
Atomistic insight into the adsorption site selectivity of stepped Au(111) surfaces

Using classical and ab initio simulations, we study the interplay between the Au(111) surface reconstruction and monoatomic steps on a vicinal face. The experimentally observed discommensuration line patterns on a specific vicinal are reproduced and explained, and a complete description of the structure is given. An unusual atomic arrangement is shown to be responsible for the lower reactivity of hcp segments of step edges compared to the one of fcc segments. Our results provide an unprecedented understanding of the electronic and geometric properties of the complex Au(111) surface.
MUSCULAR CONTRACTION MIMICED BY MAGNETIC GELS

The ability of magnetic-field-sensitive gels to undergo a quick controllable change of shape can be used to create an artificially designed system possessing sensor- and actuator functions internally in the gel itself. The peculiar magneto-elastic properties may be used to create a wide range of motion and to control the shape change and movement, that are smooth and gentle similar to that observed in muscle. Magnetic field sensitive gels provide attractive means of actuation as artificial muscle for biomechanics and biomimetic applications.
High-order harmonic generation in Ag nanoparticle-containing plasma

High-order harmonic generation up to the 55th order was achieved using 15 nm and 110 nm silver nanoparticle-containing plumes, when femtosecond radiation propagated through the preformed plasma. These results are compared with the high-order harmonics generated from the plasma produced on the surface of bulk silver at different delays between the subnanosecond prepulse and the femtosecond pulse.