Miracle-dz/UniFAR-FTUs huggingface dataset:
A Totally Stable Adaptive Control for Path Tracking of Time-Varying Autonomous Underwater Vehicles

Abstract This paper deals with the problem of adaptive path tracking of autonomous underwater vehicles with time-varying dynamics. The controller design is based on a speed-gradient adaptive law. A high-performance control behavior is aimed, so the full actuator dynamics is considered together with that of the vehicle. To this end, a state/disturbance observer is developed in the state feedback employing inverse dynamics. It is proved that the error paths can converge asymptotically to null when only the nonlinear static characteristic of the thrusters is involved in the design. When the actuator dynamics is considered too, only attractivity of the error paths to a residual set can be stated. The framework for this last proof relies on the concept of total stability. One main characteristic of our approach is that it can cope with a wide variety of bounded time-varying parameters with no limitations at all on their rates or a-priori knowledge.
Bayesian species delimitation using multilocus sequence data

In the absence of recent admixture between species, bipartitions of individuals in gene trees that are shared across loci can potentially be used to infer the presence of two or more species. This approach to species delimitation via molecular sequence data has been constrained by the fact that genealogies for individual loci are often poorly resolved and that ancestral lineage sorting, hybridization, and other population genetic processes can lead to discordant gene trees. Here we use a Bayesian modeling approach to generate the posterior probabilities of species assignments taking account of uncertainties due to unknown gene trees and the ancestral coalescent process. For tractability, we rely on a user-specified guide tree to avoid integrating over all possible species delimitations. The statistical performance of the method is examined using simulations, and the method is illustrated by analyzing sequence data from rotifers, fence lizards, and human populations.
Automatic verification of data-centric business processes

We formalize and study business process systems that are centered around "business artifacts", or simply "artifacts". Artifacts are used to represent (real or conceptual) key business entities, including both their data schema and lifecycles. The lifecycle of an artifact type specifies the possible sequencings of services that can be applied to an artifact of this type as it progresses through the business process. The artifact-centric approach was introduced by IBM, and has been used to achieve substantial savings when performing business transformations. In this paper, artifacts carry attribute records and internal state relations (holding sets of tuples) that services can consult and update. In addition, services can access an underlying database and can introduce new values from an infinite domain, thus modeling external inputs or partially specified processes described by pre-and-post conditions. The lifecycles associate services to the artifacts using declarative, condition-action style rules. We consider the problem of statically verifying whether all runs of an artifact system satisfy desirable correctness properties expressed in a first-order extension of linear-time temporal logic. We map the boundaries of decidability for the verification problem and provide its complexity. The technical challenge to static verification stems from the presence of data from an infinite domain, yielding an infinite-state system. While much work has been done lately in the verification community on model checking specialized classes of infinite-state systems, the available results do not transfer to our framework, and this remains a difficult problem. We identify an expressive class of artifact systems for which verification is nonetheless decidable. The complexity of verification is PSPACE-complete, which is no worse than classical finite-state model checking. This investigation builds upon previous work on verification of data-driven Web services and ASM transducers, while addressing significant new technical challenges raised by the artifact model.
Biochemical and Molecular Characterization of Three New Variants of AmpC β-Lactamases from Morganella morganii

