Miracle-dz/UniFAR-FTUs huggingface dataset:
A robust control strategy for mobile robots navigation in dynamic environments

This work introduces a novel control strategy to allow a class of mobile robots to robustly navigate in dynamics and potentially cluttered environments. The proposed approach combines a high-level motion planner and a low-level stabilizing feedback control law designed considering the nonlinear dynamic model of the vehicle. Taking advantage of a symbolic description of the vehicle dynamics and of the environment, the reference trajectories are sequences of elementary primitives which are obtained with a reduced computational cost. However, the resulting references may fail to be functionally controllable for the actual dynamical model of the vehicle. Accordingly, to obtain a desired tracking error, sufficient conditions are then derived by investigating the interconnection between the discrete time planner and the continuous time closed-loop nonlinear system. The effectiveness of the obtained results is demonstrated by considering, as application, a ground robot navigating in a cluttered environment.
The Hi content of early-type galaxies from the ALFALFA survey - II. The case of low density environments

Aims. We present the analysis of the Hi content of a sample of early-type galaxies (ETGs) in low-density environments (LDEs) using the data set provided by the Arecibo Legacy Fast ALFA (ALFALFA) survey. We compare their properties to the sample in the Virgo cluster that we studied in a previous paper (di Serego Alighieri et al. 2007, A&A, 474, 851, Paper I). Our aim is both to investigate how the cool interstellar medium (ISM) of these systems depends on the galaxy mass and the environment and to relate the properties of the neutral hydrogen to the warm phases of the ISM. Methods. We have selected a sample of 62 nearby ETGs (V −17). In both cases it is 10 times higher than that of the Virgo cluster. The presence of gas can be related to a recent star formation activity: 60% of all ETGs with Hi have optical emission line ratios typical of star-forming galaxies and blue colours suggesting the presence of young stellar populations, especially in the dwarf subsample. Conclusions. We show that the Hi detection rate of ETGs depends both on the environment and mass. The fraction of early-type systems with neutral hydrogen is higher in more massive objects when compared to early-type dwarfs. The ETGs in LDEs seem to have more heterogeneous properties than their Virgo cluster counterparts, since they are able to retain a cold interstellar gas component and to support star formation activity even at recent epochs.
Naked-eye star visibility and limiting magnitude mapped from DMSP-OLS satellite data

We extend the method introduced by Cinzano et al. to map the artificial sky brightness in large territories from DMSP satellite data, in order to map the naked-eye star visibility and telescopic limiting magnitudes. For these purposes we take into account the altitude of each land area from GTOPO30 world elevation data, the natural sky brightness in the chosen sky direction, based on Garstang modelling, the eye capability with the naked eye or a telescope, based on the Schaefer and Garstang approach, and the stellar extinction in the visual photometric band. For near-zenith sky directions we also take into account screening by terrain elevation. Maps of naked-eye star visibility and telescopic limiting magnitudes are useful for quantifying the capability of the population to perceive our Universe, evaluating the future evolution, making cross-correlations with statistical parameters, and recognizing areas where astronomical observations or popularization can still acceptably be made. We present, as an application, maps of naked-eye star visibility and total sky brightness in the V band in Europe at the zenith with a resolution of approximately 1 km.
2C-Cas9: a versatile tool for clonal analysis of gene function

CRISPR/Cas9-mediated targeted mutagenesis allows efficient generation of loss-of-function alleles in zebrafish. To date, this technology has been primarily used to generate genetic knockout animals. Nevertheless, the study of the function of certain loci might require tight spatiotemporal control of gene inactivation. Here, we show that tissue-specific gene disruption can be achieved by driving Cas9 expression with the Gal4/UAS system. Furthermore, by combining the Gal4/UAS and Cre/loxP systems, we establish a versatile tool to genetically label mutant cell clones, enabling their phenotypic analysis. Our technique has the potential to be applied to diverse model organisms, enabling tissue-specific loss-of-function and phenotypic characterization of live and fixed tissues.
Online Multi-Task Learning Using Active Sampling

One of the long-standing challenges in Artificial Intelligence for goal-directed behavior is to build a single agent which can solve multiple tasks. Recent progress in multi-task learning for goal-directed sequential tasks has been in the form of distillation based learning wherein a single student network learns from multiple task-specific expert networks by mimicking the task-specific policies of the expert networks. While such approaches offer a promising solution to the multi-task learning problem, they require supervision from large task-specific (expert) networks which require extensive training. We propose a simple yet efficient multi-task learning framework which solves multiple goal-directed tasks in an online or active learning setup without the need for expert supervision.
Divergent Patterns of Recent Retroviral Integrations in the Human and Chimpanzee Genomes:Probable Transmissions between Other Primates and Chimpanzees

