Miracle-dz/UniFAR-FTUs huggingface dataset:
A new exponential separation between quantum and classical one-way communication complexity

We present a new example of a partial boolean function whose one-way quantum communication complexity is exponentially lower than its one-way classical communication complexity. The problem is a natural generalisation of the previously studied Subgroup Membership problem: Alice receives a bit string x, Bob receives a permutation matrix M, and their task is to determine whether Mx = x or Mx is far from x. The proof uses Fourier analysis and an inequality of Kahn, Kalai and Linial.
Remote estimation of the Wiener process over a channel with random delay

In this paper, we consider a problem of sampling a Wiener process, with samples forwarded to a remote estimator via a channel that consists of a queue with random delay. The estimator reconstructs a real-time estimate of the signal from causally received samples. Motivated by recent research on age-of-information, we study the optimal sampling strategy that minimizes the mean square estimation error subject to a sampling frequency constraint. We prove that the optimal sampling strategy is a threshold policy, and find the optimal threshold. This threshold is determined by the sampling frequency constraint and how much the Wiener process varies during the channel delay. An interesting consequence is that even in the absence of the sampling frequency constraint, the optimal strategy is not zero-wait sampling in which a new sample is taken once the previous sample is delivered; rather, it is optimal to wait for a non-zero amount of time after the previous sample is delivered, and then take the next sample. Further, if the sampling times are independent of the observed Wiener process, the optimal sampling problem reduces to an age-of-information optimization problem that has been recently solved. Our comparisons show that the estimation error of the optimal sampling policy is much smaller than those of age-optimal sampling, zero-wait sampling, and classic uniform sampling.
Yangians and Capelli identities

We study the image of the universal $R$-matrix for the Yangian $Y(gl_N)$ with respect to the evaluation homomorphism of $Y(gl_N)$ to the enveloping algebra $U(gl_N)$. We use the fusion procedure as defined by I. Cherednik. As a corollary we get a generalization of the classical Capelli identity.
Using the level set method to study the effects of heterogeneity and anisotropy on hyporheic exchange

The level set method was used to simulate the interface movement when a conservative solute migrated from stream water to subsurface water, and study the effects of streambed heterogeneity and anisotropy on solute penetration. The level set method is a numerical technique for tracking moving interfaces based on the idea that the interface is a level set curve of a higher‐dimensional function. Numerical simulations were compared to experiments conducted in a recirculating flume. Streambed heterogeneity led to water exchange between multiple bed forms, while in homogeneous streambeds the water exchange was restricted within a single bed form. A thin layer of homogeneous sediments at the top of the heterogeneous streambeds significantly increased the interfacial water influx, resulting in faster solute penetration and stream concentration decrease. Streambed heterogeneity generated horizontal preferential flow paths in the upper part of the bed while decreasing pore water velocities deeper in the bed, which hindered vertical penetration and consequently led to slower stream concentration decrease. Decreasing vertical permeability or increasing horizontal permeability led to slower vertical penetration and stream concentration decrease. Decreasing vertical permeability had a much more significant impact on solute penetration than increasing horizontal permeability, because mass transfer in hyporheic exchange is greatly dominated by vertical advection which depends primarily on the vertical permeability. This study was the first to apply the level set method in the study of hyporheic exchange. The theoretical and numerical methods have important applications in subsurface flow and transport processes.
Parallel programming languages for collections