ABSTRACT Morganella morganii produces an inducible, chromosomally encoded AmpC β-lactamase. We describe in this study three new variants of AmpC within this species with apparent pIs of 6.6 (M19 from M. morganii strain PP19), 7.4 (M29 from M. morganii strain PP29), and 7.8 (M37 from M. morganii strain PP37). After gene sequencing, deduced amino acid sequences displayed one to six substitutions when compared to the available Morganella AmpC sequences. An AmpR-encoding gene was also found upstream of ampC, including the LysR regulators' helix-turn-helix DNA-binding domain and the putative T-N11-A-protected region in the ampR-ampC intercistronic sequence. All three AmpC variants were purified from in vitro-generated derepressed mutants and showed overall similar kinetic parameters. None of the observed amino acid changes, occurring at the surface of the protein, appear to have a major influence in their catalytic properties. Morganella AmpCs exhibit the highest catalytic efficiencies (kcat/Km) on classical penicillins, cefoxitin, narrow-spectrum cephalosporins, and cefotaxime. Cefotaxime was more effectively hydrolyzed than other oxyimino-cephalosporins, whereas cefepime was 3 log-fold less efficiently hydrolyzed than other cephalosporins such as cephalothin. Several differences with other AmpC β-lactamases were found. Ampicillin was more efficiently hydrolyzed than benzylpenicillin. High kcat/Km values were observed for oxacillin and piperacillin, which are usually poor substrates for AmpC. A fairly efficient hydrolysis of imipenem was detected as well. Aztreonam, carbenicillin, and tazobactam were effective transient inactivators of these variants.
Entropy Bounds and String Cosmology

After discussing some old (and not-so-old) entropy bounds both for isolated systems and in cosmology, I will argue in favour of a "Hubble entropy bound" holding in the latter context. I will then apply this bound to recent developments in string cosmology, show that it is naturally saturated throughout pre-big bang inflation, and claim that its fulfilment at later times has interesting implications for the exit problem of string cosmology.
Pilus‐facilitated adherence of Neisseria meningitidis to human epithelial and endothelial cells: modulation of adherence phenotype occurs concurrently with changes in primary amino acid sequence and the glycosylation status of pilin

Adherence of capsulate Neisseria meningitidis to endothelial and epithelial cells is facilitated in variants that express pili. Whereas piliated variants of N. meningitidis strain C311 adhered to endothelial cells in large numbers (<150 bacteria/cell), derivatives containing specific mutations that disrupt pilE encoding the pilin subunit were both non‐piliated and failed to adhere to endothelial cells (<1 bacterium/ cell). In addition, meningococcal pili recognized human endothelial and epithelial cells but not cells originating from other animals. Variants of strain C311 were obtained that expressed pilins of reduced apparent Mr and exhibited a marked increase in adherence to epithelial cells. Structural analysis of pilins from two hyper‐adherent variants and the parent strain were carried out by DNA sequencing of their pilE genes. Deduced molecular weights of pilins were considerably tower compared with their apparent Mr values on SDS‐PAGE. Hyper‐adherent pilins shared unique changes in sequence including substitution of Asn‐113 for Asp‐113 and changes from Asn‐Asp‐Thr‐Asp to Thr‐Asp‐Ala‐Lys at residues 127‐130 in mature pilin. Asn residues 113 and 127 of‘parental’pilin both form part of the typical eukaryotic N‐glycosylation motif Asn‐X‐Ser/Thr and could potentially be glycosylated post‐translationally. The presence of carbohydrate on pilin was demonstrated and when pilins were deglycosylated, their migration on SDS‐PAGE increased, supporting the notion that variable glycosylation accounts for discrepancies in apparent and deduced molecular weights. Functionally distinct pilins produced by two fully piliated variants of a second strain (MC58) differed only in that the putative glycosylation motif Asn‐60‐Asn‐61‐Thr‐62 in an adherent variant was replaced with Asp‐60‐Asn‐61‐Ser‐62 in a non‐adherent variant. Fully adherent backswitchers obtained from the non‐adherent variant always regained Asn‐60 but retained Ser‐62. We propose, therefore, that functional variations in N. meningitidis pili may be modulated in large part by primary amino acid sequence changes that ablate or create N‐linked glycosylation sites on the pilin subunit.
Voronoi-Dirichlet tesselation as a tool for investigation of polymorphism in molecular crystals with CwHxNyOz composition and photochromic properties.