ABSTRACT The human genome is littered by endogenous retrovirus sequences (HERVs), which constitute up to 8% of the total genomic sequence. The sequencing of the human (Homo sapiens) and chimpanzee (Pan troglodytes) genomes has facilitated the evolutionary study of ERVs and related sequences. We screened both the human genome (version hg16) and the chimpanzee genome (version PanTro1) for ERVs and conducted a phylogenetic analysis of recent integrations. We found a number of recent integrations within both genomes. They segregated into four groups. Two larger gammaretrovirus-like groups (PtG1 and PtG2) occurred in chimpanzees but not in humans. The PtG sequences were most similar to two baboon ERVs and a macaque sequence but neither to other chimpanzee ERVs nor to any human gammaretrovirus-like ERVs. The pattern was consistent with cross-species transfer via predation. This appears to be an example of horizontal transfer of retroviruses with occasional fixation in the germ line.
Deformable sensors for soft robot by electrical impedance tomography

Soft robots are by now an established trend in the robotic community. They are made by soft, deformable materials that enable them to easily conform to unstructured environment like biological systems do. In order to control this ability, sensors that return information about their spatial configuration and feedbacks from the environments are needed. Common solutions consist in the use of traditional type of sensors that can limit the capabilities of the deformable material. A different type of sensor has to be developed in order to exploit all the features of the material used for the robot structure. In this paper a first step toward the development of a novel type of sensor that enables sensing capabilities without limiting the deformation property of the soft material is presented. The sensor is based on a imaging technique known as Electrical Impedance Tomography.
The Cross-Depiction Problem: Computer Vision Algorithms for Recognising Objects in Artwork and in Photographs

The cross-depiction problem is that of recognising visual objects regardless of whether they are photographed, painted, drawn, etc. It is a potentially significant yet under-researched problem. Emulating the remarkable human ability to recognise objects in an astonishingly wide variety of depictive forms is likely to advance both the foundations and the applications of Computer Vision. In this paper we benchmark classification, domain adaptation, and deep learning methods; demonstrating that none perform consistently well in the cross-depiction problem. Given the current interest in deep learning, the fact such methods exhibit the same behaviour as all but one other method: they show a significant fall in performance over inhomogeneous databases compared to their peak performance, which is always over data comprising photographs only. Rather, we find the methods that have strong models of spatial relations between parts tend to be more robust and therefore conclude that such information is important in modelling object classes regardless of appearance details.
Complete Dictionary Recovery Over the Sphere II: Recovery by Riemannian Trust-Region Method

We consider the problem of recovering a complete (i.e., square and invertible) matrix <inline-formula> <tex-math notation="LaTeX">$ A_{0}$ </tex-math></inline-formula>, from <inline-formula> <tex-math notation="LaTeX">$ Y \in \mathbb R ^{n \times p}$ </tex-math></inline-formula> with <inline-formula> <tex-math notation="LaTeX">$Y = \boldsymbol A_{0} X_{0}$ </tex-math></inline-formula>, provided <inline-formula> <tex-math notation="LaTeX">$ X_{0}$ </tex-math></inline-formula> is sufficiently sparse. This recovery problem is central to theoretical understanding of dictionary learning, which seeks a sparse representation for a collection of input signals and finds numerous applications in modern signal processing and machine learning. We give the first efficient algorithm that provably recovers <inline-formula> <tex-math notation="LaTeX">$ A_{0}$ </tex-math></inline-formula> when <inline-formula> <tex-math notation="LaTeX">$ X_{0}$ </tex-math></inline-formula> has <inline-formula> <tex-math notation="LaTeX">$O \left ({ n }\right )$ </tex-math></inline-formula> nonzeros per column, under suitable probability model for <inline-formula> <tex-math notation="LaTeX">$ X_{0}$ </tex-math></inline-formula>. Our algorithmic pipeline centers around solving a certain nonconvex optimization problem with a spherical constraint, and hence is naturally phrased in the language of manifold optimization. In a companion paper, we have showed that with high probability, our nonconvex formulation has no “spurious” local minimizers and around any saddle point, the objective function has a negative directional curvature. In this paper, we take advantage of the particular geometric structure and describe a Riemannian trust region algorithm that provably converges to a local minimizer with from arbitrary initializations. Such minimizers give excellent approximations to the rows of <inline-formula> <tex-math notation="LaTeX">$ X_{0}$ </tex-math></inline-formula>. The rows are then recovered by a linear programming rounding and deflation.
Comparison of 2D and 3D image-based aggregate morphological indices

Significant progress has been made over the last two decades in the characterisation of aggregate shape using automated image analysis and processing methods. Aggregate shape characteristics have been quantified using three distinct shape parameters, namely the aggregate form, angularity and surface texture. Several mathematical procedures have been developed to quantify these parameters. For practical reasons, most of these procedures were limited to two-dimensional (2D) and utilised 2D aggregate images. This paper investigates the ability of some of the most widely used 2D aggregate form and angularity indices to describe the shape of five different types of aggregates (natural gravel, basalt, granite, diabase and slate). In addition, it provides a comparison between 2D and three-dimensional (3D) aggregate shape indices developed based on fitting the 3D aggregate shape using spherical harmonic functions.
Stimulation of extracellular matrix remodeling by the first type III repeat in fibronectin

