检索结果-内蒙古大学图书馆

Soil Organic Carbon Stock as Affected by Land Use/Cover Changes in the Humid Region of Northern Iran

Journal of Mountain science 2014年第2期11卷 507-518页

作者： Samereh FALAHATKAR Seyed Mohsen HOSSEINI Abdolrassoul SALMAN MAHINY Shamsollah AYOUBI WANG Shao-qiang Faculty of Natural Resource and Marine Science Tarbiat Modares University Department of Environmental Sciences Gorgan University of Agricultural Sciences and Natural Resources Department of Soil Sciences College of Agriculture Isfahan University of Technology Key Lab of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research

【Title】【Author】 This study was conducted to determine the changes in the soil carbon stocks as influenced by land use in a humid zone of Deylaman district （10,876 ha）, a mountainous region of northern Iran. For this, land use maps were produced from TM and ETM＋ images for 1985, 2000 and 2010 years; and this was supplemented by field measurement of soil carbon in 2010. The results showed that the mean soil organic carbon （SOC） density was 6.7±1.8 kg C m-2, 5.2±3.4 kg C m-2 and 3.2±1.8 kg C m-2 for 0-20 cm soil layer and 4.8±1.9 kg C m-2, 3.1±2 kg C m-2 and 2.7±1.8 kg C m-2 for 20-40 cm soil layer in forest, rangeland and cultivated land, respectively. During the past 25 years, 14.4% of the forest area had been converted to rangeland; and 28.4% of rangelands had been converted to cultivated land. According to the historical land use changes in the study area, the highest loss of SOC stocks resulted from the conversion of the forest to rangeland （0.45×104 Mg C in 0-40 cm depth layer）; and the conversion of rangeland to cultivated land （0.37×104 Mg C in 0-40 cm）, which typically led to the loss of soil carbon in the area studied. The knowledge on the historical land use changes and its influence on overall SOC stocks could be helpful for making management decision for farmers and policy managers in the future, for enhancing the potential of C sequestration in northern Iran.

关键词： Soil organic carbon stocks Land cover Land use Iran

来源：评论

学校读者我要写书评

暂无评论

Make It Possible: Multilingual Sentiment Analysis without Much Prior Knowledge

Make It Possible: Multilingual Sentiment Analysis without Mu...

引用

IEEE WIC ACM International Conference on Web Intelligence (WI)

作者： Zheng Lin Xiaolong Jin Xueke Xu Yuanzhuo Wang Songbo Tan Xueqi Cheng CAS Key Laboratory on Network Data Science and Technology Institute of Computing Technology Chinese Academy of Sciences Beijing China

ISBN: (纸本)9781479941421

Sentiment analysis is a hard problem, while multilingual sentiment analysis is even harder due to the different expression styles in different languages. Although many methods for multilingual sentiment analysis have been developed in the open literature, most of them suffer from two major problems. The first is their excessive dependence on external tools or resources (e.g., Machine translation systems or bilingual dictionaries), which may not be readily obtained, especially for minority languages, The second is conflictive sentiments, i.e., The sentiment polarity of some parts of a text is inconsistent with its overall sentiment polarity. It is observed that in a product or service review there usually exist a few sentences which play a more important role in determining its sentiment polarity, as compared to others. Therefore, differentiating key sentences from trivial ones may be helpful to improve sentiment analysis. Inspired by this observation in this paper we propose a novel framework to estimate the sentiment polarity of reviews by virtue of opinion lexica and key sentences automatically extracted from unlabelled data. This framework cannot only overcome the problem of excessive dependence on external resources, but also is able to capture the overall sentiment polarity of reviews. Experimental results on realistic review datasets demonstrate that the proposed framework is effective and competitive with the representative baselines.

关键词： Sentiment analysis Dictionaries data mining Training Algorithm design and analysis Google Feature extraction

来源：评论

学校读者我要写书评

暂无评论

A filtering algorithm for scattered point cloud based on curvature features classification

引用

Journal of Information and Computational science 2015年第2期12卷 525-532页

作者： Gu, Xiaoying Liu, Yongshan Wu, Qiong College of Information Science and Engineering Yanshan University Qinhuangdao China The Key Laboratory for Computer Virtual Technology and System Integration of Hebei Province Yanshan University Qinhuangdao China Data Industry Research Lab Qinhuangdao China

In order to remove the noise of three-dimensional scattered point cloud, and to smooth point cloud model effectively, an algorithm which uses different filtering strategies on different feature regions of a point cloud model is proposed. The algorithm firstly estimates the normal vectors of a point cloud model by using covariance analysis method, then estimates Gaussian curvatures of the point cloud model by using parabolic fitting method, and uses the average Gaussian curvature in the k-neighborhood as the threshold, to divide the point cloud model into flat neighborhood type regions and mutant neighborhood type regions, and, we use improved median filtering algorithm and bilateral filtering algorithm on different feature regions, so as to achieve the purpose of smoothing scattered point cloud. Experimental results show that it has a very good smoothing effect and maintains the detail features of the point cloud model, which has proved the algorithm is simple and effective. Copyright © 2015 Binary Information Press.

关键词： Three dimensional computer graphics

来源：评论

学校读者我要写书评

暂无评论

Constrained least squares regression for semi-supervised learning

Constrained least squares regression for semi-supervised lea...

