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Unexpected Twinning and Phase-Transition of the Indentation Standards, Their Transition Energies, and Scientific Dichotomy
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作者 Gerd Kaupp 《Journal of Applied Mathematics and Physics》 2024年第6期2119-2159,共41页
The general use of aluminium as an indentation standard for the iteration of contact heights for the determination of ISO-14577 hardness and elastic modulus is challenged because of as yet not appreciated phase-change... The general use of aluminium as an indentation standard for the iteration of contact heights for the determination of ISO-14577 hardness and elastic modulus is challenged because of as yet not appreciated phase-changes in the physical force-depth standard curve that seemed to be secured by claims from 1992. The physical and mathematical analyses with closed formulas avoid the still world-wide standardized energy-law violation by not reserving 33.33% (h2 belief) (or 20% h3/2 physical law) of the loading force and thus energy for all not depth producing events but using 100% for the depth formation is a severe violation of the energy law. The not depth producing part of the indentation work cannot be done with zero energy! Both twinning and structural phase-transition onsets and normalized phase-transition energies are now calculated without iterations but with physically correct closed arithmetic equations. These are reported for Berkovich and cubecorner indentations, including their comparison on geometric grounds and an indentation standard without mechanical twinning is proposed. Characteristic data are reported. This is the first detection of the indentation twinning of aluminium at room temperature and the mechanical twinning of fused quartz is also new. Their disqualification as indentation standards is established. Also, the again found higher load phase-transitions disqualify aluminium and fused quartz as ISO-ASTM 14577 (International Standardization Organization and American Society for Testing and Materials) standards for the contact depth “hc” iterations. The incorrect and still world-wide used black-box values for H- and Er-values (the latter are still falsely called “Young’s moduli” even though they are not directional) and all mechanical properties that depend on them. They lack relation to bulk moduli from compression experiments. Experimentally obtained and so published force vs depth parabolas always follow the linear FN = kh3/2 + Fa equation, where Fa is the axis-cut before and after the phase-transition branches (never “h2” as falsely enforced and used for H, Er and giving incorrectly calculated parameters). The regression slopes k are the precise physical hardness values, which for the first time allow for precise calculation of the mechanical qualities by indentation in relation to the geometry of the indenter tip. Exactly 20% of the applied force and thus energy is not available for the indentation depth. Only these scientific k-values must be used for AI-advises at the expense of falsely iterated indentation hardness H-values. Any incorrect H-ISO-ASTM and also the iterated Er-ISO-ASTM modulus values of technical materials in artificial intelligence will be a disaster for the daily safety. The AI must be told that these are unscientific and must therefore be replaced by physical data. Iterated data (3 and 8 free parameters!) cannot be transformed into physical data. One has to start with real experimental loading curves and an absolute ZerodurR standard that must be calibrated with standard force and standard length to create absolute indentation results. . 展开更多