The thesis discusses the design, expressive power, and implementation of parallel programming languages for collections, the fragment dealing with collections of an object-oriented query language. The Relational Algebra has a simple, intrinsic parallel semantics, which enabled the successful development of parallel relational database systems. But the implementation techniques of these systems do not carry over to the more complex object-oriented databases. In order to develop efficient parallel object-oriented database systems, one needs to (1) design their query languages with parallelism in mind, and (2) find new implementation techniques, specially designed for these languages. Here we pursue these goals for parallel languages for collections. The collections of interest for us are sets, bags, and sequences (lists). We start by describing a basic collection calculus and additional forms of recursion on collections. They have an idealized parallel "execution", assuming unbounded resources and instant communication, which gives us high-level parallel complexity measures. An interesting fragment of the calculus expresses exactly the queries in the parallel complexity class NC. Here the salient construct is divide and conquer recursion on sets. Sub-languages obtained by imposing a bound k on the number of recursion nesting correspond to the subclasses $AC\sp{k}$, for $k \ge$ 1. We break the implementation of the calculus into three steps. First, sets and bags are implemented on sequences, using high-level parallel algorithms: we express such algorithms in a high-level language for sequences called ${\cal MAP}$, built around a new form of recursion. Second, we describe a complexity-preserving compilation of ${\cal MAP}$ on a simple vector-parallel model. Third, we implement the vector model on a parallel multiprocessor. Here we choose as target the LogP model, which can be instantiated to simulate various multiprocessors. All but one of the vector model instructions require only restricted forms of communication patters on LogP, called monotone communications. These in turn admit efficient implementations on LogP. We ran two simple benchmarks on a LogP simulator, measuring the speedup and the scaleup. We report conditions under which good speedup and scaleup can be expected.
On links of vertices in simplicial $d$-complexes embeddable in euclidean $2d$-space

We consider $d$-dimensional simplicial complexes which can be PL embedded in the $2d$-dimensional euclidean space. In short, we show that in any such complex, for any three vertices, the intersection of the link-complexes of the vertices is linklessly embeddable in the $(2d-1)$-dimensional euclidean space. These considerations lead us to a new upper bound on the total number of $d$-simplices in an embeddable complex in $2d$-space with $n$ vertices, improving known upper bounds, for all $d \geq 2$. Moreover, the bound is also true for the size of $d$-complexes linklessly embeddable in the $(2d+1)$-dimensional space.
Semi-Flatland

We study perturbative compactifications of Type II string theory that rely on a fibration structure of the extra dimensions a la SYZ. Non-geometric spaces are obtained by using T-dualities as monodromies. These vacua generically preserve N=1 supersymmetry in four dimensions, and are U-dual to M-theory on G2 manifolds. Several examples are discussed, some of which admit an asymmetric orbifold description. The massless spectrum is matched to that of the dual M-theory compactification on a Joyce manifold when a comparison is possible. We explore the possibility of twisted reductions where left-moving spacetime fermion number Wilson lines are turned on in the fiber. We also give an explanation from this semiflat viewpoint for the Hanany-Witten brane-creation effect and for the equivalence of the Type IIA orientifold on T5/Z2 and Type IIB on S1 x K3.
A VLT/FLAMES survey for massive binaries in Westerlund 1. II. Dynamical constraints on magnetar progenitor masses

Context. Westerlund 1 is a young, massive Galactic starburst cluster that contains a rich coeval population of Wolf-Rayet stars, hot- and cool-phase transitional supergiants, and a magnetar. Aims. We use spectroscopic and photometric observations of the eclipsing double-lined binary W13 to derive dynamical masses for the two components, in order to determine limits for the progenitor masses of the magnetar CXOU J164710.2-455216 and the population of evolved stars in Wd1. Methods. We use eleven epochs of high-resolution VLT/FLAMES spectroscopy to construct a radial velocity curve for W13. R-band photometry is used to constrain the inclination of the system. Results. W13 has an orbital period of 9.2709 ± 0.0015 days and near-contact configuration. The shallow photometric eclipse rules out an inclination greater than 65°, leading to lower limits for the masses of the emission-line optical primary and supergiant optical secondary of 21.4 ± 2.6 and 32.8 ± 4.0 respectively, rising to 23.2-3.0+3.3 and 35.4-4.6+5.0 for our best-fit inclination 62-4+3 degrees. Comparison with theoretical models of Wolf-Rayet binary evolution suggest the emission-line object had an initial mass in excess of ~35 , with the most likely model featuring highly non-conservative late-Case A/Case B mass transfer and an initial mass in excess of 40 . Conclusions. This result confirms the high progenitor mass of the magnetar CXOU J164710.2-455216 inferred from its membership in Wd1, and represents the first dynamical constraint on the progenitor mass of any magnetar. The red supergiants in Wd1 must have similar progenitor masses to W13 and are therefore amongst the most massive stars to undergo a red supergiant phase, representing a challenge for population models that suggest stars in this mass range end their redwards evolution as yellow hypergiants.
Laboratory studies of heavy ozone

