期刊文献+
共找到19篇文章
< 1 >
每页显示 20 50 100
基于Python的流水线计数计量应用
1
作者 吕晖 徐佳琪 《电子制作》 2021年第17期50-51,27,共3页
随着信息技术发展,车间生产进入自动化已成为形势所趋。尤其大规模的生产企业,实现流水线自动化计数计量可以大大提高生产效率和精度。本文通过进行视频预处理,掌握边缘检测、区域分割、特征点检测与匹配技术。可对匀速移动的流水线上... 随着信息技术发展,车间生产进入自动化已成为形势所趋。尤其大规模的生产企业,实现流水线自动化计数计量可以大大提高生产效率和精度。本文通过进行视频预处理,掌握边缘检测、区域分割、特征点检测与匹配技术。可对匀速移动的流水线上的相对位置固定的产品进行计数统计。减少人力劳动,提高自动化水平,计数准确性。 展开更多
关键词 PYTHON 视频预处理 计数计量 大津阈值法
下载PDF
火工品可靠性计量-计数评估方法的有效性研究 被引量:6
2
作者 董海平 蔡瑞娇 穆慧娜 《含能材料》 EI CAS CSCD 2008年第5期553-555,559,共4页
采用Monte Carlo方法研究了GJB376规定的用计数数据估计火工品可靠度的方法和已建立的计量-计数评估方法在试验方面的等效性,根据评定准则采用这两种方法判定试验结果合格的接收率最大误差小于1%。对20种不同类型的火工品及两种人为设... 采用Monte Carlo方法研究了GJB376规定的用计数数据估计火工品可靠度的方法和已建立的计量-计数评估方法在试验方面的等效性,根据评定准则采用这两种方法判定试验结果合格的接收率最大误差小于1%。对20种不同类型的火工品及两种人为设定为不合格产品,采用计量-计数法和步进法进行了对比试验研究,两种方法得到的可靠性评估结果一致。分析结果表明,计量-计数评估方法与GJB376规定的用计数数据估计火工品可靠度的方法等效,工程应用可行,对评估高可靠性的火工品,能大幅度降低样本量。 展开更多
关键词 军事化学与烟火技术 火工品 可靠性 评估 计量-计数
下载PDF
Varian Clinac-6X直线加速器剂量计数激增的处理
3
作者 张书旭 《中国医疗器械杂志》 CAS 2001年第1期55-55,共1页
关键词 直线加速器 计量计数 医用设备 故障 维修
下载PDF
电子计时计数器
4
作者 徐为民 《内蒙古质量技术监督》 2001年第2期18-18,共1页
在检定冲击试验机过程中,用自动计时、计数方式代替手动秒表计时、默记周期数,测摆长,降低了测试的失误率,消除了人为误差,提高了测试精度。
关键词 冲击试验机 检定 工作原理 精度 电子计量计数
下载PDF
Parameter Estimations of Rayleigh Distribution 被引量:20
5
作者 林金官 《Chinese Quarterly Journal of Mathematics》 CSCD 2000年第4期49-54,共6页
设随机变量X服从Rayleigh分布,其密度函数为p(x;β)=2x/βe-x^2/β,x>0,β>0为参数,对变换群G={gc;gc(x)=c^2x,c>0},本文分别在平方损失和熵损失下研究了β在G上的最优同变估计;当β有先验信息时,给出了β的Bayes估计。
关键词 Rayleigh distribution transformation group minimum risk equivariant estimations Bayesian estimations
下载PDF
A LINEAR APPROACH TO METRIC CIRCUMFERENCE COMPUTATIO FOR DIGITIZED CONVEX SHAPES 被引量:3
6
作者 Chen Ken Zhao Pan Yang Rener 《Journal of Electronics(China)》 2008年第4期572-575,共4页
Metric measurement of digitized shapes is commonly applied in optical measuring systems.In this letter,three shape-related factors defined by the authors are used in the construction of amultiple linear regression mod... Metric measurement of digitized shapes is commonly applied in optical measuring systems.In this letter,three shape-related factors defined by the authors are used in the construction of amultiple linear regression model which is utilized to compute the circumference of the convex shapes inmillimeter unit.The model is first built upon the relationship hypothesis and then its adequacy ismathematically validated.The results of applying the developed model to the given number of convexshapes in a finite circumferential length range suggest that,in terms of percent error,the model pre-cision is to satisfaction by being within±4%.The test also shows the model’s robustness against theshape’s orientation anisotropy. 展开更多
关键词 Metric measurement Circumference computation Digital image analysis Modeling
下载PDF
Closure of q-Quantum Languages
7
作者 莫智文 郭秀红 舒兰 《Journal of Donghua University(English Edition)》 EI CAS 2007年第2期252-254,共3页
η-quantum languages are discussed and some of their properties are derived. Furthermore the q-quantum language is defined. It is shown that L(A1A2)=L(A1)∩L(A2), L(A)=L(A1)∪L(A2). So over the same alphabet the inter... η-quantum languages are discussed and some of their properties are derived. Furthermore the q-quantum language is defined. It is shown that L(A1A2)=L(A1)∩L(A2), L(A)=L(A1)∪L(A2). So over the same alphabet the intersection and union of two different q-quantum languages are also q-quantum languages. 展开更多
关键词 quantum automata quantum language quantum computing
下载PDF
Column Analyses of Chloride Breakthrough and Lead Retention in Amended Sandy Soils
8
作者 Mark E. Grismer Michael P. Hogan Dave E. Steinfeld 《Journal of Environmental Science and Engineering(A)》 2012年第4期503-513,共11页
