Miracle-dz/UniFAR-FTUs huggingface dataset:
Estimating Causal Effects under Network Interference with Bayesian Generalized Propensity Scores

Real-world systems are often comprised of interconnected units, and can be represented as networks, with nodes and edges. In a social system, for instance, individuals may have social ties and financial relationships. In these settings, when a node (the unit analysis) is exposed to a treatment, its effects may spill over to connected units; then estimating both the direct effect of the treatment and its spillover effects presents several challenges. First, assumptions about the mechanism through which spillover effects occur along the observed network are required. Second, in observational studies, where the treatment assignment has not been randomized, confounding and homophily are further potential threats to the identification and to the estimation of causal effects, on networks. Here, we make two structural assumptions: (i) neighborhood interference, which assumes interference operates only through a function of the immediate neighbors’ treatments, and (ii) unconfoundedness of the individual and neighborhood treatment, which rules out the presence of unmeasured confounding variables, including those driving homophily. Under these assumptions we develop a new covariate-adjustment estimator for direct treatment and spillover effects in observational studies on networks. We proposed an estimation strategy based on a generalized propensity score that balances individual and neighborhood covariates across units under different levels of individual treatment and of exposure to neighbors’ treatment. Adjustment for propensity score is performed using a penalized spline regression. Our inference strategy capitalizes on a three-step Bayesian procedure, which allows to take account for the uncertainty in the propensity score estimation, and avoids model feedback. The correlation among connected units is taken into account using a community detection algorithm, and incorporating random effects in the outcome model. All these sources of variability, including variability of treatment assignment, are accounted for in the posterior distribution of the finite-sample causal estimands we target. We design a simulation study ©2022 Laura Forastiere, Fabrizia Mealli, Albert Wu and Edoardo M. Airoldi. License: CC-BY 4.0, see https://creativecommons.org/licenses/by/4.0/. Attribution requirements are provided at http://jmlr.org/papers/v23/18-711.html. Forastiere , Mealli, Wu and Airoldi to assess the performance of the proposed estimator on different network topologies, both on synthetic networks and on real friendship network from the Add-Health study.
Experimental study of Brillouin scattering in perfluorinated polymer optical fiber at telecommunication wavelength

Brillouin scattering properties in a perfluorinated graded-index polymer optical fiber (POF) with 120 μm core diameter were experimentally investigated using a laser with an operating wavelength of 1.55 μm. The Brillouin frequency shift and the Brillouin bandwidth were 2.83 GHz and 105 MHz, respectively. The calculated Brillouin gain coefficient of 3.09×10−11 m/W was comparable to that of fused silica fibers. The Brillouin threshold power of the 100 m POF was estimated to be 24 W, which we believe can be reduced by employing POFs with smaller cores.
Pyroelectric conversion cycles

The effect of the type of power cycle upon the amount of output electrical work for a pyroelectric converter has been measured. Output electrical energy densities are reported for ceramic lead zirconate modified with Sn4+ and Ti4+ in the execution of a variety of thermal‐electrical cycles. The effect upon the energy density due to changes in the voltage cycle limits and changes in the load resistance were also studied. A conversion cycle which is an electric analog of the Ericsson cycle is shown to yield the largest output energy density (100 mJ/cm3 for a 12.6 K temperature excursion and a 28‐kV/cm electric field excursion).
Experimental and Simulation of Kinematics of Multi-Droplet of Emulsion under Electric Field

Experiments have been performed to observe the kinematics of multi-droplet moving in a stationary emulsion exposed to a horizontal electric field of different magnitude. The droplet motion is recorded by a high-speed CCD camera. A Lagrangian framework is outlined to simulate the kinematics of multi-droplet by means of cluster integration method. The droplet size distributions computed are qualitatively consistent with the experimental picture. It is clarified from computation that the effect of the electric field intensity and the viscosity of the oil on the droplet motion. Experiments have been performed to observe the kinematics of multi-droplet moving in a stationary emulsion exposed to a horizontal electric field of different magnitude. The droplet motion is recorded by a high-speed CCD camera. A Lagrangian framework is outlined to simulate the kinematics of multi-droplet by means of cluster integration method. The droplet size distributions computed are qualitatively consistent with the experimental picture. It is clarified from computation that the effect of the electric field intensity and the viscosity of the oil on the droplet motion.
A large-scale model of the functioning brain - Supplemental material

