检索结果-南通市图书馆

overflow probability of the Salt Lake in Hoh Xil Region

Journal of Geographical Sciences 2018年第5期28卷 647-655页

作者：姚晓军孙美平宫鹏刘宝康李晓锋安丽娜闫露霞 College of Geography and Environment Sciences Northwest Normal University State Key Laboratory of Cryosphere Sciences Northwest Institute of Eco-Environment and Resources CAS Qinghai Institute of Meteorological Sciences

After the bursting of Huiten Nor in Hoh Xil Region in September, 2011, the topic on whether the water overflowed from the Salt Lake would enter into the Chumaer River and become the northernmost source of the Yangtze River has aroused wide concern from public and academic field. Based on Landsat TM/ETM+/OLI remote sensing images during 2010–2015, SRTM 1 arc-second data, Google Earth elevation data and the observation data from the Wudaoliang meteorological station, the study initially analyzed the variations of the Salt Lake and its overflowing condition and probability. The results showed that the area of the Salt Lake expanded sharply from October 2011 to April 2013, and then it stepped into a stable expansion period. On October 27, 2015, the area of the Salt Lake had arrived at 151.38 km^2, which was about 3.35 times the area of the lake on March 3, 2010. The Salt Lake will overflow when its area reaches the range from 218.90 km^2 to 220.63 km^2. Due to the differences between SRTM DEM and Google Earth elevation data, the water level of the Salt Lake simulated would be 12 m or 9.6 m higher than the current level when the lake overflowed, and its reservoir capacity would increase by 23.71 km^3 or 17.27 km^3, respectively. Meanwhile, the overflowed water of the Salt Lake would run into the Qingshui River basin from its eastern part. Although the Salt Lake does not overflow in the coming decade, with watershed expansion of the Salt Lake and the projected precipitation increase in Hoh Xil region, the probability of water overflow from the Salt Lake and becoming a tributary of the Yangtze River will exist in the long term.

关键词： water overflow reservoir capacity Salt Lake Hoh Xil Tibetan Plateau

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Research on conversion time between lost circulation and overflow for the fractured stratum

引用

Petroleum 2020年第1期6卷 98-105页

作者： Rongguo Nie Hongwei Xia Liangjie Mao Mingjie Cai School of Engineering Southwest Petroleum UniversityNanchong637000China State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum UniversityChengdu610500China Engineering Technology Research Institute PetroChina Southwest Oil&Gas Field CompanyGuanghan618300China Chengdu Gaopu Petroleum Engineering Technology Co.Ltd Chengdu610000China

A new model was established based on the flow model of the drilling fluid in one-dimensional radial fracture to research the influencing factors on conversion time between lost circulation and overflow for multi-pressure system in fractured *** the equation of the conversion time between lost circulation and overflow is obtained by solving the mathematical *** model were validated by reproducing the field data from Sichuan oil field and the simulation results of *** influences of consistency index,liquidity index,dynamic shear force,drilling fluid density,drilling fluid intrusion depth,pressure of lost circulation layer,crack width,decreased height of annular liquid level,pressure of high-pressure layer were *** indicate that conversion time between lost circulation and overflow increases with the increasing consistency index,liquidity index,dynamic shear force,drilling fluid density,drilling fluid intrusion depth,pressure of lost circulation *** time between lost circulation and overflow decreases with the increasing crack width,decreased height of annular liquid level,pressure of high-pressure *** time interval of“Hang's Muddingoff”operating should be appropriately less than the conversion time between lost circulation and *** the premise of ensuring wellbore safety,appropriately increasing the consistency index,liquidity index and dynamic shear force of the drilling fluid can effectively increase the conversion time between lost circulation and overflow in large fractured stratum.

