检索结果-南通市图书馆

Node ordinal encoded genetic algorithm for the optimal allocation of water resources

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2005年第5期15卷 448-452页

作者： YANG Xiaohua1*, YANG Zhifeng 1,2. SHEN Zhenyao1 and LI Jianqiang3.1. State Key Laboratory of Water Environment Simulation, school of Environment, {2. Normal University, {2. 100875,{3. 2. Key Laboratory for Water and Sediment Sciences Ministry of Education, school of Environment, {2. Normal University, {2. 100875,{3. 3. Water Resources and Hydropower Planning and Design General Institute, MWR, {2. 100011,{3.) State Key Laboratory of Water Environment Simulation School of Environment Beijing Normal University Beijing 100875 China Key Laboratory for Water and Sediment Sciences Ministry of Education School of Environment Beijing Normal University Beijing 100875 China Water Resources and Hydropower Planning and Design General Institute MWR Beijing 100011 China

A new method, node ordinal encoded genetic algorithm (NOEGA), is proposed for solving water resources optimal allocation problems, in which the capacity of water resources is split into a number of smaller parts so that successive operations can be overlapped. Our objective is to maximize the whole benefit function. To overcome the “dimensionality and algorithm complexity curse” while searching for solutions and looking for an optimal solution, the operations of one-point crossover operator, gene exchange operator, gene random operator, gene shift operator and node ordinal strings are established. It is proved to be an effective optimal method in searching for global solutions. The NOEGA does not need a diversity of initial population, and it does not have the problem of immature convergence. The results of two cases show that using NOEGA to solve the optimal allocation model is very efficient and robust. In addition, the algorithm complexity of NOEGA is discussed.

关键词： water resources optimal allocation node ordinal code genetic algorithm.

Spatial heterogeneity of the driving forces of cropland change in china

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china Earth Sciences 2005年第12期48卷 2231-2240页

作者： LIU Xuhua1,2. WANG Jinfeng1, LIU Mingliang4,1 & MENG Bin1,2.3.1. Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, beijing 100101,{2. 2. graduate {3. of the Chinese Academy of Sciences, beijing 10003.,{2. 3. College of Arts and Sciences of beijing Union University, beijing 100083.{2. 4. {3. of Forestry and Wildlife Sciences, Auburn University, Auburn, Alabama, AL3.849, USA 1. Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences 100101 Beijing China 2. graduate school of the Chinese Academy of Sciences 100039 Beijing China 3. school of Forestry and Wildlife Sciences Auburn University Auburn AL36849 Alabama USA 4. College of Arts and Sciences of beijing Union University 100083 Beijing China

By using digital satellite remote sensing data acquired in 1987―1989 and 1999―2.00 and GIS combined with the natural and socio-economic data, this paper drew an integrated zonation of the cropland change and its driving forces in china. The results indicated that the cropland change in the study period was constrained by geographical factors and driven by cli-mate change as well as socio-economic system. Moreover, the regional differences of the drivers for cropland change were significant. In the midwest of china, natural condition changes and geographical background were the main constraints and drivers, while in Eastern china, social and economic changes and economic policies were the main driving forces. The cropland loss was nationwide. The dominant factors to cause this decrease included buildup of developing area to attract foreign capital and technologies, changes of industry structure due to urban in-fluence, the change of employment notions thanks to living standard improvement, rapid ur-banization due to the expansion of cities and towns, the diminished farming net income partly because of the global warming effects, and the rapid economic growth stimulated by the con-venient transportation system. These factors interact and interdepend with each other to cause the cropland loss in china recently. The reasons for the increase of cropland were primarily the cultivation and deforestation by the farmers who want to increase income. This study on the mechnism of LUCC relied on the cropland change integrated classification considering the natural or human factors both inside and outside the region, which provides a new approach to study the integrated regionalization and LUCC mechanism.

关键词： land use change, driving force, integrated classification, spatial statistics, cropland, china.

