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In this paper, we present a new scheme for implementing virtual keyboards, which uses only two to four motion-recognition rings per hand and a two-dimensional keyboard template (e.g., an A4 size paper with printed key positions). It has the benefit of portability, customizability, and low-cost when compared with existing approaches. Essentially, we have shown that wearing two wireless IoT rings on the middle phalanges of two fingers of each hand, users can input the alphabetic characters into a computing device by typing on a flat paper on a desk, and potentially in mid-air. We have demonstrated that two rings are sufficient in capturing the gestures and motions of all fingers in a typing hand for keystrokes recognition. A single wireless IoT ring, which weighs 7.8 grams, consists of a Bluetooth low energy (BLE) unit, a micro inertial measurement unit (mIMU), and a cell battery. The 3-axes attitude angles and the Z-axis acceleration of each ring are adopted as the features for keystroke recognition. The overall keystroke recognition accuracy rate can reach as high as 94.8% when two IoT rings are worn by a user on each hand; this accuracy rate increases to 98.6%, when four rings are worn on each typing hand.

Free fall motion in air medium is only influenced by gravitation acceleration. However, there are several variables that caused the observations to be different with the concept. Variables, such as air drag and terminal velocity, are often teachers not presented in detail, causing misconceptions. This study aims to develop a simple experiment on free fall motion by identifying air drag and terminal velocity. The data in this study is the video of free fall motion of paper and scraper analyzed using Tracker video analyze. From the video analyzed, information is obtained in the form of time (t), track (l, θ), and velocity (v) of the object. This study shows that the air drag force increase unto the terminal velocity. The calculation of the drag coefficient giving the number of the paper 2,16 and the scraper 2,10. According to data analyzed, the air drag force is affected by the mass (m), area (A), and the air drag force (FD) with the linear correlation until it reaches the terminal velocity. The result of this study may use as references of free fall motion experiment with other objects and analyze.

With the trend of adopting FPGAs in data centers, various FPGA acceleration platforms have been developed in recent years. Each server could incorporate one or many of these FPGAs at different compute hierarchy levels to match its workload intensity. FPGAs could either be used as IO-attached accelerators or be closely integrated with CPU as on-chip co-processors. For a more data-centric approach, an FPGA could be moved closer to the data medium (RAM or disk) and serve as a near-memory or near-storage accelerator. In this work, we present a quantitative model and in-depth analysis of application characteristics to determine when an application is more suitable for each acceleration hierarchy. We analyze 18 benchmarks from six domains and create a preliminary guideline for both application and hardware developers.

We reported that we developed a new air permeability tester with which we could measure the acceleration of the air permeability (AAP) of coated paper under high temperatures and high pressures during a short time. And we found that AAP was more strongly related to the blistering tendency of coated paper, before.In this paper, we used various base papers, and studied the influence of base paper to blistering resistance of coated paper with AAP. Then we found that a new factor, the slope which was obtained through AAP and coating weight (less than 5 g/m2 on side) plot, was strongly related to the blistering tendency. So, the result indicates that the interface property between base paper and coating layer has an influence upon the blistering resistance.

Electronic line-shafting control has demonstrated very promising features when applied to paper machine drives. To apply this new control methodology, it is necessary to develop a starting procedure for each individual section and a method for setting the parameters of the virtual line-shaft drive and in-shafts. This paper proposes and evaluates startup and commissioning procedures for electronically line-shafted paper machine drives. The procedure for acceleration of the individual sections is implemented using virtual variable-ratio gearboxes that emulate the physical clutches and conical pulleys used in the era of line-shafts. System stiffness is implemented using virtual in-shafts with active damping. Evaluation shows that the proposed virtual clutch/conical pulley assembly and active damping allow smooth acceleration of each section and maintain well-behaved response during load disturbances for all operating conditions, even with different numbers of sections effectively connected.

The paper focuses on the robust control design of a look-ahead cruise control system. The aim of the look-ahead control is to consider the topographic conditions and speed regulations of the oncoming road sections. The look-ahead cruise control leads to an optimization method, which generates a fuel and time optimal reference speed for the vehicle. It requires external topographic and road information, and measurements concerning the vehicle, such as speed and acceleration. Since the signals of the vehicle are considered in the generation of the reference speed, the generator has an impact on the stability of the cruise control system. In the paper a robust H∞ cruise control design method is proposed, which considers the efect of the reference speed generation, and guarantees the stability and the speed tracking performance of the entire system. The efciency of the method is analyzed through a simulation example with real highway data.

