Miracle-dz/UniFAR-FTUs huggingface dataset:
Object-Centric Grasping Transferability: Linking Meshes to Postures

Attaining human hand manipulation capabilities is a sought-after goal of robotic manipulation. Several works have focused on understanding and applying human manipulation insights in robotic applications. However, few considered objects as central pieces to increase the generalization properties of existing methods. In this study, we explore context-based grasping information transferability between objects by using mesh-based object representations. To do so, we empirically labeled, in a mesh point-wise manner, 10 grasping postures onto a set of 12 purposely selected objects. Subsequently, we trained our convolutional neural network (CNN) based architecture with the mesh representation of a single object, associating grasping postures to its local regions. We tested our network across multiple objects of distinct similarity values. Results show that our network can successfully estimate non-feasible grasping regions as well as feasible grasping postures. Our results suggest the existence of an abstract relation between the predicted context-based grasping postures and the geometrical properties of both the training and test objects. Our proposed approach aims to expand grasp learning research by linking local segmented meshes to postures. Such a concept can be applied to grasp new objects using anthropomorphic robot hands.
Investigating changes in transport, kinetics and heat generation over NCA/Gr-SiOx battery lifetime

We present a study of battery ageing, comparing pristine, calendar-aged, and cycle-aged lithium-ion cells. Insight into degradation was obtained via differential voltage analysis and by estimating and tracking changes in a subset of electrochemical model parameters of the single particle model through inverse modelling. We show that both diffusion time and kinetic overpotential increase in cycle-aged cells, while calendar-aged cells experienced no diffusion time changes but some kinetic overpotential increase. The latter is also evident in 50% higher irreversible heat generation in cycle-aged cells. This study highlights the importance of updating battery model parameters during ageing.
Self‐consistent injection and acceleration of pickup ions at the solar wind termination shock

A unified description of pickup and anomalous cosmic ray proton transport in the near ecliptic regions of the upwind heliosphere is presented. Multiply reflected ion acceleration theory is used for the injection of pickup protons into the diffusive shock acceleration mechanism, so yielding the anomalous cosmic ray component at the quasi‐perpendicular termination shock. The results show that both the multiply reflected and simultaneously accelerated pickup protons and the anomalous protons significantly modify the termination shock. Although the shock mediation lowers the cut‐off speed of the accelerated pickup protons, a sufficient large population of anomalous protons is accelerated at the termination shock to give a favorable comparison of the modulated anomalous proton spectra up‐stream with observations at large heliocentric distances.
Evaluation of Graph Routing Single Objective Paths Using Pre-set Unequal Clustering

Multi-hop network paths and path redundancy enhance the reliability of communications in the Graph Routing of Industrial Wireless Sensor Networks (IWSNs). However, the centralised management of IWSNs creates unbalanced energy consumption between battery-powered wireless sensor nodes. This creates a hotspot challenge in Graph Routing. The inability to balance energy consumption with single-objective paths in mesh topologies was revealed in our previous work that used the Covariance-Matrix Adaptation Evolution Strategy (CMA-ES) to improve Graph Routing [1]. In this paper, we address this problem by combining the single-objective paths of the Graph Routing algorithm with a pre-set unequal clustering topology. First, this study detects isolated nodes within pre-set unequal clustering and then creates new clusters for these nodes. Second, the objective function of CMA-ES is used to select the best cluster head by considering node centrality between the nodes in the same cluster and the distance between other cluster heads or the gateway. Once the cluster heads are selected, single-objective paths of Graph Routing that are minimum-distance (PODis), maximum residual energy (POEng), and minimum end-to-end transmission time (POE2E) can be effectively evaluated. Simulation experiments reveal that using the single-objective paths of Graph Routing by the topology of pre-set unequal clustering results in more balanced energy consumption.
Multi-Objective Optimization of the Iron Bridge between Segmeted PMs for an Outer-Rotor Brushless DC Motor

