bluuebunny/crossref_metadata_2025 huggingface dataset:
Safe Trajectory Synthesis for Autonomous Driving in Unforeseen Environments
Authors: Kousik Shreyas , Vaskov Sean , Johnson-Roberson Matthew , Vasudevan Ram
Published: November 2017

Path planning for autonomous vehicles in arbitrary environments requires a guarantee of safety, but this can be impractical to ensure in real-time when the vehicle is described with a high-fidelity model. To address this problem, this paper develops a method to perform trajectory design by considering a low-fidelity model that accounts for model mismatch. The presented method begins by computing a conservative Forward Reachable Set (FRS) of a high-fidelity model’s trajectories produced when tracking trajectories of a low-fidelity model over a finite time horizon. At runtime, the vehicle intersects this FRS with obstacles in the environment to eliminate trajectories that can lead to a collision, then selects an optimal plan from the remaining safe set. By bounding the time for this set intersection and subsequent path selection, this paper proves a lower bound for the FRS time horizon and sensing horizon to guarantee safety. This method is demonstrated in simulation using a kinematic Dubin’s car as the low-fidelity model and a dynamic unicycle as the high-fidelity model.
Battery Capacity Estimation From Partial-Charging Data Using Gaussian Process Regression
Authors: Richardson Robert R. , Birkl Christoph R. , Osborne Michael A. , Howey David A.
Published: November 2017

Accurate on-board capacity estimation is of critical importance in lithium-ion battery applications. Battery charging/discharging often occurs under a constant current load, and hence voltage vs. time measurements under this condition may be accessible in practice. This paper presents a novel diagnostic technique, Gaussian Process regression for In-situ Capacity Estimation (GP-ICE), which is capable of estimating the battery capacity using voltage vs. time measurements over short periods of galvanostatic operation.

The approach uses Gaussian process regression to map from voltage values at a selection of uniformly distributed times, to cell capacity. Unlike previous works, GP-ICE does not rely on interpreting the voltage-time data through the lens of Incremental Capacity (IC) or Differential Voltage (DV) analysis. This overcomes both the need to differentiate the voltage-time data (a process which amplifies measurement noise), and the requirement that the range of voltage measurements encompasses the peaks in the IC/DV curves. Rather, GP-ICE gives insight into which portions of the voltage range are most informative about the capacity for a particular cell. We apply GP-ICE to a dataset of 8 cells, which were aged by repeated application of an ARTEMIS urban drive cycle. Within certain voltage ranges, as little as 10 seconds of charge data is sufficient to enable capacity estimates with ∼ 2% RMSE.
Nonlinear Model Predictive Control for the Coordination of Electric Loads in Smart Homes
Authors: Divecha Avinash , Stockar Stephanie , Rizzoni Giorgio
Published: November 2017

Demand-response programs offer a viable solution for improving the grid efficiency and reliability though the shaping of the consumer’s power demand. For the customers to fully benefit from varying electricity prices, an energy management strategy that coordinates the electrical loads is required. In this framework, this paper uses a Nonlinear Model Predictive Control (MPC) strategy to solve the coupled problem of optimally scheduling home appliances, Heating, Ventilation and Air Conditioning (HVAC) system and controlling electric vehicle charging. Simulation results are presented on selected case studies to demonstrate the ability of the Particle Swarm Optimization (PSO) to solve the optimization problem for a single home faster than real-time. Results show that this strategy is always able to provide near-optimal solutions with limited computation time and no reconfiguration of the control scheme for applications to houses equipped with different technologies.
A General Framework for Minimizing Energy Consumption of Series Elastic Actuators With Regeneration
Authors: Bolívar Edgar , Rezazadeh Siavash , Gregg Robert
Published: November 2017

The use of actuators with inherent compliance, such as series elastic actuators (SEAs), has become traditional for robotic systems working in close contact with humans. SEAs can reduce the energy consumption for a given task compared to rigid actuators, but this reduction is highly dependent on the design of the SEA’s elastic element. This design is often based on natural dynamics or a parameterized optimization, but both approaches have limitations. The natural dynamics approach cannot consider actuator constraints or arbitrary reference trajectories, and a parameterized elastic element can only be optimized within the given parameter space. In this work, we propose a solution to these limitations by formulating the design of the SEA’s elastic element as a non-parametric convex optimization problem, which yields a globally optimal conservative elastic element while respecting actuator constraints. Convexity is proven for the case of an arbitrary periodic reference trajectory with a SEA capable of energy regeneration. We discuss the optimization results for the tasks defined by the human ankle motion during level-ground walking and the natural motion of a single mass-spring system with a nonlinear spring. For all these tasks, the designed SEA reduces energy consumption and satisfies the actuator’s constraints.
Experimental Evaluation of Different Controllers for Cooperative Adaptive Cruise Control
Authors: Lin Yuan , Eskandarian Azim
Published: November 2017

