IDL: Evaluating software quality based on PageRank algorithm

In the traditional method, the software quality is measured by various metrics of the software, such as decoupling level (DL), which can be used to predict software defect. However, DL, which treats all the ?les equally, has not taken file importance into consideration. Therefore, a novel software quality metric, named as improved decoupling level (IDL), based on the importance of documents was proposed. First, the PageRank algorithm was used to calculate the importance of ?les to obtain the weights of the dependencies, and then defect prediction models was established by combining the software scale, dependencies, scores and software defects to assess the software quality. Compared to most existing module-based software quality evaluation methods, IDL has similar or even superior performance in the prediction of software quality. The results indicate that IDL measures the importance of each ?le in the software more accurately by combining the PageRank algorithm in DL, which indirectly re?ects the quality of software by predicting the bug information in software and improves the accuracy of prediction result of software bug information.     

一种基于直流输电中反激式逆变器功率解耦控制研究

针对直流输电并网系统中反激式逆变器存在大量二倍于工频谐波分量等问题,提出了一种新型反激式逆变器解耦电路,从而减少了母线和直流侧二次谐波分量。通过主动控制功率解耦电路中开关管开断,研究解耦电容充电模式和放电模式的4个工作阶段,使得储能电容可以有效地依次放电。最终,通过仿真和实验结果一致可以稳定输出100 Hz和100 V电压,表明该解耦方法的有效性和合理性。     

解析GB/T 17626.5-2019

详细阐述了GB/T 17626.5-2019在术语、试验等级、浪涌主机、耦合去耦网络、试验配置等方面的新要求,以及这些变化对测试的影响,以便帮助设备校准和测试人员更好地理解和运用此项标准。     

Structural analysis of unstable norbixin isomers guided by pure shift nuclear magnetic resonance

We report the analysis of complex samples obtained during the microwave irradiation/heating of norbixin, which has been identified as a potential therapeutic target for age-related macular degeneration (AMD). In this context, identifying the different isomers that are obtained during its degradation is of primary importance. However, this characterization is challenging because, on the one hand, some of these isomers are unstable, and on the other hand, the ¹H spectra of these isomeric mixtures are poorly resolved. We could successfully apply 1D pure shift experiments to obtain ultrahigh-resolution ¹H nuclear magnetic resonance (NMR) spectra of the norbixin isomer samples and exploit their information content to analyze complementary 2D NMR data and describe accurately their isomeric composition.     

一种基于关键帧的分布式视频分析解耦机制

近年来云计算逐渐应用于海量视频数据分析,但视频的处理单位是视频帧,而视频帧的大小是不固定的,所以不能直接用云平台处理视频,否则会出现帧不完整、找不到视频头文件、视频解码不成功等情况.通常的解决办法是对视频数据进行预处理,将视频分成若干独立可解码的视频块提交到文件系统中进行处理,但是当数据量很大时,预处理的工作量也很大.因此提出了一种基于关键帧的分布式视频分析解耦机制,将文件系统中的视频块按关键帧位置对视频数据进行巧妙分片.实验表明,提出的分布式视频分析解耦机制可有效对视频进行并行处理,保证了帧的完整性,且与云平台默认的分块方式相比计算负载更加均衡,提高了整体处理效率.     

模块化多电平静止无功补偿器控制策略研究

随着多电平逆变器在电力系统无功功率补偿领域的广泛应用,提出了一种基于模块化多电平( MMC)技术的新型静止无功补偿器( STATCOM)的拓扑结构。该拓扑结构具有模块化程度高、可靠性好、便于维护及容量拓展等特点,是一种极具发展潜力的拓扑结构。首先对MMC-STATCOM的工作原理和数学模型进行了分析,提出了无功功率解耦控制策略以及提出了一种新的控制子模块电容电压平衡的控制算法。仿真和测试结果均表明MMC-STATCOM具有补偿效果好,动态响应速度快等优点,是一种具有工程应用价值的大容量STATCOM主电路拓扑。     

我国行业碳生产率度量及演化动态

提高碳生产率对保持碳的稳定和经济持续增长具有重要意义.基于投入产出模型对中国2002-2012年26个行业的碳生产率进行测算,并通过构建Tapio脱钩指标对其进行动态分析.结果显示我国碳生产率总体在波动中上升,存在阶段性特征,行业差异明显,且第二产业总体水平偏低;行业脱钩指数总体呈现出弱脱钩—增长连结交替出现的发展特征.     

Heteronuclear chemical shift correlation and J-resolved MAS NMR spectroscopy of lipid membranes

Direct observation of J-couplings remains a challenge in high-resolution solid-state NMR. In some cases, it is possible to use Lee-Goldburg (LG) homonuclear decoupling during rare spin observation in MAS NMR correlation spectroscopy of lipid membranes to obtain J-resolved spectra in the direct dimension. In one simple implementation, a wide line separation-type (13)C-(1)H HETCOR can provide high-resolution (1)H/(13)C spectra, which are J-resolved in both dimensions. Coupling constants, (1)J(HC), obtained from (1)H doublets, can be compared with scaled (1)J(θ)(CH)-values obtained from the (13)C multiplets to assess the LG efficiency and scaling factor. The use of homonuclear decoupling during proton evolution, LG-HETCOR-LG, can provide J-values, at least in the rare spin dimension, and allows measurements in less mobile membrane environments. The LG-decoupled spectroscopic approach is demonstrated on pure dioleoylphosphatidylcholine (DOPC) membranes and used to investigate lipid mixtures of DOPC/cholesterol and DOPC/cholesterol/sphingomyelin.     

光伏并网发电与有源电力滤波的统一控制研究

论文分析了电能质量光伏并网系统的拓扑结构和工作原理。在此基础上对PQPV系统中谐波抑制和光伏并网最大功率跟踪之间的解耦控制进行了研究,并针对谐波治理过程中负载突变导致系统直流侧电压变化,进而对最大功率输出造成影响这一问题,在PQPV系统的直流侧电压控制环节中引入了输出电流前馈控制,解决了负载变化过程中谐波抑制环节对PQPV系统最大功率跟踪的影响。最后对所提出的前馈控制方法进行了实验研究并得出相应结论。