关键词 Aluminium Fused Quartz Copper TWINNING Structural phase-Transitions Undue Indentation Standards data Manipulation ZerodurR Absolute Hardness
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Mechanical Fault Diagnosis Based on Band-phase-randomized Surrogate Data and Multifractal 被引量:3
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作者 ZHANG Shuqing ZHAO Yuchun ZHANG Liguo JIN Mei 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2011年第5期885-890,共6页
The vibration signals of machinery with various faults often show clear nonlinear characteristics.Currently,fractal dimension analysis as the common useful method for nonlinear signal analysis,is a kind of single frac... The vibration signals of machinery with various faults often show clear nonlinear characteristics.Currently,fractal dimension analysis as the common useful method for nonlinear signal analysis,is a kind of single fractal form,which only reflects the overall irregularity of signals,but cannot describe its local scaling properties.For comprehensive revealing of internal properties,a combinatorial method based on band-phase-randomized(BPR) surrogate data and multifractal is introduced.BPR surrogate data method is effective to eliminate nonlinearity in specified frequency band for a fault signal,which can be utilized to detect nonlinear degree in whole fault signal by nonlinear titration method,and the overall nonlinear distribution of fault signal is displayed in nonlinear characteristic curve that can be used to analyze the fault signal qualitatively.Then multifractal theory as a quantitative analysis method is used to describe geometrical characteristics and local scaling properties,and asymmetry coefficient of multifractal spectrum and multifractal entropy for fault signals are extracted as new criterions to diagnose machinery faults.Several typical faults include rotor misalignment,transversal crack,and static-dynamic rubbing fault are analyzed,and the results indicate that those faults can be distinguished by the proposed method effectively,which provides a qualitative and quantitative analysis way in the field of machinery fault diagnosis. 展开更多
关键词 fault diagnosis band-phase-randomized surrogate data nonlinear titration MULTIFRACTAL
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Unconventional phase transition of phase-change-memory materials for optical data storage 被引量:2
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作者 陈念科 李贤斌 《Chinese Physics B》 SCIE EI CAS CSCD 2019年第10期73-82,共10页