When dealing with material classification in baggage at airports, Dual-Energy Computed Tomography (DECT) allows characterization of any given material with coefficients based on two attenuative effects: Compton scattering and photoelectric absorption. However, straightforward projection-domain decomposition methods for this characterization often yield poor reconstructions due to the high dynamic range of material properties encountered in an actual luggage scan. Hence, for better reconstruction quality under a timing constraint, we propose a splitting-based, GPU-accelerated, statistical DECT reconstruction algorithm. Compared to prior art, our main contribution lies in the significant acceleration made possible by separating reconstruction and decomposition within an ADMM framework. Experimental results, on both synthetic and real-world baggage phantoms, demonstrate a significant reduction in time required for convergence.

This paper proposes and evaluates two robust sheet tension estimation algorithms based on unwind and rewind variables, respectively. The proper sheet tension estimation is guaranteed by a continuous monitoring of the differences between the actual estimated values and the values predicted from the last calibration of the estimation parameters. The evaluation was performed with the aid of a developed winder emulator that allowed the off-line testing in a real-time field environment, including the inertial setting of the estimation constants, and evaluation of both 4 and 6 shipping-roll cycles. The sheet tension estimation results confirm the precise and stable operation of the proposed robust estimation algorithms, in estimation tests conducted with signals from a winder model, and with tests involving actual field signals from an operational winder.

In the re-entry comtrol system, errors apt to induce because the time deriviative of drag acceleration is analytically estimated. Still more, the difficulty of estimation of th exact drag coefficient in hypersonic velocity and the non-reality of the scale height cause a steady-state drag errer. In the Space-Shuttle, a steady-state drag error is reduced by the addition of the integral term of drag acceleation error into the control system. This method, however, induces a difficulties in respect to the modern controller composition due to the multi-poles in a closed-loop system. Thus, this paper proposes the additional method of the disturbance observer. This reduces the steady-state drag error according to the following by the analytic calculation, and then creates the new drag acceleration time derivative using the estimated error. The performance of the re-entry control system is verified about 32 refernce trajectories.

It is proposed that the coincidence of higher brightness and upward electric current observed by Janvier et al. during a flare indicates electron acceleration by field-parallel potential drops sustained by extremely strong field-aligned currents of order 104 A m−2. A few consequences are discussed here.

One of the major topics that attracts constantly the interest of research community is the acceleration of computationally-intensive applications. Towards this direction, different technologies are competing each other and are all characterized by a common tendency; they evolve continuously towards improving their products so as to serve better their customers and attract new ones. Each company stresses the stronger advantages of its technology to convince people from academia and industry, and either individuals to use it. However, none of the existing technologies monopolizes all domains yet. This is because each one has its own benefits and drawbacks and cannot serve well all application domains. Another reason is that different people prefer to acquire skills in a specific technology and avoid switching between different technologies, even though this could benefit the application under development. Hence, from the one side a technology itself imposes performance margins in terms of factors such as speed, power, energy, and cost, while on the other side stands the willingness of the user to adopt a technology. This adoption can be affected heavily by the flexibility and the “friendliness” (i.e. easy-to-use) of the technology. Present paper discusses problems in using reconfigurable technology and suggests some research directions. We delve into the details of two systems equipped with specific reconfigurable platforms and explore the capabilities offered to the user for accessing this technology. We point out some problems in adopting reconfigurable technology and we study some performance characteristics. Aim of the paper is to signify issues that could gain the attention of the research community, and trigger the exploration of solutions that will foster the adoption of reconfigurable technology by a wider range of people.

This is a report on the findings of the SNR/cosmic-ray working group for the white paper on the status and future of ground-based gamma-ray astronomy. The white paper is an APS commissioned document, and the overall version has also been released and can be found on astro-ph. This detailed section of the white paper discusses the status of past and current attempts to observe shell-type supernova remnants and diffuse emission from cosmic rays at GeV-TeV energies. We concentrate on the potential of future ground-based gamma-ray experiments to study the acceleration of relativistic charged particles which is one of the main unsolved, yet fundamental, problems in modern astrophysics. The acceleration of particles relies on interactions between energetic particles and magnetic turbulence. In the case of SNRs we can perform spatially resolved studies in systems with known geometry, and the plasma physics deduced from these observations will help us to understand other systems where rapid particle acceleration is believed to occur and where observations as detailed as those of SNRs are not possible.