Stormwater quality design manuals lack scientifically creditable bases for many novel LID (Low-Impact Development) designs presently proposed to meet stormwater runoff management requirements. Potential stormwater p... Stormwater quality design manuals lack scientifically creditable bases for many novel LID (Low-Impact Development) designs presently proposed to meet stormwater runoff management requirements. Potential stormwater pollutant adsorption and infiltration enhancement capabilities of forest-derived by-products (e.g. woodchips, bio-char) provide an opportunity to combine these readily availability materials into stormwater quality designs. On-site stormwater runoff treatment through determination of the soil-water transport and lead (Pb) retention capacity of two sandy soils from Oregon is considered. Using synthetic stormwater (-120 mg CI/L and -5 mg Pb/L) displacement tests in pairs ofABS (Acrylonitrile butadiene styrene) soil columns (75 mm dia by 0.46 m tall) with upward flow (to minimize air entrapment) saturated hydraulic conductivity, chloride dispersion and Pb retention by plain and amended soils is evaluated. Generally, soil amendment incorporation (woodchips, compost or biochar) as compared to an amendment layer resulted in improved hydraulic conductivities as compared to that of the soil alone. Chloride breakthrough curves verified that resident soil-water displacement occurred with 0.9 to 1.6 pore volumes and residence times for most columns were 15-30 minutes. No synthetic stormwater Pb "breakthrough" within the displaced or replaced soil-water was found, rather most Pb was adsorbed within the first 150 mm of soil. 展开更多
关键词 REVEGETATION chloride dispersion STORMWATER BIORETENTION LID.
下载PDF
Views on Piracy: Threats to International Peace
9
作者 Alimen A. Rolando Jeson C. Fernandez Cesar I. Mongan 《Journal of Shipping and Ocean Engineering》 2016年第2期110-116,共7页
The study was conducted to ascertain the views on piracy among marine engineering students and marine officers who had encountered piracy on international waters thereby suggesting threats to international peace. The ... The study was conducted to ascertain the views on piracy among marine engineering students and marine officers who had encountered piracy on international waters thereby suggesting threats to international peace. The respondents of the study were 50, specifically distributed to thirty (30) onboard marine engineering students enrolled for the current school year 2014-2015 and twenty (20) marine officers who had experienced piracy at Somalia and other places. The researchers employed quantitative-qualitative research method design. The questionnaire on "Piracy at Sea" was validated by experts in research, statistics, qualitative research, and maritime international conventions. To test the reliability, this same instrument was pilot-tested among marine officers and students who had been on board international ships. Qualitative data were captured through interviews by using open-ended questions. Frequency count, percentage, and rank were used in this study for descriptive-quantitative statistics. The data were analyzed using appropriate statistics through computer-processed software (SPSS). Qualitative analysis was employed to determine the views of the respondents on piracy so that mitigation measures were elicited for protection of life at sea leading towards international peace among identified HRAs (high-risk areas). Results revealed that seafarers were familiar of piracy. They were aware that piracy usually happens in areas like Somalia water sand other threatening territories. To combat piracy, the participants have pointed out the role of the international community in their concerted effort to help seafarers safeguard their lives specifically during these hard times. Somalia also needs to effectively check their organization by whether or not strict implementation of the Anti Piracy Law was being observed. Full knowledge of piracy, techniques for avoiding it, and surviving pirate attacks are necessary among seafarers. Satellite system called shiplock allows shipping companies to monitor location of ships particularly useful during pirate attacks, hijacks, or ship theft. They also install non-lethal electrical fences around a ship's perimeter to protect them during these times. IMO regulations require ships to send distress signals and warnings covertly in case of pirate attacks. 展开更多
关键词 PIRACY threats international peace maritime university marine engineering students marine officers high-risk areas(HRAs) satellite system international community.