Cooperative Adaptive Cruise Control (CACC) systems which enable vehicle following with tight inter-vehicle head-way offer unique advantage to promote transportation mobility. CACC systems are a step forward the commercially available Adaptive Cruise Control (ACC) systems as they utilize inter-vehicle wireless communication for more advanced control system design. This work studies different wireless communication topologies, i.e., receiving wireless communication from one or more preceding vehicles, and different error-regulation controllers, i.e., linear vs non-linear, for CACC. Through robot following experiments, we show that appropriately designed CACC systems can all achieve vehicle following. For emergency hard braking, however, a non-linear vehicle-following controller which generates strong braking action at short inter-vehicle distances can reduce the risk of collision.
Pure Pursuit Guidance for Car-Like Ground Vehicle Trajectory Tracking
Authors: Chen Yuanyan , Zhu J. Jim
Published: November 2017

Trajectory tracking guidance and control for nonholonomic (car-like) Autonomous Ground Vehicles (AGV), such as self-driving cars and car-like wheeled mobile robots, is a more challenging control problem than path following control, because the latter does not impose a speed requirement on the vehicle motion. The tracking error dynamics along the nominal path are nonlinear and time-varying in nature, which need to be exponentially stabilized. This paper presents a Line-of-Sight (LOS) Pure-Pursuit Guidance (PPG) trajectory design algorithm that generates a three Degrees of Freedom (DOF) spatial trajectory for an AGV equipped with a 3DOF trajectory tracking controller. The LOS PPG can be used for cooperative, passive (neutral) and adversarial tracking tasks, such as, respectively, formation driving, autonomous lane keeping with speed requirement, and chasing an evading vehicle. The algorithm is verified with computer simulations on a 1/6 scale electric car model, and will be further validated on that model car in the near future.
Visual Object Tracking on the Inverse Perspective Map for Autonomous Vehicles
Authors: Sridhar Srivatsan , Eskandarian Azim
Published: November 2017

Visual object detection and tracking is a crucial element of Autonomous vehicles. Vision-based sensors are used to detect road entities such as pedestrians and vehicles, and track them in real-time. Various filters such as Kalman Filters and Particle Filters are used in tracking. However, the tracking of these objects is predominantly done on the image plane. The output from the camera is a perspective image of the environment, where the same number of pixels along different directions of the image may not correspond to the same distance in real-world units. Thus, any motion model assigned to the entity would not capture the exact dynamics of the object as the object moves in the 3D world but is being tracked on a perspective view. In this paper, a system is proposed to track the objects on the Inverse Perspective Map, which is a birds eye view of the environment obtained through a homography transformation of the perspective image. Experiments are conducted to show the working of the technique and the results are presented.
Steady-State System Analysis of a Proton Exchange Membrane Fuel Cell Nonlinear Mathematical Model
Authors: Radisavljevic-Gajic Verica , Graham Kyle
Published: November 2017

In this paper we analyze the steady state dynamic behavior of a nonlinear model of a Proton Exchange Membrane (PEM) fuel cell. This model is used in several theoretical studies and application papers of PEM fuel cells. We indicate limitations and discuss potential constraints of this mathematical model. We establish conditions for the asymptotic stability at steady state by using the first stability method of Lyapunov. We find that the linearized model at steady state is uncontrollable. Specifically, the state variable corresponding to the hydrogen pressure is not controllable. This means that dynamics deviations of the state space variable corresponding to the hydrogen pressure around the steady state equilibrium point cannot be controlled. Due to its stability, the hydrogen pressure we go to the equilibrium point according to its internal (uncontrolled) dynamics so that the model is still applicable for theoretical and practical studies.
Geometric Gait Design for a Starfish-Inspired Robot With Curvature-Controlled Soft Actuators
Authors: Scott William L. , Paley Derek A.
Published: November 2017

This paper presents a geometric gait design and optimization framework for an idealized model of a planar starfish-inspired robot with curvature-controlled soft actuator arms. We describe the range of motion for each arm under the assumption of constant curvature along the length. Two modes of attachment of the ends of the arms to the ground are considered: fixed in position and orientation, and fixed in position but free to rotate. For each mode, we derive mathematical expressions for the local connection relating controlled shape changes to the displacement of the robot’s center. For the rotating case, we additionally model the individual arms as ideal elastica beams and design gaits based on expected buckling behavior for a special case of symmetric (mirrored) curvature inputs via numerical simulations.
Study of an Impact Driven Frequency Up-Conversion Piezoelectric Harvester
Authors: Abedini Amin , Onsorynezhad Saeed , Wang Fengxia
Published: November 2017

Frequency up-conversion is an effective way to increase the output power from a piezoelectric beam, which converts the ambient low-frequency vibration to the resonant vibration of the piezoelectric energy harvesters (PEH) to achieve high electric power output. Frequency up-conversion technologies are realized via impact or non-impact magnetic force to mediate the interaction between the driving beam and the generating beam. Most studies focus on the either linear model prediction or experimental verification of the linear analysis. Few, if any, study the effects of the impact induced nonlinear phenomena on power generation efficiency. In this work, we investigate how to use discontinuous theory to improve the power efficiency of the frequency up-conversion process caused by impacts. The energy harvesting performance of a piezoelectric beam in interaction with a softer beam in periodic motion is studied. The discontinuous dynamical system theory is applied to this problem to study the piezoelectric behavior under periodic motions and its bifurcations.

