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Random testing for system-level functional verification of system-on-chip 被引量:4
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作者 Ma Qinsheng Cao Yang +1 位作者 Yang Jun Wang Min 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2009年第6期1378-1383,共6页
In order to deal with the limitations during the register transfer level verification, a new functional verification method based on the random testing for the system-level of system-on-chip is proposed.The validity o... In order to deal with the limitations during the register transfer level verification, a new functional verification method based on the random testing for the system-level of system-on-chip is proposed.The validity of this method is proven theoretically.Specifically, testcases are generated according to many approaches of randomization.Moreover, the testbench for the system-level verification according to the proposed method is designed by using advanced modeling language.Therefore, under the circumstances that the testbench generates testcases quickly, the hardware/software co-simulation and co-verification can be implemented and the hardware/software partitioning planning can be evaluated easily.The comparison method is put to use in the evaluation approach of the testing validity.The evaluation result indicates that the efficiency of the partition testing is better than that of the random testing only when one or more subdomains are covered over with the area of errors, although the efficiency of the random testing is generally better than that of the partition testing.The experimental result indicates that this method has a good performance in the functional coverage and the cost of testing and can discover the functional errors as soon as possible. 展开更多
关键词 VLSI circuit VERIFICATION random process FUNCTION testING SYSTEM-ON-CHIP system-level.
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Output Type Guided Random Test Case Generation for String Validation Routines
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作者 Chenhui Cui Rubing Huang +1 位作者 Jinfu Chen Yunan Zhou 《Tsinghua Science and Technology》 2025年第6期2467-2486,共20页
String validation routines have been widely used in many real-world applications,such as email validation and postcode validation.String test cases are adopted to test these validation routines,to identify potential d... String validation routines have been widely used in many real-world applications,such as email validation and postcode validation.String test cases are adopted to test these validation routines,to identify potential defects and security risks.Random Testing(RT)is a well-known testing approach to randomly generate string test cases from the input domain(i.e.,the set of all possible test inputs),which is simple to implement at a low cost.However,its testing effectiveness may be unsatisfactory for string validation routines.The main reason for this is that RT may have a high probability to generate invalid rather than valid string test cases,due to its randomness property.This research proposes a new RT approach based on the output types(i.e.,valid and invalid strings)for string validation routines,namely Output-type-guided Random Testing(RTO),which attempts to randomly generate both valid and invalid string test cases with a certain probability.This research performed an empirical study involving several real-world string validation routines collected from ten Java open-source projects,to investigate and compare testing performances of RT-O against the previous two widely-used RT methods.The results show that the generated string test cases by RT-O outperform test cases generated by other RT methods. 展开更多
