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铁路工程材料运输方式及费用计列研究
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作者 于昊然 《环球市场》 2016年第16期128-129,共2页
随着铁路工程建设新技术、新工艺、新设备、新材料“四新技术”和机械化、工厂化、专业化、信息化“四个支持手法”的推广应用,铁路工程材料运输方法发生了很大改变,概预算编制单位对材料运输费用计列的处理方法的不一样,形成材料运输... 随着铁路工程建设新技术、新工艺、新设备、新材料“四新技术”和机械化、工厂化、专业化、信息化“四个支持手法”的推广应用,铁路工程材料运输方法发生了很大改变,概预算编制单位对材料运输费用计列的处理方法的不一样,形成材料运输费用漏记或重复计列疑问.鉴于此,文章根据现场调研,对铁路工程材料运输方式模型和费用计列方法进行研究. 展开更多
关键词 铁路工程 材料运输方法及费用计列
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铁路工程材料运输组织方式及运输费用分析 被引量:4
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作者 赵民有 《铁路工程造价管理》 2014年第1期31-33,37,共4页
铁路工程建设所用材料种类较多,其运输组织方式和所需费用,是建设项目投资的主要组成部分,其费用组成是否合理,直接影响到工程投资的合理确定和有效控制。此文针对铁路建设跨越区域广,涉及的专业多等特点,在分析现行工程造价体系材料运... 铁路工程建设所用材料种类较多,其运输组织方式和所需费用,是建设项目投资的主要组成部分,其费用组成是否合理,直接影响到工程投资的合理确定和有效控制。此文针对铁路建设跨越区域广,涉及的专业多等特点,在分析现行工程造价体系材料运输模式及费用组成的基础上,结合工程设计,通过研究提出6种材料运输组织方案,并对每一种运输组织方案及其运输费用组成与计列方法进行论述,提出意见和建议。 展开更多
关键词 铁路工程 材料 运输方案 运输费用 计列方法
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COMPUTATIONALLY EFFICIENT ESPRIT METHOD FOR DIRECTION FINDING 被引量:4
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作者 Bao Zhiqiang Wu Shunjun Zhang Linrang 《Journal of Electronics(China)》 2007年第5期655-661,共7页
In this paper,a low complexity ESPRIT algorithm based on power method and Orthogo- nal-triangular (QR) decomposition is presented for direction finding,which does not require a priori knowledge of source number and th... In this paper,a low complexity ESPRIT algorithm based on power method and Orthogo- nal-triangular (QR) decomposition is presented for direction finding,which does not require a priori knowledge of source number and the predetermined threshold (separates the signal and noise ei- gen-values).Firstly,according to the estimation of noise subspace obtained by the power method,a novel source number detection method without eigen-decomposition is proposed based on QR de- composition.Furthermore,the eigenvectors of signal subspace can be determined according to Q matrix and then the directions of signals could be computed by the ESPRIT algorithm.To determine the source number and subspace,the computation complexity of the proposed algorithm is approximated as (2log_2 n+2.67)M^3,where n is the power of covariance matrix and M is the number of array ele- ments.Compared with the Single Vector Decomposition (SVD) based algorithm,it has a substantial computational saving with the approximation performance.The simulation results demonstrate its effectiveness and robustness. 展开更多
关键词 ESPRIT Direction Of Arrival (DOA) Array signal processing Source number detection Power method
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COMPENSATION FOR THE MUTUAL COUPLING EFFECT FOR THE ESPRIT ALGORITHM IN SINGLE SNAPSHOT ARRAY PROCESSING
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作者 Lian Xiaohua Zhou Jianjiang +1 位作者 Li Hailin Cai Wenqi 《Journal of Electronics(China)》 2007年第5期662-667,共6页
An effective method is introduced to compensate the effects of mutual coupling for the Estimation of Signal Parameter via Rotational Invariance Techniques (ESPRIT) direction finding algorithm in application of signal ... An effective method is introduced to compensate the effects of mutual coupling for the Estimation of Signal Parameter via Rotational Invariance Techniques (ESPRIT) direction finding algorithm in application of signal snapshot array processing.Changing the covariance matrix into a Teoplitz matrix can achieve high resolution in the Direction Of Arrive (DOA) estimation.How the mutual coupling affects the array antennas has been discussed and a new definition of mutual im- pedance has been used to characterize the mutual coupling effects between the array elements.Based on the new mutual impedance matrix,a practical method is presented to eliminate the effects of mutual coupling for ESPRIT in the single snapshot data processing.The simulation results show that, this new method not only properly reduces the effects of mutual coupling,but also maintains its steady performance even for weak signals. 展开更多
关键词 Mutual coupling Mutual impedance Estimation Signal Parameter via Rotational In-variance Techniques (ESPRIT) Single snapshot data
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Strain and Culture Medium Optimization for Production Enhancement of Prodiginines from Marine-Derived Streptomyces sp. GQQ-10
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作者 LI Xueping ZHANG Guojian +2 位作者 ZHU Tianjiao LI Dehai GU Qianqun 《Journal of Ocean University of China》 SCIE CAS 2012年第3期361-365,共5页
A mutant (GQQ-M6) of a Sponge-Derived streptomyces sp. GQQ-10 obtained by UV-induced mutation was used for producing prodiginines (PGs). Single factor experiments and orthogonal array design (OAD) methods were employe... A mutant (GQQ-M6) of a Sponge-Derived streptomyces sp. GQQ-10 obtained by UV-induced mutation was used for producing prodiginines (PGs). Single factor experiments and orthogonal array design (OAD) methods were employed for medium optimization. In the single factor method, the effects of soluble starch, glucose, soybean flour, yeast extract and sodium acetate on PGs production were investigated individually. In the subsequent OAD experiments, the concentrations of these 5 key nutritional components combined with salinity were further adjusted. The mutant strain GQQ-M6 gave a 2.2-fold higher PGs production than that of the parent strain; OAD experiments offered a PGs yield of 61mg L-1, which was 10 times higher than that of the initial GQQ-10 strain under the original cultivation mode. 展开更多