Dissociation of ozone in the Chappuis bands has been used as an O atom source to study isotope effects occurring in the O({sup 3}P) + O{sub 2}({sup 3}{Sigma}{sub g}) recombination reaction. The ozone produced was found to be enriched in both of its heavy isotopes. The pressure dependence (5-1,000 torr) and temperature dependence (127-360 K) of this isotope effect have been investigated. The enrichment is approximately constant from 5 torr to 100 torr and decreases at higher pressures. It increases with temperature, with {sup 50}O{sub 3} showing a slightly faster rate of increase than {sup 49}O{sub 3}. The results of this experiment have clearly isolated the source of the isotope effect to the gas phase O({sup 3}P) + O{sub 2}({sup 3}{Sigma}{sub g}) recombination reaction. For comparison, the authors also present isotope ratios of ozone formed in an electric discharge. None of the results, however, have shown the large enhancement of 40% or more in mass 50 observed in some stratospheric measurements.
Accretion and recent deformation of sediments along the northern Cascadia subduction zone

New multichannel seismic reflection profiles, acoustic imagery, and swath bathymetric data from the Vancouver Island continental margin reveal the surface morphology, cross-sectional geometry, and deformation style of this part of the Cascadia accretionary prism. The incoming 3- to 5-km-thick sediment section fails most commonly along landward-dipping thrusts that penetrate to or very close to the top of the underlying oceanic crust. The faults are listric with approximately circular cross sections, and hanging-wall sediments are back-tilted in a planar manner. High, near-lithostatic pore pressures in the deeper part of the section are inferred from the flattening of the faults near the decollement, and from the long distances over which the decollement has propagated seaward. The faults dip more steeply at 40°-45° near the surface where Pleistocene turbidites are displaced. Similar folds have developed where the turbidites are particularly thick (>4 km), and near-hydrostatic pore pressures are inferred to occur in the turbidite part of the section. An increase in pore pressure with depth is expected as a consequence of sedimentation and tectonic loading, particularly because the deeper hemipelagic sediments are probably far less permeable than are the overlying turbidites. The top of the downgoing Juan de Fuca plate, which defines the base of the accreted sedimentary wedge beneath the margin, is well imaged in the new seismic reflection profiles and is further defined by land reflection data, seismic refraction, and earthquake hypocenters. The landward-dipping continental backstop to the prism is also well located. If these constraints are used for the geometry of the accretionary prism, a general balance is found between the present prism volume and the estimated total sediment supply over the approximately 42-m.y. accretion history. This result, along with the observation that deformation-front faults penetrate most or all of the sediment section, suggests that little or no sediment has been subducted since initiation of the present phase of subduction in the Eocene. Application of the critically tapered wedge model of Davis and others to the observed prism geometry suggests that high average pore pressures occur in the prism, particularly the seawardmost part beneath the lower slope. Beneath the continental shelf, the dip of the subducting slab increases to greater than 11°, a dip that according to the critically tapered wedge model, is too steep to allow upward growth of an accretionary prism. This provides a simple explanation for ongoing subsidence of the Tofino sedimentary basin over the older part of the accretionary complex. To the southeast, the Juan de Fuca plate dips much more gently beneath the Olympic Peninsula of northern Washington, allowing the accretionary prism to grow upward well above sea level to form the Olympic Mountains.
A new model for dust emission by saltation bombardment