Recent years, optically controlled phase-change memory draws intensive attention owing to some advanced applications including integrated all-optical nonvolatile memory, in-memory computing, and neuromorphic computing... Recent years, optically controlled phase-change memory draws intensive attention owing to some advanced applications including integrated all-optical nonvolatile memory, in-memory computing, and neuromorphic computing. The light-induced phase transition is the key for this technology. Traditional understanding on the role of light is the heating effect. Generally, the RESET operation of phase-change memory is believed to be a melt-quenching-amorphization process. However, some recent experimental and theoretical investigations have revealed that ultrafast laser can manipulate the structures of phase-change materials by non-thermal effects and induces unconventional phase transitions including solid-to-solid amorphization and order-to-order phase transitions. Compared with the conventional thermal amorphization,these transitions have potential superiors such as faster speed, better endurance, and low power consumption. This article summarizes some recent progress of experimental observations and theoretical analyses on these unconventional phase transitions. The discussions mainly focus on the physical mechanism at atomic scale to provide guidance to control the phase transitions for optical storage. Outlook on some possible applications of the non-thermal phase transition is also presented to develop new types of devices. 展开更多
关键词 light-matter interaction phase-CHANGE MEMORY NON-THERMAL phase transition optical data storage
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Research on Data Combination for Phased-Array Ground Penetrating Radar 被引量:1
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作者 ZouLian ChenShu-zhen +1 位作者 ShiJing XiaoBo-xun 《Wuhan University Journal of Natural Sciences》 CAS 2003年第04A期1111-1115,共5页
To resolve the data combination of Phased-array Ground Penetrating Radar (PAGPR), we first build a model of PAGPR and a layered model, and then a new data combination algorithm is presented based on it. This method ca... To resolve the data combination of Phased-array Ground Penetrating Radar (PAGPR), we first build a model of PAGPR and a layered model, and then a new data combination algorithm is presented based on it. This method calculates time delay of multi-receivers, basing on the signal of the nearest receiver, then shifts other signals and adds them up, and gets one signal at last. It has been proved that this method can restrain noise, multiple waves, clutter waves and improve the precision of time location. In the end, an example is given to prove the method's efficiency. 展开更多
关键词 data combination phased-array radar ground penetrating radar signal processing
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Thermodynamic data calculation for iron phases in sulfoaluminate cementitious materials prepared using solid wastes
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作者 WenlongWang Guolin Li +1 位作者 Lizhi Zhou Changzai Ren 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2019年第12期2989-2993,共5页
The preparation of sulfoaluminate cementitious materials(SCM)is a promising way to massively utilize solid wastes.Iron phases are significant in SCM system but the thermodynamic data of some key minerals,such as6 CaO&... The preparation of sulfoaluminate cementitious materials(SCM)is a promising way to massively utilize solid wastes.Iron phases are significant in SCM system but the thermodynamic data of some key minerals,such as6 CaO·Al2 O3·2 Fe2 O3(C6 AF2)and 6 CaO·2 Al2 O3·Fe2 O3(C6 A2 F),are missing,which greatly hinders the SCM optimization in a theoretical way.This