关键词 software testing random testing(RT) string validation routines string test cases test case generation
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Random-Like Testing of Very Large Scale Integration Circuit 被引量:2
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作者 Xu Shiyi (School of Computer Engineering and Science) 《Advances in Manufacturing》 SCIE CAS 1998年第4期21-25,共5页
A new approach to improve the test efficiency of random testing is presented in this paper. In conventional random testing, each test pattern is selected randomly regardless of the tests previously generated. This pap... A new approach to improve the test efficiency of random testing is presented in this paper. In conventional random testing, each test pattern is selected randomly regardless of the tests previously generated. This paper introduces the concept of random like testing. The method provided appears to have the same concepts as used in random testing,but actually takes an opposite way to it in order to improve the efficiency of random testing.In a random like testing sequence, the total distance among all test patterns is chosen to be maximal so that the fault sets detected by one test pattern are as different as possible from that detected by the tests previously applied. The procedure to construct a random like testing sequence (RLTS) is described in detail. Theorems to justify the effectiveness and usefulness of the procedure presented are developed. Experimental results on benchmark circuits as well as on other circuit are also given to evaluate the performance of the new approach. 展开更多
关键词 random testing fault coverage Hamming distance total Hamming distance
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Probabilistic Models for Estimation of Random and Pseudo-Random Test Length
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作者 向东 魏道政 陈世松 《Journal of Computer Science & Technology》 SCIE EI CSCD 1992年第2期164-174,共11页
A new probabilistic testability measure is presented to ease test length analyses of random testing and pseudorandom testing.The testability measure given in this paper is oriented to signal conflict of reconvergent f... A new probabilistic testability measure is presented to ease test length analyses of random testing and pseudorandom testing.The testability measure given in this paper is oriented to signal conflict of reconvergent fanouts.Test length analyses in this paper are based on a hard fault set,calculations of which are practicable and simple.Experimental results have been obtained to show the accuracy of this test length analyser in comparison with that of Savir,Chin and McCluskey,and Wunderlich by using a pseudorandom test generator combined with exhaustive fault simulation. 展开更多
关键词 test Probabilistic Models for Estimation of random and Pseudo-random test Length LENGTH test
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Control method for multi-input multi-output non-Gaussian random vibration test with cross spectra consideration 被引量:12
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作者 Ronghui ZHENG Huaihai CHEN Xudong HE 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2017年第6期1895-1906,共12页
