Privacy Preserving K-means Clustering with Chaotic Distortion

Randomized data distortion is a popular method used to mask the data for preserving the privacy. But the appropriateness of this method was questioned because of its possibility of disclosing original data. In this paper, the chaos system, with its unique characteristics of sensitivity on initial condition and unpredictability, is advocated to distort the original data with sensitive information for privacy preserving k-means clustering. The chaotic distortion procedure is proposed and three performance metrics specifically for k-means clustering are developed. We use a large scale experiment (with 4 real world data sets and corresponding reproduced 40 data sets) to evaluate its performance. Our study shows that the proposed approach is effective; it not only can protect individual privacy but also maintain original information of cluster cente

Research on the equivalent virtual space vector modulation output of diode clamped n-level converter under multi-modulation carrier modulation

Diode-clamped multi-level converters have DC-side capacitors in series, which will lead to the unbalance of DC-side capacitor voltage, the distortion of the output waveform, the increase of total harmonic distortion (THD), and even the damage of switching devices, which will make the system inoperable. The proposal of virtual space vector pulse-width modulation (VSVPWM) realizes the balanced control of the capacitor voltage, but when the output level of converter increases, the implementation of VSVPWM becomes very complicated, and the amount of calculation also increases greatly, thus hindering its application in the multi-level circuit. Compared with VSVPWM, the carrier-based pulse-width modulation (CBPWM) is simple to operate and easy to implement. If the equivalent relationship between CBPWM and VSVPWM can be found, the application of VSVPWM can be generalized to any level, and the advantages of VSVPWM can be fully utilized. This paper aims to study the inner relationship of VSVPWM and the multi-modulation carrier CBPWM (MCBPWM). After strict theoretical analysis, the equivalent relationship of VSVPWM and MCBPWM in the three-level and four-level and converter is realized by injecting the zero-sequence component into the modulation waves. Furthermore, the equivalent relationship between VSVPWM and MCBPWM is deduced to the N-level converter. Finally, the correctness of the relevant theoretical analysis is verified by the experiment

A robust free-standing MoS2/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) film for supercapacitor applications

Two-dimensional molybdenum disulfide (MoS2) is a promising energy storage material due to its high surface area and unique electronic structure. Free-standing flexible MoS2-based electrode is of importance for use in flexible energy storage devices, whereas there are limited reports available. In this work we developed a robust hybrid film, MoS2 incorporated with highly conductive poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate). This free-standing film possesses excellent mechanical properties with a fracture strength of 18.0 MPa and a Young\u27s modulus of 2.0 GPa. It can deliver a large volumetric capacitance of 141.4 F cm-3, a high volumetric energy density of 4.9 mWh cm-3, and a capacitance retention rate of 98.6% after 5000 charge/discharge cycles. This film has demonstrated its application in an all-solid-state bendable supercapacitor as well

A robust free-standing MoS2/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) film for supercapacitor applications

Two-dimensional molybdenum disulfide (MoS2) is a promising energy storage material due to its high surface area and unique electronic structure. Free-standing flexible MoS2-based electrode is of importance for use in flexible energy storage devices, whereas there are limited reports available. In this work we developed a robust hybrid film, MoS2 incorporated with highly conductive poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate). This free-standing film possesses excellent mechanical properties with a fracture strength of 18.0 MPa and a Young\u27s modulus of 2.0 GPa. It can deliver a large volumetric capacitance of 141.4 F cm-3, a high volumetric energy density of 4.9 mWh cm-3, and a capacitance retention rate of 98.6% after 5000 charge/discharge cycles. This film has demonstrated its application in an all-solid-state bendable supercapacitor as well

Application of A* algorithm in intelligent vehicle path planning

Path planning is one of the important directions in the field of intelligent vehicles research. Traditional path planning algorithms generally use Dijkstra algorithm, Breadth-First-Search (BFS) algorithm and A* algorithm. Dijkstra algorithm is a search-based algorithm, which can search to an optimal path, but the disadvantage is too many expansion nodes, which leads to insufficient search efficiency. BFS algorithm is a heuristic search algorithm, which reduces the disadvantage of too many expansion nodes and improves the search efficiency by heuristic function. A* algorithm is a heuristic search algorithm that combines Dijkstra’s algorithm and BFS algorithm, which has higher search efficiency and can search to an optimal path at the same time, but it is still lacking in the search mode and smoothness of the planned route. This paper first introduces the general path planning algorithm, then introduces and analyzes the A* algorithm, and proposes improvement measures for its shortcomings; finally, the executability and effectiveness of the improved algorithm are tested using simulation, and compared with the traditional A* algorithm, and the results show that the improved A* algorithm has good effect on path planning of intelligent vehicles