work,for the first time,calculated the standard formation enthalpy,Gibbs free energy of formation,entropy and molar heat capacity for C6 AF2 and C6 A2 F and lowered the errors to the least with the reference of C4 AF data in the literature.By building the function diagram of Gibbs free energy changes with temperature for the basic iron phase formation reactions with the obtained thermodynamic data,it is proved that the formation likeliness of C6 AF2 is higher than that of C6 A2 F,as is accordant to the literatures and verifies the correctness of obtained data.This work provides a good theoretical foundation to optimize SCM mineral system and to study relevant mechanism deeply. 展开更多
关键词 Sulfoaluminate CEMENT IRON phase THERMODYNAMIC data Gibbs free energy Solid WASTE UTILIZATION
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ASSESSMENT AND OPTIMIZATION OF THE PHASE DIAGRAMS AND THERMODYNAMIC DATA OF SOME BINARY SYSTEMS CONTAINING PRASEODYMIUM CHLORIDES
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作者 乔芝郁 王明生 +1 位作者 郑朝贵 段淑贞 《Journal of Rare Earths》 SCIE EI CAS CSCD 1990年第2期92-98,共7页
In this paper a critical assessment and optimization of the phase diagrams and thermodynamic properties of the PrCl_3-MCl(M=Li,Na)and PrCl_3-MCl_2(M=Mg,Ca,Sr,Ba) binary systems have been per- formed.The assessed and o... In this paper a critical assessment and optimization of the phase diagrams and thermodynamic properties of the PrCl_3-MCl(M=Li,Na)and PrCl_3-MCl_2(M=Mg,Ca,Sr,Ba) binary systems have been per- formed.The assessed and optimized binary phase diagrams and thermodynamic data with self consistency are a better basis for constructing multicomponent phase diagrams. 展开更多
关键词 ASSESSMENT AND OPTIMIZATION OF THE phase DIAGRAMS AND THERMODYNAMIC data OF SOME BINARY SYSTEMS CONTAINING PRASEODYMIUM CHLORIDES
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Enhancing manual P-phase arrival detection and automatic onset time picking in a noisy microseismic data in underground mines 被引量:4
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作者 Mborah Charles Ge Maochen 《International Journal of Mining Science and Technology》 EI CSCD 2018年第4期683-691,共9页
Accurate detection and picking of the P-phase onset time in noisy microseismic data from underground mines remains a big challenge. Reliable P-phase onset time picking is necessary for accurate source location needed ... Accurate detection and picking of the P-phase onset time in noisy microseismic data from underground mines remains a big challenge. Reliable P-phase onset time picking is necessary for accurate source location needed for planning and rescue operations in the event of failures. In this paper, a new technique based on the discrete stationary wavelet transform(DSWT) and higher order statistics is proposed for processing noisy data from underground mines. The objectives of this method are to(i) improve manual detection and picking of P-phase onset; and(ii) provide an automatic means of detecting and picking P-phase onset time accurately. The DSWT is first used to filter the signal over several scales. The manual P-phase onset detection and picking are then obtained by computing the signal energy across selected scales with frequency bands that capture the signal of interest. The automatic P-phase onset, on the other hand, is achieved by using skewness-and kurtosis-based criterion applied to selected scales in a time-frequency domain. The method was tested using synthetic and field data from an underground limestone mine. Results were compared with results obtained by using the short-term to long-term average(STA/LTA) ratio and that by Reference Ge et al.