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基于块均值调制的彩色图像公开水印技术 被引量:1
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作者 谢伟蔚 肖德贵 《计算机工程与应用》 CSCD 北大核心 2007年第6期52-54,共3页
为了解决彩色图像的水印嵌入、空间域水印的低稳健性和公开水印的设计等问题,提出一种新的空间域公开水印技术。该技术将水印嵌入到视觉不太敏感的蓝色通道中,通过调制图像子块均值在映射区间上的分布,构建新的图像稳定特征,并实现水印... 为了解决彩色图像的水印嵌入、空间域水印的低稳健性和公开水印的设计等问题,提出一种新的空间域公开水印技术。该技术将水印嵌入到视觉不太敏感的蓝色通道中,通过调制图像子块均值在映射区间上的分布,构建新的图像稳定特征,并实现水印的嵌入和盲检测。讨论了调制区间的最大精度以及映射区间长度对算法稳健性的影响。实验结果表明本方法对多种图像处理具有稳健性。 展开更多
关键词 公开水印技术 块均值调制 映射区间 调制区间 盲检测
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三相逆变器高效调制下的谐波抑制
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作者 杜刚强 刘涛 《应用科技》 CAS 2021年第6期28-33,共6页
为提高三相逆变器效率,本文提出一种新型分区间调制策略。该策略在同一时刻只有两相开关管工作在高频斩波状态,另一相开关管工作在低频开关状态,降低了开关损耗,从而提高了逆变器效率。分析过程中,将逆变器在各分区等效为buck变换器,使... 为提高三相逆变器效率,本文提出一种新型分区间调制策略。该策略在同一时刻只有两相开关管工作在高频斩波状态,另一相开关管工作在低频开关状态,降低了开关损耗,从而提高了逆变器效率。分析过程中,将逆变器在各分区等效为buck变换器,使分析过程变得简单易懂。采用分区间调制策略后,输出电压电流波形在区间切换处产生畸变,通过分析产生畸变的原理,提出了抑制输出波形畸变的方法。采用仿真与样机实验的方法验证了所提分区间调制策略以及控制策略的正确性。 展开更多
关键词 三相逆变器 区间调制 高效率 谐波抑制 BUCK变换器 平均开关模型 dq变换 仿真
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Synthesis Scheme for Low Power Designs Under Timing Constraints 被引量:5
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作者 王玲 温东新 +1 位作者 杨孝宗 蒋颖涛 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2005年第2期287-293,共7页
To minimize the power consumption with resources operating at multiple voltages a time-constrained algorithm is presented.The input to the scheme is an unscheduled data flow graph (DFG),and timing or resource constrai... To minimize the power consumption with resources operating at multiple voltages a time-constrained algorithm is presented.The input to the scheme is an unscheduled data flow graph (DFG),and timing or resource constraints.Partitioning is considered with scheduling in the proposed algorithm as multiple voltage design can lead to an increase in interconnection complexity at layout level.That is,in the proposed algorithm power consumption is first reduced by the scheduling step,and then the partitioning step takes over to decrease the interconnection complexity.The time-constrained algorithm has time complexity of O(n 2),where n is the number of nodes in the DFG.Experiments with a number of DSP benchmarks show that the proposed algorithm achieves the power reduction under timing constraints by an average of 46 5%. 展开更多
关键词 low power multiple supply voltages partitioning timing constraints SCHEDULING
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An improved SVPWM control algorithm for three-level inverter 被引量:1
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作者 HUANG Xiao-feng WANG Xiao-peng SUN Chun-xia 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2017年第3期277-282,共6页
In the traditional three-level space vector pulse width modulation(SVPWM)algorithm,the sector judgment is computationallycomplex since the sector is divided into triangles and hexagons.In addition,the switching freque... In the traditional three-level space vector pulse width modulation(SVPWM)algorithm,the sector judgment is computationallycomplex since the sector is divided into triangles and hexagons.In addition,the switching frequency is high becausethe seven-segment switching sequence is adopted.For this reason,a new SVPWM control algorithm for three-level inverteris proposed,in which the sector judgment is simplified by dividing the sector into quasi hexagons?and the new four-segmentswitching sequence is adopted to reduce the switching frequency.Simulation results show that the total harmonic distortiongrows down with the switching frequency decreasing,moreover,the algorithm runtime is also decreased. 展开更多
关键词 three-level inverter space vector pulse width modulation (SVPWM) sector determination switching sequence
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