A control method for Multi-Input Multi-Output(MIMO) non-Gaussian random vibration test with cross spectra consideration is proposed in the paper. The aim of the proposed control method is to replicate the specified ... A control method for Multi-Input Multi-Output(MIMO) non-Gaussian random vibration test with cross spectra consideration is proposed in the paper. The aim of the proposed control method is to replicate the specified references composed of auto spectral densities, cross spectral densities and kurtoses on the test article in the laboratory. It is found that the cross spectral densities will bring intractable coupling problems and induce difficulty for the control of the multioutput kurtoses. Hence, a sequential phase modification method is put forward to solve the coupling problems in multi-input multi-output non-Gaussian random vibration test. To achieve the specified responses, an improved zero memory nonlinear transformation is utilized first to modify the Fourier phases of the signals with sequential phase modification method to obtain one frame reference response signals which satisfy the reference spectra and reference kurtoses. Then, an inverse system method is used in frequency domain to obtain the continuous stationary drive signals. At the same time, the matrix power control algorithm is utilized to control the spectra and kurtoses of the response signals further. At the end of the paper, a simulation example with a cantilever beam and a vibration shaker test are implemented and the results support the proposed method very well. 展开更多
关键词 Cross spectra Kurtosis control Multi-input multi-output NON-GAUSSIAN random vibration test
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TESTING FOR VARYING DISPERSION OF LONGITUDINAL BINOMIAL DATA IN NONLINEAR LOGISTIC MODELS WITH RANDOM EFFECTS 被引量:2
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作者 林金官 韦博成 《Acta Mathematica Scientia》 SCIE CSCD 2004年第4期559-568,共10页
In this paper, it is discussed that two tests for varying dispersion of binomial data in the framework of nonlinear logistic models with random effects, which are widely used in analyzing longitudinal binomial data. O... In this paper, it is discussed that two tests for varying dispersion of binomial data in the framework of nonlinear logistic models with random effects, which are widely used in analyzing longitudinal binomial data. One is the individual test and power calculation for varying dispersion through testing the randomness of cluster effects, which is extensions of Dean(1992) and Commenges et al (1994). The second test is the composite test for varying dispersion through simultaneously testing the randomness of cluster effects and the equality of random-effect means. The score test statistics are constructed and expressed in simple, easy to use, matrix formulas. The authors illustrate their test methods using the insecticide data (Giltinan, Capizzi & Malani (1988)). 展开更多
关键词 Longitudinal binomial data logistic regression nonlinear models power calculation random effects score test varying dispersion
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EMPIRICAL BAYES TEST PROBLEMS OF VARIANCE COMPONENTS IN RANDOM EFFECTS MODEL 被引量:3
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作者 韦来生 张伟平 《Acta Mathematica Scientia》 SCIE CSCD 2005年第2期274-282,共9页
Bayes decision rule of variance components for one-way random effects model is derived and empirical Bayes (EB) decision rules are constructed by kernel estimation method. Under suitable conditions, it is shown that t... Bayes decision rule of variance components for one-way random effects model is derived and empirical Bayes (EB) decision rules are constructed by kernel estimation method. Under suitable conditions, it is shown that the proposed EB decision rules are asymptotically optimal with convergence rates near O(n-1/2). Finally, an example concerning the main result is given. 展开更多