We adopt the methods of the Semantic Pointer Architecture (SPA) to construct Spaun (21). The central kinds of representation employed in the SPA are “semantic pointers. ” Semantic pointers are neurally realized representations of a vector space generated through a compression method. In the main text, we refer to these representations only as firing patterns, to avoid the introduction of new theoretical terminology. However, introducing this terminology is helpful for describing the methods used to construct the Spaun model. Semantic pointers are constructed by compressing information from one or more other highdimensional neural vector representations, which can themselves be semantic pointers. The newly generated semantic pointer is of a similar or lower dimensionality than its constituents. Any semantic pointer can be subsequently decompressed (or “dereferenced”) to recover (much of) the original information. Semantic pointers are compact ways of referencing large amounts of data; consequently they function similarly to “pointers” as understood in computer science. Typically, in computer science a “pointer” is the address of some large amount of data stored in memory. Pointers are easy to transmit, manipulate and store, because they are a few bytes. Hence they can act as an efficient proxy for the data they point to. Semantic pointers provide the same kind of efficiency benefits in a neural setting. Unlike pointers in computer science, however, semantic pointers are semantic. That is, they are systematically related to the information that they are used to reference, because they
Tau and muon pair production cross-sections in electron-positron annihilations at s**(1/2) = 10.58-GeV

The calculational precision of $\ee\to\tautau$ and $\ee\to\mumu$ production cross-sections in electron-positron annihilations at \roots = 10.58 \gev are studied for the \kk Monte Carlo simulation program. We determine $\sigma(\ee\to\tautau) = (0.919 \pm 0.003) \nb$ and $\sigma(\ee\to\mumu) = (1.147 \pm 0.005) \nb$, where the error represents the precision of the calculation.
A novel high-resolution and large-range diffractive wavefront sensor

Based on the Talbot self-imaging principle, a diffraction-based wavefront sensor, the Z-ViewTM wavefront sensor, has been developed at Ophthonix Inc. According to the Talbot effect, a periodic grating can be self-imaged at certain distances behind the grating, commonly known as Talbot distances, without the aid of any imaging device. The fidelity of the Talbot image to the grating pattern is affected by the wavefront aberration in the illumination beam. Therefore, the wavefront distortion can be retrieved through numerical analysis of the Talbot image. Unlike the well-known Shack-Hartmann wavefront sensor, where a group of pixels on the camera is responsible for only one wavefront data point, each camera pixel in the Z-View wavefront sensor has a corresponding wavefront data. The Z-View wavefront sensor measures the wavefront at 1024 x 1048 data points, and can achieve a dynamic range of wavefront curvature of 20 diopters. The Z-View wavefront sensor has been successfully used for wavefront sensing in ophthalmic aberrometry, adaptive optics, and lensometry at Ophthonix.
Bias‐stress‐induced stretched‐exponential time dependence of charge injection and trapping in amorphous thin‐film transistors

The threshold voltage instabilities in nitride/oxide dual gate dielectric hydrogenated amorphous silicon (a‐Si:H) thin‐film transistors are investigated as a function of stress time, stress temperature, and stress bias. The obtained results are explained with a multiple trapping model rather than weak bond breaking model. In our model, the injected carriers from the a‐Si:H channel first thermalize in a broad distribution of localized band‐tail states located at the a‐Si:H/aSiNx:H interface and in the a‐SiNx:H transitional layer close to the interface, then move to deeper energies in amorphous silicon nitride at longer stress times, larger stress electric fields, or higher stress temperatures. The obtained bias‐stress‐temperature induced threshold voltage shifts are accurately modeled with a stretched‐exponential stress time dependence where the stretched‐exponent β cannot be related to the β=TST/T0 but rather to β≂TST/T0*−β0 for TST≤80 °C; for TST≥80 °C, the β is stress temperature independent. We have al.
DNS of stochastically forced laminar plane Couette flow