It is shown that the common response spectrum method for synchronous ground motion can be extended to make it applicable for earthquake response analyses of extended structures experiencing differential out-of-plane ground motion. A relative displacement spectrum for design of first-story columns SDC (T, TT, z, zT, t, d) is defined. In addition to the natural period of the out-of-plane response, T, and the corresponding fraction of critical damping, z, this spectrum also depends on the fundamental period of torsional vibrations, TT, and the corresponding fraction of critical damping, zT, on the ‘‘travel time,’’ t (of the waves in the soil over a distance of about one-half the length of the structure), and on a dimensionless factor d, describing the relative response of the first floor. The new spectrum, SDC, can be estimated by using the empirical scaling equations for relative displacement spectra, SD, and for peak ground velocity, vmax. For recorded strong-motion acceleration, and for symmetric buildings, the new spectrum can be computed from Duhamel’s integrals of two uncoupled equations for dynamics equilibrium describing translation and rotation of a two-degree-offreedom system. This representation is accurate when the energy of the strong-motion is carried by waves in the ground the wavelengths of which are one order of magnitude or more longer than the characteristic length of the structure. r 2006 Elsevier Ltd. All rights reserved.

In response to environmental pollution and the spread of Coronavirus Disease 2019 (COVID‐19), this paper proposes a new type of smart mask design, and specifically proposes an optimized double closed‐loop control method, especially an improved filtering fusion algorithm. Using the filtering fusion algorithm proposed in this paper, after the Kalman filter (KF) filters the raw data of the attitude sensor, explicit complementary filtering and data fusion are used to obtain the attitude angle of the body. At the same time, the obtained attitude angle is combined with acceleration and blood oxygen concentration to obtain the behaviour characteristic value. On this basis, the speed of the oxygen supply fan captured by the photoelectric sensor is used to form a closed loop with the characteristic value of the behaviour. Finally, the structure of the mask is upgraded and optimized through fluid mechanics simulation, and experiments have verified that the combination of the replaceable filter cloth, the intelligent control system and the ultraviolet disinfection device can effectively protect people's health.

In recent years, several studies have investigated upper-limb motion in a variety of scenarios including motor control, physiology, rehabilitation and industry. Such applications assess people’s kinematics and muscular performances, focusing on typical movements that simulate daily-life tasks. However, often only a limited interpretation of the EMG patterns is provided. In fact, rarely the assessments separate phasic (movement-related) and tonic (postural) EMG components, as well as the EMG in the acceleration and deceleration phases. With this paper, we provide a comprehensive and detailed characterization of the activity of upper-limb and trunk muscles in healthy people point-to-point upper limb movements. Our analysis includes in-depth muscle activation magnitude assessment, separation of phasic (movement-related) and tonic (postural) EMG activations, directional tuning, distinction between activations in the acceleration and deceleration phases. Results from our study highlight a predominant postural activity with respect to movement related muscular activity. The analysis based on the acceleration phase sheds light on finer motor control strategies, highlighting the role of each muscle in the acceleration and deceleration phase. The results of this study are applicable to several research fields, including physiology, rehabilitation, design of robots and assistive solutions, exoskeletons., Graphical abstract Image 1, Highlights • Upper-limb motion is assessed with kinematics and EMG in many scenarios: motor control, physiology, rehabilitation, industry • Separation of phasic (movement-related) and tonic (postural) EMG, and of acceleration and deceleration phases • Comprehensive and detailed characterization of the EMG of upper-limb and trunk muscles in point-to-point upper limb movements • EMG magnitude assessment, phasic and tonic EMG activations, directional tuning, acceleration and deceleration phases

This work reports a reversible braking system for micromotors that can be controlled by small temperature changes (≈5 °C). To achieve this, gated‐mesoporous organosilica microparticles are internally loaded with metal catalysts (to form the motor) and the exterior (partially) grafted with thermosensitive bottle‐brush polyphosphazenes to form Janus particles. When placed in an aqueous solution of H2O2 (the fuel), rapid forward propulsion of the motors ensues due to decomposition of the fuel. Conformational changes of the polymers at defined temperatures regulate the bubble formation rate and thus act as brakes with considerable deceleration/acceleration observed. As the components can be easily varied, this represents a versatile, modular platform for the exogenous velocity control of micromotors., A robust and easily tunable micromotor platform is reported, based on Janus gated‐mesoporous organosilica microparticles with reversible, external responsive braking systems using bottle‐brush polyphosphazenes to control acceleration/deceleration by small changes in temperature.

It is well known in planar kinematics of rigid bodies that the acceleration of the material point coinciding with the instantaneous center of rotation (or pole) is perpendicular to the so-called pole changing velocity. In the present paper, the concept of pole changing velocity is generalized to spatial motions. Using this result, the acceleration of the material points along the instantaneous screw axis can be expressed in a straightforward way, without the tools of advanced differential geometry.