Stability of Gorenstein flat categories with respect to a semidualizing module

In this paper, we first introduce $\mathcal {W}_F$-Gorenstein modules to establish the following Foxby equivalence: \xymatrix@C=80pt{\mathcal {G}(\mathcal {F})\cap \mathcal {A}_C(R) \ar@[r]^{C\otimes_R-} & \mathcal {G}(\mathcal {W}_F) \ar@[l]^{\textrm{Hom}_R(C,-)}} where $\mathcal {G}(\mathcal {F})$, $\mathcal {A}_C(R)$ and $\mathcal {G}(\mathcal {W}_F)$ denote the class of Gorenstein flat modules, the Auslander class and the class of $\mathcal {W}_F$-Gorenstein modules respectively. Then, we investigate two-degree $\mathcal {W}_F$-Gorenstein modules. An $R$-module $M$ is said to be two-degree $\mathcal {W}_F$-Gorenstein if there exists an exact sequence \mathbb{G}_\bullet=\indent ...\longrightarrow G_1\longrightarrow G_0\longrightarrow G^0\longrightarrow G^1\longrightarrow... in $\mathcal {G}(\mathcal {W}_F)$ such that $M \cong$ \im(G_0\rightarrow G^0) and that $\mathbb{G}_\bullet$ is Hom$_R(\mathcal {G}(\mathcal {W}_F),-)$ and $\mathcal {G}(\mathcal {W}_F)^+\otimes_R-$ exact. We show that two notions of the two-degree $\mathcal {W}_F$-Gorenstein and the $\mathcal {W}_F$-Gorenstein modules coincide when R is a commutative GF-closed ring.Comment: 18 page

Diagnosis and Location of Open-Circuit Fault in Modular Multilevel Converters Based on High-order Harmonic Analysis

Open-Circuit faults of Submodules (SMs) are the most common fault type of modular multilevel converter (MMC). Thus, in order to improve the reliability of MMC, it is very important to detect and locate faulty MMC SMs. In this paper, a new fault diagnosis and location method based on high-order harmonic analysis of the bridge arm voltage is proposed, and the characteristics of SM open-circuit faults are analyzed. In the proposed method, faults are detected by comparing the amplitude of the bridge arm voltage at the switching frequency with a variable threshold, and the phase angle of the bridge arm voltage at the switching frequency is used to locate the faulty SM. The proposed method can detect faulty SM with just one voltage sensor per arm bridge. Moreover, this method can effectively avoid misjudgment of a fault detection signal in the normal transient state. Finally, a MMC model was built using a MATLAB/Simulink environment and simulations were conducted. The experimental results show that the proposed method can not only diagnose a SM fault quickly, but can also locate the faulty SM accurately

Target localization in wireless sensor networks for industrial control with selected sensors

This paper presents a novel energy-based target localization method in wireless sensor networks with selected sensors. In this method, sensors use Turbo Product Code (TPC) to transmit decisions to the fusion center. TPC can reduce bit error probability if communication channel errors exist. Moreover, in this method, thresholds for the energy-based target localization are designed using a heuristic method. This design method to find thresholds is suitable for uniformly distributed sensors and normally distributed targets. Furthermore, to save sensor energy, a sensor selection method is also presented. Simulation results showed that if sensors used TPC instead of Hamming code to transmit decisions to the fusion center, localization performance could be improved. Furthermore, the sensor selection method used can substantially reduce energy consumption for our target localization method. At the same time, this target localization method with selected sensors also provides satisfactory localization performance

A New Algorithm for Bearings-Only Parametric Trajectory Tracking

AbstractFor the single sensor target tracking with bearings-only measurements, a novel trajectory invariable-information target tracking algorithm was proposed, and bearings-only target can be tracked by the parameter trajectory. For the measure frequency of sensor is high, the mathematic model of bearings-only tracking is analyzed by dividing the trajectory into many linearization parts. The tracking parameter of bearings-only target trajectory is deduced, so the bearings-only target can be tracked by the parameter trajectory. The simulation results show that the new algorithm has a favorable tracking precision