In this paper, we present an analysis on the mechanism of dust emission and describe a new model for the prediction of dust emission rate caused by saltation bombardment, based on the volume removal by impacting sand grains as they plough into the soil surface. The model predicts a relationship between the removed volume V and the particle impacting velocity U of the form V ∝ Un, with n = 2 ∼ 3. The dust emission rate is found to be proportional to u*n + 1, where u* is friction velocity. These model predictions are consistent with wind tunnel and field observations. The model offers a new interpretation of observed data and a simple scheme for the calculation of dust emission.
The Declaratron, semantic specification for scientific computation using MathML

We introduce the Declaratron, a system which takes a declarative approach to specifying mathematically based scientific computation. This uses displayable mathematical notation (Content MathML) and is both executable and semantically well defined. We combine domain specific representations of physical science (e.g. CML, Chemical Markup Language), MathML formulae and computational specifications (DeXML) to create executable documents which include scientific data and mathematical formulae. These documents preserve the provenance of the data used, and build tight semantic links between components of mathematical formulae and domain objects---in effect grounding the mathematical semantics in the scientific domain. The Declaratron takes these specifications and i) carries out entity resolution and decoration to prepare for computation ii) uses a MathML execution engine to run calculations over the revised tree iii) outputs domain objects and the complete document to give both results and an encapsulated history of the computation. A short description of a case study is given to illustrate how the system can be used. Many scientific problems require frequent change of the mathematical functional form and the Declaratron provides this without requiring changes to code. Additionally, it supports reproducible science, machine indexing and semantic search of computations, makes implicit assumptions visible, and separates domain knowledge from computational techniques. We believe that the Declaratron could replace much conventional procedural code in science.
MEMORY EFFECT IN HOMOGENIZATION OF A VISCOELASTIC KELVIN–VOIGT MODEL WITH TIME-DEPENDENT COEFFICIENTS

This paper is motivated by modeling the procedure of formation of a composite material constituted of solid fibers and of a solidifying matrix. The solidification process for the matrix depends on the temperature and on the reticulation rate which thereby influence the mechanical properties of the matrix. The mechanical properties are described by a viscoelastic medium equation of Kelvin-Voigt type with rapidly oscillating periodic coefficients depending on the temperature and the reticulation rate. That is modeled as an initial boundary value problem with time-dependent elasticity and viscosity tensors to account for the solidification, and the mechanical and/or thermal forcing. First we prove the existence and uniqueness of the solution for the problem and obtain a priori estimates. Then we derive the homogenized problem, characterize its coefficients including explicit memory terms, and prove that it admits a unique solution. Finally, we prove error bounds for the asymptotic solution, and establish some related regularity properties of the homogenized solution.
Aided target recognition from 3D laser radar data

This paper presents our ongoing research activities on target recognition from data generated by 3-D imaging laser radar. In particular, we focus on future full flash imaging 3-D sensors. Several techniques for laser range imaging are applied for modelling and simulation of data from this kind of 3-D sensor systems. Firstly, data from an experimental gated viewing system is used. Processed data from this system is useful in assisting an operator in the target recognition task. Our recent work on target identification at long ranges, using range data from the gated viewing system, provides techniques to handle turbulence, platform motion and illumination variances from scintillation and speckle noise. Moreover, the range data is expanded into 3-D by using a gating technique that provides reconstruction of the target surface structure. This is shown at distances out to 7 km. Secondly, 3-D target data is achieved at short ranges by using different scanning laser radar systems. This provides high-resolution 3-D data from scanning a target from one single view. However, several scans from multiple viewing angles can also quite easily be merged for more detailed target representations. This is, for example, very useful for recognizing targets in vegetation. Hereby, we achieve simulated 3-D sensor data from both short and long ranges (100 meters out to 7 km) at various spatial resolutions. Thirdly, real data from the 3-D flash imaging system by US Air Force Research Lab (AFRL/SNJM), Wright Patterson Air Force Base, has recently been made available to FOI and also used as input in the development of aided target recognition methods. High-resolution 3-D target models are used in the identification process and compared to the 3-D target data (point cloud) from the various laser radar systems. Finally, we give some examples from our work that clearly show that future 3-D laser radar systems in cooperation with signal- and image analysis techniques have a great potential in the non-cooperative target recognition task and will provide several new and interesting capabilities, for example, to reveal targets hidden in vegetation.
Peering into the Fog of War: The Geography of the WikiLeaks Afghanistan War Logs, 2004-2009