To facilitate the processing, transportation and assembly of permanent magnet, a segmented PM design with positioning slots is proposed for an outer-rotor brushless DC motor in this article. First, the effect of the iron bridge between the segmented PMs on the motor performance is investigated by the method of finite element analysis. Further, a multi-objective optimization algorithm based on metamodel of optimal prognosis is employed to optimize the geometry of the iron bridge and the optimal solution is determined from the Pareto front by taking a tradeoff design between different objectives. After optimization, a detailed comparative analysis of the motor performance between initial and optimized design is carried out to verify the superiority of the optimized motor.
An approach for solving perpetual optimal stopping problems driven by Lévy processes

In this paper, we expose an approach for solving perpetual optimal stopping problems for a general class of payoff functions under Lévy processes. This approach was inspired by the work of Boyarchenko and Levendorski. In contrast to Boyarchenko and Levendorsikii, our approach does not appeal to a free boundary problem associated to the optimal stopping problem nor to the theory of pseudodifferential operators to solve the problem. Instead, we introduce an averaging problem from which we obtain using the Wiener–Hopf factorization a fluctuation identity for overshoots of a Lévy process. This identity constitutes the main principle in solving the optimal stopping problem. If a solution to the averaging problem can be found and has certain monotonicity properties, we show using the fluctuation identity that an optimal solution to the optimal stopping problem can be written in terms of such monotone function. Using the optimal solution, we give sufficient and necessary conditions for the smooth pasting condition to occur in the considered problem. Our conclusion over the smooth pasting condition extends further the recent result of Alili and Kyprianou into a more general payoff function.
Effect of swirl decay on vortex breakdown in a confined steady axisymmetric flow

This numerical study of the steady axisymmetric motion of a viscous incompressible fluid in a sealed cylindrical container with one end wall rotating reveals that swirl decay, induced by friction at the sidewall, plays an important role in the development of vortex breakdown (VB). When the flow is slow, it is multi-cellular. As the flow strength increases (i) meridional circulation becomes global, (ii) flow convergence toward the axis focuses near the still end wall, (iii) a few local minima of pressure appear, (iv) a few flow reversals occur near the axis, and (v) circulation regions merge and an elongated double counterflow develops. Stages (i)–(v) are common for a number of vortex devices. If the swirl decay is diminished by additional rotation of the sidewall, VB disappears.
A Fast OCV Characterization Approach for Battery Reuse Applications

This paper considers the problem of open circuit voltage (OCV) to state of charge(SOC) characterization in rechargeable batteries for battery reuse applications. The traditional approach to OCV-SOC characterization is done by collecting voltage and current data through a slow discharge and charge process; this process usually takes about 60 hours. Such OCV-SOC characterization is performed on a few sample batteries because the OCV-SOC characterization is the same for new batteries coming out of the same manufacturing process. However, the characteristics of a battery may change as it is used for years in different environmental and usage conditions. Hence, they may need to be re-characterized before secondary use. Unlike primary characterization, secondary characterization may have to be done faster in order to save time and cost. This paper presents a new and faster approach for OCV-SOC characterization. The proposed approach in this paper consists of constant current profiles that halve in magnitude after a specified time. Such reducing current magnitude allows for fully depleting the battery; similarly, the battery is charged back with a reducing current profile in order to make sure the battery is fully charged back. The resulting current profile reduces the total characterization time by 1/5. It was hypothesized that the changing current magnitude may result in hysteresis voltage bias. For this, a new OCV modelling approach consisting of separate resistance estimation at each pulse was developed. The proposed approach was tested using data collected from four cylindrical Li-ion batteries. Compared to the traditional OCV modelling approach, the proposed approach results in 3% of SOC error and takes 20% of the time.
Kubernetes Orchestration of High Availability Distributed Control Systems

