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数据库管理系统中自动统计计算的实现技术——CRDS的统计表达式
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作者 张文彬 冯玉才 《计算机工程与应用》 CSCD 北大核心 1989年第9期1-3,共3页
在传统的数据管理系统中,没有自动统计计算的功能。用户若要对数据库中某些关系的某些属性、变量或常量进行代数运算,都必须针对具体问题编写程序才能达到目的。本文介绍在我们研制的汉字关系数据库管理系统CRDS中,是如何圆满地解决上... 在传统的数据管理系统中,没有自动统计计算的功能。用户若要对数据库中某些关系的某些属性、变量或常量进行代数运算,都必须针对具体问题编写程序才能达到目的。本文介绍在我们研制的汉字关系数据库管理系统CRDS中,是如何圆满地解决上述难题的。使用该系统,用户不需编制程序,可以在任一时候,根据需要定义他所要的统计计算表达式。表达式的左边是要统计的数据项名,如职工的“实发工资”,学生的“平均成绩”和“总分”等等;而右边是由属性名、常量及四则运算符组成的表达式。只要属性名对应的值已存在数据库中,系统就能自动输出表达式左边所定义的统计信息,从而实现了自动统计计算的功能。 展开更多
关键词 数据库 自动统计计算 统计表达式
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对物理化学中两个公式的异议 被引量:1
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作者 牛家治 《淮北煤师院学报(自然科学版)》 2001年第4期77-79,82,共4页
对理想气体化学势的统计表达式及过渡态理论中速率常数的热力学表达式重新推导,其结果与所见教材中的有所不同,在此提出讨论.
关键词 化学势 标准态 速率常数 物理化学 理想气体 统计表达式 热力学表达式 过渡态
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Improved performance of process monitoring based on selection of key principal components 被引量:2
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作者 宋冰 马玉鑫 侍洪波 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2015年第12期1951-1957,共7页
Conventional principal component analysis(PCA) can obtain low-dimensional representations of original data space, but the selection of principal components(PCs) based on variance is subjective, which may lead to infor... Conventional principal component analysis(PCA) can obtain low-dimensional representations of original data space, but the selection of principal components(PCs) based on variance is subjective, which may lead to information loss and poor monitoring performance. To address dimension reduction and information preservation simultaneously, this paper proposes a novel PC selection scheme named full variable expression. On the basis of the proposed relevance of variables with each principal component, key principal components can be determined.All the key principal components serve as a low-dimensional representation of the entire original variables, preserving the information of original data space without information loss. A squared Mahalanobis distance, which is introduced as the monitoring statistic, is calculated directly in the key principal component space for fault detection. To test the modeling and monitoring performance of the proposed method, a numerical example and the Tennessee Eastman benchmark are used. 展开更多
关键词 Principal component analysis Information loss Fault detection Key principal component
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Performance Analysis of Physical Layer Security over α-η-κ-μ Fading Channels 被引量:1
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作者 Shaobo Jia Jiayan Zhang +1 位作者 Honglin Zhao Yao Xu 《China Communications》 SCIE CSCD 2018年第11期138-148,共11页
In this paper, we consider the secure data transmission over α-η-κ-μ fading channels, which are recently proposed to encompass nearly all the well-known statistical models adopted in the literature. In particular,... In this paper, we consider the secure data transmission over α-η-κ-μ fading channels, which are recently proposed to encompass nearly all the well-known statistical models adopted in the literature. In particular, we address the secrecy performance in terms of the average secrecy capacity(ASC) and the secrecy outage probability(SOP), for which novel analytical expressions are derived. Simulation results verify the analysis and demonstrate the impact of the physical parameters on the secrecy performance of this new channel fading model. 展开更多
关键词 Physical layer security α-η-κ-μgeneralized fading channels average secrecycapacity secrecy outage probability
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Clinical Significance of CENP-H Expression in Uterine Cervical Cancer 被引量:2
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作者 Mei-ying Weng Lin Li +1 位作者 Shun-jia Hong Shu-ying Feng 《Clinical oncology and cancer researeh》 CAS CSCD 2012年第3期192-196,共5页
Objective This work aims to investigate the expression pattern and clinicopathologic significance of centromere protein H(CENP-H) in uterine cervical cancer(UCC). Methods The level of CENP-H expression in the paraffin... Objective This work aims to investigate the expression pattern and clinicopathologic significance of centromere protein H(CENP-H) in uterine cervical cancer(UCC). Methods The level of CENP-H expression in the paraffin sections of 62 UCC cases was determined by the SP immunohistochemical method,with complete clinicopathologic data in all cases.Statistical analysis was conducted to evaluate the prognostic and diagnostic significance of CENP-H using SPSS13.0 software package. Results Immunohistochemical assay showed strong CENP-H expression in 61.29% (38/62) of the paraffin-embedded cervical cancer tissues.Statistical analysis revealed a strong correlation between the CENP-H expression and the clinical classification(P=0.038) of the cervical carcinoma.The expression increased with rise of the stages.The analysis of Cox proportional hazards regression model suggested that CENP-H expression(P=0.002) and tumor stage(P=0.001) were independent prognostic markers for the survival of UCC patients.The survival analysis showed that the survival rate was significantly lower in patients with high expression of CENP-H than in those with low expression of CENP-H(P=0.001). Conclusions CENP-H is likely to be a valuable marker for carcinogenesis and progression of UCC.It might be used as the important diagnostic and prognostic marker for cervical carcinoma patients,especially for those at early stage. 展开更多