A team of U.S. political geographers analyzes the secret Afghanistan war logs released by WikiLeaks.org. They offer the chance to examine in detail the dynamics of the conflict in that country. Doing so in a spatial framework is possible because each of the 77,000 events has geographic coordinates and dates. Using cartographic and geostatistical tools, the authors map the changing distribution of the events and compare them to the well-known violent-events ACLED database (see O'Loughlin et al., 2010 in this issue). They conclude that ACLED comprises a representative set of the more comprehensive data in the released files. The released war logs show that the Afghan insurgency spread rapidly in 2008-2009, that the insurgency is moving out of its traditional Pashtun heartlands, and remains mostly rural in location. Hotspot and cluster analysis identifies the key locations of the current war, which indicate that it is relocating to new provinces in Afghanistan while intensifying in the eastern border regions and in the south.
Atmosphere turbulence phase compensation in synthetic aperture ladar data processing

Accurately simulating the effect of atmospheric turbulence on the laser beams to make an effective compensation will improve the imaging ability of practical synthetic aperture ladar (SAL). Based on the modeling of atmospheric turbulence with phase screens generated by Monte Carlo algorithm and power spectrum method, and using the theory of Fourier propagation, the SAL backscattered signal of assumed Gaussian beam from point objects is simulated. The results show that phase distortion in atmospheric turbulence is severe that could reduce SAL imaging ability. A corresponding method, iterative Fourier phase conjugation (IFPC) algorithm, is provided to minimize the phase aberrations, and compensation results show that this algorithm can give us a better SAL solution.
The radiative budgets of a tropical mesoscale convective system during the EMEX‐STEP‐AMEX experiment: 1. Observations

This paper is the first of a series of two that aim to describe the spatial and temporal variation of the radiative heating associated with tropical mesoscale convective systems (MCSs). This paper describes the analysis of data collected in and around a tropical cloud cluster system studied as part of the Equatorial Mesoscale Experiment (EMEX). The data analysis indicates that the cluster originated off the northern coast of Australia along the midlevel monsoon trough and lasted approximately 12 hours. The system moved with a velocity of about 12 m/s toward the northeast and the low-level surface northwesterly flow at the vicinity of the premonsoon trough area seems continuously to feed the EMEX 9 cloud cluster with energetic warm, moist equatorial air. Data obtained from aircraft penetrations show features similar to tropical MCSs reported elsewhere (such as an area of strong to moderate convection surrounded by a broad region of stratiform precipitation, radar echo bright band in the stratiform region, “onion” type sounding behind the convective region). The vertical structures of the EMEX 9 cloud cluster also contain two types of imbedded convection: an upright vertical structure and a pronounced rearward slope (approximately 17°), having a vertical extent of 14.5 km and above and a horizontal scale of about 40 km. The cloud base and cloud top altitude in the stratiform region are estimated to be of the order of 4.8 km and 15 to 16 km, respectively. The composite aircraft shortwave radiation data from the stratiform region show a significant attenuation of shortwave flux through the cloud (the estimated transmission is 14% at cloud base). The upward and downward solar flux profiles are almost parallel to each other in the atmosphere inside and below the cloud base, suggesting very little solar heating in these regions. The upward and downward infrared radiation fluxes measured in the tropical MCS also show little infrared heating above and below the cloud cluster.