Dead-time insertion increases noise and torque pulsation in motors under open-loop constant V/f control, it results instability sensorless field-orientated control or direct at low speed, degrading performance of motor drive systems. In order to overcome the drawback dead-time insertion, a novel current-detection-independent compensation technique based on terminal voltage A/D conversion is proposed this paper. Both current polarity time can be extracted from sampled voltage. Experiments an...

Insertion of dead time in space vector pulse width modulation (SVPWM) causes phase voltage and current distortion or even zero-current clamping phenomenon, degrading the control performance ac induction motor. In addition, analysis becomes more complicated due to existence parasitic capacitance power switching device source inverter (VSI). This paper tries make clear that how influences VSI's output independently. First, an equivalent circuit VSI containing is constructed. On basis,...

The protograph LDPC (P-LDPC) coded modulation is an efficient scheme using the variable degree matched mapping (VDMM) based on structure. We propose a VDMM optimization strategy, as crucial part for P-LDPC modulation, by checking different permutation patterns between nodes in and modulated bits. Then, we develop modified EXIT analysis evaluating thresholds modulation. For some specified codes 16QAM constellations, optimum can be obtained limited number of searches analysis. find that...

The collapse of circuits is usually a cascading failure rather than simple event. It difficult to model this kind due the complex structural and functional coupling. In article, impedance network introduced as prototypical for characterizing circuit. A current-flow redistribution approach proposed analyze mechanisms circuits. Specific factors two typical modes, i.e., open circuit short circuit, are put forward determine effect failed component on remaining components. health confidence value...

Spalling, a common failure mechanism of gear systems, greatly affects the dynamics gears operation, which is reflected in time-varying mesh stiffness (TVMS). Current TVMS models often overestimate asymmetric spalling phenomenon and may lead to inaccuracy identifying predicting failure. To address this problem, paper, new stiffness, namely torsional introduced quantify effect defects, an equivalent calculation method for different shapes proposed. Based on this, shape-independent model...

In this paper, we propose an efficient and fault tolerant topology control algorithm named AWSF for large-scale wireless sensor networks, which introduces the scale-free characteristic of complex networks into to minimize transmission delay increase robustness. It is a distributed algorithm, letting each node locally adjust its power determine neighbor relationship based on certain arbitrary weights are random real numbers following negative power-law probability distribution. The...

The reliability of circuit systems is primarily affected by cascading failures due to their complex structural and functional coupling. Causes failure during operation include the continuous degradation process components external random shocks. Circuit can exhibit asymmetric changes loss propagation coupling shock uncertainty effects. To tackle this issue, paper abstracts into an impedance network constructs a component behavior model that considers correlation between shock. interactions...

In this paper, we present a Distributed Geography-based Fault Tolerant topology control algorithm (DGFT) for static large-scale wireless sensor networks. We introduce the scale-free characteristic of complex networks into large- scale to obtain robustness and time efficiency. DGFT enables nodes define by neighbor relationship, based on certain initialized weights whose distribution follows negative power law. prove that constructed under is strongly connected bidirectional. Simulation...

Gear as a critical component of transportation, its operating status has direct impact on traffic safety. Under the high speed and heavy load, spalling is one main failure mechanisms gear teeth. This study focuses effect defects in different positions time-varying mesh stiffness (TVMS). By studying distribution meshing force process, torque was found when teeth region. Thus, torsional introduced to indicate positions. And model considering established. The result shows that TVMS decreases...

Salt rock is a kind ofthe most suitablemedium for energy storages, because of its strongcreep behavior. "Burgers" and "Norton" the two classic creep models. This paper starts from establishment constitutive model to obtain determination method parameters.Finally, it takes Nanjing salt test (2003) as an example solve parameters in Burgers Norton equations.

Achievements of network traffic simulation provide realistic, feasible and accurate methods measuring bandwidth, latency, jitter so on. However as the development networking technology, traditional manners are becoming insufficient to high bandwidth matching real network, nor statistics characteristic such self-similarity. In this paper we propose Network Traffic Simulation platform based on Processor (NTS-NP). The has achieved: 1) real-time generation; 2) precision self-similarity flow,...

Based on primary/secondary gait method used for quadruped robot, this paper proposes a new free generation the cockroach robot. A heuristic graph search procedure based A* algorithm has been in of secondary to resolve problem that too many support pattern choose hexapod The primary composes fixed sequence leg transfers, while is flexible one which generated adjust pattern. works only when cannot move machine. Four constraints, namely, stability constraint, kinematic sequential and...

Based on LabVIEW, the comprehensive evaluation system of armored vehicle cabin environment is designed and developed. Combining function demand system, process proposed general structure designed. Through method dynamic calling subvi subpanel, hybrid programming with MATLAB organic combination For Loop Structure form controls, specification software interface design, data input/output weighted filtering analysis test in time-frequency domain other technical problems are solved.

A product characterized by fatigue-induced failure is subjected to complex cyclic load which cause fatigue damage accumulated over time. At the same time, under may suffer from low-energy impact during whole service life. For its discontinuity, does not lead immediately. The only structural and residual strength degradation instantly but also influence effect of load. And has for in return. This article shows an approach life prediction based on continuum mechanics with coupling relationship...

This work considers the communication scenario where multiple sources transmit information to one or more receivers and these request from all sources. We construct a secret reliable coding mechanism for noncoherent multisource network by extending case. Although suffers an adversary that can re-select μ tapping links in different time slot inject z erroneous packets into network, transmission suffer ρ packet erasures, our scheme retrieve original secretly accurately corrupt deficient...

Similar product information is valuable for reliability evaluation. How to define and measure similarity the key making good use of similar information. In this paper, a new measurement in terms margin newly developed based on belief theory system theory. Subsequently, fusion evaluation method proposed assess products combination with failure data from old products. To demonstrate effectiveness above methods, case study seed source generation circuit employed, which shows methods can...

Network traffic generation has always been a hot spot in network measurement and simulation research. However, traditional methods of generating are either insufficient fulfilling bandwidth requirement or matching the characteristics real network. In this paper we propose platform high real-time with self-similarity characteristic. The feature guarantees feasibility characteristic makes more reliable. platform, choose Cavium OCTEON CN3860 as core implemented ON/OFF aggregation model...