Outage Constrained Design in NOMA-Based D2D Offloading Systems

Non-orthogonal multiple access (NOMA) is a new multiple access method that has been considered in 5G cellular communications in recent years, and can provide better throughput than traditional orthogonal multiple access (OMA) to save communication bandwidth. Device-to-device (D2D) communication, as a key technology of 5G, can reuse network resources to improve the spectrum utilization of the entire communication network. Combining NOMA technology with D2D is an effective solution to improve mobile edge computing (MEC) communication throughput and user access density. Considering the estimation error of channel, we investigate the power of the transmit nodes optimization problem of NOMA-based D2D networks under the rates outage probability (OP) constraints of all single users. Specifically, under the channel statistical error model, the total system transmit power is minimized with the rate OP constraint of a single device. Unfortunately, the problem presented is thorny and non-convex. After equivalent transformation of the rate OP constraints by the Bernstein inequality, an algorithm based on semi-definite relaxation (SDR) can efficiently solve this challenging non-convex problem. Numerical results show that the channel estimation error increases the power consumption of the system. We also compare NOMA with the OMA mode, and the numerical results show that the D2D offloading systems based on NOMA are superior to OMA.

A Method to Deduce and Synthesize the Dafny Programs

We propose a systematic method to deduce and synthesize the Dafny programs. First, the specification of problem is described in strict mathematical language. Then, the derivation process uses program specification transformation technology to perform equivalent transformation. Furthermore, Dafny program is synthesized through the obtained recursive relationship and loop invariants. Finally, the functional correctness of Dafny program is automatically verified by Dafny verifier or online tool. Through this method, we deduce and synthesize Dafny programs for many typical problems such as the cube sum problem, the minimum (or maximum) contiguous subarray problems, several searching problems, several sorting problems, and so on. Due to space limitation, we only illustrate the development process of Dafny programs for two typical problems: the minimum contiguous subarray problem and the new local bubble sorting problem. It proves that our method can effectively improve the correctness and reliability of Dafny program developed. What’s more, we demonstrate the potential of the deductive synthesis method by developing a new local bubble Sorting program.

A Nonlinear Fatigue Damage Model Based on Equivalent Transformation of Stress

It is rather difficult for engineers to apply many of the fatigue damage models for requiring a knee point, material-dependent coefficient, or extensive testing, and some of them are only validated by a fatigue test of two-stage loading rather than higher-stage loading. In this paper, we propose a new model of fatigue cumulative damage in variable amplitude loading, which just requires the information of the S-N curve determined from the fatigue experiment. Specifically, the proposed model defines a stress equivalent transformation way to translate the damage of one stress to another stress through simple calculation. Experimental data of fatigue including two-, three-, and four-block loading verify the superiority of the proposed model by comparing it with the Miner model and Manson model. The results show that the proposed model can be generalized to any type of loading and presents a better prediction. Therefore, the advantage of the proposed model can be easily used by an engineer.

Enhanced Stability Criteria of Network-Based Load Frequency Control of Power Systems with Time-Varying Delays

The stability problem for load frequency control (LFC) of power systems with two time-varying communication delays is studied in this paper. The one-area and two-area LFC systems are considered, respectively, which are modeled as corresponding linear systems with additive time-varying delays. An improved stability criterion is proposed via a modified Lyapunov-Krasovskii functional (LKF) approach. Firstly, an augmented LKF consisting of delay-dependent matrices and some single-integral items containing time-varying delay information in two different delay subintervals is constructed, which makes full use of the coupling information between the system states and time-varying delays. Secondly, the novel negative definite inequality equivalent transformation lemma is used to transform the nonlinear inequality to the linear matrix inequality (LMI) equivalently, which can be easily solved by the MATLAB LMI-Toolbox. Finally, some numerical examples are presented to show the improvement of the proposed approach.