The non-bonded interactions in five sets of polymorph substances with photochromic properties have been investigated within the Voronoi-Dirichlet approach. Twenty compounds with the general formula C(w)H(x)N(y)O(z) were analyzed. Among ten possible types of non-bonded interactions at least five types are observed in the crystal structures of compounds under discussion. For all the structures the majority of interactions involve H atoms, namely London forces (H.H and H.C) and hydrogen bonds (H.O and H.N). A conformational polymorph was stated to be characterized by a unique set of inter- and intramolecular non-bonded interactions. It was quantitatively demonstrated that molecules in the same conformation can pack in a different way, and, vice versa, the change in conformation of a molecule does not prevent a substance from realising the same set of intermolecular contacts. In accordance with the data obtained for 2,4-dinitrobenzylpyridine derivatives, only conformational polymorphs with an intramolecular N.N interaction between a nitro group and a pyridine are photochromic.
Segmentation of unknown objects in indoor environments

We present a framework for segmenting unknown objects in RGB-D images suitable for robotics tasks such as object search, grasping and manipulation. While handling single objects on a table is solved, handling complex scenes poses considerable problems due to clutter and occlusion. After pre-segmentation of the input image based on surface normals, surface patches are estimated using a mixture of planes and NURBS (non-uniform rational B-splines) and model selection is employed to find the best representation for the given data. We then construct a graph from surface patches and relations between pairs of patches and perform graph cut to arrive at object hypotheses segmented from the scene. The energy terms for patch relations are learned from user annotated training data, where support vector machines (SVM) are trained to classify a relation as being indicative of two patches belonging to the same object. We show evaluation of the relations and results on a database of different test sets, demonstrating that the approach can segment objects of various shapes in cluttered table top scenes.
LODOP - Multi-Query Optimization for Linked Data Profiling Queries

The Web of Data contains a large number of different, openlyavailable datasets. In order to effectively integrate them into existing applications, meta information on statistical and structural properties is needed. Examples include information about cardinalities, value patterns, or co-occurring properties. For Linked Datasets such information is currently very limited or not available at all. Data profiling techniques are needed to compute respective statistics and meta information. However, current state of the art approaches can either not be applied to Linked Data, or exhibit considerable performance problems. We present Lodop, a framework for computing, optimizing, and benchmarking data profiling techniques based on MapReduce with Apache Pig. We implemented 15 of the most important data profiling tasks, optimized their simultaneous execution, and evaluate them with four typical datasets from the Web of Data. Our optimizations focus on reducing the amount of MapReduce jobs and minimizing the communication overhead between multiple jobs. Our evaluation shows the significant potential in optimizing the runtime costs for Linked Data profiling.
Composite Channel Estimation in Massive MIMO Systems

We consider a multiuser (MU) multiple-input multiple-output (MIMO) time-division duplexing (TDD) system in which the base station (BS) is equipped with a large number of antennas for communicating with single-antenna mobile users. In such a system the BS has to estimate the channel state information (CSI) that includes large-scale fading coefficients (LSFCs) and small-scale fading coefficients (SSFCs) by uplink pilots. Although information about the former FCs are indispensable in a MU-MIMO or distributed MIMO system, they are usually ignored or assumed perfectly known when treating the MIMO CSI estimation problem. We take advantage of the large spatial samples of a massive MIMO BS to derive accurate LSFC estimates in the absence of SSFC information. With estimated LSFCs, SSFCs are then obtained using a rank-reduced (RR) channel model which in essence transforms the channel vector into a lower dimension representation. We analyze the mean squared error (MSE) performance of the proposed composite channel estimator and prove that the separable angle of arrival (AoA) information provided by the RR model is beneficial for enhancing the estimator's performance, especially when the angle spread of the uplink signal is not too large.
Structural stability and mechanical properties of Be3N2 under high pressure