The beams are modeled with two spring-mass-damper systems, and the analytical model of the piezoelectric beam is created based on the linear mechanical-electrical constitutive law of the piezoelectric material, and the linear elastic constitutive law of the substrate. Based on the theoretical model, the analytical solution of the output power is derived in terms of the vibration amplitude, frequency, and the electrical load. The soft beam is subjected to a sinusoidal base excitation, and the impacts of the more flexible beam excite the piezoelectric beam. The performance of the energy harvesting of period one and period two motions have been studied and bifurcation trees for impact velocities, times, displacements and harvested power versus the frequency of the base excitation are obtained.
Stochastic Dynamics of a Piezoelectric Energy Harvester Subjected to Lévy Flight Excitations
Authors: Ramakrishnan Subramanian , Lambrecht Collin , Edlund Connor
Published: November 2017

Vibration energy harvesting seeks to exploit the energy of ambient random vibration for power generation, particularly in small scale devices. Piezoelectric transduction is often used as a conversion mechanism in harvesting and the random excitation is typically modeled as a Brownian stochastic process. However, non-Brownian excitations are of potential interest, particularly in the nonequilibrium regime of harvester dynamics. In this work, we investigate the averaged power output of a generic piezoelectric harvester driven by Brownian as well as (non-Brownian) Lévy stable excitations both in the linear and the Duffing regimes. First, a coupled system of stochastic differential equations that model the electromechanical system are presented. Numerical simulation results (based on the Euler-Maruyama scheme) that show the average power output from the system under Brownian and Lévy excitations are presented for the cases where the mechanical degree of freedom behaves as a linear as well as a Duffing oscillator. The results demonstrate that Lévy excitations result in higher expectation values of harvested power. In particular, increasing the noise intensity leads to significant increase in power output in the Levy case when compared with Brownian excitations.
Comparison of a target-equalization-cancellation approach and a localization approach to source separation
Authors: Mi Jing , Groll Matti , Colburn H. Steven
Published: November 2017

Interaural differences are important for listeners to be able to maintain focus on a sound source of interest in the presence of multiple sources. Because interaural differences are sound localization cues, most binaural-cue-based source separation algorithms attempt separation by localizing each time-frequency (T-F) unit to one of the possible source directions using interaural differences. By assembling T-F units that are assigned to one direction, the sound stream from that direction is enhanced. In this paper, a different type of binaural cue for source-separation purposes is proposed. For each T-F unit, the target-direction signal is cancelled by applying the equalization-cancellation (EC) operation to cancel the signal from the target direction; then, the dominance of the target in each T-F unit is determined by the effectiveness of the cancellation. Specifically, the energy change from cancellation is used as the criterion for target dominance for each T-F unit. Source-separation performance using the target-EC cue is compared with performance using localization cues. With simulated multi-talker and diffuse-babble interferers, the algorithm based on target-EC cues yields better source-separation performance than the algorithm based on localization cues, both in direct comparison with the ideal binary mask and in measured speech intelligibility for the separated target streams.
Ship localization in Santa Barbara Channel using machine learning classifiers
Authors: Niu Haiqiang , Ozanich Emma , Gerstoft Peter
Published: November 2017

Machine learning classifiers are shown to outperform conventional matched field processing for a deep water (600 m depth) ocean acoustic-based ship range estimation problem in the Santa Barbara Channel Experiment when limited environmental information is known. Recordings of three different ships of opportunity on a vertical array were used as training and test data for the feed-forward neural network and support vector machine classifiers, demonstrating the feasibility of machine learning methods to locate unseen sources. The classifiers perform well up to 10 km range whereas the conventional matched field processing fails at about 4 km range without accurate environmental information.
The genetics of PKMζ and memory maintenance
Authors: Sacktor Todd Charlton , Hell Johannes W.
Published: November 2017

Two atypical PKC isoforms can compensate for each other during short- and long-term memory.
Papers of note in
Nature
551
(7679)
Authors: VanHook Annalisa M.
Published: November 2017

This week’s articles highlight interactions between astrocytes and neurons that influence both cell types’ form and function; a genetic basis for individual variation in aging; and the mechanism by which an E3 ubiquitin ligase adaptor affects synaptic transmission.
Electrosclerotherapy for capillary malformations: study protocol for a randomised within-patient controlled pilot trial
Authors: Horbach Sophie E R , Wolkerstorfer Albert , de Bruin Daniel Martijn , van der Horst Chantal M A M
Published: November 2017

Introduction

The current state-of-the-art treatment modality for hypertrophic capillary malformations (CMs), laser therapy, has a considerable rate of non-responders and recurrence. Intralesional bleomycin injections (or ‘sclerotherapy’) are commonly used to treat venous and lymphatic malformations with an excellent effect, but these intravascular injections are not possible in CMs due to the small diameter of the vessels. Electroporation—an electric field applied to the tissue—could increase the permeability of endothelial cells, which could theoretically facilitate targeted localised bleomycin delivery. We therefore hypothesise that bleomycin injections in combination with electroporation—‘electrosclerotherapy’ (EST), also known as ‘electrochemotherapy’—could potentially be a novel alternative treatment option for CMs.

