Anti-Noise Performance of the FT Continuous Zoom Analysis Method for Discrete Spectrum

As a discrete spectrum correction method, the Fourier transform （FT） continuous zoom analysis method is widely used in vibration signal analysis, but little effort had been made on this method＇s anti-noise performance. It is widely believed that the analysis accuracy of the method can be substantially improved by increasing the zoom multiple, however, with the zoom multiple increases, the frequency estimation accuracy may decline sometimes in practices. Aiming at the problems above, this paper analyzes the sources of frequency estimation error when a harmonic signal mixed with and without noise is processed using the FT continuous zoom analysis. According to the characteristics that the local maximum of the zoom spectrum may be wrongly selected when the signal is corrupted with noise, the number of wrongly selected spectrum lines is deduced under different signal-to-noise ratio and local zoom multiple, and then the maximum frequency estimation error is given accordingly. The validity of the presented analysis is confirmed by simulations results. The frequency estimation accuracy of this method will not improve any more under the influence of noise, and there is a best zoom multiple, when the zoom multiple is larger than the best zoom multiple; the maximum frequency estimation error will fluctuate back and forth. The best zoom multiple curves under different signal-to-noise ratios given provide a theoretical basis for the choice of the appropriate zoom multiples of the FT continuous zoom analysis method in engineering applications.

Performance analysis and comparison of PoW,PoS and DAG based blockchains

In the blockchain,the consensus mechanism plays a key role in maintaining the security and legitimation of contents recorded in the blocks.Various blockchain consensus mechanisms have been proposed.However,there is no technical analysis and comparison as a guideline to determine which type of consensus mechanism should be adopted in a specific scenario/application.To this end,this work investigates three mainstream consensus mechanisms in the blockchain,namely,Proof of Work(PoW),Proof of Stake(PoS),and Direct Acyclic Graph(DAG),and identifies their performances in terms of the average time to generate a new block,the confirmation delay,the Transaction Per Second(TPS)and the confirmation failure probability.The results show that the consensus process is affected by both network resource(computation power/coin age,buffer size)and network load conditions.In addition,it shows that PoW and PoS are more sensitive to the change of network resource while DAG is more sensitive to network load conditions.

Comparison of pharmacokinetics of different oral Panax notoginseng saponins using ultra-high performance liquid mass spectrometry

Objective:To discuss and compare the plasma pharmacokinetics after three oral Panax notoginseng saponin(PNS)administrations in beagle dogs.PNS is the main active ingredient of the traditional Chinese medicine(TCM)Panax notoginseng.Although its outstanding therapeutic efficacy has been demonstrated by various researchers,its broader application is restricted by the low bioavailability of PNS.Methods:An ultra-high performance liquid chromatographyetandem mass spectrometry(UPLC-MS/MS)method for the simultaneous quantification of notoginsenoside R1,ginsenoside Rg1,ginsenoside Rb1,ginsenoside Rd,and ginsenoside Re in beagle dog plasma was developed and validated.The plasma samples were subjected to liquideliquid extraction with acetone and methanol,and separated on an ACQUITY C18 column(100×2.1 mm ID,1.7 mm)using acetonitrile and water as the mobile phase with a run time of 4.5 min.Results:The analytes were detected without interference in Selected Reaction Monitoring mode with positive electrospray ionization.The validated method was successfully used in comparative pharmacokinetic studies of the five saponins in beagle dogs after oral administration of three PNS preparations.Blood samples were collected up to 192 h after administration and pharmacokinetic parameters were calculated using DAS 3.20 and SPSS 17.0.The AUC_(0-t)values of Re and R1 were significantly higher in soft capsules than in hard capsules.However,the AUC_(0-t)values between hard and soft capsules were not significantly different for the other three componentsdRb1,Rd and Rg1.Conclusion:Our intuitive analysis suggests that the bioavailability of PNS in soft capsules is greater than in hard capsules.

PERFORMANCE EVALUATION AND COMPARISON OF THREE COUNTING BLOOM FILTER SCHEMES

The Counting Bloom Filter(CBF) is a kind of space-efficient data structure that extends a Bloom filter so as to allow approximate multiplicity queries on a dynamic multi-set.This paper evaluates the performance of multiplicity queries of three simple CBF schemes-the Na?ve Counting Bloom Filter(NCBF), the Space-Code Bloom Filter(SCBF) and the d-left Counting Bloom Filter(dlCBF)-using metrics of space complexity and counting error under both uniform and zipfian multiplicity distributions.We compare their counting error under same space complexity, and their space complexity when similar counting errors are achieved respectively.Our results show that dlCBF is the best while SCBF is the worst in terms of both space-efficiency and accuracy.Furthermore, the performance gap between dlCBF and the others has a trend of being enlarged with the increment of space occupation or counting accuracy.