(2009). The results show that the method provides a more reliable estimate of the P-phase onset arrival than the STA/LTA method when the signal to noise ratio is very low. Also, the results obtained from the field data matched accurately with the results from Reference Ge et al.(2009). 展开更多
关键词 时间频率 顺序统计 石灰石矿 数据获得 信号 偏斜度 参考书 STA
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A ROBUST PHASE-ONLY DIRECT DATA DOMAIN ALGORITHM BASED ON GENERALIZED RAYLEIGH QUOTIENT OPTIMIZATION USING HYBRID GENETIC ALGORITHM 被引量:2
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作者 Shao Wei Qian Zuping Yuan Feng 《Journal of Electronics(China)》 2007年第4期560-566,共7页
A robust phase-only Direct Data Domain Least Squares (D3LS) algorithm based on gen- eralized Rayleigh quotient optimization using hybrid Genetic Algorithm (GA) is presented in this letter. The optimization efficiency ... A robust phase-only Direct Data Domain Least Squares (D3LS) algorithm based on gen- eralized Rayleigh quotient optimization using hybrid Genetic Algorithm (GA) is presented in this letter. The optimization efficiency and computational speed are improved via the hybrid GA com- posed of standard GA and Nelder-Mead simplex algorithms. First, the objective function, with a form of generalized Rayleigh quotient, is derived via the standard D3LS algorithm. It is then taken as a fitness function and the unknown phases of all adaptive weights are taken as decision variables. Then, the nonlinear optimization is performed via the hybrid GA to obtain the optimized solution of phase-only adaptive weights. As a phase-only adaptive algorithm, the proposed algorithm is sim- pler than conventional algorithms when it comes to hardware implementation. Moreover, it proc- esses only a single snapshot data as opposed to forming sample covariance matrix and operating matrix inversion. Simulation results show that the proposed algorithm has a good signal recovery and interferences nulling performance, which are superior to that of the phase-only D3LS algorithm based on standard GA. 展开更多
关键词 混合遗传算法 相位优化 Nelder-Mead单纯形算法 鲁棒性
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基于地震频相融合的智能化高分辨率反演
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作者 杨培杰 《石油地球物理勘探》 EI CSCD 北大核心 2024年第3期548-557,共10页
目前的地震反演主要以模型驱动为主,对噪声较敏感,反演结果的分辨率往往较低,通常只使用地震数据的振幅信息,没有充分利用相位信息。研究表明,波阻抗和地震振幅、相位的相关性较强,因此联合应用振幅谱和相位谱可以有效减小反演结果的多... 目前的地震反演主要以模型驱动为主,对噪声较敏感,反演结果的分辨率往往较低,通常只使用地震数据的振幅信息,没有充分利用相位信息。研究表明,波阻抗和地震振幅、相位的相关性较强,因此联合应用振幅谱和相位谱可以有效减小反演结果的多解性。为此,结合深度学习与地震数据的频(振幅谱)、相(相位谱)信息,提出基于数据驱动的频相智能波阻抗反演,有效提高了反演结果的分辨率和精度。具体步骤为:(1)基于高分辨率时频分析提取地震道的频相信息;(2)应用图像处理技术融合频相信息;(3)结合频相信息和地层波阻抗制作数据标签对,用数据标签对训练优选的深度网络;(4)提取待反演三维地震数据的频相信息并输入训练好的深度网络,即可得到高分辨率波阻抗反演结果。与现有的深度学习地震反演方法相比,所提方法主要创新点在于首次在地震反演中同时应用了地震数据的频相信息。模型测试结果表明,频相信息的联合应用有效地减小了反演结果的多解性,提高了反演精度。实际应用结果表明,与传统的稀疏脉冲反演相比,所提方法提高了反演结果的纵向分辨率,益于进一步推广、应用。 展开更多
关键词 频相信息 数据驱动 深度学习 高分辨率反演
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Wigner Frequency Point Slice Analysis of Superposition Data for Phased-Array Ground Penetrating Radar 被引量:2