Methods and analysis

In this randomised within-patient controlled pilot trial, 20 patients with hypertrophic CMs will be enrolled. Three regions of interest (ROIs) within the CM will be randomly allocated for treatment with (A) EST, (B) bleomycin sclerotherapy without electroporation and (C) no treatment. Patients and outcome assessors are blinded for the treatment allocation. Treatment outcome for each ROI will be measured approximately 7 weeks after the treatment procedure, using patient-reported and physician-reported global assessment scores, colorimetry, laser speckle imaging and reporting of adverse events.

Ethics and dissemination

The study protocol is approved by the ethics review committee of the Academic Medical Center, Amsterdam. Results will be published in peer-reviewed medical journals and will be presented at international conferences and scientific meetings. Study results will be fed back to the patient population through website and social media notifications.

Trial registration number

NCT02883023;Pre-results. NTR6169.
Health literacy in Italy: a cross-sectional study protocol to assess the health literacy level in a population-based sample, and to validate health literacy measures in the Italian language
Authors: Lorini Chiara , Santomauro Francesca , Grazzini Maddalena , Mantwill Sarah , Vettori Virginia , Lastrucci Vieri , Bechini Angela , Boccalini Sara , Bussotti Alessandro , Bonaccorsi Guglielmo
Published: November 2017

Introduction

Health literacy (HL) concerns the knowledge and competences necessary for people to meet complex health demands. The aims of this study are to assess the level of HL in a sample using the Italian version of the Newest Vital Sign and the association of HL and selected antecedents with health outcomes, and to develop and validate the Italian version of the three Brief Health Literacy Screeners, two subjective numeracy items and the short form and the short-short form of the European Health Literacy Survey Questionnaire.

Methods and analysis

The study adopts a cross-sectional design and is being conducted in Florence, with information collected through telephone interviews. The population-based sample has been randomly selected using the registries of eight general practitioners (GPs). Based on a power calculation, 480 subjects will be included. Participants have been randomly offered two different questionnaires, each containing different HL measures. Data on sociodemographics and important antecedents and consequences of HL will be collected and the distribution of HL levels calculated. The mediating role of HL will be assessed using Preacher and Hayes’ model. To assess the concurrent validity of the HL scales, correlation and receiver operating characteristic analyses will be performed.

Ethics and dissemination

The study protocol has been approved by the Ethics Committee of the Area Vasta Centro. Results will be disseminated via scientific journals and conference presentations, and individual data made available to the GPs.
Expression and prognostic significance of human epidermal growth factor receptors 1, 2 and 3 in oesophageal and gastric adenocarcinomas preneoadjuvant and postneoadjuvant treatment
Authors: Hedner Charlotta , Borg David , Nodin Björn , Karnevi Emelie , Jirström Karin , Eberhard Jakob
Published: November 2017

Aims

Neoadjuvant treatment has now become the standard of care for oesophageal and gastric cancer. The aim of this study was to investigate the influence of neoadjuvant therapy on the expression of human epidermal growth factor receptor 1 (HER1/EGFR), HER2 and HER3, in oesophageal and gastric adenocarcinoma.

Methods

Immunohistochemical expression of EGFR, HER2 and HER3 was examined and compared in pretreatment biopsies, post-treatment surgical resection specimens and metastases in a retrospective cohort of 166 patients with adenocarcinoma of the oesophagus or stomach. The relationship between expression of the investigative markers and histopathological response to neoadjuvant treatment, overall survival (OS) and recurrence free survival (RFS) was analysed.

Results

Conversion of protein expression between pretreatment biopsy and post-treatment surgical resection was seen in 4.6% of the cases for EGFR, 5.9% for HER2% and 19.4% for HER3. Histopathological response to neoadjuvant treatment was significantly and stepwise associated with OS and RFS . High HER3 protein expression in post-treatment surgical resection specimens was significantly associated with a prolonged OS in univariable analysis (HR=0.39; 95% CI 0.17 to 0.93), but did not remain significant in multivariable analysis. Expression of EGFR and HER2 in post-treatment surgical resection specimens was not prognostic. No correlation between pretreatment HER-protein expression and histopathological response was seen.

Conclusions

The results from this study underscore the need for further studies on the influence of neoadjuvant treatment on biomarker expression, as this may influence treatment strategy as well as prognosis. Histopathological response is validated as a useful prognostic factor.
Effectiveness of a school-based program focusing on diet and health habits taught through physical exercise
Authors: Pablos Ana , Nebot Vicente , Vañó-Vicent Vicente , Ceca Diego , Elvira Laura
Published: November 2017