关键词 prodiginines marine-derived streptomycete optimization culture media mutation
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Estimation of Number Of Small Cattle Through ARIMA Models in Turkey
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作者 Senol CELIK 《Journal of Mathematics and System Science》 2015年第11期464-473,共10页
In this study, the number of sheep and goats in Turkey were analysed by time series analysis method, and the number of great cattle for next years predicted through the most appropriate time series model.Time series w... In this study, the number of sheep and goats in Turkey were analysed by time series analysis method, and the number of great cattle for next years predicted through the most appropriate time series model.Time series was formed using the data on the number of sheep and goats belonging to the period between 1930 and 2014 in Turkey It was determined through autocorrelation function graphic that the series weren't stationary at first, but they became stationary after their first difference were calculated. A stagnancy test was performed through extended Dickey-Fuller test. So as to determine the suitability of the model, it was reviewed if autocorrelation and partial autocorrelation graphs were white noise series and also the results of Box-Ljung test were reviwed. Through the "tested models, the model estimations, of which parameter estimates were significant and Akaike information criterion (AIC) was the smallest, were performed. The most appropriate model in terms of both the number of sheep and goats is first-level integrated moving average model stated as ARIMA(0,1,1). In this model, it was estimated that there would be an increase in the number of sheep and goats in Turkey between the years of 2015 and 2020, however, the increase in the number of sheep would be more than the increase in the number of goats. 展开更多
关键词 ARIMA Models AUTOCORRELATION the number of sheep the number of goats.
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Crosswind stability of high-speed trains in special cuts 被引量:3
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作者 张洁 高广军 +1 位作者 刘堂红 李志伟 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第7期2849-2856,共8页
Analysis of the aerodynamic performance of high-speed trains in special cuts would provide references for the critical overturning velocity and complement the operation safety management under strong winds.This work w... Analysis of the aerodynamic performance of high-speed trains in special cuts would provide references for the critical overturning velocity and complement the operation safety management under strong winds.This work was conducted to investigate the flow structure around trains under different cut depths,slope angles using computational fluid dynamics(CFD).The high-speed train was considered with bogies and inter-carriage gaps.And the accuracy of the numerical method was validated by combining with the experimental data of wind tunnel tests.Then,the variations of aerodynamic forces and surface pressure distribution of the train were mainly analyzed.The results show that the surroundings of cuts along the railway line have a great effect on the crosswind stability of trains.With the slope angle and depth of the cut increasing,the coefficients of aerodynamic forces tend to reduce.An angle of 75°is chosen as the optimum one for the follow-up research.Under different depth conditions,the reasonable cut depth for high-speed trains to run safely is 3 m lower than that of the conventional cut whose slope ratio is 1:1.5.Furthermore,the windward slope angle is more important than the leeward one for the train aerodynamic performance.Due to the shield of appropriate cuts,the train body is in a minor positive pressure environment.Thus,designing a suitable cut can contribute to improving the operation safety of high-speed trains. 展开更多
关键词 high-speed train crosswind stability cut pressure distribution numerical simulation
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Study on the critical diameter of the subway tunnel based on the pressure variation 被引量:4
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作者 SUN ZhenXu YANG GuoWei ZHU Lan 《Science China(Technological Sciences)》 SCIE EI CAS 2014年第10期2037-2043,共7页
