检索结果-南通市图书馆

IFNN时变模型在建立大坝位移监控中的应用

在线全文

学校读者我要写书评

暂无评论

水电能源科学 2008年第5期26卷 101-103页

作者：武金坤李波河海大学水利水电工程学院江苏南京210098 河海大学水资源高效利用与工程安全国家工程研究中心江苏南京210098

针对时变监控模型比常规监控模型更有效且能准确进行变量分离,通过改进的模糊神经网络(IFNN)结合时变模型对陈村水库大坝的水平位移进行拟合与预测,并与BP模型做了比较。结果表明,该模型拟合及预测精度均较BP模型高,与工程实例相近,可... 详细信息

针对时变监控模型比常规监控模型更有效且能准确进行变量分离,通过改进的模糊神经网络(IFNN)结合时变模型对陈村水库大坝的水平位移进行拟合与预测,并与BP模型做了比较。结果表明,该模型拟合及预测精度均较BP模型高,与工程实例相近,可推广应用。

关键词：时变模型 BP模型改进的模糊神经网络水平位移

A Multi-objective Optimal Approach to Automated Construction of Sacrificial Multi-piece Molds

在线全文

学校读者我要写书评

暂无评论

Journal of Shanghai Jiaotong university(Science) 2008年第5期13卷 542-546页

作者：王会凤周雄辉陈巍 national Die and Mold CAD engineering research center Shanghai Jiaotong University

Sacrificial multi-piece molds can be used for producing complex parts. To obtain the optimal design of molds automatically, a multi-objective optimal approach is proposed. Mold pieces number, material utilization and partitioning area are taken as the objective functions, and the machinability of each mold piece is taken as constraint condition. Genetic algorithm (GA) is adopted to realize global optimization of partitioning process. Each mold piece in optimal scheme can be manufactured by milling and drilling operations, which reduce the tooling cost and shorten product cycle obviously. Using the proposed approach, mold design can be significantly automated for making complex parts.

关键词： sacrificial multi-piece molds multi-objective optimization machinability genetic algorithm (GA)

Degradation of lignite model compounds by the action of white rot fungi

在线全文

学校读者我要写书评

暂无评论

Mining Science and Technology 2010年第1期20卷 76-81页

作者： DU Ying, TAO Xiuxiang, SHI Kaiyi, LI Yang School of Chemical engineering and Technology, china university of Mining & Technology, Xuzhou 221000, china School of Chemical engineering and Technology China University of Mining & Technology Xuzhou 221000 China

Three compounds modeled on the lignite structure were chosen for experimental degradation by different fungi strains. Culture conditions and extracellular enzyme activities were optimized. The growth curves of the strains were determined to study mycelium dry weight and protein content changes. Gas chromatography and infrared spectroscopy were used to detect changes of functional groups before and after the action of the fungi on the model compounds. Possible decomposition products and degrada-tion mechanisms were proposed. The research findings show that C. Versicolor and Golden Mushroom can grow in presence of the model compounds. The optimum culture conditions were a pH of 6.0, a carbon-nitrogen ratio of five and a Tween-80 concentration of 0.1%. Newly produced substances were found by gas chromatography. Infrared analysis showed that the model compounds degraded under the action of the microorganisms.

关键词： coal biotransformation white rot fungi mechanism model compound

Identifying heavy hitters in high-speed network monitoring

在线全文

学校读者我要写书评

暂无评论

Science china(Information Sciences) 2010年第3期53卷 659-676页

作者： ZHANG Yu1, FANG BinXing1,2 & ZHANG YongZheng2 1research center of Computer Network and Information Security Technology, Harbin Institute of Technology, Harbin 150001, china 2research center of Information Security, Institute of Computing Technology, Chinese Academy of Sciences, Beijing 100190, china research center of Computer Network and Information Security Technology Harbin Institute of Technology Harbin China research center of Information Security Institute of Computing Technology Chinese Academy of Sciences Beijing China