PERFORMANCE COMPARISON OF ECG COMPRESSION ALGORITHMS BASED ON CLINICAL DIAGNOSIS

This paper reviewed the recent progress in the field of electrocardiogram (ECG) compression and compared the efficiency of some compression algorithms. By experimenting on the 500 cases of ECG signals from the ECG database of China, it obtained the numeral indexes for each algorithm. Then by using the automatic diagnostic program developed by Shanghai Zhongshan Hospital, it also got the parameters of the reconstructed signals from linear approximation distance threshold (LADT), wavelet transform (WT), differential pulse code modulation (DPCM) and discrete cosine transform (DCT) algorithm. The results show that when the index of percent of root mean square difference(PRD) is less than 2.5%, the diagnostic agreement ratio is more than 90%; the index of PRD cannot completely show the damage of significant clinical information; the performance of wavelet algorithm exceeds other methods in the same compression ratio (CR). For the statistical result of the parameters of various methods and the clinical diagnostic results, it is of certain value and originality in the field of ECG compression research.

Performance Model Analysis of Armenian Premier League Soccer Players Using Global Positioning System Technology and Comparison between European Championship

The aim of this research was to analyze the PPM of Armenian Premier League using 25 GPS 10 Hz(K-Sport,Montelabbate,Italy),in order to compare data from literature from major European championship.In total 25 matches were analyzed from one team militant in Armenian Premier League(10 wins,10 loses and 5 draws),33 different players(age 24.3±4.2,height 1.76±4.2 and weight 74±3.5)and in total 270 performances(10.8 for matches).Matches were divided in First Half(T1),Second Half(T2),Second Half Substitution(T2 Sub),Full Match,Full Match Substitution(Full Match Sub)and Total Match(Total)that include all the players detected during a games.Furthermore,all matches were divided even by quarters 0-15,15-30,30-45,45-60,60-75 and 75-90,only players that played all match were included in this analyses,in order to check the performance decreasing during the time.All data were added in an Excel Spreadsheet in order to build a database,to organize and better analyze data,cataloging events for data,results,and role of players.Average data from Armenian Premier League in comparison with literature data from European and Italian Championship show that in every parameter,the Armenian Premier League is under the average.This is obviously related to the non-high level of the Armenian football that is in fact placed at the 106°place of the FIFA ranking(update 7 June 2019).Physical data represent an indicator of performance but also of the qualitative level of the league and of individual players.For this reason,the use of the match analysis can be decisive to verify the PPM,in order to better evaluate the championships,teams,and players,in order to build an easier search and discovery of talents.

A Comparison of GaN VS GaAs System Performance

Traditionally RF power amplifiers used Gallium Arsenide(GaAs) technology which has a well behaved and understood performance. Over the past few years Gallium Nitride(GaN) technology is replacing GaAs because GaN is more efficient and has a higher power density resulting in higher power MMICs and FETs.Subject to system link budgets, we usually want to run a given amplifier as close to saturation as possible to minimize CAPEX costs. Running an amplifier closer to saturation causes many non-linear effects that can cause link performance degradation and interfere with other users.To better understand and quantify the differences between GaN and GaAs amplifiers and the impact of this on system performance, some amplifier and system measurements will be taken. The findings will be documented in a white paper.

Research on the Comparison between the Different Policies by Service Level and Inventory Level Performance of Auto Parts in N.A.C.C.(North Automobile Components Company)

As after sales services become more and more popular,particularly preven­tive or corrective maintenance,the intervention and repair of the custom­er’s goods in a timely and efficient manner ensure customer satisfaction and contribute to the establishment of brand image in the market of the suppliers.The availability and quality of spare parts are key elements of this strategy while ensuring minimal management costs.The reuse of spare parts retrieved from customer systems is a growing maintenance strategy practice which impacts the traditional spare parts supply chain.This reuse is primarily driven by extending the economic life of goods,initially re­garded as waste and therefore without added value,by transforming them into valuable spare parts that can be reused;secondly,for environmental or regulatory reasons,demanding responsibility for the treatment of products at the end of their life;and thirdly,to improve the availability of parts for maintenance,especially parts that the organization can no longer purchase or that are impacted by other issues.It also involves the analysis of their condition and their eventual return to working order as they are retrieved from the customer’s systems in a defective condition.In this paper,we will identify and classify the different customers and spare parts by estimating the critical level of rationing policy based on forecasts,identify the thresh­olds of inventory management policies,and finally,compare the different policies by service level and inventory level performance for the N.A.C.C.company.