关键词： Fractured stratum Conversion time Lost circulation overflow

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Stack overflow上机器学习相关问题的大规模实证研究

引用

浙江大学学报（工学版） 2019年第5期53卷 819-828页

作者：万志远陶嘉恒梁家坤才振功苌程乔林周巧妮浙江大学计算机科学与技术学院浙江杭州310027 浙江大学软件学院浙江宁波315048 国网辽宁省电力有限公司信息通信分公司辽宁沈阳110006

为了调查机器学习相关主题分布和发展趋势,从在线问答网站Stack overflow上,利用过滤标签,从4 178多万帖子中提取出60 028个与机器学习相关的问题帖.通过分析问题帖,统计各个机器学习平台的讨论量,发现Scikit-learn、TensorFlow、Keras... 详细信息

为了调查机器学习相关主题分布和发展趋势,从在线问答网站Stack overflow上,利用过滤标签,从4 178多万帖子中提取出60 028个与机器学习相关的问题帖.通过分析问题帖,统计各个机器学习平台的讨论量,发现Scikit-learn、TensorFlow、Keras是前3位频繁被讨论的机器学习平台,占总讨论量的58%.为了进一步分析机器学习相关讨论主题,进行潜在狄利克雷分布(LDA)主题模型训练,提出自适应LDA中的主题数渐进搜索方法,采用主题一致性系数评估输出结果,获得主题最佳数量,从而发现9个讨论主题,分属3个类别:代码相关、模型相关、理论相关.基于主题中问题帖的浏览数、评论数,分析不同主题的流行度和回答困难程度.

关键词：实证研究机器学习 Stack overflow 潜在狄利克雷分布(LDA) 主题一致性

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Multi-Level Approach of the Ecotoxicological Impact of a Combined Sewer overflow on a Peri-Urban Stream

引用

Journal of Water Resource and Protection 2012年第11期4卷 984-992页

作者： Céline Becouze-Lareure Christine Bazin Philippe Namour Pascal Breil Yves Perrodin INSAVALOR Division POLDEN Villeurbanne France Irstea (Cemagref) Unité de Recherche Hydrologie Hydraulique Lyon France Université de Lyon ENTPE CNRS UMR 5023 Lehna Vaulx-en-Velin France Université de Lyon UCB Lyon 1 Institut des Sciences Analytiques UMR 5280 Villeurbanne France

In periurban zones, urban wet weather discharges have been recognized as the most significant vector of pollution in aquatic environments. The discharge of this water without treatment into the aquatic environment could present an ecotoxicological risk for biocenosis. The aim of the INVASION project is to assess the potential ecotoxicological impact of a combined sewer overflow (CSO) on a peri-urban stream. A comparative study between upstream and downstream areas of the CSO allowed observing significant effects of this overflow on the river. We studied three layers of stream: surface water, benthic layer and hyporheic layer. To characterize the potential ecotoxicological risk of water and sediments, we used a battery of 4 bioassays: Daphnia magna, Vibrio fischeri, Brachionus calyciflorus and Heterocypris incongruens. In parallel, we measured the physico-chemical parameters: ammonium (NH4+), chromium (Cr), copper (Cu) and lead (Pb). An ecological risk is greatest for the hyporheic zone in downstream river, particularly for the solid phase. These results corroborated with the physico-chemical data obtained.

关键词： Combined Sewer overflow Ecotoxicity Pollutants Stormwater Stream Urban Wet-Weather Flow

来源：

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

On the Importance of Sanitary Sewer overflow on the Total Discharge of Microplastics from Sewage Water

引用

Journal of Environmental Protection 2019年第9期10卷 1105-1118页

作者： Christian Baresel Mikael Olshammar IVL Swedish Environmental Research Institute Stockholm Sweden

The paper provides an investigation and understanding of the significance of various wastewater flows on microplastics retainment and emission to the environment. WWTPs and sewer overflows as an important pathway of microplastics to the environment are assessed by considering the removal of microplastics in WWTPs with different treatment processes and several sewer overflow types and their contribution to microplastic loads to recipients. On the example of the Baltic Sea basin, presented results indicate a considerable discharge of microplastic from WWTPs despite the relatively good overall removal efficiency. Results show that the discharge of microplastics from sewer overflows can be in the same magnitude as from treated wastewater although the total flow is much lower than that of treated wastewater. Sewer overflow events frequently occur and are expected to increase due to climate change and urbanization, unless infrastructure is adapted. At the same time, sewer overflows are often neglected in conventional wastewater handling.