Recommendation Method for Contrastive Enhancement of Neighborhood Information

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2024年第1期78卷 453-472页

作者： Hairong Wang beijing Zhou Lisi Zhang He Ma school of Computer Science and Engineering North Minzu UniversityNingxia750021China

Knowledge graph can assist in improving recommendation performance and is widely applied in various person-alized recommendation ***,existing knowledge-aware recommendation methods face challenges such as weak user-item interaction supervisory signals and noise in the knowledge *** tackle these issues,this paper proposes a neighbor information contrast-enhanced recommendation method by adding subtle noise to construct contrast views and employing contrastive learning to strengthen supervisory signals and reduce knowledge ***,first,this paper adopts heterogeneous propagation and knowledge-aware attention networks to obtain multi-order neighbor embedding of users and items,mining the high-order neighbor informa-tion of users and ***,in the neighbor information,this paper introduces weak noise following a uniform distribution to construct neighbor contrast views,effectively reducing the time overhead of view *** paper then performs contrastive learning between neighbor views to promote the uniformity of view information,adjusting the neighbor structure,and achieving the goal of reducing the knowledge noise in the knowledge ***,this paper introduces multi-task learning to mitigate the problem of weak supervisory *** validate the effectiveness of our method,experiments are conducted on theMovieLens-1M,MovieLens-2.M,Book-Crossing,and Last-FM *** results showthat compared to the best baselines,our method shows significant improvements in AUC and F1.

关键词： Contrastive learning knowledge graph recommendation method

Exsolution of ilmenite and Cr-Ti magnetite from olivine of garnet-wehrlite

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science china Earth Sciences 2005年第9期48卷 1368-1376页

作者： LIU Xiangwen1,2. JIN Zhenmin1,3. QU Jing2.& WANG Lu2.1. State Key Laboratory of Geological Processes and Mineral Resources, china University of Geosciences, Wuhan 43.074, china 2. graduate {3. of china University of Geosciences, Wuhan 43.074, china 3. Faculty of Earth Sciences, china University of Geosciences, Wuhan 43.074, china 1. State Key Laboratory of Geological Processes and Mineral Resources China University of Geosciences 430074 Wuhan China 2. graduate school of{2. University of Geosciences 430074 Wuhan China 3. Faculty of Earth Sciences China University of Geosciences 430074 Wuhan China

Exsolution of rod-like ilmenite (Ilm) and Cr-Ti magnetite (Mt) have been found in olivine of garnet-wehrlite from the core of Chinese Continental Sciences Drilling (CCSD). Their composition, morphology, crystal structure and their topotaxies with host olivine have been studied in detail by the transmission electron microscopy (TEM) and electron probe microanaly- sis (EPMA) technique. It shows that rod-like Ilm exsolution reported in this paper has similar characteristic with that of Alpe Arami olivine, while Cr-Ti magnetite exsolution mentioned in this paper has large discrepancy with chromite exsolution in Alpe Arami olivine. These observations suggest that both of the exsolutions found in this paper should be solid solution phases in β-olivine at their first period, then experiencing decomposition of solid solution and therefore forming Ilm and Cr-Ti magnetite exsolution with the pressure decreasing. So, this garnet-wehrlite perhaps had been ever located in mantle transition zone with a minimum depth of 3.0 km.

关键词： garnet-wehrlite, ilmenite, magnetite, exsolution, CCSD.

Population information extraction in Chaohu watershed based on RS and GIS

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2003年第2期48卷 181-183页

作者： LIU Jianjun1,2.& LI Chunlai3.1. Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002. china 2. {2. school, Chinese Academy of Sciences,{3., china 3. National Astronomical Observatories, Chinese Academy of Sciences, beijing 100012. china Correspondence should be addressed to Liu Jianjun (e-mail: dhsliujj@ ***) Institute of Geochemistry Chinese Academy of Sciences Guiyang China graduate school Chinese Academy of Sciences Beijing China National Astronomical Observatories Chinese Academy of Sciences Beijing China

It is always difficult to extract population in-formation of small watershed during the region environment assessment. The report adopted compound areal interpola-tion to study the population in Chaohu watershed with the GIS technique and landuse interpretation data from remote sensing. The result indicated that the method is effective to extract population information of small watershed.