Abstract A theoretical investigations on the structural stability and mechanical properties of Be3N2 crystallising in α and β phases was performed using first-principles calculations based on density functional theory. The obtained ground state structure and mechanical properties are in excellent agreement with the available experimental and theoretical data. A full elastic tensor and crystal anisotropy of Be3N2 in two phases are determined in the wide pressure range. Results indicated that the two phases of Be3N2 are mechanically stable and strongly pressure dependent in the range of pressure from 0 to 80 GPa. The superior mechanical properties show that the two phases of Be3N2 are potential candidate structures to be the hard material. And the α-Be3N2 has better mechanical properties than β-Be3N2. By the calculated B/G ratio, it is predicted that both phases are intrinsically brittleness and strongly prone to ductility when the pressure is above 65.6 and 68.5 GPa, respectively. Additionally, the pressure-induced elastic anisotropy analysis indicates that the elastically anisotropic of Be3N2 in both phases is strengthening with increasing pressure, and strongly dependent on the propagation direction.
Interchangeability between heart rate and photoplethysmography variabilities during sympathetic stimulations

Photoplethysmography variability (PPGV) is currently considered to be a good surrogate to heart rate variability (HRV) measurements using the time between two pulse waves instead of RR intervals. Nevertheless, the interchangeability between HRV and PPGV has never been evaluated in situations with severe alterations in the autonomic nervous system (ANS). We aimed to identify the conditions for a correct utilization of PPGV in evaluating the consequences of sympathetic stimulations. Nine subjects performed three tests: active orthostatic test, slow walk and moderate and exhaustive cycling exercises in the supine position. Pulse waves at the fingertip and RR intervals were recorded at the same time. We used correlations and the Bland and Altman method to compare and evaluate interchangeability between several HRV indices. Bland and Altman analysis highlighted small discrepancies between PPGV and HRV for all HRV indices in the supine position and for , , LFpeak and RMSSD in the upright position. During the slow walk, it was impossible to detect properly PPG peaks. We observed large differences between the two methods during the cycling exercise. In conclusion, PPGV can be used instead of HRV without reserve in the supine position but only for some HRV indices in the upright position and not during slow walk and cycling exercise.
Evaluating the Impact of Routing andQueuing Techniques on the QoS of VoIP OverIP/MPLS Networks

this paper describes performance evaluation of VoIP over IP/MPLS networks using OPNET tool. The simulation study is completed by running VoIP application in different network scenarioswith different interior routing protocols; namely: RIP, OSPF and EIGRP and with different queuing techniques to measure quality of service. However, the main network model is built of TCP/IP routers with MPLS routers in the core of the network case study (middle). This model enables different TCP/IP networks communicating to each other through the MPLS core routers. The following performance parameters: the delay (jitter) (sec), packet delay variation, packet end-to-end delay (sec), and number of packets sent/received are used to compare the efficiency of different networks.
Preliminary evaluation of the interactive drama facade

There is growing interest in technologies that support user experiences emphasizing aesthetic satisfaction and enjoyment rather than task accomplishment. Evaluating such experiences remains an open research problem. Here we describe a methodology for evaluating the interactive drama Façade, and present the first experimental results. Interactive dramas are "pure" hedonic experiences, forcing a focus on experience quality rather than efficiency and ease of use. Through the coding of retroactive protocols, we reveal play patterns whereby interaction failures are leveraged into new player goals, thus supporting players in maintaining positive interest in the experience even in the face of interaction failures.
On the performance of OFDM Index Modulation over Nakagami fading channels

Recently, Orthogonal Frequency Division Multiplexing with Index Modulation (OFDM-IM) has been introduced as a novel multi-carrier system to carry additional information bits compared to conventional OFDM. In this paper, we provide a closed-form expression of an OFDM-IM system for M-ary signal constellations such as M - QAM and M - PSK modulation schemes over a Nakagami-m fading channel. Simulation results illustrate that OFDM-IM improves system performance in high data-rate transmission over conventional OFDM under various Nakagami fading factor m.
ESAIM: Control, Optimisation and Calculus of Variations

The purpose of this paper is to show that the method of controlled Lagrangians and its Hamiltonian counterpart (based on the notion of passivity) are equivalent under rather general hypotheses. We study the particular case of simple mechanical control systems (where the underlying Lagrangian is kinetic minus potential energy) subject to controls and external forces in some detail. The equivalence makes use of almost Poisson structures (Poisson brackets that may fail to satisfy the Jacobi identity) on the Hamiltonian side, which is the Hamiltonian counterpart of a class of gyroscopic forces on the Lagrangian side. Mathematics Subject Classification. 34D20, 70H03, 70H05, 93D15. Received December 27, 2001. Revised February 26, 2002.
Active Markov information-theoretic path planning for robotic environmental sensing