关键词 Empirical Bayes test variance components random effects model convergence rates
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Matrix Power Control Algorithm for Multi-input Multi-output Random Vibration Test 被引量:13
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作者 CUI Xuli CHEN Huaihai HE Xudong JIANG Shuangyan 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2011年第6期741-748,共8页
Both auto-power spectrum and cross-power spectrum need to be controlled in multi-input multi-output (MIMO) random vibration test. During the control process with the difference control algorithm (DCA), a lower tri... Both auto-power spectrum and cross-power spectrum need to be controlled in multi-input multi-output (MIMO) random vibration test. During the control process with the difference control algorithm (DCA), a lower triangular matrix is derived from Cholesky decomposition of a reference spectrum matrix. The diagonal elements of the lower triangular matrix (DELTM) may become negative. These negative values have no meaning in physical significance and can cause divergence of auto-power spectrum control. A proportional root mean square control algorithm (PRMSCA) provides another method to avoid the divergence caused by negative values of DELTM, but PRMSCA cannot control the cross-power spectrum. A new control algorithm named matrix power control algorithm (MPCA) is proposed in the paper. MPCA can guarantee that DELTM is always positive in the auto-power spectrum control. MPCA can also control the cross-power spectrum. After these three control algorithms are analyzed, three-input three-output random vibration control tests are implemented on a three-axis vibration shaker. The results show the validity of the proposed MPCA. 展开更多
关键词 multi-input multi-output environmental testing vibration control random vibration auto-power spectrum cross-power spectrum
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Use of Random Regression Test-Day Model to Estimate Genetic Parameters of Milk Yield in Holstein Cows
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作者 Yaser Fazel Masoud Asadi Fozi +4 位作者 Ali Esmailizadeh Fatemeh Fazel Ahmad Massoud Niazi Shahpoor Rahmati Mohammad Ibrahim Qasimi 《Open Journal of Animal Sciences》 2018年第1期27-38,共12页
(Co) variance components and genetic parameters were estimated for milk yield of Iranian Holstein cows. A total number of 68,945 milk test-day records of first, second and third lactations of 8515 animals from 100 sir... (Co) variance components and genetic parameters were estimated for milk yield of Iranian Holstein cows. A total number of 68,945 milk test-day records of first, second and third lactations of 8515 animals from 100 sires and 7743 dams originated from 34 herds collected during 2007 to 2009 by Iranian animal breeding center were used. The ASReml computer program was used to analyze the milk test-day records using the random regression procedure. Herd test date (HTD), milking times per day (milking frequency), number of lactations, year of birth, year of calving, age of animal at calving and days in milk (DIM) considered as fixed effects and additive genetic effects and animal permanent environmental effects were considered as the random effects. Additive genetic variance, animal permanent environment variance, residual variance, phenotypic variance, heritability and repeatability were estimated during different months of lactation between 5.7 - 19.6, 15.3 - 27.1, 31.4 - 17.2, 45.8 - 64.83, 0.1 - 0.32 and 0.4 - 0.6, respectively. Genetic correlation and phenotypic correlation were also estimated between months of lactation in range of -0.35 - 0.98 and 0.03 - 0.67, respectively. Genetic correlation and phenotypic correlation both showed the same changing pattern and they decreased as the interval between months of lactation increased. 展开更多