Background of three dimensional hydrodynamic/vortical fluctuations in a stochastically forced, laminar, incompressible, plane Couette flow is simulated by direct numerical simulations (DNS). It was found that the fluctuating field has well pronounced peculiarities: (i) The hydrodynamic fluctuations exhibits non–exponential, transient growth; (ii) Streamwise non–constant fluctuations with the characteristic length scale of the order of the channel width are predominant in the fluctuating spectrum; (iii) Existence of coherent structures in the fluctuating background; (iv) Stochastic forcing breaks the spanwise reflection symmetry (inherent to the linear and full Navier–stokes equations in a case of the Couette flow) and inputs an asymmetry on dynamical processes. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Observing Electroluminescence from Yellow Luminescence-Like Defects in GaN High Electron Mobility Transistors

A yellow band electroluminescence (EL) characteristic, which might be attributed to the same origin as the yellow luminescence (YL) defects, was observed in GaN high electron mobility transistors (HEMTs) at room temperature. The YL-like defect origin has been tentatively confirmed by comparing EL and photoluminescence (PL) results. To further explore the properties of YL-like EL centers, EL dependence on the drain-to-source and gate-to-source voltage were investigated. The direct comparison between the EL and temperature distribution images from the same GaN HEMT suggests that two distinct EL emission mechanisms exist at the off-state breakdown. The other type of EL emission at off-state is attributed to carrier intravalley transition due to hot carrier generation by impact ionization at localized breakdown sites. This type of hot carrier induced light emission was observed at on-state and off-state operations. The YL-like emission was shown to have a stronger electric field than the hot carrier induced emission.
Application of a static quadrupole deviator to the deposition of size-selected cluster ions from a laser vaporization source

An electrostatic quadrupole deviator is used to separate charged from neutral clusters produced by a laser vaporization source. Because of their rather constant velocity, this device which is basically an energy selector also acts as an efficient mass filter. We have simulated and studied its capability to generate beams of size-selected charged clusters. Typical beam currents of a few tens of pA allow the formation of two-dimensional cluster deposits within a few minutes. Platinum and indium clusters are deposited on electron microscopy grids coated with an amorphous carbon film. For low-density assemblies of particles in the nanometer range, size histograms are discussed in relation with the mass selectivity of the apparatus. An upper limit for the dispersion of selected cluster diameters is found to be of the order of ±8% which is at least five times better than the dispersion of neutral species.
Avanços recentes na pesquisa em fixação biológica de nitrogênio no Brasil

Abiologia do solo oferece inumeras alternativas para o desenvolvimento de novas biotecnologias que visam substituir sistemas agricolas tradicionais baseados no crescente uso de fertilizantes quimicos e agrotoxicos. Devido ao alto custo dos fertilizantes nitrogenados (70% dos custos dos fertilizantes), a fixacao biologica de nitrogenio que permite o uso, pelas plantas, do N2 molecular da atmosfera, e o processo mais estudado na biologia do solo, e os desenvolvimentos da biotecnologia moderna em muito contribuiram para os progressos recentes neste campo. A agricultura tropical nao so e sujeita a erosao e, portanto, menos apropriada para agrossistemas baseados em uso intensivo de fertilizantes; ela ainda oferece umidade e temperaturas otimas durante todo o ano para a atividade microbiologica. Na presente conferencia, os avancos biotecnologicos mais recentes na pesquisa relacionada com fixacao biologica de nitrogenio no Brasil (FBN) e as suas implicacoes com a agricultura tropical serao discutidos. Fixacao de N2 em leguminosas As leguminosas possuem o mecanismo simbiotico mais sofisticado e eficiente entre as associacoes de plantas superiores com bacterias fixadoras de N2 e as leguminosas de grao e forrageiras tem papel importante na agricultura tropical. O sucesso da soja no Brasil se deve a um programa de melhoramento direcionado a obtencao de cultivares com alta producao sem adubacao nitrogenada e ao desenvolvimento em paralelo de inoculantes contendo rizobios adaptados as condicoes e solos brasileiros. O avanco da soja para os cerrados se deve, alem da identificacao e solucao dos problemas de fertilidade, principalmente a obtencao de inoculantes novos capazes de competir com a microflora de um ecossistema perturbado apos a conversao dos cerrados em terras de cultura. A adubacao e calagem destes solos resulta numa multiplicacao indiscriminada de actinomicetos produtores de antibioticos (COELHO e DROZDOWICZ, 1979) e a sobrevivencia dos rizobios inoculados nestes solos depende da resistencia a streptomicina e varios outros antibioticos (SCOTTI et al., 1982).
SU(2) structure of the Poincaré sphere for light beams with orbital angular momentum