标准钢卷尺计量比对关键技术研究

标准钢卷尺是线纹计量器具检定系统中的三等线纹标准,用于我国大量钢卷尺等带状工作线纹尺的量值传递。为了保障我国标准钢卷尺的量值一致性,并科学评估我国计量机构标准钢卷尺的测量校准能力(CMC),中国计量科学研究院主导组织了首次全国标准钢卷尺计量比对(项目编号2019-B-05)。介绍了比对的基本情况、方案及比对结果,分析了比对结果及参比装置,研究了标准钢卷尺校准中关键技术问题及主要误差来源,提出了解决问题的方法,以推动标准钢卷尺量值校准能力的提升。

四款主流语料对齐工具性能对比探析

利用实验研究的方法,以科技、旅游、文学、政治四种中英双语文本为样本,对四款语料对齐工具进行了对比研究。研究发现,从基础技术指标来看,Matecat Aligner、ABBYY Aligner 2.0、Tmxmall Aligner更有优势;从非基础技术指标来看,Matecat Aligner和DéjàVu X3 Alignment在断句准确率方面更为突出,ABBYY Aligner 2.0在对齐准确率方面要优于其他工具;ABBYY Aligner 2.0和Matecat Aligner具有纠错功能。通过具体分析发现,使用不同类型的文本,对齐质量也有所不同;不同的语料对齐工具适合不同文本的对齐。

薄膜电容器数据挖掘与分析

作为电力系统的重要元件之一,薄膜电容器因长使用寿命、高可靠性等优点而受到广泛应用,然而却极少有研究从数据角度挖掘电容器的自身属性。为了填补这一空白,本文选取收集自网络的40793条薄膜电容器数据作为分析基础,首先利用散点图和箱线图从横向角度分析了不同材料制备而成的电容器的容值、最高最低温度、交直流运行电压等差异,然后利用饼图从纵向角度对比了电容器的运行温度和应用场合,最后计算出这些性能指标的皮尔逊系数并进行了相关性分析。结果表明金属化聚丙烯材料作为目前的主流材料在容值和交直流运行电压方面比其他材料均具有显著的优势,而金属化聚苯硫醚在运行温度上占优,电容器除温度和运行电压外的各项参数之间的相关性并不显著。未来可以进一步对数据进行处理和学习,达到性能预测的效果。

基于无服务器边缘计算下的服务负载调度算法

随着边缘计算的不断发展,其在资源管理配置方面逐渐出现相关问题,无服务器计算作为一种新的方式可以有效解决边缘计算的相关问题。然而,无服务器计算不具备在分布式边缘场景中高效处理请求所需服务负载调度的能力,针对这一问题,提出了一种基于无服务器边缘计算的服务负载调度算法(service load scheduling algorithm,SLSA)。SLSA的核心是通过隐式建模充分考虑了动态变化的节点状态、负载调度器放置等影响因素来优化整体时延,然后通过改进的平滑加权轮询调度(smooth weighted round robin,SWRR)算法进行服务调度。经仿真实验分析,SLSA在资源消耗上有着明显下降,同时在单城市场景与多城市场景下均有良好的性能表现,其中在单城市场景中相对于集中式轮询调度(round robin centralized,RRC)算法提升了43.01%,在多城市场景中提升了53.81%。实验结果表明,SLSA可以有效降低资源消耗率并提升性能。

锂离子电池隔膜物理及电化学性能评价及对比

对目前被广泛使用的聚乙烯隔膜、聚丙烯隔膜、聚丙烯/聚乙烯/聚丙烯三层复合隔膜和氧化铝涂覆聚乙烯隔膜的物理性能和电化学性能进行了详细的分析对比.研究表明:氧化铝涂覆聚乙烯隔膜相比于其他三种隔膜,除拉伸强度略低于聚丙烯/聚乙烯/聚丙烯三层复合隔膜外,在耐穿刺性、热稳定性、润湿性及离子电导率等方面均具有更突出的性能.其穿刺强度达到了426.91 N·mm^(-1),并且在140℃下热处理1 h基本没有热收缩.氧化铝颗粒的亲水性提高了隔膜与电解液之间的润湿性,使得隔膜具有优异的离子电导率(0.719 mS·cm^(-1)),并且100次循环后容量保持率为91.19%,优于聚乙烯隔膜、聚丙烯隔膜、聚丙烯/聚乙烯/聚丙烯三层复合隔膜.表明氧化铝涂覆聚乙烯隔膜与其他三种隔膜相比在长循环、高功率和高安全性的锂离子电池中具有最好的应用前景.

