Parallel electric hydraulic hybrid powertrain (PEHH) is a promising substitute for electric direct drive to extend battery lifetime. The convex programming (CP) based simultaneous optimization method has been adopted ...
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Parallel electric hydraulic hybrid powertrain (PEHH) is a promising substitute for electric direct drive to extend battery lifetime. The convex programming (CP) based simultaneous optimization method has been adopted in electric hybrid system parameter optimization, but it is difficult to extend it for PEHH due to its non-convexity. In this paper, a combined exhaustive search - convex programming (ES-CP) system parameter optimization method is proposed to address the non-convexity of PEHH system parameter optimization problem. In this method, the PEHH system parameter optimization problem is modeled and reformulated in convex form and the convex part is decoupled from the optimization problem. The CP method is used for the convex part and the ES method is used for the remained non-convex part. The ES-CP method is applied to the PEHH powertrain to extend its battery lifetime. optimization results show that the battery lifetime of the ES-CP optimized PEHH system is 6.8% longer than that of the non-optimized system. The computing time of ES-CP is 97 % lower than Latin hypercube sampling and 90 % lower than genetic algorithm methods.
Converting three-dimensional (3D) point cloud data to two-dimensional (2D) image based on virtual structured-light system is a popular method in 3D data compression because the image format is easier to process by the...
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Converting three-dimensional (3D) point cloud data to two-dimensional (2D) image based on virtual structured-light system is a popular method in 3D data compression because the image format is easier to process by the exiting storing and transmitting methods. When this method is used in the 3D point cloud compression, the quantization error is introduced during the coordinate mapping. To solve this problem, a virtual structured-light 3D point cloud compression algorithm based on geometric reshaping is presented. And a least-square system parameter optimization method is proposed to further improve the data decoding accuracy. In the proposed method, the 3D spatial coordinates are reshaped to a 2D matrix first, and then the 2D matrix is stored as a "Holoimage" by using the parameter optimized virtual structured-light system. The quantization error introduced by coordinate mapping between X and Y coordinates of the 3D point cloud and the 2D image pixel coordinates is suppressed, so the decoding accuracy is improved. In addition, the geometric information of the 3D point cloud is hidden synchronously when the 3D point cloud is compressed, which is of great significance in the copyright protection of the point cloud data. Experiments verify the effectiveness of the proposed algorithm. The decoding root mean square error (RMSE) of the proposed method is decreased by 79.86% on average compared with the traditional one under the same compression ratio, and the compression ratio of the proposed method is 1.96 times bigger than the traditional one under the similar decoding accuracy. (C) 2022 SPIE and IS&T
This paper described the architecture and working mechanism of the content centric network, and proposed the idea of introducing it into the sea-sky information network. The corresponding simulation model was built by...
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ISBN:
(纸本)9781728114507
This paper described the architecture and working mechanism of the content centric network, and proposed the idea of introducing it into the sea-sky information network. The corresponding simulation model was built by taking the ship based wireless video monitoring system as the research target. The relationship among the frequency of the user request, the number of different content types and the node cache capacity on the system performance was summarized through a large number of experiments. Then the system performance under given parameters was evaluated to verify the feasibility and advantages for the application of the content centric network.
A pilot project of the solar water heating system combined with a low temperature air source heat pump (ASHP) unit was established in 2014 in a detached residential house in the rural region of Beijing, in order to in...
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A pilot project of the solar water heating system combined with a low temperature air source heat pump (ASHP) unit was established in 2014 in a detached residential house in the rural region of Beijing, in order to investigate the system application prospect for single family houses via systemoptimization design and economic analysis. The established system was comprised of the glass heat-pipe based evacuated tube solar collectors with a gross area of 18.8 m(2) and an ASHP with a stated heating power of 8 kW for the space heating of a single family rural house of 81.4 m(2). The dynamic thermal performance of the pilot system was measured for continuous 20 days under typical cold climate conditions and the test data was used to validate the TRNSYS simulation model established. On the basis of model validation, systemoptimizations of both the existing pilot household and the typical rural house with good building insulation were undertaken to figure out the system economical efficiency in the rural regions of Beijing. The results show that the payback periods of the solar space heating system combined with the ASHP with the collector areas 15.04-22.56 m(2) are 173-22.4 years for the established pilot household on the current electricity price level of 0.5 RMB/kWh, comparing with the reference condition of the fully ASHP space heating. It is further found that the equivalent solar heat price per kWh is too high under the current solar market cost price and collector technology. To put forward the integrated solar space heating for reducing carbon emission, it is suggested that the Beijing municipal government should offer some financial subsidy to compensate the equivalent solar heat price per kWh. (C) 2016 Elsevier B.V. All rights reserved.
Pulsed eddy current non-destructive testing (PECT) has been proved to be the most effective method for defect detection on aircraft riveted structures. In this paper, a study of PECT systemoptimization was made using...
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ISBN:
(纸本)9781457715846
Pulsed eddy current non-destructive testing (PECT) has been proved to be the most effective method for defect detection on aircraft riveted structures. In this paper, a study of PECT systemoptimization was made using "Method of Phase-shift and Logic-operation" (MPL) and DDS technique on the basis of analysis about the effects that systemparameters exert upon the inspecting results. A novel auto-differentially rotary sensor for defect detection on riveted structures was proposed and presented from structure designing and working principle. The advantages and key performances of the optimized system were analyzed and PECT experiments on the specimen of rivet structures are carried out. The experimental results testify the availability of the optimized system and the necessity to optimize the PECT systemparameters.
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