The fibronectin matrix contains cryptic sites which are thought to modulate cellular biological responses. One of these sites, located in fibronectin's first type III repeat (III1c), influences signaling pathways that are relevant to cytoskeletal organization and cell cycle progression. The purpose of this study was to identify possible mechanisms responsible for the effects of III1c on cell behavior. Recombinant peptides representing various type III repeats of fibronectin were compared for their effects on fibronectin matrix organization and activation of intracellular signaling pathways. III1c and III13 but not III11c or III10 bound to monolayers of human skin fibroblasts in a dose- and time-dependent manner and were localized to the extracellular matrix. Binding of III13, but not III1c, to matrix was sensitive to heparitinase, suggesting that the association of III1c with the matrix was not dependent on heparan sulfate proteoglycans. Quantitative and morphological assessment indicated that, in contrast to previously published reports, the binding of III1c to cell layers did not result in the loss or disruption of matrix fibronectin. Binding of III1c but not III13 to the extracellular matrix did result in the loss of a conformationally sensitive epitope present within the EDA type III module of cellular fibronectin. III1c-induced loss of the EDA epitope did not require the presence of cells, occurred within 1 hour and was associated with the activation of p38 mitogen-activated protein kinase (MAPK) followed by the formation of filopodia. Maximal phosphorylation of p38 MAPK occurred within 1 hour, whereas cytoskeletal changes did not appear until 12 hours later. These findings are consistent with a model in which the binding of III1c to the extracellular matrix results in a conformational remodeling of the fibronectin matrix, which has both short- and long-term effects on cell physiology.
Semantic Representation of Cloud Services: A Case Study for Microsoft Windows Azure

Starting with the provision of ready-to-use infrastructures, such as storage and compute resources, cloud computing quickly became a flexible, cost-effective and complete environment for a wide range of IT services offered over the Internet. A growing number of cloud providers started to expose their own services to the market, to answer consumer's need, engaging a competition in the attempt to offer the easiest access to resources and the wider catalogue of services. Being integrated with proprietary services and infrastructures, these offerings makes difficult to switch between different underlying technologies, so that the customer is tied to the service provider's strategy. This lack in standards interfaces, service requirements and technologies brings into the cloud the vendor lock-in problem. Due to this complex scenery, a categorization of services to support the choice of the right solution, as well as a semantic and computable description of services that enables the comparison and the mapping between different providers' services, proves to be extremely appealing. In an attempt to take a first important step in this context we propose the semantic description of some cloud services, exposing them in terms of functionalities, parameters exchanged, and collaboration between services. In particular in this paper we present the semantic representation of Microsoft Windows Azure APIs, describing functional and non-functional properties of the services.
Planning of Fast EV Charging Stations on a Round Freeway

A novel planning method of fast electric vehicle (EV) charging stations on a round freeway was developed, considering the spatial and temporal transportation behaviors. A spatial and temporal model based on the origin-destination (OD) analysis was developed to obtain all the EV charging points (the location on the round freeway that an EV needs recharging due to the low battery capacity). Based on a shared nearest neighbor (SNN) clustering algorithm, a location determination model was developed to obtain the specific locations for EV charging stations with their service EV clusters. A capacity determination model based on the queuing theory was proposed to determine the capacity of each EV charging station. The round-island freeway in Hainan Island of China was employed as a test system to illustrate the planning method. Simulation results show that the developed planning method can not only accurately determine the most suitable locations for EV fast charging stations considering the travelling convenience of EV users, but also minimize the sum of waiting cost and charger cost.
The 300 kpc Long X-Ray Jet in PKS 1127–145, z = 1.18 Quasar: Constraining X-Ray Emission Models

We present a ~100 ks Chandra X-ray observation and new VLA radio data of the large-scale, 300 kpc long X-ray jet in PKS 1127-145, a radio-loud quasar at redshift z = 1.18. With this deep X-ray observation we now clearly discern the complex X-ray jet morphology and see substructure within the knots. The X-ray and radio jet intensity profiles are seen to be strikingly different, with the radio emission peaking strongly at the two outer knots while the X-ray emission is strongest in the inner jet region. The jet X-ray surface brightness gradually decreases by an order of magnitude going out from the core. The new X-ray data contain sufficient counts for spectral analysis of the key jet features. The X-ray energy index of the inner jet is relatively flat with αX = 0.66 ± 0.15 and steep in the outer jet with αX = 1.0 ± 0.2. We discuss the constraints implied by the new data on the X-ray emission models and conclude that "one-zone" models fail and that at least a two-component model is needed to explain the jet's broadband emission. We propose that the X-ray emission originates in the jet proper while the bulk of the radio emission comes from a surrounding jet sheath. We also consider intermittent jet activity as a possible cause of the observed jet morphology.
Performance Modeling Based Scheduling and Rescheduling of Parallel Applications on Computational Grids

