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基于数据依赖的过程合理性分析 被引量:1
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作者 丁婧 董广智 +1 位作者 田勇 柳军飞 《计算机应用与软件》 CSCD 北大核心 2008年第2期106-108,共3页
软件过程模型的很多语义上的错误和歧义都是由数据依赖关系引起的,例化阶段数据依赖关系的研究,对过程的执行效率有很大影响。首先介绍了过程模型SPM,在其基础上,提出了数据依赖的概念,并给出一种活动-数据关系;然后通过对该关系进行分... 软件过程模型的很多语义上的错误和歧义都是由数据依赖关系引起的,例化阶段数据依赖关系的研究,对过程的执行效率有很大影响。首先介绍了过程模型SPM,在其基础上,提出了数据依赖的概念,并给出一种活动-数据关系;然后通过对该关系进行分析,提出了保证过程模型实例语义合理的基本规则;最后应用有穷状态自动机理论,实现了保证这些规则的算法。 展开更多
关键词 软件过程 过程合理性 数据依赖 活动-数据关系
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Reconstructing provincial cropland area in eastern China during the early Yuan Dynasty(AD1271–1294) 被引量:3
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作者 李美娇 何凡能 +1 位作者 杨帆 李士成 《Journal of Geographical Sciences》 SCIE CSCD 2018年第12期1994-2006,共13页
Reconstructing historical land use and land cover change(LUCC) at the regional scale is an important component of global environmental change studies and of improving global historical land use datasets. By analyzing ... Reconstructing historical land use and land cover change(LUCC) at the regional scale is an important component of global environmental change studies and of improving global historical land use datasets. By analyzing data in historical documents, including military-oriented cropland(hereafter M-cropland) area, the number of households engaged in M-cropland(hereafter M-household) reclamation, cropland area, and the number of households, we propose a conversion relationship between M-cropland area and cropland area reclaimed by each household. A provincial cropland area estimation method for the Yuan Dynasty is described and used to reconstruct the provincial cropland area for AD1290. Major findings are as follows.(1) Both the M-cropland and cropland areas of each household were high in the north and low in the south during the Yuan Dynasty, which resulted from different natural conditions and planting practices. Based on this observation, the government-allocated M-cropland reclamation area to each household was based on the cropland area reclaimed by each household.(2) The conversion relationship between M-cropland and cropland areas per household showed conversion coefficients of 1.23 and 0.65 for the south and north, respectively.(3) The cropland area in the entire study area in AD1290 was 535.4×106 mu(Chinese area unit, 1 mu=666.7 m^2), 57.8% in the north and 42.2% in the south. The fractional cropland areas for the entire study area, north, and south were 6.8%, 6.6%, and 7.1%, respectively and the per capita cropland areas for the whole study area, north, and south were 6.7, 15.6, and 4.1 mu, respectively.(4) Cropland was mainly distributed in the middle and lower reaches of the Yellow River(including the Fuli area), Huaihe River Basin(including Henan Province), and middle and lower reaches of the Yangtze River(including Jiangzhe, Jiangxi, and Huguang provinces). 展开更多
关键词 historical LUCC CROPLAND area estimation historical documents Yuan Dynasty
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