关键词 GENETIC Parameters random Regression Model test-Day RECORDS MILK Yield HOLSTEIN COWS
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TESTING OF CORRELATION AND HETEROSCEDASTICITY IN NONLINEAR REGRESSION MODELS WITH DBL(p,q,1) RANDOM ERRORS
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作者 刘应安 韦博成 《Acta Mathematica Scientia》 SCIE CSCD 2008年第3期613-632,共20页
Chaos theory has taught us that a system which has both nonlinearity and random input will most likely produce irregular data. If random errors are irregular data, then random error process will raise nonlinearity (K... Chaos theory has taught us that a system which has both nonlinearity and random input will most likely produce irregular data. If random errors are irregular data, then random error process will raise nonlinearity (Kantz and Schreiber (1997)). Tsai (1986) introduced a composite test for autocorrelation and heteroscedasticity in linear models with AR(1) errors. Liu (2003) introduced a composite test for correlation and heteroscedasticity in nonlinear models with DBL(p, 0, 1) errors. Therefore, the important problems in regression model axe detections of bilinearity, correlation and heteroscedasticity. In this article, the authors discuss more general case of nonlinear models with DBL(p, q, 1) random errors by score test. Several statistics for the test of bilinearity, correlation, and heteroscedasticity are obtained, and expressed in simple matrix formulas. The results of regression models with linear errors are extended to those with bilinear errors. The simulation study is carried out to investigate the powers of the test statistics. All results of this article extend and develop results of Tsai (1986), Wei, et al (1995), and Liu, et al (2003). 展开更多
关键词 DBL(p Q 1) random errors nonlinear regression models score test HETEROSCEDASTICITY CORRELATION
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Robustness self-testing of states and measurements in the prepare-and-measure scenario with 3 → 1 random access code
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作者 Shi-Hui Wei Fen-Zhuo Guo +1 位作者 Xin-Hui Li Qiao-Yan Wen 《Chinese Physics B》 SCIE EI CAS CSCD 2019年第7期144-151,共8页
Recently, Tavakoli et al.proposed a self-testing scheme in the prepare-and-measure scenario, showing that self-testing is not necessarily based on entanglement and violation of a Bell inequality [Phys.Rev.A 98 062307(... Recently, Tavakoli et al.proposed a self-testing scheme in the prepare-and-measure scenario, showing that self-testing is not necessarily based on entanglement and violation of a Bell inequality [Phys.Rev.A 98 062307(2018)].They realized the self-testing of preparations and measurements in an N → 1(N ≥ 2) random access code(RAC), and provided robustness bounds in a 2 → 1 RAC.Since all N → 1 RACs with shared randomness are combinations of 2 → 1 and 3 → 1 RACs, the3 → 1 RAC is just as important as the 2 → 1 RAC.In this paper, we find a set of preparations and measurements in the3 → 1 RAC, and use them to complete the robustness self-testing analysis in the prepare-and-measure scenario.The method is robust to small but inevitable experimental errors. 展开更多
关键词 ROBUSTNESS SELF-testING prepare-and-measure SCENARIO 3 1 random access CODE
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随机信息自由度超声检测信号压缩及参数重构方法研究