Abstract As computational grids have become popular and ubiquitous, users have access to large num-ber and different types of geographically distributed grid resources. Many computational gridframeworks are composed of multiple distributed sites with each site consisting of one or morededicated or non-dedicated clusters. Jobs submitted to a grid are handled by a mataschedulerwhich interacts with the local schedulers of the clusters for scheduling jobs to the individualclusters. Computational grids have been found to be powerful research-beds for execution ofvarious kinds of parallel applications. When a parallel application is submitted to a grid, themetascheduler has to choose a set of resources from a cluster for application execution. Toselect the best set of resources for application execution, it is important to determine the per-formance of the application. Accurate performance estimates of an application is essential inassisting a grid meta scheduler to efciently schedule user jobs.Thus models that predict execution times of parallel applications on a set of resources anda search procedure (scheduling strategy) which selects the best set of machines within a clusterfor application execution are of importance for enabling the parallel applications on grids. Forefcient execution of large scientic parallel applications consisting of multiple phases, per-formance models of the individual phases should be obtained. Efcient rescheduling strategiesthat can use the per-phase models to adapt the parallel applications to application and resourcedynamics are necessary for maintaining high performance of the applications on grids. A prac-tical and robust grid computing infrastructure that integrates components related to applicationand resource monitoring, performance modeling, scheduling and rescheduling techniques, ishighly essential for large-scale deployment and high performance of scientic applications ongrid systems and hence for fostering high performance computing.4
Deletion of the Highly Conserved N-Glycan at Asn260 of HIV-1 gp120 Affects Folding and Lysosomal Degradation of gp120, and Results in Loss of Viral Infectivity

N-linked glycans covering the surface of the HIV-1 glycoprotein gp120 are of major importance for the correct folding of this glycoprotein. Of the, on average, 24 N-linked glycans present on gp120, the glycan at Asn260 was reported to be essential for the correct expression of gp120 and gp41 in the virus particle and deletion of the N260 glycan in gp120 heavily compromised virus infectivity. We show here that gp160 containing the N260Q mutation reaches the Golgi apparatus during biosynthesis. Using pulse-chase experiments with [35S] methionine/cysteine, we show that oxidative folding was slightly delayed in case of mutant N260Q gp160 and that CD4 binding was markedly compromised compared to wild-type gp160. In the search of compensatory mutations, we found a mutation in the V1/V2 loop of gp120 (S128N) that could partially restore the infectivity of mutant N260Q gp120 virus. However, the mutation S128N did not enhance any of the above-mentioned processes so its underlying compensatory mechanism must be a conformational effect that does not affect CD4 binding per se. Finally, we show that mutant N260Q gp160 was cleaved to gp120 and gp41 to a much lower extent than wild-type gp160, and that it was subject of lysosomal degradation to a higher extent than wild-type gp160 showing a prominent role of this process in the breakdown of N260-glycan-deleted gp160, which could not be counteracted by the S128N mutation. Moreover, at least part of the wild-type or mutant gp160 that is normally targeted for lysosomal degradation reached a conformation that enabled CD4 binding.
Exchanging Secrets without Using Cryptography

We consider the problem where a group of n nodes, connected to the same broadcast channel (e.g., a wireless network), want to generate a common secret bitstream, in the presence of an adversary Eve, who tries to obtain information on the bitstream. We assume that the nodes initially share a (small) piece of information, but do not have access to any out-of-band channel. We ask the question: can this problem be solved without relying on Eve's computational limitations, i.e., without using any form of public-key cryptography? We propose a secret-agreement protocol, where the n nodes of the group keep exchanging bits until they have all agreed on a bit sequence that Eve cannot reconstruct with very high probability. In this task, the nodes are assisted by a small number of interferers, whose role is to create channel noise in a way that bounds the amount of information Eve can overhear. Our protocol has polynomial-time complexity and requires no changes to the physical or MAC layer of network devices. First, we formally show that, under standard theoretical assumptions, our protocol is information-theoretically secure, achieves optimal secret-generation rate for n = 2 nodes, and scales well to an arbitrary number of nodes. Second, we adapt our protocol to a small wireless 14-square-meter testbed; we experimentally show that, if Eve uses a standard wireless physical layer and is not too close to any of the nodes, 8 nodes can achieve a secret-generation rate of 38 Kbps. To the best of our knowledge, ours is the first experimental demonstration of information-theoretic secret exchange on a wireless network at a rate beyond a few tens of bits per second.