关键词 uterine cervical cancer uterine cervix CENP-H IMMUNOHISTOCHEMISTRY tumor staging PROGNOSIS
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Correct Path-Integral Formulation of Quantum Thermal Field Theory in Coherent State Representation
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作者 SUJun-Chen ZHENGFu-Hou 《Communications in Theoretical Physics》 SCIE CAS CSCD 2005年第4期641-656,共16页
The path-integral quantization of thermal scalar, vector, and spinor fields is performed newly in the coherent-state representation. In doing this, we choose the thermal electrodynamics and psi(4) theory as,examples. ... The path-integral quantization of thermal scalar, vector, and spinor fields is performed newly in the coherent-state representation. In doing this, we choose the thermal electrodynamics and psi(4) theory as,examples. By this quantization, correct expressions of the partition functions and the generating functionals for the quantum thermal electrodynamics and psi(4) theory are obtained in the coherent-state representation. These expressions allow us to perform analytical calculations of the partition functions and generating functionals and therefore are useful in practical applications. Especially, the perturbative expansions of the generating functionals are derived specifically by virtue of the stationary-phase method. The generating functionals formulated in the position space are re-derived from the ones given in the coherent-state representation. 展开更多
关键词 thermal fields partition function generating functional coherent-state representation
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Modeling of shear wave velocity in limestone by soft computing methods 被引量:2
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作者 Behnia Danial Ahangari Kaveh Moeinossadat Sayed Rahim 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2017年第3期423-430,共8页
The main purpose of current study is development of an intelligent model for estimation of shear wave velocity in limestone. Shear wave velocity is one of the most important rock dynamic parameters. Because rocks have... The main purpose of current study is development of an intelligent model for estimation of shear wave velocity in limestone. Shear wave velocity is one of the most important rock dynamic parameters. Because rocks have complicated structure, direct determination of this parameter takes time, spends expenditure and requires accuracy. On the other hand, there are no precise equations for indirect determination of it; most of them are empirical. By using data sets of several dams of Iran and neuro-genetic, adaptive neuro-fuzzy inference system (ANFIS), and gene expression programming (GEP) methods, models are rendered for prediction of shear wave velocity in limestone. Totally, 516 sets of data has been used for modeling. From these data sets, 413 ones have been utilized for building the intelligent model, and 103 have been used for their performance evaluation. Compressional wave velocity (Vp), density (7) and porosity (.n), were considered as input parameters. Respectively, the amount of R for neuro-genetic and ANFIS networks was 0.959 and 0.963. In addition, by using GEP, three equations are obtained; the best of them has 0.958R. ANFIS shows the best prediction results, whereas GEP indicates proper equations. Because these equations have accuracy, they could be used for prediction of shear wave velocity for limestone in the future. 展开更多
关键词 Shear wave velocity Limestone Neuro-genetic Adaptive neuro-fuzzy inference system Gene expression programming
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FEM Edge Effect and Capacitance Evaluation on Cylindrical Capacitors
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作者 Jose-M. Bueno-Barrachina Cesar-S. Cafias-Penuelas Saturnino Catalan-Izquierdo 《Journal of Energy and Power Engineering》 2012年第12期2063-2069,共7页
The purpose of this paper is to show the influence of the edge-effect on the electric field distribution, and hence on the inner capacitance and outer capacitance of a cylindrical capacitor surrounded by an insulating... The purpose of this paper is to show the influence of the edge-effect on the electric field distribution, and hence on the inner capacitance and outer capacitance of a cylindrical capacitor surrounded by an insulating medium. To generalize the results, a two-dimensional axisymmetric finite element model of a cylindrical capacitor has been generated and the problem has been resolved taking into account the distance between the conductors for a complete set of dimensions. The available obtained results have been compared with previous published works. Finally, using statistical tools, the mathematical expression for computing the relationship between capacitance and insulation gap and cylindrical plates dimensions has been obtained. 展开更多
关键词 CAPACITANCE electric field effects SIMULATION space charge.
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