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作者 宋寿鹏 沈宏泽 《压电与声光》 北大核心 2026年第1期37-44,共8页
针对超声波长时间自动检测复杂构件缺陷时,界面与缺陷回波相互干涉使回波信号呈现随机多峰性,难以实时准确地解析缺陷信息,且事后解读也将带来海量数据存储的技术瓶颈,提出了一种随机信息自由度超声检测信号的压缩及参数重构方法。通过... 针对超声波长时间自动检测复杂构件缺陷时,界面与缺陷回波相互干涉使回波信号呈现随机多峰性,难以实时准确地解析缺陷信息,且事后解读也将带来海量数据存储的技术瓶颈,提出了一种随机信息自由度超声检测信号的压缩及参数重构方法。通过先验能量分布,自适应匹配采样核的频域支撑区间及参数,将随机多峰回波脉冲流通过自适应采样核调制,再以低速率对其进行等间隔稀疏采样,最后通过零化滤波器重构多峰回波信号幅值与时延特征。以钢轨缺陷超声检测为例,相较于奈奎斯特采样法,本文所提方法在保留轨头、轨腰、轨底、人工缺陷及二次回波信息的同时,数据量减少了90%。 展开更多
关键词 超声检测 随机信息自由度 压缩采样 参数重构
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Predicting test data of aluminum honeycomb sandwich board based on volterra adaptive filters 被引量:2
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作者 何蕊 罗文波 +1 位作者 王本利 孔宪仁 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2011年第1期145-148,共4页
Random vibration test was done on aluminum honeycomb sandwich board. The result suggested that chaotic behavior is found in the test data. The Volterra expression can not be gained from the input and output data direc... Random vibration test was done on aluminum honeycomb sandwich board. The result suggested that chaotic behavior is found in the test data. The Volterra expression can not be gained from the input and output data directly in this paper. The state space reconstruction was used to convert the system observed data into the quasi-input/output pairs, and the second-order Voherra adaptive filter was used to predict the test data. It is shown that combining the state space reconstruction with the Volterra adaptive filter, these chaotic series could be accurately predicted. 展开更多
关键词 chaotic behavior: Voherra: aluminum honeycomb sandwich board: random test
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基于随机森林模型的无砟轨道板形变识别
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作者 郭高冉 许红彬 秦杰 《铁道工程学报》 北大核心 2026年第1期32-38,共7页
研究目的:由于随机森林模型具有参数少、分类准确率高、对噪声鲁棒性强的特点,因此本文提出基于随机森林模型的高速铁路无砟轨道板形变识别方法。首先,采用现场试验的方法获得CRTSⅡ型无砟轨道板正常和形变状态的监测数据;其次,利用经... 研究目的:由于随机森林模型具有参数少、分类准确率高、对噪声鲁棒性强的特点,因此本文提出基于随机森林模型的高速铁路无砟轨道板形变识别方法。首先,采用现场试验的方法获得CRTSⅡ型无砟轨道板正常和形变状态的监测数据;其次,利用经验模态分解方法对现场获得的轨道振动进行分解并用皮尔逊相关系数对得到的本征模态函数分量(Intrinsic Mode Function,IMF)进行筛选得到特征IMF,计算特征IMF的时域特征参数作为随机森林模型的初始特征矩阵;最后,将无砟轨道板正常状态和形变状态的初始特征向量输入到随机森林模型中进行分类识别。研究结论:(1)提出了基于轨旁振动的高速铁路桥上无砟轨道结构损伤监测方法,实现了服役期高速铁路桥上无砟轨道结构的实时监测;基于实测轨旁振动信号,利用基于EMD分解的时域特征提取方法,有效提取了轨道板形变敏感特征;(2)利用随机森林模型对高速铁路无砟轨道板的形变状态进行分类自动识别,自动识别的准确率能够达到93.4%;(3)提出的无砟轨道结构形变监测方法和智能识别方法还适用于其他土木工程结构病害的监测与识别。 展开更多
关键词 无砟轨道板 形变 现场监测 损伤识别 随机森林模型
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振动试验夹具疲劳破坏分析方法研究
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作者 黄鑫 许地鑫 +2 位作者 邵洪婷 娄宇航 孙超 《工程与试验》 2026年第1期23-26,共4页
本文总结了几种常用结构振动试验夹具的疲劳破坏现象,分析了导致疲劳破坏的原因,并提出了基于名义应力法的振动试验夹具疲劳破坏分析方法。为研究该分析方法在振动试验夹具设计中的适用性,结合某试件的随机振动试验,对该分析方法的结果... 本文总结了几种常用结构振动试验夹具的疲劳破坏现象,分析了导致疲劳破坏的原因,并提出了基于名义应力法的振动试验夹具疲劳破坏分析方法。为研究该分析方法在振动试验夹具设计中的适用性,结合某试件的随机振动试验,对该分析方法的结果进行了验证。结果表明,采用该疲劳破坏分析方法计算得出的疲劳寿命值比试验记录值偏小。本文进一步分析了计算值偏小的原因,得出了该疲劳破坏分析方法适合在振动试验夹具设计中应用的结论。 展开更多
关键词 振动试验 分析方法 随机振动试验 夹具 疲劳破坏 疲劳寿命
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炎症因子、白细胞与腰椎间盘突出症的关系
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作者 辜山 张龙 李志刚 《中国组织工程研究》 北大核心 2026年第18期4782-4790,共9页