下载PDF
Analysis on Mathematics Teaching Goal Design Technology and Its Detection
10
作者 Yong Huang Xingcong Mao 《International Journal of Technology Management》 2013年第8期65-67,共3页
Teaching goal design is an important link of teaching design, which has the teaching, learning and measurement function. How to establish the appropriate teaching goal and properly state to enhance its guidance and de... Teaching goal design is an important link of teaching design, which has the teaching, learning and measurement function. How to establish the appropriate teaching goal and properly state to enhance its guidance and detection function are the important tasks of teaching design. This paper makes a programming and systematic analysis on the aspects of teaching goal design theory, teaching goal statement mode and technology, teaching goal statement and design and teaching goal design detection. 展开更多
关键词 teaching goal design guidance and detection statement technology
下载PDF
Adaptive Surface Reconstruction Based on Tensor Product Algebraic Splines
11
作者 Xinghua Song Falai Chen 《Numerical Mathematics(Theory,Methods and Applications)》 SCIE 2009年第1期90-99,共10页
Surface reconstruction from unorganized data points is a challenging problem in Computer Aided Design and Geometric Modeling. In this paper, we extend the mathematical model proposed by Juttler and Felis (Adv. Comput... Surface reconstruction from unorganized data points is a challenging problem in Computer Aided Design and Geometric Modeling. In this paper, we extend the mathematical model proposed by Juttler and Felis (Adv. Comput. Math., 17 (2002), pp. 135-152) based on tensor product algebraic spline surfaces from fixed meshes to adaptive meshes. We start with a tensor product algebraic B-spline surface defined on an initial mesh to fit the given data based on an optimization approach. By measuring the fitting errors over each cell of the mesh, we recursively insert new knots in cells over which the errors are larger than some given threshold, and construct a new algebraic spline surface to better fit the given data locally. The algorithm terminates when the error over each cell is less than the threshold. We provide some examples to demonstrate our algorithm and compare it with Juttler's method. Examples suggest that our method is effective and is able to produce reconstruction surfaces of high quality. 展开更多
关键词 Surface reconstruction algebraic spline surface adaptive knot insertion.
下载PDF
A New Statistical Tool: Scalar Score Function
12
作者 Zdenek Fabian 《Computer Technology and Application》 2011年第2期109-116,共8页
The basic inference function of mathematical statistics, the score function, is a vector function. The author has introduced the scalar score, a scalar inference function, which reflects main features of a continuous ... The basic inference function of mathematical statistics, the score function, is a vector function. The author has introduced the scalar score, a scalar inference function, which reflects main features of a continuous probability distribution and which is simple. Its simplicity makes it possible to introduce new relevant numerical characteristics of continuous distributions. The t-mean and score variance are descriptions of distributions without the drawbacks of the mean and variance, which may not exist even in cases of regular distributions. Their sample counterparts appear to be alternative descriptions of the observed data. The scalar score itself appears to be a new mathematical tool, which could be used in solving traditional statistical problems for models far from the normal one, skewed and heavy-tailed. 展开更多
关键词 STATISTICS inference function data characteristics point estimates heavy tails.