关键词： Microplastics Wastewater Treatment Sanitary Sewer overflow Emissions Baltic Sea Basin

来源：

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

Risk Assessment of Rainwater overflow from Lake Warouwaye in the Case of a Ten-Year Rainfall in Yeumbeul North, Senegal

引用

Open Journal of Modern Hydrology 2021年第3期11卷 39-53页

作者： Benewende Anthelme Victor Sondo Saïdou Ndao Papa Babacar Diop Thioune El Hadji Bamba Diaw Laboratory of Sciences and Technology of Water and Environment (LaSTEE) Polytechnic School of Thiès Thiès Senegal Faculty of Science and Technology University of Thiès Thiès Senegal Higher Institute of Agricultural and Rural Training (ISFAR) University of Thies Bambey Senegal

This study is a part of a global approach in which, the main purpose is to understand the reasons behind the upsurge of flood events in the peri-urban area of the city of Dakar. Hydrological and hydraulics simulations were carried out to assess the risks of overflowing of the Lake Warouwaye after a so-called exceptional rain. Data were collected through field surveys, as well as site observations of dwellings before and after rain episodes. The simulations were performed using EPA’s Storm Water Management Model (SWMM) software with input data obtained from sub-software and supervisory applications such as Google Earth, Excel, and Global Mapper. The simulation results show factors of natural and anthropogenic origin may contribute to dysfunction hydrological elements such as the watershed capacity to drain and store water. In light of the results of this study, institutional governance efforts are to be made and to be sustained in order to reverse the tendency to occupy rainwater natural flow channels. It will also be necessary to involve the first actors who are the potential victims of flooding caused by the recurrent overflow of reservoirs.

关键词： Flood overflow Warouwaye Lake Simulation Epaswmm

来源：

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

DYNAMIC GUARD CHANNEL ASSIGNMENT FOR BIDIRECTIONAL CALL-overflow SCHEME IN HIERARCHICAL CELLULAR SYSTEM

引用

Journal of Electronics(China) 2003年第4期20卷 255-264页

作者： Shan Wenhao Fan Pingzhi(institute of Mobile Communications, Southwest Jiaotong University, Chengdu 610031) Institute of Mobile Communications Southwest Jiaotong University Chengdu 610031

In this paper, a Hierarchical Cellular System (HCS) supporting two classes of users with high and low velocity is considered. Based on the analytical model of the bidirectional calloverflow scheme, a new dynamic guard channel assignment method is proposed In this method, the number of guard channels in both macrocells and microcells varies in realtime according to the different call traffic load in the HCS, and as a result, the lowest dissatisfaction grade of users is achieved.

关键词： HCS overflow Markov process Guard channel Dissatisfaction grade

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Program Slicing Based Buffer overflow Detection

引用

Journal of Software Engineering and Applications 2010年第10期3卷 965-971页

作者： Yingzhou Zhang Wei Fu Xiaofei Qian Wei Chen 不详

The development of the information technology has brought threats to human society when it has influenced seriously the global politics, economics and military etc. But among the security of information system, buffer overrun vulnerability is undoubtedly one of the most important and common vulnerabilities. This paper describes a new technology, named program slicing, to detect the buffer overflow leak in security-critical C code. First, we use slicing technology to analyze the variables which may be with vulnerability and extract the expressions which will bring memory overflow. Secondly, we utilize debug technology to get the size of memory applied by the variable and the size of memory used for these code segments (the slicing result) further. Therefore we can judge whether it will overflow according to the analysis above. According to the unique excellence of program slicing performing in the large-scale program’s debugging, the method to detect buffer overrun vulnerability described in this paper will reduce the workload greatly and locate the code sentences affected by corresponding variable set quickly, particularly including the potential vulnerability caused by parameter dependence among the subroutines.