The global rate of obesity in childhood is becoming an epidemic and many authors have established a significant association between childhood obesity and overweight in adulthood. It is therefore necessary to seek effective strategies to reduce these levels of obesity. The aim of this study was to evaluate the impact of the Healthy Habits Program (HHP). The participants comprised 158 children from the fifth and sixth grades (intervention group, n = 82; control group, n = 76). The HHP is a school-based physical activity program focusing on promoting a healthy lifestyle. It lasted for 8 months, and measurements were taken at the beginning and end of the program. Physiological variables (total cholesterol, triglycerides, blood glucose, blood pressure, and maximal oxygen consumption), anthropometric variables (body mass index (BMI)) and behavioral variables (breakfast, quality of diet, meal frequency, physical activity, sedentary behavior, sleep, and perceived health) were evaluated. Repeated-measures ANOVA showed significant improvements (p < 0.05) after the intervention for the intervention group in triglycerides, blood glucose and maximal oxygen consumption. Significant improvements were also observed in breakfast habits and quality of diet. Finally, a significant improvement in prevalence of normal levels was observed for total cholesterol, blood pressure, and BMI. It can therefore be stated that the HHP is an innovative and useful school-based program that can help to improve diet and health in childhood.
Investigations of pile–soil interaction under thermo-mechanical loading
Authors: Rui Yi , Yin Mei
Published: November 2017

Thermo-active piles that couple load bearing with ground source heat pump systems are one of the new technologies in geotechnical engineering. This paper investigates the pile–soil interaction behaviour of a thermo-active pile in overconsolidated London clay by conducting a thermo-hydro-mechanical finite element analysis using an advanced soil constitutive model. Negative and positive excess pore pressures are computed around the pile during cooling and heating, respectively. However, the difference in the radial effective stress acting on the pile–soil interface between the cooling and heating stages is small, and the pile–soil interaction is governed by the shear mobilization associated with thermally induced cyclic movements of pile expansion and contraction. During the first cooling stage, the shear stress at a small portion in the upper part of the pile reaches close to the yield values, which leads to an additional settlement about 3 mm from the original mechanical load–induced settlement of 2 mm. The shear stresses in subsequent heating and cooling cycles are much smaller than the ultimate shear stress values, because of the heavily overconsolidated nature of the London clay.
Thermal acclimation of leaf respiration as a way to reduce source–sink imbalance at low temperatures in Erythronium americanum, a spring ephemeral
Authors: Dong Yanwen , Gérant Dominique , Lapointe Line
Published: November 2017

Many spring geophytes exhibit greater growth at colder than at warmer temperatures. Previous studies have suggested that there is less disequilibrium between source and sink activity at low temperatures, which delays leaf senescence and leads to higher accumulation of biomass in the perennial organ. We hypothesized that dark respiration acclimates to temperature at both the leaf and bulb levels, mainly via the alternative respiratory pathway, as a way to reduce source–sink imbalance. Erythronium americanum Ker-Gawl. was grown under three temperature regimes: 8/6 °C, 12/8 °C, and 18/14 °C (day/night). Plant respiratory rates were measured at both growth and common temperatures to determine whether differences were due to the direct effects of temperature on respiratory rates or to acclimation. Leaf dark respiration exhibited homeostasis, which together with lower assimilation at low growth temperature, most likely reduced the quantity of C available for translocation to the bulb. No temperature acclimation was visible at the sink level. However, bulb total respiration varied through time, suggesting potential stimulation of bulb respiration as sink limitation builds up. In conclusion, acclimation of respiration at the leaf level could partly explain the better equilibrium between source and sink activity in plants grown in low-temperatures, whereas bulb respiration responds to source–sink imbalance.
Symmetry breaking and tunneling dynamics of a dipolar Bose–Einstein condensate in a double-well potential
Authors: Wang Yuan Sheng , Long Ping , Zhang Bo , Zhang Hong
Published: November 2017

We investigate the properties of a three-dimensional (3D) dipolar Bose–Einstein condensate (BEC) in a double-well potential (DWP). Symmetry breaking and tunneling dynamics phenomena are demonstrated for 164Dy atoms in the 3D DWP using an effective two-mode model. The results show that the symmetry properties of the dynamics are affected markedly by the long-range nature and anisotropy of the dipolar interaction and the isotropic contact interaction.
Underwater optical environment in the coastal waters of British Columbia, Canada
Authors: Loos Eduardo , Costa Maycira , Johannessen Sophia
Published: November 2017

We describe the underwater light field of the Strait of Georgia in spring and summer, using apparent optical properties (reflectance, attenuation coefficient of downwelling irradiance, the average cosine of downwelling irradiance, and the attenuation of scalar irradiance). Both the attenuation and reflectance of photosynthetically available radiation (PAR; 400–700 nm) are highest in the turbid waters of the Fraser River plume, due to scattering by mainly inorganic particles and absorption by coloured dissolved organic matter, phytoplankton, and other organic particles. Light is most diffuse in the surface waters of the plume and least diffuse at depth and away from the plume. Throughout the Strait, blue and red wavelengths are attenuated most rapidly resulting in a green peak of reflectance, the portion of the electromagnetic spectrum that penetrates the most deeply. PAR is attenuated to 1% of its surface intensity within 6–22 m in the spring and 4–23 m in the summer. For red and blue light, the depth of 1% penetration is never deeper than 9 m. All of the visible radiation, with the exception of some green light, is absorbed within the outflowing layer (15–30 m) that is exported from the Strait with the estuarine circulation. The rapid extinction of light helps to explain the very shallow distribution of phytoplankton.
Neural Correlates of Phrase Quadrature Perception in Harmonic Rhythm: An EEG Study Using a Brain–Computer Interface
Authors: Fernández-Soto Alicia , Martínez-Rodrigo Arturo , Moncho-Bogani José , Latorre José Miguel , Fernández-Caballero Antonio
Published: November 2017