背景:腰椎间盘突出症是一种临床高发的脊柱疾病,现有研究证据提示细胞因子、白细胞与腰椎间盘突出症发生、发展有重要联系,但具体机制尚不明确。目的:应用孟德尔随机化分析,探究细胞因子、白细胞与腰椎间盘突出症的因果关系。方法:选取G... 背景:腰椎间盘突出症是一种临床高发的脊柱疾病,现有研究证据提示细胞因子、白细胞与腰椎间盘突出症发生、发展有重要联系,但具体机制尚不明确。目的:应用孟德尔随机化分析,探究细胞因子、白细胞与腰椎间盘突出症的因果关系。方法:选取GWAS Catalog数据库中的91个细胞因子数据和来自血细胞联盟的6种白细胞数据为暴露,最新版R12芬兰数据库中的腰椎间盘突出症数据为结局,采用双向两样本孟德尔随机化和全基因组关联研究共定位分析方法探寻细胞因子、白细胞与腰椎间盘突出症的因果关系。采用Steiger检验、Cochran’s Q检验、MR-Egger截距评估、留一法分析等敏感性检验方法验证结果的准确性。主要使用逆方差加权法进行统计分析。结果与结论:①嗜碱性粒细胞和嗜酸性粒细胞与腰椎间盘突出症具有因果关系(OR=0.93,95%CI:0.87-0.99;OR=0.94,95%CI:0.88-1.00);②S100钙结合蛋白A12水平(OR=0.74,95%CI:0.55-1.00)、成纤维细胞生长因子水平(OR=1.03,95%CI:1.00-1.07)、白细胞介素20受体α蛋白水平(OR=1.09,95%CI:1.04-1.15)、白细胞介素6水平(OR=1.07,95%CI:1.00-1.13)、白细胞介素7水平(OR=1.08,95%CI:1.01-1.16)、干细胞因子水平(OR=1.05,95%CI:1.01-1.09)、白细胞介素2水平(OR=0.94,95%CI:0.89-0.99)与腰椎间盘突出症具有因果关系;③共定位分析发现,干细胞因子水平H3+H4=0.80,其中最显著的单核苷酸多态性为rs6073966。结果表明,嗜碱性粒细胞、嗜酸性粒细胞、S100钙结合蛋白A12、成纤维细胞生长因子、白细胞介素20受体α蛋白、白细胞介素2、白细胞介素6、白细胞介素7、干细胞因子对腰椎间盘突出症具有单向因果作用;干细胞因子和腰椎间盘突出症之间可能存在相关通路。 展开更多
关键词 细胞因子 炎症 双向两样本孟德尔随机化 共定位 Steiger检验 腰椎间盘突出症
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基于路谱等效转换PSD的新能源汽车集成式电源管理模块支架振动疲劳分析与试验研究
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作者 曾维和 苟黎刚 +3 位作者 陈海潮 王明庆 王磊 俞荣贵 《机械强度》 北大核心 2026年第2期105-119,共15页
【目的】针对某新能源车在道路耐久试验中集成式车载电源管理模块(简称为ODP)支架发生的疲劳开裂问题,建立一套从材料特性测试到整车路谱等效转换的完整振动疲劳分析与验证体系。【方法】首先,测试了DC01和B280VK材料的应变-寿命数据,... 【目的】针对某新能源车在道路耐久试验中集成式车载电源管理模块(简称为ODP)支架发生的疲劳开裂问题,建立一套从材料特性测试到整车路谱等效转换的完整振动疲劳分析与验证体系。【方法】首先,测试了DC01和B280VK材料的应变-寿命数据,拟合了Manson-Coffin-Basquin模型参数;其次,采集了实车路谱加速度激励,基于损伤等效原理将其加速转换为三向等效强化功率谱密度(Power Spectrum Density,PSD);再次,利用频率响应法(频域法)和Dirlik概率密度函数计算了支架随机振动疲劳损伤;最后,通过台架加速振动试验及整车道路耐久试验验证了所提优化方案。【结果】研究表明,初始支架方案最大损伤值为1.90,超出临界值,且失效位置预测与实车一致。结构局部强化及更换B280VK材质后,最大损伤降至0.10,疲劳安全系数由低于1.0提升至10.0。台架24 h加速试验与整车31490 km耐久路试均未出现裂纹,证明了所提等效转换与优化方法的有效性。 展开更多
关键词 ODP支架 功率谱密度 随机振动 疲劳分析 试验验证
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高BMI孕妇NIPT检测时点优化模型研究
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作者 曹弦 《现代信息科技》 2026年第6期175-179,共5页
为提高高BMI孕妇无创产前检测(NIPT)精准度、降低临床风险,基于高BMI孕妇NIPT实测数据开展研究。经GC含量筛选、孕周格式转换等数据清洗后,采用Pearson相关分析、多元线性回归构建Y染色体浓度-孕周/BMI关联模型(F检验验证),结合K-means... 为提高高BMI孕妇无创产前检测(NIPT)精准度、降低临床风险,基于高BMI孕妇NIPT实测数据开展研究。经GC含量筛选、孕周格式转换等数据清洗后,采用Pearson相关分析、多元线性回归构建Y染色体浓度-孕周/BMI关联模型(F检验验证),结合K-means聚类、随机森林回归及误差分析,优化BMI分组并确定最佳检测时点。结果显示,男胎Y染色体浓度与孕周呈正相关,与BMI呈负相关(模型整体显著),仅孕妇体重影响Y染色体达标时间;按BMI聚为3组,无误差时最佳时点均在13~27周高风险期,控制误差后结果稳定。高BMI孕妇NIPT需结合孕周、BMI及体重进行分层检测,控制误差可降低风险,未来可补充多地区样本优化模型。 展开更多
关键词 高BMI孕妇 无创产前检测 Y染色体浓度 最佳检测时点 K-MEANS聚类 随机森林回归 检测误差控制
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工业产品监督抽查“抽检分离”的必要性及抽样环节应对策略
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作者 严欣 姚海军 +1 位作者 刘琪 木合塔尔·买买提依明 《中国标准化》 2026年第6期223-226,共4页
工业产品质量监督抽查作为政府质量监督的一种重要手段,在强化产品质量监管、提高产品质量安全、采集质量信息、指导政府决策、引导消费等方面发挥了积极作用。2025年,新疆维吾尔自治区市场监管部门首次在工业产品质量安全监督抽查中采... 工业产品质量监督抽查作为政府质量监督的一种重要手段,在强化产品质量监管、提高产品质量安全、采集质量信息、指导政府决策、引导消费等方面发挥了积极作用。2025年,新疆维吾尔自治区市场监管部门首次在工业产品质量安全监督抽查中采取抽检物理分离的形式,由不同的机构承担抽样和检验任务,抽样队伍建立初期,由于人员能力参差不齐,相关制度规范亟须制定。笔者结合实际情况,从实行监督抽查抽检分离的必要性、优劣势分析、抽样环节应对策略等方面进行了全面分析,供从事工业产品安全监管工作的同仁参考。 展开更多
关键词 抽检分离 监督抽查 应对措施
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CONSISTENCY OF MLE OF THE PARAMETER OF EXPONENTIAL LIFETIME DISTRIBUTION FOR RANDOM CENSORING MODEL WITH INCOMPLETE INFORMATION 被引量:18
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作者 YE ERHUA 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 1995年第4期379-386,共8页
In this paper, we have discussed a random censoring test with incomplete information, and proved that the maximum likelihood estimator(MLE) of the parameter based on the randomly censored data with incomplete informat... In this paper, we have discussed a random censoring test with incomplete information, and proved that the maximum likelihood estimator(MLE) of the parameter based on the randomly censored data with incomplete information in the case of the exponential distribution has the strong consistency. 展开更多
关键词 random censoring test with incomplete information exponential distribution maximum likelihood estimator consistency.
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