Audiometry and doping control in competitive deaf sport

In the past forty years both the participating countries and the participants at the Summer Deaflympics Games have increased by 2.5-fold. Furthermore, there are approximately fifty European or World sports events organized for the hearing impaired. The aim of the paper was to discuss the procedures and requirements related to doping control in deaf people’s competitive sport in the context of the rising number of sports events and the participating athletes.For the sake of the fair play spirit of the dynamically developing deaf sports, The International Committee of Sports for the Deaf (ICSD) introduced rules governing the participation of hard-of-hearing athletes in sports events. Healthy individuals with a hearing loss of at least 55 dB are allowed. Thus, audiometric examination constitutes the first doping control criterion. Since 2004, ICSD has been cooperating with the World Anti-Doping Agency. The second criterion is, therefore, blood and urine sample control for prohibited substances. The 23rd Summer Deaflympics in 2017 involved 2858 athletes. Overall, 842 (29.5%) participants were randomly subjected to an audiological test; 9 competitors from different countries were disqualified because of non-compliance with the ICSD standards. A total of 300 randomly selected athletes underwent doping control for prohibited substances; 1 was disqualified. The world literature lacks scientific reports on deaf sports, including doping control.

Chaotic Dynamics and Chaos Control in a Fractional-Order Satellite Model and Its Time-Delay Counterpart

Fractional analysis provides useful tools to describe natural phenomena, and therefore, it is more convenient to describe models of satellites. This work illustrates rich chaotic behaviors that exist in a fractional-order model for satellite with and without time-delay. The proof for existence and uniqueness of the satellite model’s solution with and without time-delay is shown. Chaos control is achieved in this system via a simple linear feedback control criterion. Chaotic attractors and chaos control are also found in a time-delay version of the proposed fractional-order satellite system. Various tools based on numerical simulations such as 2D and 3D attractors and bifurcation diagrams are used to illustrate the variety of rich chaotic dynamics in the satellite models.

Robust model reference adaptive backstepping sliding-mode control for quadrotor attitude with disturbance observer

Purpose The purpose of this research paper is to design a disturbance observer-based control based on the robust model reference adaptive backstepping sliding-mode control for attitude quadrotor model subject to uncertainties and disturbances. Design/methodology/approach To estimate and reject the disturbance, a disturbance observer is designed for the exogenous disturbances with perturbation while a control criterion is developed for the tracking of desired output. To achieve the control performance, backstepping and sliding-mode control techniques are patched together to obtain robust chattering-free controller. Furthermore, a model reference adaptive control criterion is also combined with the design of robust control for the estimation and rejection of uncertainties and unmodeled dynamics of the attitude quadrotor. Findings The findings of this research work includes the design of a disturbance observer-based control for uncertain attitude quadrotor system with the ability of achieving tracking control objective in the presence of nonlinear exogenous disturbance with and without perturbation. Practical implications In practice, the quadrotor flight is opposed by different kinds of the disturbances. In addition, being an underactuated system, it is difficult to obtain an accurate mathematical model of quadrotor for the control design. Thus, a quadrotor model with uncertainties and disturbances is inevitable. Hence, it is necessary to design a control system with the ability to achieve the control objectives in the presence of uncertainties and disturbances. Originality/value Designing the control methods for quadrotor control without uncertainties and disturbances is a common practice. However, investigating the uncertain quadrotor plant in the presence of nonlinear disturbances is rarely taken into consideration for the control design. Hence, this paper presents a control algorithm to address the issues of the uncertainties and disturbances as well as investigate a control algorithm to achieve tracking performance.

Sector stability criteria for a nonlinear axial motion string system

The paper investigates the exponential stability criterion for an axially moving string system driven by a nonlinear partial differential equation with nonlinear boundary feedback.The control criterion based on a sector condition contains a large class of nonlinearities, which is a negative feedback of the velocity at the right boundary of the moving string. By invoking nonlinear semigroup theory, the well-posedness result of the closed-loop system is verified under the sector criteria. Furthermore, a novel energy like function is constructed to establish the exponential stability of the closed-loop system by using a integral-type multiplier method and the generalized Gronwall-type integral inequality.

