With the development of The Times and the continuous progress of information technology, computer programming technology has been paid more and more attention. In the process of computer programming, people mainly opt...
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The larger volume of capacitor and higher leakage current of transistor have become the inherent disadvantages for the traditional one transistor (1T)-one capacitor (1C) dynamic random access memory (DRAM). Recently, ...
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The larger volume of capacitor and higher leakage current of transistor have become the inherent disadvantages for the traditional one transistor (1T)-one capacitor (1C) dynamic random access memory (DRAM). Recently, the tunneling FET (TFET) is applied in DRAM cell due to the low off-state current and high switching ratio. The dual-gate TFET (DG-TFET) DRAM cell with the capacitorless structure has the superior performance-higher retention time (RT) and weak temperature dependence. But the performance of TFET DRAM cell is sensitive to programming condition. In this paper, the guideline of programming optimization is discussed in detail by using simulation tool-Silvaco Atlas. Both the writing and reading operations of DG-TFET DRAM depend on the band-to-band tunneling (BTBT). During the writing operation, the holes coming from BTBT governed by Gate2 are stored in potential well under Gate2. A small negative voltage is applied at Gate2 to retain holes for a long time during holding "1". The BTBT governed by Gate1 mainly influences the reading current. Using the optimized programming condition, the DG-TFET DRAM obtains the higher current ratio of reading "1" to reading "0" (10(7)) and RT of more than 2 s. The higher RT reduces the refresh rate and dynamic power consumption of DRAM.
Oil-impregnated paper (OIP) bushing is essential equipment in traction power supply systems, and its moisture status is directly related to the power transmission of high-speed railway. Also, the moisture distribution...
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Oil-impregnated paper (OIP) bushing is essential equipment in traction power supply systems, and its moisture status is directly related to the power transmission of high-speed railway. Also, the moisture distribution in the OIP bushing insulation is usually nonuniform. The frequency-domain dielectric spectroscopy (FDS) method is now widely accepted as the most potential method for evaluating the moisture status of the OIP traction bushing with nonuniform moisture distribution. However, as far as the FDS curve reconstruction of field bushing is concerned, it remains a challenge. In this article, based on the extended Debye model, a new curve reconstruction method (including equivalent circuit and mathematical models) of the bushing dielectric response is proposed. Then, the reconstruction method is converted into a mathematical problem of programming optimization. Based on the advantages of metaheuristic algorithms such as simplicity, flexibility, derivative-free mechanism, and local optimal avoidance, an improved metaheuristic algorithm was used to address the optimization problem. Finally, the proposed method was tested on bushing samples and real bushings. The research shows that the proposed method of curve reconstruction can well characterize the FDS curves of the traction bushing insulation with the nonuniform moisture distribution.
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