关键词：巢湖流域人口分布信息提取 RS GIS 小流域生态环境评价

Indian Ocean-MORB-type isotopic signature of Yushigou ophiolite in North Qilian Mountains and its implications

在线全文

学校读者我要写书评

暂无评论

Science china Earth Sciences 2006年第6期49卷 561-572页

作者： HOU Qingye1,2. ZHAO Zhidan1,2. ZHANG Hongfei3. ZHANG Benren3.& CHEN Yuelong2.1. State Key Laboratory of Geological Processes and Mineral Resources,{2. University of Geosciences, beijing 100083.{2. 2. {3. of Earth Science and Mineral Resources,{2. University of Geosciences, beijing 100083.{2. 3. Faculty of Earth Sciences,{2. University of Geosciences, Wuhan 43.074,{2. 1. State Key Laboratory of Geological Processes and Mineral Resources China University of Geosciences Beijing 100083 China 2. school of Earth Science and Mineral Resources China University of Geosciences Beijing 100083 China 3. Faculty of Earth Sciences China University of Geosciences Wuhan 430074 China

In order to explore the disputed issue concerning the tectonic affinity ofthe ancient ocean mantle of North Qilian Mountains (NQM), geochemical and Sr, Nd, Pb isotopiccompositions of pillow basalts of the Yushigou Ophiolite (YSGO) suite from NQM have been analyzedsystematically. The pillow basalts exhibit tholeiitic characteristics, with flatchondrite-normalized REE patterns ((La/Yb)_N = 0.98—1.2.). They display no Nb, Ta, Zr, Hf negativeanomalies, and show MORB features in 2.b-Zr/4-Y and Ti/100-Zr-YX3.tectonic discrimination *** results indicate that the Yushigou ophiolite is most likely to be formed in a mid-ocean ridgeor mature back-arc basin. Their isotopic data show a relatively broad and enriched ^(87)Sr/^(86)Sr(0.70509 — 0.70700), restricted ^(143.Nd/^(144)Nd (0.512.55-0.512.78). Pb isotopes are in the rangeof ^(2.6)Pb/^(2.4)Pb (18.054-2..562., ^(2.7)Pb/^(2.4)Pb (15.53.-15.743. and ^(2.8)Pb/^(2.4)Pb(3..068-3..53.). These isotopic data imply that the basalts originated from the depleted mantle(DMM), with the involvement of enriched mantle components (mainly EMII). Geochemical comparisonsbetween the basalts in YSGO and the MORB-type basalts of ophiolite suites occurring in the knownancient Tethyan tectonic domain indicate that the ancient oceanic mantle represented by YSGO suiteforming in early Paleozoic in the North Qilian Moutains is very similar to the Tethyan mantle inboth trace elements and isotopic compositions. The North Qilian Mountains should be a part of theTethyan tectonic domain in early Paleozoic. This further implies that the Tethyan tectonic domaincan be deduced to early Paleozoic in the study area, which will be helpful to discussing thetectonic affinity and evolution of the North Qilian Mountains.

关键词： geochemistry, Indian Ocean-MORB-type isotopic signatures, Tethyan tectonic domain, Yushigou ophiolite, North Qilian Mountains.

Quick image-processing method of UAV without control points data in earthquake disaster area

在线全文

学校读者我要写书评

暂无评论

中国有色金属学会会刊：英文版 2011年第S3期21卷 523-528页

作者： LI Chang-chun1, ZHANG Guang-sheng1, LEI Tian-jie2. 3. GONG A-du2. 3.1. {2. of Surveying & Land Information Engineering, Henan Polytechnic University, Jiaozuo 454000, china 2. Key Laboratory of Environmental Change and Natural Disaster, Ministry of Education, beijing Normal University, beijing 100875, china 3. Ministry of Civil Affairs/Ministry of Education of china Academy of Disaster Reduction and Emergency Management, beijing Normal University, beijing 100875, china [a] school of Surveying & Land Information Engineering Henan Polytechnic University Jiaozuo 454000 China [b] Key Laboratory of Environmental Change and Natural Disaster Ministry of Education Beijing Normal University Beijing 100875 China [c] Ministry of Civil Affairs/Ministry of Education of china Academy of Disaster Reduction and Emergency Management Beijing Normal University Beijing 100875 China

The methods of unmanned aerial vehicles images splicing rapidly and rectifying without control points data, only using auxiliary data recorded by unmanned aerial vehicle (UAV) system, were researched. Two algorithms were proposed, including UAV images auto- splicing rapidly after image blocking and UAV images rectifying based on pseudo center points of auxiliary data. When SIFT algorithm for UAV images splicing is applied, the accuracy is very high, but the efficiency is very low. The splicing efficiency is improved greatly based on SIFT algorithm after image blocking. The results show that rectifying accuracy is very high and has no visual dislocation when pseudo center points of auxiliary data is applied.