Distributed control systems transform with the Industry 4.0 paradigm shift. A mesh-like, network-centric topology replaces the traditional controller-centered architecture, enforcing the interest of cloud-, fog-, and edge-computing, where lightweight container-based virtualization is a cornerstone. Kubernetes is a well-known container management system for container orchestration in cloud computing. It is gaining traction in edge- and fog-computing due to its elasticity and failure recovery properties. Orchestrator failure recovery can complement the manual replacement of a failed controller and, combined with controller redundancy, provide a pseudo-one-out-of-many redundancy. This paper investigates the failure recovery performance obtained from an out-of-the-box Kubernetes installation in a distributed control system scenario. We describe a Kubernetes based virtualized controller architecture and the software needed to set up a bare-metal cluster for control systems. Further, we deploy single and redundant configured containerized controllers based on an OPC UA compatible industry middleware software on the bare-metal cluster. The controllers expose variables with OPC UA PubSub. A script-based daemon introduces node failures, and a verification controller measures the downtime when using Kubernetes with an industry redundancy solution.
Multiscale and unsteady aspects of a deep föhn event during MAP

A strong föhn event occurring during the Mesoscale Alpine Programme Intensive Observing Period 2b (19–20 September) is simulated with the non‐hydrostatic model Meso‐NH. The grid‐nesting techniques and a suitable turbulence scheme allow a coherent downscaling from the analysed scales to the movements inside the Rhine Valley. The flow regime around the Alps changes from a flow‐around regime to a flow‐partly‐over regime, when the wind increases ahead of the cold front. Simplified simulations allow us to estimate a non‐dimensional height for the Alps which controls the flow regime. The föhn characteristics and its temporal evolution are discussed using both measurements and simulation. Backward trajectories show that the föhn air comes from an altitude around 2 km above the Po Valley. Nonlinear phenomena, such as wave breaking near 5 km above sea level just behind some secondary crests, and hydraulic jumps in the foothills, are found in the highest‐resolution simulation, using a mesh of 625 m. This mesh clearly improves the comparison of the numerical simulation with the observations collected in the Rhine Valley. Mass budgets detail the progressive building of the föhn jet in the Rhine Valley. Copyright © 2003 Royal Meteorological Society.
Head Trauma and Concussions in Film and Television Stunt Performers

Despite the wide appeal of film and television, stunt performers are underserved regarding their injuries and healthcare access, especially for concussions. To our knowledge, this is the first study to quantify stunt performers’ head trauma and its effects on these industrial athletes, so advocacy and improved care are encouraged. Objectives The aims of the study were to assess prevalence and management of head impacts in stunt performers and to evaluate performers’ quality of life and ability to work after head injury. Methods Stunt performers completed an online survey about head impacts/head whips history, diagnosed concussions, reasons for not reporting injuries, health care sought after head impacts, attitudes toward on-set concussion management, perceived ability to work as a stunt performer, and health-related quality of life. Results One hundred seventy-three performers (80%) indicated at least one head impact/head whip during their stunt career. Of these, 86% exhibited concussion-like symptoms and 38% received one or more concussion diagnoses. Sixty-five percent continued working with concussion-like symptoms. Short Form-12 mental component scores were suggestive of depression in 42%. Conclusions Concussion seems to be a serious occupational health issue in stunt performers. We suggest that concussion management, risk reduction, and education should be addressed in this community.
Oxygen abundances in unevolved metal-poor stars: interpretation and consequences

The oxygen abundance has been determined by analysis of the O I infrared triplet in 30 unevolved field stars of metallicities in the range Fe/H abundance ratio between -0.2 and -3.5. The data show that the O/Fe abundance ratio increases monotonically as metallicity decreases from solar, reaching values in the range 1.0-1.2 at an Fe/H abundance ratio of about -2. The results, when compared with those already published for metal-deficient red giants, suggest that oxygen could have been depleted in the latter. A discussion of the O/Fe abundance ratios in connection with the chemical evolution of the Galaxy is also presented. 83 refs.
EX Hydrae in outburst