For the sake of establishing the neural correlates of phrase quadrature perception in harmonic rhythm, a musical experiment has been designed to induce music-evoked stimuli related to one important aspect of harmonic rhythm, namely the phrase quadrature. Brain activity is translated to action through electroencephalography (EEG) by using a brain–computer interface. The power spectral value of each EEG channel is estimated to obtain how power variance distributes as a function of frequency. The results of processing the acquired signals are in line with previous studies that use different musical parameters to induce emotions. Indeed, our experiment shows statistical differences in theta and alpha bands between the fulfillment and break of phrase quadrature, an important cue of harmonic rhythm, in two classical sonatas.
Foreground Detection by Competitive Learning for Varying Input Distributions
Authors: López-Rubio Ezequiel , Molina-Cabello Miguel A. , Luque-Baena Rafael Marcos , Domínguez Enrique
Published: November 2017

One of the most important challenges in computer vision applications is the background modeling, especially when the background is dynamic and the input distribution might not be stationary, i.e. the distribution of the input data could change with time (e.g. changing illuminations, waving trees, water, etc.). In this work, an unsupervised learning neural network is proposed which is able to cope with progressive changes in the input distribution. It is based on a dual learning mechanism which manages the changes of the input distribution separately from the cluster detection. The proposal is adequate for scenes where the background varies slowly. The performance of the method is tested against several state-of-the-art foreground detectors both quantitatively and qualitatively, with favorable results.
Singular knots and involutive quandles
Authors: Churchill Indu R. U. , Elhamdadi Mohamed , Hajij Mustafa , Nelson Sam
Published: November 2017

The aim of this paper is to define certain algebraic structures coming from generalized Reidemeister moves of singular knot theory. We give examples, show that the set of colorings by these algebraic structures is an invariant of singular links. As an application, we distinguish several singular knots and links.
CHARACTERIZATION OF TiCN COATING SYNTHESIZED BY THE PLASMA ENHANCED PHYSICAL VAPOUR DEPOSITION PROCESS ON A CEMENTED CARBIDE TOOL
Authors: SAMPATH KUMAR T. , VINOTH JEBARAJ A. , SIVAKUMAR K. , SHANKAR E. , TAMILOLI N.
Published: November 2017

In the present investigation, Titanium Carbonitride (TiCN) coating was deposited on a cemented carbide substrate, by means of Plasma Enhanced Physical Vapour Deposition (PEPVD) process. The microstructure of the deposited film was characterized using the Scanning Electron Microscope (SEM). Highly dense, less porous and uniformly distributed TiCN coating was observed on the coated surface. X-Ray diffraction analysis was carried out to access the phases present in the coated layer. The scratch resistance and hardness were measured using the scratch tester and Nanoindenter, respectively. The TiCN coating gives higher hardness and superior scratch resistance when compared to the substrate. The surface morphology of the coated film was characterized using the Atomic Force Microscope (AFM) and was found that the surface roughness was lesser for TiCN coating when compared to cemented carbide substrate. The intensified TiCN coating on the substrate will be useful in improving the surface behavior of cemented carbide cutting tool.
INVESTIGATIONS ON AZO/Al/AZO MULTILAYER STRUCTURE GROWN AT ROOM TEMPERATURE
Authors: AMARA SAAD , BOUAFIA MOHAMED
Published: November 2017

In this work we investigate the effect of metal layer in the Al-doped ZnO (AZO)/Al/AZO structure. AZO and Al thin films are deposed successively at room temperature using DC magnetron sputtering by rotating the substrate holder without breaking the vacuum. The optical characterization of AZO/Al/AZO structure was performed by the spectroscopic ellipsometry under different incidence angles (55[Formula: see text], 65[Formula: see text] and 75[Formula: see text]). For the AZO monolayer structure, it was found that the complex refractive index and the complex permittivity coefficient varied differently according to the incidence angle. The addition of Al layer (5[Formula: see text]nm thicknesses) in this monostructure reduces significantly this influence on the measurement, homogenizes the real refractive index variation and significantly reduces the real electrical coefficient permittivity in the visible range. In addition, the obtained depolarization values confirm the results of the AFM roughness revealing that the Al layer addition makes the surface smoother so that it meets the required conditions as the bottom electrode of organic light emitting diodes. The photoluminescence (PL) measurements indicate that the Al layer alters the PL emission. Actually, the Al layer enhances subsequently the PL emission and promotes the blue and red emission.
Klebsiella PneumoniaeCAUSING SPONDYLODISCITIS: AN UNUSUAL CAUSE OF BACK PAIN IN AN ELDERLY PATIENT
Authors: Raval Pradyumna , Abbas Ammar
Published: November 2017