Identifying heavy hitters in a network traffic stream is important for a variety of network applications ranging from traffic engineering to anomaly detection such as detection of denial-of-service attacks. Existing methods generally examine newly arriving items in the stream, perform a small number of operations using a small amount of memory, and still provide guarantees on the identifying accuracy. In high-speed network monitoring, the update speed per item is extremely critical. However, so far as we know, there are no identifying algorithms which can provide constant update time (O(1)) in a weighted data stream. In this paper, we present an algorithm named Weighted Lossy Counting (WLC) which is able to identify heavy hitters in a high-speed weighted data stream with constant update time. WLC employs a novel efficient partially ordered data structure which is able to provide a fast per-item update speed while keeping the memory cost relatively low. We compare WLC with state-of-the-art algorithms for finding heavy hitters in real traffic traces. The experimental results show that WLC performs well in accuracy (recall, precision and average relative error) as other algorithms; moreover it has a much higher update speed at the cost of relatively larger memory space used. A theoretical worst-case memory bound of WLC is also derived in this paper; however, experiments with long real traffic traces show that WLC requires much less space than the theoretical bound in practice.

关键词： network traffic monitoring heavy hitter weighted data streams

Achieving efficient Channel utilization for Data Communications in IEEE 802.11 WLAN

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Transactions of Tianjin university 2005年第6期11卷 422-427页

作者：张亮舒炎泰 School of Electronic Information engineering Tianjin UniversityTianjin 300072China

In the IEEE g02. 11 protocol, the adoption of the exponential backoff technique leads to throughput performance strongly dependent on the initial contention window size and, most importantly, on the number of contending stations considered in the network. This paper proposes a simple but accurate method to dynamically estimate the number of contending stations in a wireless local area network （ WLAN ）. Based on estimation, all the mobile stations dynamically adjust the initial contention window in medium access control （ MAC ） layer to avoid collisions. The simulation results show that the proposed algorithm can achieve efficient channel utilization, higher system throughput, and better fairness performance.

关键词： IEEE 802.11 wireless local area network( WLAN ) distributed coordination function ( DCF )

Analysis of Bacterial Communities Present in Agaricus bisporus Phase II Compost Using Amplified Ribosomal DNA Restriction Analysis (ARDRA)(Ⅰ)——Construction of a Bacterial 16S rDNA Library

在线全文

学校读者我要写书评

暂无评论

食用菌学报 2008年第4期 16-19页

作者： HE Lihong~(1,2) YU Rongli~1 CHEN Mingjie~(1*) PAN Yingjie~3(~1Key Laboratory of Applied Mycological resources and utilization,Ministry of Agriculture,the People's Republic of china,Shanghai research center for Edible Fungi Biotechnology and engineering,Shanghai Key Laboratory of Agricultural Genetics and Breeding,Institute of Edible Fungi,Shanghai Academy of Agricultural Sciences,Shanghai 201106,china ~2Department of Microbiology,College of Life Sciences,nanjing Agricultural university,nanjing,Jiangsu 210095,china ~3Shanghai Ocean university,Shanghai 200090,china)

An efficient and cost effective method for obtaining good quality DNA from composts containing high levels of organic matter has been *** protocol consisted of sample washing with sodium phosphate and EDTA,cell wall disruption using combined chemical and enzyme treatment prior to extraction,removal of humic acid and other inhibitors in high salt buffer containing polyvinyl polypyrrolidone (PVPP),and precipitation of DNA with polyethylene glycol (PEG-8000).The method was used to extract 16S ribosomal DNA from four samples taken at different stages in the preparation of PhaseⅡcompost used for Agaricus bisporus *** DNA was sufficiently free of contaminants to allow PCR amplification of products derived from bacteria,actinomycetes and *** products derived from PCR amplification of the extracted 16S rDNA using primers F27 and R1498 were used to construct 16S rDNA *** amplification of ten randomly selected positive clones using primer M13 revealed that the 16S rDNA insertion rate was higher than 90%.

关键词： Agaricus bisporus compost phaseⅡ bacterial 16S rDNA library

Identification of antixenosis and antibiosis in two newly explored brown planthopper-resistance rice lines

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Identification of antixenosis and antibiosis in two newly ex...