An SU(2) basis for the recently proposed analog of the Poincare sphere for light beams with orbital angular momentum is presented. The work of Padgett Courtial [Opt. Lett.24, 430 (1999)] is generalized in several directions, including quantized as well as partially coherent beams with orbital angular momentum. The SU(N) version of the present theory can be used for higher-order Laguerre–Gauss beams.
Wavelength-tunable add-drop multiplexers using fiber Fabry-Perot tunable filters for bidirectional wavelength-division multiplexing networks

A novel wavelength-tunable add-drop multiplexer (ADM) us- ing fiber Fabry-Perot tunable filters (FFP-TFs) for the bidirectional wave- length division multiplexing (WDM) network is proposed and demon- strated. The wide tuning range, low loss, and low polarization dependence properties of the FFP-TFs are used for the ADM operation. The experimental results show that the wavelength tuning range of this wavelength-tunable ADM can be up to 40 nm. The bit-error-rate perfor- mance of the dropped and pass-through channels for a 2.5 Gbit/s sys- tem shows the feasibility of ADM. © 2004 Society of Photo-Optical Instrumentation Engineers. (DOI: 10.1117/1.1787835)
Dynamic Planning Pipeline for Indoor Inspection Flights

In this report a basic pipeline for planning and operating an indoor drone ﬂight is presented and evaluated in detail. We introduce the structure and interface considerations of a Planner Manager enabling autonomous indoor ﬂights. The interaction routines of diﬀerent planners are introduced in detail before we evaluate the system in both simulation and real test ﬂights. We show that the system is capable of managing the typical building blocks of a mobile robotics system. Most of the components can be swapped easily to allow for rapid prototyping without the need to rework the whole pipeline.
ON LIMIT BEHAVIOURS FOR FELLER’S UNFAIR-FAIR-GAME AND ITS RELATED MODEL

Feller introduced an unfair-fair-game in his famous book [3]. In this game, at each trial, player will win 2 k yuan with probability p k = 1 / 2 k k ( k + 1), k ∈ N , and zero yuan with probability p 0 = 1 − (cid:80) ∞ k =1 p k . Because the expected gain is 1, player must pay one yuan as the entrance fee for each trial. Although this game seemed “fair”, Feller [2] proved that when the total trial number n is large enough, player will loss n yuan with its probability approximate 1. So it’s an “unfair” game. In this paper, we study in depth its convergence in probability, almost sure convergence and convergence in distribution. Furthermore, we try to take 2 k = m to reduce the values of random variables and their corresponding probabilities at the same time, thus a new probability model is introduced, which is called as the related model of Feller’s unfair-fair-game. We ﬁnd out that this new model follows a long-tailed distribution. We obtain its weak law of large numbers, strong law of large numbers and central limit theorem. These results show that their probability limit behaviours of these two models are quite diﬀerent.
On the Aldous diffusion on Continuum Trees. I

Consider a Markov chain on the space of rooted real binary trees that randomly removes leaves and reinserts them on a random edge and suitably rescales the lengths of edges. This chain was introduced by David Aldous who conjectured a diffusion limit of this chain, as the size of the tree grows, on the space of continuum trees. We prove the existence of a process on continuum trees, which via a random time change, displays properties one would expect from the conjectured Aldous diffusion. The existence of our process is proved by considering an explicit scaled limit of a Poissonized version of the Aldous Markov chain running on finite trees. The analysis involves taking limit of a sequence of splitting trees whose age processes converge but the contour process does not. Several formulas about the limiting process are derived.
Pion photoproduction cross section at large momentum transfer