Photometry and red spectroscopy of the intermediate polar EX Hya in its rare outburst state are presented. Photometry during the declining phase of the July-August 1986 outburst shows the 67-min (spin) modulation to be present with similar characteristics to that in quiescence. In contrast, photometry from near the peak of the 1987 May outburst shows little evidence of the 67-min modulation, while spectroscopy obtained nearly simultaneously is similarly lacking in such evidence, despite its presence in quiescent spectroscopic data. Near the beginning of the May 1987 outburst the H alpha emission line develops a broad, high velocity base component whose velocity is modulated with the orbital cycle. The velocity and phase of the broad base component suggest that it is produced near the magnetosphere of the white dwarf at a point along the projected trajectory of the gas stream from the companion. The feature disappears later in the outburst and is not present during quiescence. It is suggested that the outbursts in EX Hya are caused by an increase in the rate of mass transfer from the companion, and that part of this enhanced mass-transfer stream skims over the top of the accretion disk to strike the magnetosphere directly. The interaction of the stream with the magnetosphere gives rise to the broad-base component observed.
Optical monitoring of photoacoustic pulse propagation in silicon wafers

We demonstrate a new optical and noncontact method for direct and fast detection of photoacoustic pulse propagation in thin silicon wafers. A probe beam deflection technique is used to monitor both longitudinal and Lamb wave propagations from which information on the elastic constants and the sample orientation can be obtained. Results obtained for wafers of different orientations and doping levels are compared with previous contact measurements.
Alfvénic collisionless magnetic reconnection and the Hall term

The Geospace Environment Modeling (GEM) Challenge Harris current sheet problem is simulated in 2 1/2 dimensions using full particle, hybrid, and Hall MHD simulations. The same gross reconnection rate is found in all of the simulations independent of the type of code used, as long as the Hall term is included. In addition, the reconnection rate is independent of the mechanism which breaks the frozen-in flux condition, whether it is electron inertia or grid scale diffusion. The insensitivity to the mechanism which breaks the frozen-in condition is a consequence of whistler waves, which control the plasma dynamics at the small scales where the ions become unmagnetized. The dispersive character of whistlers, in which the phase velocity increases with decreasing scale size, allows the flux of electrons flowing away from the dissipation region to remain finite even as the strength of the dissipation approaches zero. As a consequence, the throttling of the reconnection process as a result of the small scale size of the dissipation region, which occurs in the magnetohydrodynamic model, iio longer takes place. The important consequence is that the minimum physical model necessary to produce physically correct reconnection rates is a Hall MHD description which includes the Hall term in Ohm's law. A density depletion layer, which lies just downstream from the magnetic separatrix, is identified and linked to the strong in-plane Hall currents which characterize kinetic models of magnetic reconnection.
Term rank preservers of Boolean matrices

We obtain some characterizations of linear operators that preserve the term rank of Boolean matrices. That is, a linear operator over Boolean matrices preserves the term rank if and only if it preserves the term ranks 1 and k(≠1) if and only if it preserves the term ranks 2 and l(≠2). Other characterizations of term rank preservers are given.
Polarization dependent loss in III-nitride optical waveguides for telecommunication devices

Excess polarization dependent loss (PDL) was investigated for GaN waveguide devices grown by molecular beam epitaxy (MBE). The loss for transverse magnetic polarization strongly depended on the edge dislocation density in the crystal, because the dislocations capture electrons and act like a wire-grid polarizer. By means of MBE regrowth on GaN grown with metal-organic chemical vapor deposition (MOCVD), the PDL was reduced to 1∼2dB∕mm with an edge dislocation density of 3×109cm−2, whereas it was approximately 10dB∕mm for an all-MBE-grown sample. An ultrafast all-optical switch utilizing the intersubband transition was fabricated with a multiple quantum well structure that was regrown with MBE on MOCVD-grown GaN. An extinction ratio of as high as 11.5dB was achieved with a control pulse energy of 150pJ, which is attributable to the reduction of the excess PDL.
Matrix analysis of interregional population growth and distribution