Spondylodiscitis is a manifestation of a blood borne infection in the elderly. The diagnosis can be really challenging, especially in those patients with significant co-morbidities. Although Staphylococcus aureus has been incriminated as the most common causative microorganism, other rare pathogens have been described in literature. We present a rather unusual case of an octogenarian who presented with back pain and no obvious foci of infection anywhere else. Blood culture revealed Klebsiella Pneumoniae as the causative microorganism. This patient showed dramatic improvement on intravenous antibiotics and was asymptomatic on follow up with complete resolution of his back pain.
Elliptic equations with critical exponent on a torus invariant region of 𝕊3
Authors: Rey Carolina A.
Published: November 2017

We study the multiplicity of positive solutions of a Brezis–Nirenberg-type problem on a region of the three-dimensional sphere, which is invariant by the natural torus action. In the paper by Brezis and Peletier, the case in which the region is invariant by the [Formula: see text]-action is considered, namely, when the region is a spherical cap. We prove that the number of positive solutions increases as the parameter of the equation tends to [Formula: see text], giving an answer to a particular case of an open problem proposed in the above referred paper.
EDUCATING SOCIAL ENTREPRENEURSHIP: INSIGHTS FROM THE HIGHER EDUCATION COURSES IN HONG KONG
Authors: TAM KIN YUEN RAYMOND
Published: November 2017

The purpose of this article is to uncover the trend of developing education courses for social entrepreneurship in higher education institutions in Hong Kong. The author had searched the syllabi or course descriptions across the websites of the higher education institutions in Hong Kong with the keywords of entrepreneurship, social entrepreneurship and social innovation. It was found that most of the social entrepreneurship courses offered were one-off single subject for undergraduate students, General Education courses, and minor courses, with only a few courses targeting postgraduates. It was also found that curricular differences among the courses offered by various schools or faculties were not that obvious. To understand this, the author had undertaken an analysis of the schools where these courses resided, course objectives, course content, and teaching and learning strategies among these various social entrepreneurship courses. Discussion of these has given insights to arguing for the need of multidisciplinary collaborations among social entrepreneurship educators.
Non-orthogonal fusion frames in Hilbert C∗-modules
Authors: Alijani Azadeh
Published: November 2017

Fusion frames or frames of subspaces are an extension of frames that have many applications in science. The paper presents non-orthogonal fusion frames with real valued bounds and [Formula: see text]-valued bounds in Hilbert [Formula: see text]-modules which they are called NOFF and NO[Formula: see text]FF, respectively. Their elementary properties are studied, for example, the relations between NOFF and NO[Formula: see text]FF in Hilbert [Formula: see text]-modules are established. More precisely, we investigate these fusion frames in Hilbert [Formula: see text]-modules over different [Formula: see text]-algebras.
Comparison of different approaches for identifying subnetworks in metabolic networks
Authors: Rezvan Abolfazl , Eslahchi Changiz
Published: November 2017

A metabolic network model provides a computational framework for studying the metabolism of a cell at the system level. The organization of metabolic networks has been investigated in different studies. One of the organization aspects considered in these studies is the decomposition of a metabolic network. The decompositions produced by different methods are very different and there is no comprehensive evaluation framework to compare the results with each other. In this study, these methods are reviewed and compared in the first place. Then they are applied to six different metabolic network models and the results are evaluated and compared based on two existing and two newly proposed criteria. Results show that no single method can beat others in all criteria but it seems that the methods introduced by Guimera and Amaral and Verwoerd do better on among metabolite-based methods and the method introduced by Sridharan et al. does better among reaction-based ones. Also, the methods are applied to several artificial networks, each constructed from merging a few KEGG pathways. Then, their capability to recover those pathways are compared. Results show that among metabolite-based methods, the method of Guimera and Amaral does better again, however, no notable difference between the performances of reaction-based methods was detected.
Unified formalism for Palatini gravity
Authors: Capriotti S.
Published: November 2017

This paper is devoted to the construction of a unified formalism for Palatini and unimodular gravity. The idea is to employ a relationship between unified formalism for a Griffiths variational problem and its classical Lepage-equivalent variational problem. The main geometrical tools involved in these constructions are canonical forms living on the first jet of the frame bundle for the spacetime manifold. These forms play an essential role in providing a global version of the Palatini Lagrangian and expressing the metricity condition in an invariant form. With them, we were able to find the associated equations of motion in invariant terms and, by using previous results from the literature, to prove their involutivity. As a bonus, we showed how this construction can be used to provide a unified formalism for the so-called unimodular gravity by employing a reduction of the structure group of the frame bundle to the special linear group.
Tetrads in SU(3) × SU(2) × U(1) Yang–Mills geometrodynamics
Authors: Garat Alcides
Published: November 2017