关键词： Program Slicing Buffer overflow Inter-Procedure Slicing Debug System Dependence Graph

来源：

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

An Efficient overflow Detection and Correction Scheme in RNS Addition through Magnitude Evaluation

引用

Journal of Computer and Communications 2018年第10期6卷 15-29页

作者： Peter Awon-natemi Agbedemnab Stephen Akobre Edem Kwedzo Bankas Department of Computer Science University for Development Studies Navrongo Ghana

Number Systems are media for representing numbers;the popular ones being the Weighted Number Systems (WNS), which sometimes propagate carries during arithmetic computations. The other category, Un-Weighted Number Systems, of which the Residue Number System (RNS) belongs, do not carry weights but have not yet found widespread usage in general purpose computing as a result of some challenges;one of the main challenges of RNS is overflow detection and correction. The presence of errors in calculated values due to such factors as overflow means that systems built on this number system will continue to fail until serious steps are taken to resolve the issue. In this paper, a scheme for detecting and correcting overflow during RNS addition is presented. The proposed scheme used mixed radix digits to evaluate the magnitude of the addends in order to detect the occurrence of overflow in their sum. The scheme also demonstrated a simplified technique of correcting the overflow in the event that it occurs. An analysis of the hardware requirements and speed limitations of the scheme showed that it performs considerably better in relation to similar state of art schemes.

关键词： Number Systems Weighted Number Systems (WNS) Residue Number System (RNS) overflow Detection overflow Correction Faults Mixed Radix Digits (MRDs)

来源：

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

基于CBOW-LDA主题模型的Stack overflow编程网站热点主题发现研究

引用

计算机科学 2018年第4期45卷 208-214页

作者：张景朱国宾武汉大学国际软件学院武汉430079

Stack overflow是一个热门的国外编程问答网站,通过对该网站编程提问帖的问题文本进行文本语义挖掘,能获析用户关注的编程热点。由于研究对象所代表的短文本信息具有高维性及分布不均的特点,易导致主题获取不明晰。文中提出一种基于LDA(... 详细信息

Stack overflow是一个热门的国外编程问答网站,通过对该网站编程提问帖的问题文本进行文本语义挖掘,能获析用户关注的编程热点。由于研究对象所代表的短文本信息具有高维性及分布不均的特点,易导致主题获取不明晰。文中提出一种基于LDA(Latent Dirichlet Allocation)主题模型的CBOW-LDA建模方法,该方法对目标语料进行相似词聚类后再完成主题建模,能有效降低文本输入维度,使主题分布更明确。采集Stack overflow网站上2010-2015年的问题帖数据集POST,并对其进行实验,同等主题数下采用文本建模中衡量模型性能的评价指标困惑度(Perplexity)来度量算法在不同数据集容量维度下的性能。结果表明,与现有的基于词频权重的词量化主题建模TFLDA方法相比,CBOW-LDA方法的困惑度更低,在实验语料下的困惑度降低约4.87%,证明了所提算法的性能更好。采用CBOW-LDA方法对Stack overflow进行热点挖掘,同时使用TF-LDA方法进行对比实验,建立手工标注的标准评测集对两种方法获取的热门主题和热搜词汇进行查全率、查准率及F1值的判定,结果证实CBOW-LDA表现更佳,其热点挖掘效果较好。由实验结果可知,Java为该编程网站提问帖中最热门的主题,而C和Javascript则为该网站用户提问中被提及得最频繁的词汇。

关键词： Stack overflow LDA-CBOW语言模型主题发现热门主题困惑度

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：