When the subway train operates at a speed higher than 100 km/h,the corresponding aerodynamic issue becomes severe.To meet the future requirement for the speedup of subway trains,a research on the critical diameters of... When the subway train operates at a speed higher than 100 km/h,the corresponding aerodynamic issue becomes severe.To meet the future requirement for the speedup of subway trains,a research on the critical diameters of the subway tunnel for trains operating at 120 and 140 km/h has been performed based on passengers’aural discomfort caused by rail tunnel pressure variation.A three-dimensional computational fluid dynamic approach has been adopted for analysis.Meanwhile,trains with different airtight indices are considered and the pressure variations inside and outside the trains are both under investigation.Based on the corresponding criteria for different airtight indices,critical tunnel diameters for trains running at different speeds have been determined.This study would aid in the tunnel section design for future high-speed subway trains. 展开更多
关键词 tunnel pressure waves airtight index aural discomfort blockage ratio
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Facility Layout Based on Sequence Analysis:Design of Flowshops
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作者 周瑾 吴智铭 《Journal of Shanghai Jiaotong university(Science)》 EI 2009年第6期686-689,共4页
A computer-aided method to design a hybrid layout--tree-shape planar flowlines is presented. In newtype fiowshop layout, the common machines shared by several flowlines could be located together in functional sections... A computer-aided method to design a hybrid layout--tree-shape planar flowlines is presented. In newtype fiowshop layout, the common machines shared by several flowlines could be located together in functional sections. The approach combines traditional cell formation techniques with sequence alignment algorithms. Firstly, a sequence analysis based cell formation procedure is adopted; then the operation sequences for parts are aligned to maximize machines adjacency in hyperedge representations; finally a tree-shape planar flowline will be obtained for each part family. With the help of a sample of operation sequences obtained from industry, this algorithm is illustrated. 展开更多
关键词 workshop layout flowlines sequence analysis sequence alignment algorithm
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AMERICAN OPTION PRICING UNDER GARCH DIFFUSION MODEL: AN EMPIRICAL STUDY 被引量:2
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作者 WU Xinyu YANG Wenyu +1 位作者 MA Chaoqun ZHAO Xiujuan 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2014年第1期193-207,共15页
The GARCH diffusion model has received much attention in recent years, as it describes financial time series better when compared to many other models. In this paper, the authors study the empirical performance of Ame... The GARCH diffusion model has received much attention in recent years, as it describes financial time series better when compared to many other models. In this paper, the authors study the empirical performance of American option pricing model when the underlying asset follows the GARCH diffusion. The parameters of the GARCH diffusion model are estimated by the efficient importance sampling-based maximum likelihood (EIS-ML) method. Then the least-squares Monte Carlo (LSMC) method is introduced to price American options. Empirical pricing results on American put options in Hong Kong stock market shows that the GARCH diffusion model outperforms the classical constant volatility (CV) model significantly. 展开更多
关键词 American option efficient importance sampling GARCH diffusion model least-squaresMonte Carlo maximum likelihood.
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HASM-AD Algorithm Based on the Sequential Least Squares
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作者 WANG Shihai YUE Tianxiang 《Geo-Spatial Information Science》 2010年第4期285-293,共9页
The HASM(high accuracy surface modeling) technique is based on the fundamental theory of surfaces,which has been proved to improve the interpolation accuracy in surface fitting.However,the integral iterative solution ... The HASM(high accuracy surface modeling) technique is based on the fundamental theory of surfaces,which has been proved to improve the interpolation accuracy in surface fitting.However,the integral iterative solution in previous studies resulted in high temporal complexity in computation and huge memory usage so that it became difficult to put the technique into application,especially for large-scale datasets.In the study,an innovative model(HASM-AD) is developed according to the sequential least squares on the basis of data adjustment theory.Sequential division is adopted in the technique,so that linear equations can be divided into groups to be processed in sequence with the temporal complexity reduced greatly in computation.The experiment indicates that the HASM-AD technique surpasses the traditional spatial interpolation methods in accuracy.Also,the cross-validation result proves the same conclusion for the spatial interpolation of soil PH property with the data sampled in Jiangxi province.Moreover,it is demonstrated in the study that the HASM-AD technique significantly reduces the computational complexity and lessens memory usage in computation. 展开更多
关键词 surface modeling HASM spatial interpolation sequential least squares
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