The relationship between gauge and gravity amounts to understanding the underlying new geometrical local structures. These structures are new tetrads specially devised for Yang–Mills theories, Abelian and non-Abelian in four-dimensional Lorentzian curved spacetimes. In the present paper, a new tetrad is introduced for the Yang–Mills [Formula: see text] formulation. These new tetrads establish a link between local groups of gauge transformations and local groups of spacetime transformations that we previously called LB1 and LB2. New theorems are proved regarding isomorphisms between local internal [Formula: see text] groups and local tensor products of spacetime LB1 and LB2 groups of transformations. These new tetrads define at every point in spacetime two orthogonal planes that we called blades or planes one and two. These are the local planes of covariant diagonalization of the stress–energy tensor. These tetrads are gauge dependent. Tetrad local gauge transformations leave the tetrads inside the local original planes without leaving them. These local tetrad gauge transformations enable the possibility to connect local gauge groups Abelian or non-Abelian with local groups of tetrad transformations. On the local plane one, the Abelian group [Formula: see text] of gauge transformations was already proved to be isomorphic to the tetrad local group of transformations LB1, for example. LB1 is [Formula: see text] plus two different kinds of discrete transformations. On the local orthogonal plane two [Formula: see text] is isomorphic to LB2 which is just [Formula: see text]. That is, we proved that LB1 is isomorphic to [Formula: see text] which is a remarkable result since a noncompact group plus two discrete transformations is isomorphic to a compact group. These new tetrads have displayed manifestly and nontrivially the coupling between Yang–Mills fields and gravity. The new tetrads and the stress–energy tensor allow for the introduction of three new local gauge invariant objects. Using these new gauge invariant objects and in addition a new general local duality transformation, a new algorithm for the gauge invariant diagonalization of the Yang–Mills stress–energy tensor is developed as an application. This is a paper about grand Standard Model gauge theories — General Relativity gravity unification and grand group unification in four-dimensional curved Lorentzian spacetimes.
Statefinder diagnostic for modified Chaplygin gas cosmology in f(R,T) gravity with particle creation
Authors: Singh J. K. , Nagpal Ritika , Pacif S. K. J.
Published: November 2017

In this paper, we have studied flat Friedmann–Lemaître–Robertson–Walker (FLRW) model with modified Chaplygin gas (MCG) having equation of state [Formula: see text], where [Formula: see text], [Formula: see text] and [Formula: see text] is any positive constant in [Formula: see text] gravity with particle creation. We have considered a simple parametrization of the Hubble parameter [Formula: see text] in order to solve the field equations and discussed the time evolution of different cosmological parameters for some obtained models showing unique behavior of scale factor. We have also discussed the statefinder diagnostic pair [Formula: see text] that characterizes the evolution of obtained models and explore their stability. The physical consequences of the models and their kinematic behaviors have also been scrutinized here in some detail.
Self-force of a scalar charge in the space-time of extreme charged anti-dilatonic wormhole
Authors: Popov A. A. , Aslan O.
Published: November 2017

The self-interaction for a static scalar charge in the space-time of extreme charged anti-dilatonic wormhole is calculated. We assume that the scalar charge is the source of massless scalar field with minimal coupling of the scalar field to the curvature of spacetime.
Parameters estimation of HIV infection model of CD4+T-cells by applying orthonormal Bernstein collocation method
Authors: Mirzaee Farshid , Samadyar Nasrin
Published: November 2017

The HIV infection model of CD4[Formula: see text][Formula: see text]T-cells corresponds to a class of nonlinear ordinary differential equation systems. In this study, we provide the approximate solution of this model by using orthonormal Bernstein polynomials (OBPs). By applying the proposed method, the nonlinear system of ordinary differential equations reduces to a nonlinear system of algebraic equations which can be solved by using a suitable numerical method such as Newton’s method. We prove some useful theorems concerning the convergence and error estimate associated to the present method. Finally, we apply the proposed method to get the numerical solution of this model with the arbitrary initial conditions and values. Furthermore, the numerical results obtained by the suggested method are compared with the results achieved by other previous methods. These results indicate that this method agrees with other previous methods.
hClique: An exact algorithm for maximum clique problem in uniform hypergraphs
Authors: Torres-Jimenez Jose , Perez-Torres Jose Carlos , Maldonado-Martinez Gildardo
Published: November 2017

A hypergraph [Formula: see text] with vertex set [Formula: see text] and edge set [Formula: see text] differs from a graph in that an edge can connect more than two vertices. An r-uniform hypergraph [Formula: see text] is a hypergraph with hyperedges of size [Formula: see text]. For an r-uniform hypergraph [Formula: see text], an r-uniform clique is a subset [Formula: see text] of [Formula: see text] such as every subset of [Formula: see text] elements of [Formula: see text] belongs to [Formula: see text]. We present hClique, an exact algorithm to find a maximum r-uniform clique for [Formula: see text]-uniform graphs. In order to evidence the performance of hClique, 32 random [Formula: see text]-graphs were solved.
The inverse sum indeg index of graphs with some given parameters
Authors: Chen Hanlin , Deng Hanyuan
Published: November 2017

Let [Formula: see text] be a simple connected graph. The inverse sum indeg index of [Formula: see text], denoted by [Formula: see text], is defined as the sum of the weights [Formula: see text] of all edges [Formula: see text] of [Formula: see text], where [Formula: see text] denotes the degree of a vertex in [Formula: see text]. In this paper, we derive some bounds for the inverse sum indeg index in terms of some graph parameters, such as vertex (edge) connectivity, chromatic number, vertex bipartiteness, etc. The corresponding extremal graphs are characterized, respectively.