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房建项目模板体系(周转木材)投入经济效益分析与策划
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作者 刘景雪 周洋 《长江技术经济》 2021年第S02期168-171,共4页
众所周知,木模板作为非实体性周转材料,消耗量较大,以结构施工用的木方、多层板尤为突出。模板工程造价约占总工程造价的20%~30%,故提高模板工程的经济效益,是降低施工项目物资成本的一项重要措施。在企业内部消耗数据的基础上,结合新... 众所周知,木模板作为非实体性周转材料,消耗量较大,以结构施工用的木方、多层板尤为突出。模板工程造价约占总工程造价的20%~30%,故提高模板工程的经济效益,是降低施工项目物资成本的一项重要措施。在企业内部消耗数据的基础上,结合新开项目工程概况、施工方案、施工进度进行前期投入测算,并优化模板体系(周转木材)经济效益的投入,为过程中周转木材的消耗管控提供理论管控目标及参照。 展开更多
关键词 方木模板配比系数 施工方案 周转次数 展模系数 钢包木
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Simple PSF based method for pupil phase mask’s optimization in wavefront coding system 被引量:2
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作者 ZHANG Wen-zi CHEN Yan-ping +2 位作者 ZHAO Ting-yu YE Zi YU Fei-hong 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2007年第2期180-185,共6页
By applying the wavefront coding technique to an optical system, the depth of focus can be greatly increased. Several complicated methods, such as Fisher Information based method, have already been taken to optimize f... By applying the wavefront coding technique to an optical system, the depth of focus can be greatly increased. Several complicated methods, such as Fisher Information based method, have already been taken to optimize for the best pupil phase mask in ideal condition. Here one simple point spread function (PSF) based method with only the standard deviation method used to evaluate the PSF stability over the depth of focus is taken to optimize for the best coefficients of pupil phase mask in practical optical systems. Results of imaging simulations for optical systems with and without pupil phase mask are presented, and the sharpness of image is calculated for comparison. The optimized results showed better and much more stable imaging quality over the original system without changing the position of the image plane. 展开更多
关键词 Wavefront coding Pupil phase mask Depth of focus PSF stability OPTIMIZATION SHARPNESS Imaging simulation
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A Survey of MapReduce Based Parallel Processing Technologies 被引量:1
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作者 LU Jiamin FENG Jun 《China Communications》 SCIE CSCD 2014年第A02期146-155,共10页
Along with the increasing Big Data challenges, the MapReduce based systems are extensively welcomed, because of their remarkable simplicity and scalability. However, from the first day MapReduce is proposed, its a... Along with the increasing Big Data challenges, the MapReduce based systems are extensively welcomed, because of their remarkable simplicity and scalability. However, from the first day MapReduce is proposed, its argument with parallel Dt3MSs never stops, as it over-focuses on the scalability but overlooks the efficiency. Accordingly, extended systems are proposed in order to improve the peDbrmance on the limited scale clusters. In the meantime, traditional RDBMS technologies like structured data model, transaction, SQL, etc. are also getting more attention. This paper reviews such systems, from Google and also the third parties, trying to indicate the directions for the future research. 展开更多
关键词 parallel processing MAPREDUCE VARIANTS
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Evaluation and Driving Force Analysis of Marine Sustainable Development based on the Grey Relational Model and Path Analysis 被引量:8
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作者 GAO Sheng ZHAO Lin +2 位作者 SUN Huihui CAO Guangxi LIU Wei 《Journal of Resources and Ecology》 CSCD 2020年第6期570-579,共10页
With the rapid development of the marine economy,the demand for marine resources development and the pressure on marine environmental protection are gradually increasing.It is critical to evaluate and analyze the driv... With the rapid development of the marine economy,the demand for marine resources development and the pressure on marine environmental protection are gradually increasing.It is critical to evaluate and analyze the driving forces of marine sustainable development in order to promote the coordinated development of the marine economy,resources and environment.Taking Jiangsu Province of China as an example,this paper constructs an evaluation index system for marine sustainable development from the three aspects of marine economy,resources and environment,and calculates the weight of the variation coefficient for each indicator.Based on the grey relational model,the average value of the relational degree,calculated by the average value method of correlation coefficients and the weighting method,is then used to evaluate the status of marine sustainable development in this province.The comprehensive index model is used to analyze the dynamic trend of the evolution of marine sustainable development.The driving forces of marine sustainable development are analyzed by the path analysis method combined with the average values of the grey relational degree for each indicator.This analysis found that the marine sustainable development in 2016 and 2012 was good,the situation in 2007 was bad,and the remaining years were intermediate.Compared with the previous years,the optimal conditions of 2008 and 2012 were obvious.The main driving factors of marine sustainable development are cargo throughput of coastal ports,economic losses caused by storm surges in coastal areas,the area of marine nature reserves in coastal areas,coastal wind power generation capacity,and marine biodiversity. 展开更多
关键词 marine sustainable development coefficient of variation method grey relational model composite index model path analysis
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