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作者 ZOULian CHENShu-zhen +2 位作者 YANGShen WEIDan XIAOBo-xun 《Wuhan University Journal of Natural Sciences》 EI CAS 2004年第6期904-908,共5页
According to the frequency property of Phasedarray ground penetrating radar (PGPR), this paper gives a frequency point slice method based on Wigner time-frequency analysis. This method solves the problem of analysis f... According to the frequency property of Phasedarray ground penetrating radar (PGPR), this paper gives a frequency point slice method based on Wigner time-frequency analysis. This method solves the problem of analysis for the PGPR's superposition data and makes detecting outcome simpler and detecting target more recognizable. At last, the analytical results of road test data of the Three Gorges prove the analytical method efficient. Key words phased-array ground penetrating radar - wigner time-frequency analysis - superposition data - object identification CLC number TN 715.7 Foundation item: Supported by the National Nature Science Foundation of China (50099620) and 863 Program Foundation of China (2001AA132050-03)Biography: ZOU Lian (1975-), male, Ph. D candidate, research direction: signal processing. 展开更多
关键词 phased-array ground penetrating radar wigner time-frequency analysis superposition data object identification
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Method of Phase Diagrams for the Analysis of Seism-Acoustical Spatial-Time Monitoring Data in Oil Wells
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作者 Olga Hachay Oleg Khachay 《Open Journal of Geology》 2018年第9期874-882,共9页
Experimental and theoretical studies of the mechanisms of vibration stimulation of oil recovery in watered fields lead to the conclusion that resonance oscillations develop in fractured-block formations. These oscilla... Experimental and theoretical studies of the mechanisms of vibration stimulation of oil recovery in watered fields lead to the conclusion that resonance oscillations develop in fractured-block formations. These oscillations, caused by weak but long-lasting and frequency-stable influences, create the conditions for ultrasonic wave’s generation in the layers, which are capable of destroying thickened oil membranes in reservoir cracks. For fractured-porous reservoirs in the process of exploitation by the method of water high-pressure oil displacement, the possibility of intensifying ultrasonic vibrations can have an important technological significance. Even a very weak ultrasound can destroy, over a long period of time, the viscous oil membranes formed in the cracks between the blocks, which can be the reason for lowering the permeability of the layers and increasing the oil recovery. To describe these effects, it is necessary to consider the wave process in a hierarchically blocky environment and theoretically simulate the mechanism of the appearance of self-oscillations under the action of relaxation shear stresses. For the analysis of seism acoustic response in time on fixed intervals along the borehole an algorithm of phase diagrams of the state of many-phase medium is suggested. 展开更多
关键词 phase DIAGRAMS METHOD of ANALYSIS SPACE-TIME Monitoring data Oil WELLS State of the Two Component MEDIUM