Genome-wide SNP in silico detection of Lentinula edodes via whole genome sequencing

第十三届全国植物基因组学大会

作者： Qiu Yongfu~1,Cheng Ling~2,Liu Fang~1,Li Rongbai~(1*) 1 State Key Laboratory for Conservation and utilization of Subtropical Agro-bioresources, Agricultural College,Guangxi university,Nanning,530005,china 2 engineering research center of Wetland Agriculture in the Central Yangtze,Ministry of Education,Yangtze university,Jingzhou,434025,china

The rice brown planthopper(Nilaparvata lugens Stal,BPH) is one of the typical piercing-sucking insect pests to feed on rice phloem *** studies have shown that breeding and cultivation of resistant rice varieties is the most economical and efficient method for managing the BPH,therefore it is imperative to explore and identify BPH resistance rice lines from diverse sources and incorporate the

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Genome-wide SNP in silico detection of Lentinula edodes via ...

高矿化度环境下黏性土对膨润土-砂土复合防渗层抗渗性的影响研究

中国菌物学会第五届会员代表大会暨2011年学术年会

作者： CHEN Xiang BAO Da-Peng (national research center for Edible Fungi Biotechnology and engineering Key Laboratory of Applied Mycological resources and utilization,Ministry of Agriculture,china Shanghai Key Laboratory of Agricultural Genetics and Breeding Institute of Edible Fungi,Shanghai Academy of Agricultural Sciences,Shanghai,china)

＜正＞Analysis of single nucleotide polymorphisms（SNPs） emerges as an important tool in evolutionary biology and *** we report the in silico discovery and analysis of SNPs across the whole genome of two protoplast monokaryons（TPMs） of basidiomycete fungi Lentinula edodes via the high-throughput sequencing *** our knowledge,this is a novel study in which different protoplast monokaryons are utilized for SNPs detection and *** sequence information including 210M and 250M nucleotide bases was generated from TPMs yielding approximately 80%of whole genome *** used surpassed 380K and 410K reads of TPMs for the de novo assembly of two contig sets with an overall estimated depth of 5.67-fold and 6.05-fold coverage,*** of the contigs between TPMs identified 108,235 putative SNPs owning a high probability of at least 10-fold *** SNPs reveal TPMs having similar intra-strain SNP frequencies,and the ratio of transition to transversion among these SNPs being similar to the ratio reported in other *** verify the confidence of detected SNPs,25,044 SNPs were mapped onto 43,912 positions that uniformly distributed over the sequenced chromosomes of Coprinopsis *** result shows high sequence conservation among closely related fungal *** addition,the gene structure of TPMs was constructed for SNPs classification according to their distribution in genome ***,this study indicates the utility of using next generation sequencing technologies to identify large numbers of reliable ***,the method combination of SNP detection and novel algorithm allows an efficient approach for the development of high-density genotyping platforms in fungal species.

关键词： Lentinula edodes whole genome sequencing contig assembly SNPs

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

节水灌溉 2011年第11期 67-69,72页

作者：王晓芸崔自治张群崔永成宁夏大学旱区现代农业水资源高效利用教育部工程研究中心宁夏银川750021

以宁夏广泛分布的砂土为研究对象,以黏性土掺量c、盐浓度d、盐的复合比r、膨润土掺量p为因素,渗透系数为考察参数,设计L9(34)正交实验方案和单因素实验方案,实验研究了盐对膨润土-黏性土-砂土复合防渗层抗渗性的影响,揭示了黏性土掺量c... 详细信息

以宁夏广泛分布的砂土为研究对象,以黏性土掺量c、盐浓度d、盐的复合比r、膨润土掺量p为因素,渗透系数为考察参数,设计L9(34)正交实验方案和单因素实验方案,实验研究了盐对膨润土-黏性土-砂土复合防渗层抗渗性的影响,揭示了黏性土掺量c、盐浓度d、盐的复合比r、膨润土掺量p等因素对膨润土-黏性土-砂土复合防渗层抗渗性的作用规律和作用机理,为砂土基防渗层设计、施工提供理论依据。实验研究表明:在盐溶液环境中,膨润土的作用效应降低,黏性土的作用效应显著增强,但膨润土仍然是影响砂土基防渗层渗透性最主要的因素;土样的渗透系数随着盐溶液复合比的增大,呈现出先减小,后略微增大的趋势;黏性土使盐对砂土基防渗层的抗渗性影响显著降低,尤其是在高矿化度环境下,作用效应更为显著。

关键词：膨润土黏性土盐复合防渗