1,2-环己烷二甲酸双酯在空气压缩机油中的应用

对比考察了邻苯二甲酸二异辛酯和1,2-环己烷二甲酸二异辛酯,邻苯二甲酸二异癸酯和1,2-环己烷二甲酸二异癸酯的理化性能及其相应成品油的综合性能,环己烷二元酸酯及其成品油40℃黏度相对略低,但是黏度指数相对较高;其高低温性能略差,但是其成品油的高温性能、黏度指数以及低温性能均表现良好。

单双电机机械变速器直连系统性能对比研究

双电机无同步器多挡机械变速器系统可以有效改善重型商用车经济性和动力性。为分析系统在最优参数下的最优性能,并综合考虑车质量和空满载差异的影响,本研究同时优化驱动电机参数和机械变速器速比参数,对比最优参数下单/双电机多挡驱动系统的经济性和动力性。结果表明:双电机驱动系统降低了车辆经济性对车质量以及空满载差异的敏感度;双电机驱动系统最高车速提高约8%,加速时间可节省约28%。

学生社会与情感能力:国际比较与中国表现

OECD发布了最新第二轮学生社会与情感能力的全球测评结果,中国济南在其中的表现值得关注。本文基于SSES2023的学生数据,从国际比较的视角出发,对中国学生在社会与情感能力上的表现及其国际地位进行全方位的分析。基于全球各城市能力均值分析的主要研究发现如下:(1)亚洲学生在社会与情感能力上表现突出。(2)济南10岁组学生在任务能力上居于全球首位,15岁组名列前茅,但成就动机得分稍低。(3)济南10岁组学生在情绪调节上居于全球前列,15岁组部分能力低于国际均值。(4)济南10岁组学生在协作能力上居于全球首位,15岁组居于前列。(5)济南10岁组学生在开放能力上的表现居于全球前列,15岁组低于国际均值。(6)济南10岁组学生在交往能力上居于全球首位,15岁组部分能力低于国际均值。基于社会与情感能力影响因素分析的主要研究发现如下:(1)济南学生在大部分影响因素指标上均优于国际均值,特别是同学关系方面居于全球首位。(2)影响济南学生任务能力的关键积极因素是成长型思维、师生关系、学校归属感和课外活动,其中学校归属感的影响效应居于全球首位。(3)影响济南学生情绪调节能力的关键因素是成长型思维、学校归属感和课外活动,其中学校归属感的影响居于全球首位。(4)影响济南学生协作能力的关键因素是成长型思维、同学关系、学校归属感和课外活动,其中成长型思维的影响效应居于全球首位。(5)影响济南学生开放能力的关键因素是成长型思维、学校归属感、课外活动和教师反馈,10岁组的学校归属感对部分开放能力的影响效应居于全球首位,15岁组的成长型思维对部分开放能力的影响效应相对偏低。(6)影响济南学生交往能力的关键因素是成长型思维、学校归属感和课外活动,其中学校归属感的影响效应在各个城市中居于前列。基于社会与情感能力对学生发展分析的主要研究发现如下:(1)济南学生的生活满意度居于全球首位,心理幸福感偏低。(2)乐观、信任、成就动机和抗压力是影响济南学生生活满意度的重要社会与情感能力。(3)乐观、信任和情绪控制是影响济南学生心理幸福感的重要社会与情感能力。(4)乐观和活力是影响济南学生健康行为的重要社会与情感能力。(5)情绪控制、抗压力和活力是影响济南学生学业焦虑的重要社会与情感能力。(6)乐观、信任和成就动机是影响济南学生关系满意度的重要社会与情感能力。(7)乐观、抗压力和果敢是影响济南学生身体意象的重要社会与情感能力。

中外医院绩效管理比较分析

目的对中外医院绩效管理进行比较分析,以期为我国医院绩效管理提供借鉴与参考。方法利用NVivo软件对CNKI、Web of Science数据库中国内外医院绩效管理相关文献分别进行内容质性比较分析。结果从“需求面-供给面-政策面”3个维度以及“宏观-中观-微观”3个层面分析我国与国外医院在绩效管理上的差异,发现国内外医院在绩效指标拟定、过程管理、外部评价、信息化程度、绩效工具应用等方面存在差异。结论我国医院绩效管理要关注患者的需求,适应卫生政策的变化,营造重视患者体验的绩效管理文化,完善以国考为导向的绩效评价体系,构建整合医院、科室和员工的绩效激励体系,不断推动公立医院绩效管理高质量发展。

稻虾共作种植模式下不同粳稻品种产量及其构成的比较

选择19个优质粳稻新品种进行稻虾共作种植模式下的比较试验。结果显示,稻虾共作种植模式下19个粳稻品种的667 m^(2)有效穗数、每穗总粒数、结实率、千粒重和产量均存在不同程度的差异,产量构成因素间的变幅均较大;所有参试品种中,香缘99的产量高于其他品种,主要得益于该品种在稻虾共作模式中的各项产量构成因素表现较为均衡,每穗粒数、结实率和千粒重指标整体比较优秀。