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基于相移的三维扫描数据自动配准方法研究
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作者 刘颖 刘宝华 《自动化技术与应用》 2024年第1期39-43,共5页
在三维扫描过程中,常因受到设备自身因素与点云丢失的限制而难以一次性完成数据采集。为准确实现物体三维模型重构,提出基于相移的三维扫描数据自动配准方法。首先设置旋转台,利用非接触式结构光方法获得转动轴的有关信息,从而采集目标... 在三维扫描过程中,常因受到设备自身因素与点云丢失的限制而难以一次性完成数据采集。为准确实现物体三维模型重构,提出基于相移的三维扫描数据自动配准方法。首先设置旋转台,利用非接触式结构光方法获得转动轴的有关信息,从而采集目标点云数据。在此基础上,结合任意一点与其周围点曲率信息建立曲率图,对全部顶点做曲率运算,将数据划分为连续子块,计算每个子块中平均值和方差,从而提取关键特征点。然后获取两幅具有部分重叠关系图像的相对位移,采用交叉功率谱的傅里叶变换完成位移估计,再通过构造与组合点对、粗略与精确配准去除噪声点,实现三维扫描数据自动配准。仿真实验表明,该方法能够在确保配准精度的同时提高配准方法的运行效率,可靠性和实用性较强。 展开更多
关键词 相移 三维扫描数据 数据配准 非接触采集 傅里叶变换 曲率图
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用于新型符号的频偏补偿和解调的算法与电路
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作者 林敏 史靖炜 +2 位作者 丁福建 姜帆 陈潇 《哈尔滨工业大学学报》 EI CAS CSCD 北大核心 2024年第5期121-129,共9页
为提高传统脉冲位置调制(pulse position modulation,PPM)符号的频谱效率,提出了一种新型码片内4-PPM符号调制方法,在实现1 Gbit/s通信速率的同时,又大大减少所需频谱资源。可在解调时,该符号调制的误码率性能受到发射端时钟和接收端本... 为提高传统脉冲位置调制(pulse position modulation,PPM)符号的频谱效率,提出了一种新型码片内4-PPM符号调制方法,在实现1 Gbit/s通信速率的同时,又大大减少所需频谱资源。可在解调时,该符号调制的误码率性能受到发射端时钟和接收端本地时钟之间的频率偏移的极大影响。针对此问题,又提出了一种在模拟域对该符号进行频偏补偿,并实现符号同步和高速数据解调的算法与电路。该电路系统通过消除接收数据和本地时钟的初始相差、提取两者的频偏信息、周期性改变本地时钟的瞬时相位3步实现频偏补偿,并同时在第3步利用本地时钟对接收数据进行解调。为提高相位插值器(phase interpolator,PI)的线性度,本文将延迟锁定环与PI相结合。在2π的插值范围内,实现插值区间32个,插值步长992个,分辨率2.016 ps,最大差分非线性(differential nonlinearity,DNL)0.183°,最大积分非线性(integral nonlinearity,INL)0.325°。此外,本文提出的相位控制算法有效避免了由电流毛刺所引起的输出相位突变。电路基于UMC 40 nm CMOS RF LP工艺进行设计与仿真。仿真结果表明:本文所提出的算法与电路,在典型工艺角下,将接收数据和本地时钟间的50×10^(-6)频率偏差度降至1.03×10^(-6),频偏补偿准确度达到97.94%,并实现1 Gbit/s的解调速率。该方法对高速PPM数据同步与解调具有良好的工程应用价值。 展开更多
关键词 脉冲位置调制 码片内脉冲位置调制 符号同步 频偏补偿 数据解调 相位插值器 延迟锁定环
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高明利教授治疗痛风性关节炎急性期的用药规律
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作者 汪敏 高明利 +3 位作者 齐庆 孙蓬远 关蕊 张晓雨 《风湿病与关节炎》 2024年第1期14-18,39,共6页
目的:应用数据挖掘的科研方法分析高明利教授辨治痛风性关节炎急性期的药物组方原则及用药规律,为临床用药提供科学的依据。方法:收集2017年1月15日至2021年12月15日在辽宁中医药大学附属医院风湿科高明利教授门诊就诊的206例痛风性关... 目的:应用数据挖掘的科研方法分析高明利教授辨治痛风性关节炎急性期的药物组方原则及用药规律,为临床用药提供科学的依据。方法:收集2017年1月15日至2021年12月15日在辽宁中医药大学附属医院风湿科高明利教授门诊就诊的206例痛风性关节炎急性期患者的病例数据及首诊处方,对性别、年龄、四气五味、归经、药物功效、药物的频次进行分析;采用软件IBM SPSS Modeler 18.0、SPSS 26.0对数据进行复杂网络分析、关联规则分析及聚类分析。结果:对206例病例数据进行整理,男女比为40∶1,涉及药物135味,频次最高的药物为萆薢、泽泻、知母、薏苡仁;四气多为寒、平、温;五味多为苦、甘、辛,归经多为肾、胃、肝三经。药物类别清热药、利水渗湿药、祛风湿药应用居多。关联规则分析得出常用药对及药物组,高频药物聚类分析共聚5大类。结论:高明利教授治疗痛风性关节炎急性期以清热药、利水渗湿药及祛风湿药为基准,重用清热药与利水渗湿药,用以清热利湿、通络止痛,在性味归经上重用苦寒之品,多选择从肾经上加以干预,治疗多以清热利湿为中心,佐用健脾、活血、引经、补益、解表、散结、止痛等药物。 展开更多
关键词 痛风性关节炎 急性期 数据挖掘 中药 用药规律 高明利
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基于GA的RBF神经网络气液两相流持液率预测模型优化
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作者 廖锐全 李龙威 +2 位作者 王伟 马斌 潘元 《长江大学学报(自然科学版)》 2024年第2期91-100,共10页
为了提高气液两相流持液率预测精度,针对传统径向基函数(RBF)神经网络预测气液两相流持液率网络拓扑结构困难和收敛速度慢等问题,提出一种基于遗传算法(GA)优化径向基函数神经网络的气液两相流持液率预测模型。通过系统聚类算法和灰色... 为了提高气液两相流持液率预测精度,针对传统径向基函数(RBF)神经网络预测气液两相流持液率网络拓扑结构困难和收敛速度慢等问题,提出一种基于遗传算法(GA)优化径向基函数神经网络的气液两相流持液率预测模型。通过系统聚类算法和灰色关联度分析(GRA)对收集的实验数据进行处理,优选出最优模型特征,同时结合遗传算法确定了RBF神经网络结构参数。基于室内实验数据进行训练,并与常用于持液率预测的反向传播(BP)神经网络、GA-BP神经网络及RBF神经网络进行对比,评估了模型的准确性及可行性。结果表明:GA-RBF神经网络模型均方误差为0.0017,均方根误差为0.0416,平均绝对误差为0.0281,拟合度为0.9483。相较于其他神经网络模型,该预测模型表现出更高的计算精度和更强的泛化能力。 展开更多
关键词 持液率 气液两相流 RBF神经网络 遗传算法 数据清洗
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基于数据挖掘探讨肖承悰治疗黄体功能不全性不孕的用药规律