Hybrid RPT Method On Double-Heterogeneous System Containing Dispersed Fuel Particles and Burnable Poison Particles

In this paper it was found that for DH systems containing both particle-dispersed fuel and particle-dispersed burnable poison, the TRRPT method may be invalid in some situation. In his paper a new method named Hybrid RPT (HRPT) method has been proposed for DH systems containing both particle-dispersed fuel and particle-dispersed burnable poisons. And then the HRPT are analyzed and studied on the equivalent transformation range of DH systems comparing with the TRRPT method and the IRPT method. It was found that the HRPT method not only has a wider equivalent transformation range of DH systems than the TRRPT method, but also has higher calculation accuracy than the IRPT method. Results of depletion calculations for different types, different volume fractions and different particle sizes of burnable poisons particles dispersed the DH systems with dispersed particle-type fuel and the comparison with Monte Carlo results of grain models have proved the effectiveness and applicability of HRPT method.

Two-Stage Cubature Kalman Filtering Based on T-Transform and Its Application

According to the actual application system model which has bias, this paper analyzes the shortage of the conventional augmented algorithm, the two-stage cubature Kalman filtering algorithm, which is presented on the basis of a two-stage nonlinear transformation. The core ideas of the algorithm are to obtain the block diagonalization of the covariance matrix using the matrix transformation and avoid calculating the covariance of the state and bias to reduce the amount of calculation and ensure a smooth filtering process. Then, the equivalence of the two-stage cubature Kalman filtering algorithm and the cubature Kalman filtering algorithm is proved by updating equivalent transformation. Through the experiment of trajectory tracking of a wheeled robot, it is verified that the two-stage cubature Kalman filtering algorithm can obtain good tracking accuracy and stability with the presence of unknown random bias. Simultaneously, the equivalence of the two-stage cubature Kalman filtering algorithm and cubature Kalman filtering algorithm is verified again using the contrast experiment.

Evaluation of the development ability of medical association based on evidential reasoning and prospect theory

China has proposed medical couplet body to alleviate residents’ difficulties in seeking medical treatment, and the future development ability of medical couplet body has gradually become a research interest. On the basis of prospect theory, this study constructs a comprehensive evaluation index system with qualitative and quantitative indexes, clear hierarchy, and diverse attribute characteristics. The development ability of medical couplet body is also comprehensively and systematically evaluated. In addition, the evidential reasoning method is proposed on the basis of the equivalent transformation of prospect value. Furthermore, the validity and feasibility of the model are proven through experiments, and the influence of decision makers’ risk attitude on the evaluation results is discussed.

A State-scaling Design for Prescribed-time Stabilization of High-order Nonlinear Systems with Input Quantization

This article considers global stabilization problem for a kind of uncertain high-order nonlinear systems (HONSs). Two distinct characteristics of this study are that the considered system possesses the input-quantized actuator, and the prescribed time convergence of the system states is wanted. To address these, a novel state-scaling transformation (SST) is firstly introduced to convert the aboriginal prescribed-time stabilization (PTS) to the asymptotic stabilization of the transformed one. Then, under the new framework of equivalent transformation, a quantized state feedback controller that achieves of the performance requirements is developed with the aid of the technique of adding a power integrator (API). Finally, simulation results of a liquid-level system are provided to confirm the efficacy of the proposed approach.

Design and Characteristics of a Novel QZS Vibration Isolation System with Origami-inspired Corrector

A new class of quasi-zero-stiffness (QZS) vibration isolation systems, inspired by the origami metamaterial, is proposed to achieve high-performance vibration suppression in this paper. According to the mechanical characteristics of Tachi-Miura origami (TMO) with single degree-of-freedom, the nonlinear geometric relationship is developed with the folding angle as the master variable. By utilizing equivalent transformation and virtual work principle, the static model is established, the influence of structural parameters on stiffness is investigated, and the negative stiffness mechanism of origami mechanism is revealed. By adding a linear spring with positive stiffness to the origami in parallel, the Tachi-Miura origami vibration isolator (TMOriVi) is obtained. Subsequently, the governing equation is presented by means of the harmonic balance method. Two types of instability situations, jump phenomenon and unbounded response, are studied, and their analytic criteria and relationship are derived. Finally, through the parametric influence analysis and a series of comparative studies, the effectiveness and superiority of the proposed isolator are verified. The proposed vibration isolation system with great design flexibility exhibits a significant potential in the field of low-frequency vibration isolation.