关键词： unmanned aerial vehicles SIFT algorithm blocking quickly splicing rectification

New adaptive quasi-sliding mode control for nonlinear discrete-time systems

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 2008年第1期19卷 154-160页

作者： Wang Weihong1,2.& Hou Zhongsheng3.1. school of Tra?c and Transportation, {2. Jiaotong Univ., {2. 100044, P. R.{3. 2. Dept. of Automation, Taiyuan Univ. of Science & Technology, Taiyuan 03.02., P. R.{3. 3. Advanced Control Systems Lab, school of Electronics and Information Engineering, {2. Jiaotong Univ., {2. 100044, P. R.{3. [a]school of Traffic and Transportation Beijing Jiaotong Univ. Beijing 100044 P. R. China [b]Dept. of Automation Taiyuan Univ. of Science & Technology Taiyuan 030024 P. R. China [c]Advanced Control Systems Lab School of Electronics and Information Engineering Beijing Jiaotong Univ. Beijing 100044 P. R. China

A new adaptive quasi-sliding mode control algorithm is developed for a class of nonlinear discrete-time systems, which is especially useful for nonlinear systems with vaguely known dynamics. This design is model-free, and is based directly on pseudo-partial-derivatives derived on-line from the input and output information of the system using an improved recursive projection type of identification algorithm. The theoretical analysis and simulation results show that the adaptive quasi-sliding mode control system is stable and convergent.

关键词： quasi-sliding mode control adaptive control model-free control pseudo-partial-derivative

Environmental characteristics of Mid-Holocene recorded by lacustrine sediments from Lake Daihai, north environment sensitive zone, china

在线全文

学校读者我要写书评

暂无评论

Science china Earth Sciences 2006年第9期49卷 968-981页

作者： SUN Qianli1,2. ZHOU Jie1, SHEN Ji3. CHEN Peng1,2. WU Feng1,2.& XIE Xiuping1,2.1. State Key Lab of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an 710075, china 2. {2. University of Chinese Academy of Sciences, beijing 10003., china 3. Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 2.0008, china 1. State Key Lab of Loess and Quaternary Geology Institute of Earth Environment Chinese Academy of Sciences Xi’an 710075 China 2. graduate University of Chinese Academy of Sciences Beijing 100039 China 3. Nanjing Institute of Geography and Limnology Chinese Academy of Sciences Nanjing 210008 China

Climate proxies, such as total organic carbon and nitrogen (TOC, TN), carbonate content (CaCO3., grain-size and pollen of the sediment core retrieved from enclosed Lake Daihai which lies in the north china environment sensitive zone are analyzed to reconstruct the environment evolution of the area based on high-resolution radiocarbon chronology. The results reveal that the TOC and TN contents of the sediments correlate well with pollen percentage and pollen flux variations during the Holocene, and both reach their peak values simultaneously at 6.7―3.5 ka BP (calendar age, 7.6―3.6 ka BP). Since 6.7 ka BP, both the CaCO3.and organic matter contents of the core have simultaneous variations, and their high values also occur during 6.7―3.5 ka BP. While during 9.0―6.7 ka BP (calendar age, 10―7.6 ka BP) relatively lower level of organic matter content and pollen flux corre- spond to the higher level of carbonate content. The above relations suggest that during 6.7―3.5 ka BP, the productivity and effective precipitation were greatly improved in the lake drainage area, and this would probably strengthen the hydrodynamic conditions, enhancing organic matter, pollen and carbonate inputs from terrestrial sources. Such processes would account for the enrichment of both organic matter and carbonate in the sediments. While during 9.0―6.7 ka BP, the lower level of or- ganic matter, pollen flux but high carbonate content show depressed productivity and declined vege- tation coverage. The higher carbonate content at this stage would have probably resulted from the higher evaporation ratio of the lake water under relatively drier climate conditions. Therefore, it is in- ferred that during 6.7―3.5 ka BP, the climate was more humid with abundant rainfalls and vegetation was more flourishing in the Lake Daihai area. This can be seen as Holocene Climate Optimum (HCO). As a result, this has evident discrepancies with the traditional notion that the HCO occurs at Early Holocene or early Mid

关键词： Lake Daihai, Mid-Holocene, lacustrine sediments, environmental characteristics.