Self-Learning Low-Level Controllers

Humanoid robots are complicated systems both in hardware and software designs. Furthermore, the robots normally work in unstructured environments at which unpredictable disturbances could degrade control performances of whole systems. As a result, simple yet effective controllers are favorite employed in low-level layers. Gain-learning algorithms applied to conventional control frameworks, such as Proportional-Integral-Derivative, Sliding-mode, and Backstepping controllers, could be reasonable solutions. The adaptation ability integrated is adopted to automatically tune proper control gains subject to the optimal control criterion both in transient and steady-state phases. The learning rules could be realized by using analytical nonlinear functions. Their effectiveness and feasibility are carefully discussed by theoretical proofs and experimental discussion.

Deep Q-Network for Optimal Decision for Top-Coal Caving

In top-coal caving, the window control of hydraulic support is a key issue to the perfect economic benefit. The window is driven by the electro-hydraulic control system whose command is produced by the control model and the corresponding algorithm. However, the model of the window’s control is hard to establish, and the optimal policy of window action is impossible to calculate. This paper studies the issue theoretically and, based on the 3D simulation platform, proposes a deep reinforcement learning method to regulate the window action for top-coal caving. Then, the window control of top-coal caving is considered as the Markov decision process, for which the deep Q-network method of reinforcement learning is employed to regulate the window’s action effectively. In the deep Q-network, the reward of each step is set as the control criterion of the window action, and a four-layer fully connected neural network is used to approximate the optimal Q-value to get the optimal action of the window. The 3D simulation experiments validated the effectiveness of the proposed method that the reward of top-coal caving could increase to get a better economic benefit.

On Randomized Sampling Kaczmarz Method with Application in Compressed Sensing

We propose a randomized sampling Kaczmarz algorithm for the solution of very large systems of linear equations by introducing a maximal sampling probability control criterion, which is aimed at grasping the largest entry of the absolute sampling residual vector at each iteration. This new method differs from the greedy randomized Kaczmarz algorithm, which needs not to compute the residual vector of the whole linear system to determine the working rows. Numerical experiments show that the proposed algorithm has the most significant effect when the selected row number, i.e, the size of samples, is equal to the logarithm of all rows. Finally, we extend the randomized sampling Kaczmarz to signal reconstruction problems in compressed sensing. Signal experiments show that the new extended algorithm is more effective than the randomized sparse Kaczmarz method for online compressed sensing.

Influence of profile indicators of hot-rolled strip on transverse thickness difference of cold-rolled silicon steel

In order to evaluate the transverse thickness difference of cold-rolled strips according to the information of hot-rolled strips and scientifically guide the setting of the indicators of the hot-rolled silicon strip, the influence model about the relation of the transverse thickness difference of cold-rolled strip to the profile indicators of hot-rolled strip is established in this paper based on simulation results. The transverse thickness difference of cold-rolled strip predicted based on the influence model have strong correspondences to the measured data. Based on the influence model and the statistical analysis of the measured data, the control criterion of the profile indicators of hot-rolled silicon steel according to the requirements for the transverse thickness difference of cold-rolled strip are finally recommended. The simulation results show that the transverse thickness difference of cold-rolled strip is quadratic nonlinearly related to the wedge and crown of hot-rolled strip. The influence model and statistical data analysis indicate that reducing the edge-drop of hot-rolled strip is beneficial to restrain the transverse thickness difference of cold-rolled strip.

Research of Firing Control Model of Multi-stage Synchronous Induction Coil Launcher

The problem of firing control is a critical technology of multi-stage synchronous induction coil launcher (MSSICL). Operation with high launch efficiency of MSSICL mainly depends on each stage driving coil energized when the armature moves on the proper location. In order to solve the problem of firing control for MSSICL, the firing control model of MSSICL is built based on the dynamically simulative model and the firing control criterion. The dynamically simulative model includes the voltage equations of driving circuit and the kinematic equations. The solved method is provided. In addition, the factors that influence the solved precision of the firing control model of MSSICL are analyzed.