下载PDF
Variable Selection Procedures in Linear Regression Models with Screening Consistency Property
13
作者 XIE Yanxi XIA Zhijie +1 位作者 WANG Xiaoli YAN Ruixia 《International English Education Research》 2017年第1期34-37,共4页
There are two fundamental goals in statistical learning: identifying relevant predictors and ensuring high prediction accuracy. The first goal, by means of variable selection, is of particular importance when the tru... There are two fundamental goals in statistical learning: identifying relevant predictors and ensuring high prediction accuracy. The first goal, by means of variable selection, is of particular importance when the true underlying model has a sparse representation. Discovering relevant predictors can enhance the performance of the prediction for the fitted model. Usually an estimate is considered desirable if it is consistent in terms of both coefficient estimate and variable selection. Hence, before we try to estimate the regression coefficients β , it is preferable that we have a set of useful predictors m hand. The emphasis of our task in this paper is to propose a method, in the aim of identifying relevant predictors to ensure screening consistency in variable selection. The primary interest is on Orthogonal Matching Pursuit(OMP). 展开更多
关键词 variable selection orthogonal matching pursuit high dimensional setup screening consistency
下载PDF
Analysis on the Level of Intra-industry Trade for ASEAN's Economy
14
作者 Thanet Wattanakul 《Chinese Business Review》 2016年第5期215-223,共9页
This paper aims to examine and analyse the level of intra-industry trade on economy of ASEAN. These data obtained from the accurate and reliable source of ASEAN Trade Statistics databases. The importance of intra-indu... This paper aims to examine and analyse the level of intra-industry trade on economy of ASEAN. These data obtained from the accurate and reliable source of ASEAN Trade Statistics databases. The importance of intra-industry and measurement is also described. Moreover, the linkage of intra-industry trade and investment liberalization under the ASEAN Economic Community (AEC) is also explained. The effective enhancement schemed to increase the competitiveness of specific industries had been proposed to enhance ASEAN to be efficient production hub and network of region that lead to the ultimate goal of single market. The further studies can be applied to construct and estimate the econometric model and forecasting technique to confirm the empirical results. 展开更多
关键词 intra-industry trade ASEAN AEC trade and investment liberalisation
下载PDF
A parameter-free upwind scheme for all speeds' simulations 被引量:1
15
作者 QU Feng YAN Chao +1 位作者 SUN Di YUAN Wu 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2015年第3期434-442,共9页
With the rapid development of the computational fluid dynamics(CFD),a parameter-free upwind scheme capable of simulating all speeds accurately and efficiently is in high demand.To achieve this goal,we present a new up... With the rapid development of the computational fluid dynamics(CFD),a parameter-free upwind scheme capable of simulating all speeds accurately and efficiently is in high demand.To achieve this goal,we present a new upwind scheme called AUSMPWM in this paper.This scheme computes the numerical mass flux as the AUSMPW+and computes the interfacial sound speed in a different way.Also,it computes the pressure flux by limiting the dissipation if the Mach number is less than 1.Series of numerical experiments show that AUSMPWM can satisfy the following attractive properties independent of any tuning coefficient:(1)Robustness against the shock anomaly and high discontinuity’s resolution;(2)high accuracy on hypersonic heating prediction and capability to give smooth reproductions of heating profiles;(3)low dissipation at low speeds;and(4)strong grid,reconstruction scheme,and Mach number independence in low speeds’simulations.These properties suggest that AUSMPWM is promising to be widely used to accurately and efficiently simulate flows of all speeds. 展开更多
关键词 shock anomaly AUSMPW+ ausmpwm all speeds computational fluid dynamics
原文传递
A sequence pulse counting method for shape measurement in dual-beam speckle interferometry
16
作者 LIU Liang LI XiDe 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2011年第4期640-646,共7页
A temporal approach to fast shape measurement is presented.In principle,the rotational object method is used in combination with the sequence pulse counting method (SPCM) to determine the height of the object through ... A temporal approach to fast shape measurement is presented.In principle,the rotational object method is used in combination with the sequence pulse counting method (SPCM) to determine the height of the object through calculating the related phase.Two specimens are tested to demonstrate the validity of the approach.One is an object covered by a Chinese character (tea) with a height variety of 0.3 mm,and the other is an object surface with a relatively large fluctuation of 3.5 mm.The experimental results are compared with mechanical measurements.An axis shifting method is also proposed to determine shapes with relatively large fluctuations.Effects of such parameters on the height measurement as incident angle of the dual light beams,tilting angle of the object,and azimuth angle of the measured point are discussed as well. 展开更多