In this introduction of the interregional dimension into the emerging theory of mathematical demography, the vehicle is matrix algebra and the focus is upon a simultaneous consideration of the spatial and temporal aspects of population processes. The author draws on the notational and analytical advantages conferred by matrix algebra to develop insights that are obscured or unobtainable with conventional methods of analysis. He then considers several of the more interesting theoretical and practical questions to which his approach leads. $5.00
THE INFLUENCES OF CARDIOVASCULAR PROPERTIES ON SUPRASYSTOLIC BRACHIAL CUFF WAVE STUDIED BY A SIMPLE ARTERIAL-TREE MODEL

It has been found that a pronounced secondary systolic peak appears on the oscillometric wave recorded by a brachial oscillometric cuff as cuff pressure is raised to a suprasystolic level. This finding has accordingly motivated some studies aimed to explore the potential value carried by the cuff wave for assessing arterial stiffness. However, so far, there remain considerable controversies in the literature regarding the cardiovascular properties that dominate the characteristics of the cuff wave. In this context, we developed a simple arterial-tree model and applied it to investigate the respective influence on the cuff wave of various cardiovascular properties and the associated wave interaction phenomena. It was found that (1) neither aortic stiffness nor brachial arterial stiffness can uniquely determine the time lag (Δt) between the first and secondary peaks of the cuff wave, although both of them significantly influence Δt; and (2) the BAIx (an index that characterize the height of the secondary peak relative to the first) is sensitive to most of the investigated cardiovascular properties and physiological conditions, such as arterial stiffness, intensity of wave reflection in the lower body and heart rate, etc. These findings suggest that the reliability of assessing aortic stiffness based solely on the timings and heights of the two peaks is limited. Moreover, we argued that the controversial findings presented in previous model-based studies are likely to be caused by limitations related to the research objectives or computation conditions of the studies.
A Comparison of Individual and Group Efforts to Creatively Solve Contrasting Types of Problems

ABSTRACT: Until recently, most empirical research about the creative problem-solving (CPS) process has focused on its divergent thinking aspects, but some broader conceptions of CPS inspired a trilevel matching theory that views CPS tasks as varying in needed thought styles, processing steps, and knowledge domains; views problem solvers as varying in parallel ways, and therefore predicts that different persons, groups, and organizations most effectively and efficiently may solve different kinds of problems. To begin testing these proposed matches, several cognitive traits of 326 students were measured, and these measurements were used to form 102 diverse nominal and interactive groups that solved actual problems facing a small college. All 6 tested hypotheses about matches between problem and solver attributes were confirmed when solution quantity, originality, and utility were measured. As in many other studies, nominal groups performed better than interactive groups when working a single-part task, and the effect sizes were large. Conversely, when working a multipart task, a CPS activity that has been the focus of much less empirical research, the same 51 interactive groups did better than the same 51 nominal groups; and the effect sizes were large. Implications of these new findings for future CPS research and practice are discussed.
Electron/ion emission from the plasma formed on the surface of ferroelectrics. II. Studies of electron diode operation with a ferroelectric plasma cathode

We present experimental results of electron diode operation with an active plasma cathode. The plasma was formed by a noncomplete discharge on the surface of different unpoled ferroelectric samples having the form of disks or tubes made of BaTiO3 or Pb(Zr,Ti)O3. To produce the discharge, a positive or a negative driving pulse was applied to the front or to the rear electrode of the sample. We studied the operation of planar and coaxial electron diodes under the application of an accelerating high-voltage pulse ⩽45 kV with repetition rate ⩽5 Hz or ⩽250 kV in a single-mode operation. Electron beams with a current density of several hundreds of A/cm2 and a time duration of several hundreds of ns were generated. It was shown that the parameters of the electron beam as well as the operation of the electron diode depend strongly on the method of the plasma formation and the time delay between the beginning of the plasma formation and the application of the high-voltage pulse.