Recent research in multi-robot exploration and mapping has focused on sampling environmental fields, which are typically modeled using the Gaussian process (GP). Existing information-theoretic exploration strategies for learning GP-based environmental field maps adopt the non-Markovian problem structure and consequently scale poorly with the length of history of observations. Hence, it becomes computationally impractical to use these strategies for in situ, realtime active sampling. To ease this computational burden, this paper presents a Markov-based approach to efficient information-theoretic path planning for active sampling of GP-based fields. We analyze the time complexity of solving the Markov-based path planning problem, and demonstrate analytically that it scales better than that of deriving the non-Markovian strategies with increasing length of planning horizon. For a class of exploration tasks called the transect sampling task, we provide theoretical guarantees on the active sampling performance of our Markov-based policy, from which ideal environmental field conditions and sampling task settings can be established to limit its performance degradation due to violation of the Markov assumption. Empirical evaluation on real-world temperature and plankton density field data shows that our Markov-based policy can generally achieve active sampling performance comparable to that of the widely-used non-Markovian greedy policies under less favorable realistic field conditions and task settings while enjoying significant computational gain over them.
Multicopy plasmids are clustered and localized in Escherichia coli

We localized the multicopy plasmid RK2 in Escherichia coli and found that the number of fluorescent foci observed in each cell was substantially less than the copy number of the plasmid, suggesting that many copies of RK2 are grouped into a few multiplasmid clusters. In minimal glucose media, the majority of cells had one or two foci, with a single focus localized near midcell, and two foci near the 1/4 and 3/4 cell positions. The number of foci per cell increased with cell length and with growth rate, and decreased upon entering stationary phase, suggesting a coordination of RK2 replication or segregation with the bacterial cell cycle. Time-lapse microscopy demonstrated that partitioning of RK2 foci is achieved by the splitting of a single focus into two or three smaller foci, which are capable of separating with rapid kinetics. A derivative of the high-copy-number plasmid pUC19 containing the lacO array was also localized by tagging with GFP-LacI. Whereas many of the cells contained numerous, randomly diffusing foci, most cells exhibited one or two plasmid clusters located at midcell or the cell quarter positions. Our results suggest a model in which multicopy plasmids are not always randomly diffusing throughout the cell as previously thought, but can be replicated and partitioned in clusters targeted to specific locations.
Regulation and characterization of the galactose-phosphoenolpyruvate-dependent phosphotransferase system in Lactobacillus casei

Cells of Lactobacillus casei grown in media containing galactose or a metabolizable beta-galactoside (lactose, lactulose, or arabinosyl-beta-D-galactoside) were induced for a galactose-phosphoenolpyruvate-dependent phosphotransferase system (gal-PTS). This high-affinity system (Km for galactose, 11 microM) was inducible in eight strains examined, which were representative of all five subspecies of L. casei. The gal-PTS was also induced in strains defective in glucose- and lactose-phosphoenolpyruvate-dependent phosphotransferase systems during growth on galactose. Galactose 6-phosphate appeared to be the intracellular inducer of the gal-PTS. The gal-PTS was quite specific for D-galactose, and neither glucose, lactose, nor a variety of structural analogs of galactose caused significant inhibition of phosphotransferase system-mediated galactose transport in intact cells. The phosphoenolpyruvate-dependent phosphorylation of galactose in vitro required specific membrane and cytoplasmic components (including enzyme IIIgal), which were induced only by growth of the cells on galactose or beta-galactosides. Extracts prepared from such cells also contained an ATP-dependent galactokinase which converted galactose to galactose 1-phosphate. Our results demonstrate the separate identities of the gal-PTS and the lactose-phosphoenol-pyruvate-dependent phosphotransferase system in L. casei.