关键词 shape measurement profilometry temporal speckle pattern interferometry phase measurement
原文传递
Convergence Rates of Wavelet Estimators in Semiparametric Regression Models Under NA Samples 被引量:9
17
作者 Hongchang HU Li WU 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2012年第4期609-624,共16页
Consider the following heteroscedastic semiparametric regression model:where {Xi, 1 〈 i 〈 n} are random design points, errors {ei, 1 〈 i 〈 n} are negatively associated (NA) random variables, (r2 = h(ui), and... Consider the following heteroscedastic semiparametric regression model:where {Xi, 1 〈 i 〈 n} are random design points, errors {ei, 1 〈 i 〈 n} are negatively associated (NA) random variables, (r2 = h(ui), and {ui} and {ti} are two nonrandom sequences on [0, 1]. Some wavelet estimators of the parametric component β, the non- parametric component g(t) and the variance function h(u) are given. Under some general conditions, the strong convergence rate of these wavelet estimators is O(n- 1 log n). Hence our results are extensions of those re, sults on independent random error settings. 展开更多
关键词 Semiparametric regression model Wavelet estimate Negativelyassociated random error Strong convergence rate
原文传递
OPTIMAL ALLOCATION FOR ESTIMATING THE CORRELATION COEFFICIENT OF MORGENSTERN TYPE BIVARIATE EXPONENTIAL DISTRIBUTION BY RANKED SET SAMPLING WITH CONCOMITANT VARIABLE 被引量:1
18
作者 XIE Minyu XIONG Ming WU Ming 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2013年第2期249-260,共12页
Ranked set sample is applicable whenever ranking of a set of sample units can be done easily by a judgement method of the study variable or of the auxiliary variable. This paper considers ranked set sample based on th... Ranked set sample is applicable whenever ranking of a set of sample units can be done easily by a judgement method of the study variable or of the auxiliary variable. This paper considers ranked set sample based on the auxiliary variable X which is correlated with the study variable Y, where (X, Y) follows Morgenstern type bivariate exponential distribution. The authors discuss the optional allocation for unbiased estimators of the correlation coefficient p of the random variables X and Y when the auxiliary variable X is used for ranking the sample units and the study variable Y is measured for estimating the correlation coefficient. This paper first gives a class of unbiased estimators of p when the mean 0 of the study variable Y is known and obtains an essentially complete subclass of this class. Further, the optimal allocation of the unbiased estimators is found in this subclass and is proved to be Bayes, admissible, and minimax. Finally, the unbiased estimator of p under the optimal allocation in the case of known θ is reformed for estimating p in the case of unknown θ, and the reformed estimator is shown to be strongly consistent. 展开更多
关键词 Concomitants of order statistic Morgenstern type bivariate exponential distribution optimal allocation ranked set sample unbiased estimator.
原文传递
Semi-parametric estimation for the Box-Cox transformation model with partially linear structure 被引量:1
19
作者 ZHOU GuoLiang ZHOU YaHong 《Science China Mathematics》 SCIE 2013年第3期459-481,共23页
The Box-Cox transformation model has been widely used in applied econometrics, positive accounting, positive finance and statistics. There is a large literature on Box-Cox transformation model with linear structure. H... The Box-Cox transformation model has been widely used in applied econometrics, positive accounting, positive finance and statistics. There is a large literature on Box-Cox transformation model with linear structure. However, there is seldom seen on the discussion for such a model with partially linear structure. Considering the importance of the partially linear model, in this paper, a relatively simple semi-parametric estimation procedure is proposed for the Box-Cox transformation model without presuming the linear functional form and without specifying any parametric form of the disturbance, which largely reduces the risk of model misspecification. We show that the proposed estimator is consistent and asymptotically normally distributed. Its covariance matrix is also in a closed form, which can be easily estimated. Finally, a simulation study is conducted to see the finite sample performance of our estimator. 展开更多
关键词 Box-Cox transformation model semiparametric estimation rank condition smoothed kernel
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部