Results 31 to 40 of about 12,978 (169)
Gaoya dianqi, 2019 采用抛物线拟合方法计算大容量试验短路电流波形的峰值和对应的时间坐标。理论证明短路电流波形上相邻两峰值的时间坐标中点的电流值近似等于此时的直流分量值,并据此给出波形的直流时间常数、交流（基波）分量有效值和直流分量百分数的算法。使用STL提供的标准短路电流波形,对文中算法和现有算法进行了对比测试。测试结果验证了该算法的准确性,同时表明,仅使用3个峰值点并未显著降低文中算法在计算交流分量恒定的短路电流波形参数时的准确度。通过计算直流时间常数不同 ...
周小猛 +4 more
doaj
Design of Carrier Synchronization Based on Costas Loop [PDF]
, 2010 介绍了平方变换法相干解调原理,从工程角度完善了载波提取的电路结构,消除了频移载波的误锁问题.提出用科斯塔斯环法来实现从2dPSk信号中提取相干载波,解决了提取的载波信号存在180度的相位含糊问题,为通信系统提高抗噪性能提供了条件.当载波频率很高时,工作频率较低的科斯塔斯环易于实现.并用SIMulInk设计出科斯塔斯环法提取载波的仿真电路图和进行相应的仿真实验.Theory of coherent demodulation based on method of square counterchange ...
刘美珍 +3 more
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Conservation Biology, Volume 40, Issue 1, February 2026.Abstract Spatial segregation in at‐sea distribution is frequently observed in seabirds and can have important implications for conservation and management. Globally, many albatross and petrel populations are declining due to bycatch in fisheries. In South Georgia, the decrease in wandering albatrosses (Diomedea exulans) differs among breeding sites ...
V. Warwick‐Evans +3 more
wiley +1 more source
Gaoya dianqi, 2017 直流分压器是特高压直流输电系统中不可缺少的主设备,其采集数据的准确性对电网的安全稳定运行至关重要。基于直流分压器的工作原理,分析致使直流分压器分压比变化的主要因素,通过数学公式直观的诠释分压比的不确定性,然后在研究分压比不确定性的基础上构建直流分压器校准分析计算模型,并试验证明了该模型对站用±800 kV直流分压器的校准水平高达10-510-6量级,大幅度提升了直流分压器量值测量的准确度。
王奇 +4 more
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利用TMS320C54x数字信号处理器进行JPEG算法的彩色图像压缩 [PDF]
, 2000 作为水底勘探设备的一个重要组成部分，水下彩色图像采集与传输系统主要由图像采集、图像压缩和信道编码传输三大部分组成。它必须具有小型化、高速处理的特点。而数字信号处理器（DSP），由于其独特小巧的结构和快速实现各种数字信号处理算法的突出优点，理所当然的成为了该系统核心的最佳选择。 在水下彩色图像采集与传输系统中，压缩是其中一个必不可少的环节。这是因为相比于黑白图像而言，彩色原始图像的表示需要更大量的数据。因此在进行传输之前，需要对图像信息进行数据压缩编码，以减少传输的数据量，更好地满足系统传输速率的要求 ...
王一帆
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Regulation &Governance, Volume 20, Issue 1, Page 35-63, January 2026.ABSTRACT Existing literature largely agrees that authoritarian regimes establish channels for political participation to gather valuable information on citizens' anti‐regime sentiments and policy preferences and to supervise lower‐level bureaucrats and firms.
Anton Bogs
wiley +1 more source
Rate Control Strategy Based on the Distributed Character of DCT Coefficients [PDF]
, 2001 根据缓存器的状态和信道速率为待编码帧在图像层上预分配目的视频编码比特数 ,使用DCT系数分布特性来表征图像特性 ,继而为帧内每一具体宏块选定最佳量化因子 ,提出了基于DCT系数分布特性的码率控制策略 .并分析了算法的复杂度 ,提出了改进策略 .模拟实验表明 ,该码率控制策略能有效地减少、避免缓存器出现上、下溢的情况 ,而输出码率趋于稳定 .提高了重建图像的信噪比 ,并且在视频图像质量没有明显失真的前提下 ,改进了计算复杂度 .Rate control strategy based on the ...
张红伟, 施芝元, 李晓辉
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Ultrasound in Obstetrics &Gynecology, Volume 66, Issue 5, Page 621-630, November 2025.ABSTRACT Objectives To compare the maternal hemodynamics of Chinese women at low and at high risk for preterm pre‐eclampsia (PE) and assess the differences in hemodynamic parameters between high‐risk women with or without prophylactic aspirin. Methods This was a prospective longitudinal case–control study of 857 Chinese women with a singleton pregnancy
X. Wang +11 more
wiley +1 more source
Virtual channel model for distributed video coding accounting for quantization noise [PDF]
, 2012 Due to the inaccuracy model on describing the virtual channel with Laplacian,the rate-distortion performance of distributed video coding is relatively low.The quantization noise will be taken into account for online modeling at the decoder.Further,the ...
Ming YIN +3 more
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Beyond Motivation: Modeling the Predictive Role of L2 Pride in Informal Digital Learning of English
International Journal of Applied Linguistics, Volume 35, Issue 4, Page 1938-1952, November 2025.ABSTRACT This study investigates the role of second language (L2) pride—an understudied affective factor—in shaping learners’ language learning motivation and involvement with informal digital learning of English (IDLE). Drawing on questionnaire data from 1388 Chinese university EFL students, the study employs structural equation modeling to examine ...
Minlin Minny Zou +3 more
wiley +1 more source