The Real Compton Scattering experiment was performed in all A at the Thomas Jefferson National Accelerator Facility. It was designed to measure, for Compton scattering and π 0 -photoproduction, the differential cross section over a range of kinematic points and the polarisation transfer to the proton at a single kinematic point. The full range of the experiment in Mandelstam variables t and s was 1.64−6.46 GeV 2 and 4.82−10.92 GeV 2 respectively with beam energies of 2−6 GeV. The motivation for the experiment is to test the cross section and polarisation trans- fer predictions of perturbative QCD versus that of predictions from Generalised Parton Distribution models. This thesis will give an overview of the pertinent theory, experimental setup in Hall A and the extracting of the π 0 -photoproduction cross section.
On the Geometric Structure of Flows I: The Referential Gradient. A Generally Covariant Measure of Flow Geometry

Assuming a-priori a smooth generating vector field, we introduce a generally covariant measure of the flow geometry called the referential gradient of the flow. The main result is the explicit relation between the referential gradient and the generating vector field, and is provided for from two equivalent perspectives: a Lagrangian specification with respect to a generalized parameter, and an Eulerian specification making explicit the evolution dynamics. Furthermore, we provide explicit non-trivial conditions which govern the transformation properties of the referential gradient object.
Coherence and negative sectional curvature in complexes of groups

We examine a condition on a simply connected 2-complex X ensuring that groups acting properly on X are coherent. This extends earlier work on 2-complexes with negative sectional curvature which covers the case that G acts freely. Our extension of these results involves a generalization of the notion of sectional curvature, an extension of the combinatorial Gauss-Bonnet theorem to complexes of groups, and surprisingly requires the use of L^2-Betti numbers. We also prove local quasiconvexity of G under the additional assumption that X is CAT(0) space.
The Aitchison and Aitken Kernel Function Revisited

Over three decades ago Aitchison and Aitken proposed a novel kernel function for estimating the density functions of underlying distributions in discrete input spaces. To the best of our knowledge, it has not been shown whether this kernel function is positive definite ({\it i.e.}, a reproducing kernel function) on these spaces. Its positive definiteness would have enriched and enlarged its applicability domain: a positive definite kernel function has an associated Reproducing Kernel Hilbert Space, a framework on which a variety of powerful statistical and machine learning schemes can be developed.This paper aims to demonstrate that Aitchison and Aitken's kernel function is indeed positive definite on discrete metric spaces. We also touch on possible applications of the proposed theorem.
Sensitivity extrema in multiple-angle ellipsometry

A quantitative study of sensitivity of multiple-angle-of-incidence ellipsometry in determining several parameters of stratified structures is presented. The principles of determination of parameter errors caused by random and systematic errors in measured ellipsometric angles and by the use of incorrect values of fixed parameters are given. An appropriate choice of angles of incidence is discussed. The sensitivity for dielectric films on low-loss substrates is studied in detail, and large variations with the parameters, especially with film thickness-to-wavelength ratio, are observed.
On the Maximum-Weight Basis Problem

Let M to be a matroid defined on a finite set E. A subset L of E is locked in M if L is 2-connected in M, the complement of L is 2-connected in the dual M*, and min{r(L), r*(complement of L)} is greater than 1. In this paper, we prove that the nontrivial facets of the bases polytope of M are described by the locked subsets. We deduce that finding the maximum-weight basis of M is a polynomial problem for matroids with a polynomial number of locked subsets. This class of matroids is closed under 2-sums and contains uniform matroids.
The length of an s-increasing sequence of r-tuples

We prove a number of results related to a problem of Po-Shen Loh [9], which is equivalent to a problem in Ramsey theory. Let a = (a1, a2, a3) and b = (b1, b2, b3) be two triples of integers. Define a to be 2-less than b if ai < bi for at least two values of i, and define a sequence a1, …, am of triples to be 2-increasing if ar is 2-less than as whenever r < s. Loh asks how long a 2-increasing sequence can be if all the triples take values in {1, 2, …, n}, and gives a log* improvement over the trivial upper bound of n2 by using the triangle removal lemma. In the other direction, a simple construction gives a lower bound of n3/2. We look at this problem and a collection of generalizations, improving some of the known bounds, pointing out connections to other well-known problems in extremal combinatorics, and asking a number of further questions.