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作者 柯欣吟 汤玲 肖承悰(指导) 《中国中医药信息杂志》 CAS CSCD 2024年第5期42-46,共5页
目的利用数据挖掘技术分析肖承悰教授治疗黄体功能不全性不孕的用药规律,探讨其临证经验。方法收集2007年12月-2021年12月肖承悰教授门诊患者病历资料,筛选后录入FangNet平台,通过频次统计、协同性分级、药物-症状关联、药物聚类、性味... 目的利用数据挖掘技术分析肖承悰教授治疗黄体功能不全性不孕的用药规律,探讨其临证经验。方法收集2007年12月-2021年12月肖承悰教授门诊患者病历资料,筛选后录入FangNet平台,通过频次统计、协同性分级、药物-症状关联、药物聚类、性味归经等对用药规律进行分析。结果共纳入病案90则,涉及患者90例、处方270首。肖承悰教授治疗黄体功能不全性不孕高频药物包括桑寄生、续断、巴戟天、茯苓、女贞子等,药性多温、平,药味以甘为主,主归肾经、肝经。药物聚类分析显示,桑寄生、续断、巴戟天为主要药对。结论肖承悰教授认为,黄体功能不全性不孕的病机为肾阳亏虚,治以温肾助阳为主,兼以养肝健脾,调理冲任;用药强调药性平和,临床中擅用药对,展现了燕京萧氏妇科“和合灵动”的学术思想。 展开更多
关键词 不孕症 黄体功能不全 数据挖掘 肖承悰 用药规律
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电力电缆局放在线监测神经网络自动识别精度的提升方法
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作者 孙廷玺 方义治 +4 位作者 郑晓东 雷小月 姜志彬 周智鹏 陈敏 《高压电器》 CAS CSCD 北大核心 2024年第7期210-220,共11页
为了尽可能降低电缆线路局放在线监测系统装置运行中对局放信号识别的误判误报的可能性,对局放的判读机理和识别精度进行了改进和提升。基于现场运行系统回收的数万个疑似电缆内部局放的告警记录数据进行了分析分类,对判别程序中沿用的... 为了尽可能降低电缆线路局放在线监测系统装置运行中对局放信号识别的误判误报的可能性,对局放的判读机理和识别精度进行了改进和提升。基于现场运行系统回收的数万个疑似电缆内部局放的告警记录数据进行了分析分类,对判别程序中沿用的局放自动逻辑判别程序追加了相间信号相关性过滤程序,对既有的神经网络在构造上作了优选优化,对神经网络学习数据的前置处理进行了改进。对改进提升后的局放判别程序采用了包括现场记录,模拟信号发生器和人工局放模型加电压实验的3种局放数据进行检验。结果表明,改进提升后的局放判别程序不但能够使现场的非局放告警数据的告警率降低到5%的期待水平,同时也提高了识别人工模拟产生的各种类型局放信号的准确性,大大降低了局放在线监测系统误判误报的可能性。 展开更多
关键词 电缆 局部放电 在线监测 相间关系 神经网络 学习数据 前置处理 识别精度
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Phase-Type分布数据拟合方法综述 被引量:3
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作者 黄卓 潘晓 郭波 《系统工程与电子技术》 EI CSCD 北大核心 2008年第11期2167-2174,共8页
Phase-Type(PH)分布具有良好的通用性和易于进行解析处理的特性,因此PH分布已经成为随机模型解析分析的重要工具。PH分布的数据拟合方法是应用PH分布的基础,分析了PH分布数据拟合的矩估计方法、极大似然估计方法及PH分布拟合重尾分布数... Phase-Type(PH)分布具有良好的通用性和易于进行解析处理的特性,因此PH分布已经成为随机模型解析分析的重要工具。PH分布的数据拟合方法是应用PH分布的基础,分析了PH分布数据拟合的矩估计方法、极大似然估计方法及PH分布拟合重尾分布数据方法的研究现状,并讨论了PH分布数据拟合方法进一步的研究方向。 展开更多
关键词 PH分布 数据拟合 矩估计 极大似然估计 重尾分布
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基于时序拓扑数据分析的电力电缆局部放电模式识别
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作者 李自强 李睿 孙抗 《电子科技大学学报》 EI CAS CSCD 北大核心 2024年第3期440-446,共7页
在电力电缆局部放电(PD)模式识别时,相位图谱以及统计特征往往因区分度不足而影响识别精度。为此,提出了一种基于时序拓扑数据分析(TDA)的局放特征提取和识别方法。首先,提出一种符号熵和粒子群优化(PSO)相结合的重构参数选择方法,将预... 在电力电缆局部放电(PD)模式识别时,相位图谱以及统计特征往往因区分度不足而影响识别精度。为此,提出了一种基于时序拓扑数据分析(TDA)的局放特征提取和识别方法。首先,提出一种符号熵和粒子群优化(PSO)相结合的重构参数选择方法,将预处理后的局放时域信号进行相空间重构,并生成三维局放数据点云;然后,基于TDA方法提取持续同调特征,据此生成持续散点图及持续条形码,计算并可视化表达为贝蒂曲线;最后,将贝蒂曲线输入1D-CNN模型,对4种典型局放缺陷模式进行识别并开展对比实验。实验结果表明,该方法对相空间重构时延参数的选取更加准确,且TDA特征具备良好的区分度,相比其他以相位图谱及统计特征为输入的模型,该方法整体识别准确率最高可提升15.34%,达到98.55%。 展开更多
关键词 局部放电 模式识别 相空间重构 拓扑数据分析 卷积神经网络
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中药治疗支气管哮喘慢性持续期的用药规律及作用机制
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作者 龚春霞 潘凌宇 +3 位作者 孙叶红 韩燕全 汪电雷 汪永忠 《亚太传统医药》 2024年第6期174-180,共7页
目的:基于数据挖掘探讨中药治疗支气管哮喘慢性持续期的用药规律,借助网络药理学技术探究核心药对治疗疾病的作用机制。方法:检索2010年1月-2023年1月中国知网、万方和维普数据库,收集文献中运用中医药为主治疗支气管哮喘慢性持续期有... 目的:基于数据挖掘探讨中药治疗支气管哮喘慢性持续期的用药规律,借助网络药理学技术探究核心药对治疗疾病的作用机制。方法:检索2010年1月-2023年1月中国知网、万方和维普数据库,收集文献中运用中医药为主治疗支气管哮喘慢性持续期有效的方剂,采用频次统计、关联规则分析用药规律及核心药对。利用网络药理学探索核心药对的作用机制,并使用分子对接进行验证。结果:筛选出治疗支气管哮喘慢性持续期的处方61首,中药133味。关联规则分析出三项关联规则20条,置信度和支持度最高的药对为黄芪-白术-陈皮,确定其主要活性成分为山柰酚、槲皮素、7-O-methylisomucronulatol、柚皮素和芒柄花黄素,核心靶点有鹅丝氨酸/苏氨酸蛋白激酶(AKT)1、肿瘤坏死因子(TNF)、白介素(IL)-6、肿瘤蛋白p53(TP53)和IL-1β,主要作用于PI3K-AKT信号通路、MAPK信号通路、TNF信号通路和IL-17信号通路。结论:中药治疗支气管哮喘慢性持续期的核心药对组合可通过多成分、多靶点、多通路发挥治疗作用,为临床用药提供理论依据。 展开更多
关键词 支气管哮喘 慢性持续期 中药 数据挖掘 网络药理学 分子对接
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