引用

18th Pacific-Asia Conference on Advances in Knowledge Discovery and data Mining, PAKDD 2014

作者： Liu, Bo Jing, Liping Yu, Jian Li, Jia Beijing Key Lab. of Traffic Data Analysis and Mining Beijing Jiaotong University Beijing 100044 China College of Information Science and Technology Agricultural University of Hebei Hebei 071000 China

ISBN: (纸本)9783319066042

The core tasks of graph based semi-supervised learning (GSSL) are constructing a proper graph and selecting suitable supervisory information. The ideal graph is able to outline the intrinsic data structure, and the ideal supervisory information could represent the whole data. In this paper, we propose a new graph learning method, called constrained least squares regression (CLSR), which integrates the supervisory information into graph learning process. To learn a more adaptive graph, regression coefficients and neighbor relations are combined in CLSR to capture the global and local data structures respectively. Moreover, as byproduct of CLSR, a new strategy is presented to select the high-quality data points as labeled samples, which is practical in real applications. Experimental results on different real world datasets demonstrate the effectiveness of CLSR and the sample selection strategy. © 2014 Springer International Publishing.

关键词： Least squares approximations

来源：评论

学校读者我要写书评

暂无评论

A new adaptive universal fuzzy inference system with application 6

A new adaptive universal fuzzy inference system with applica...

引用

6th International Conference on Fuzzy Computation Theory and Applications, FCTA 2014, Part of the 6th International Joint Conference on Computational Intelligence, IJCCI 2014

作者： Chai, Yuan Yuan Chen, Jun Luo, Wei Jia, Li Min Network Center China Defense Science and Technology Information Center Fucheng Road 26# Beijing China State Key Lab of Rail Traffic Control and Safety Beijing Jiaotong University Beijing China

ISBN: (纸本)9789897580536

Through comprehensive study on existing fuzzy inference systems, this paper presents a Choquet integral-OWA operator based fuzzy inference system (AggFIS) in order to solve the traditional FIS disadvantages and its adaptive model which is named Choquet integral-OWA operator based adaptive universal fuzzy inference system (Agg-AUFIS). By considering the universal fuzzy inference operators and importance factor during reasoning process, Agg-AUFIS tries to express the essence of fuzzy logic and simulate human thinking pattern sufficiently, which could provide a new methodology for fuzzy modeling in future.

关键词： Fuzzy inference

来源：评论

学校读者我要写书评

暂无评论

One forward-secure signature scheme using bilinear maps and its applications

One forward-secure signature scheme using bilinear maps and ...

引用

作者： Yu, Jia Kong, Fanyu Cheng, Xiangguo Hao, Rong Li, Guowen College of Information Engineering Qingdao University 266071 Qingdao China Shandong Provincial Key Laboratory of Computer Network 250014 Jinan China Institute of Network Security Shandong University 250100 Jinan China Key Lab of Cryptographic Technology and Information Security Ministry of Education Jinan 250100 China School of Computer Science and Technology Shandong Jianzhu University 250100 Jinan China

Forward-secure signatures are proposed to deal with the key exposure problem. Compared to regular signatures, forward-secure signatures have a special update algorithm that can evolve the new private key in each time period. Therefore, it can protect the security of signatures previous to the time period of key exposure. The efficiency is an important issue of forward-secure signatures. In this paper, we construct a new forward-secure signature scheme using bilinear maps. In this scheme, all performance parameters have complexities of log magnitude in terms of the total time periods. In addition, our scheme needs very few (only triple) pairing operations in the verifying algorithm, which is very important because the pairing operation is very time-consuming. This scheme is proved to be forward secure in the random oracle model assuming the CDH problem is hard. Finally, we give some applications of this scheme including constructing an intrusion-resilient signature scheme and constructing a forward-secure threshold signature scheme. © 2014 Elsevier Inc. All rights reserved.

关键词： Authentication

来源：评论

学校读者我要写书评

暂无评论

OpenKN: An open knowledge computational engine for network big data

OpenKN: An open knowledge computational engine for network b...

引用

International Conference on Advances in Social network Analysis and Mining, ASONAM

作者： Yantao Jia Yuanzhuo Wang Xueqi Cheng Xiaolong Jin Jiafeng Guo CAS Key Laboratory of Network Data Science and Technology Chinese Academy of Sciences Beijing P. R. China

With the coming of the era of big data, it is most urgent to establish the knowledge computational engine for the purpose of discovering implicit and valuable knowledge from the huge, rapidly dynamic, and complex network data. In this paper, we first survey the mainstream knowledge computational engines from four aspects and point out their deficiency. To cover these shortages, we propose the open knowledge network (OpenKN), which is a self-adaptive and evolutionable knowledge computational engine for network big data. To the best of our knowledge, this is the first work of designing the end-to-end and holistic knowledge processing pipeline in regard with the network big data. Moreover, to capture the evolutionable computing capability of OpenKN, we present the evolutionable knowledge network for knowledge representation. A case study demonstrates the effectiveness of the evolutionable computing of OpenKN.

关键词： Knowledge based systems Knowledge engineering Big data Engines Syntactics Semantics data mining

来源：评论

学校读者我要写书评

暂无评论

The Realization of Hierarchical Visualization Methods for database Performance

The Realization of Hierarchical Visualization Methods for Da...

引用

2012 International Conference on Applied Informatics and Communication(ICAIC 2012)

作者： Yang Tang Mengdong Chen Zheren Li School of Computer Science and Engineering Key Lab.Of Beijing Network Technology Beihang University

database,as the role of providing data services for many applications,has become increasingly ***,in order to ensure the normal operation of the database and facilitate the query of the database administrator,the performance platform of database should be simple,intuitive and structured to display the usage of database ***,the current database performance platform is not structured enough to display the relationship among kinds of parameters and it is inconvenient to generally master the performance *** response to all of these problems,this paper will display these performance parameters using hierarchy visualization *** paper will focus on two hierarchical visualization methods,tree-maps and space tree *** advantages of these two methods in the database performance parameters will be illustrated by achieving a database performance *** results of display will be compared as ***,this paper will give some prospects to other approaches of hierarchy visualization in database performance.

关键词： Hierarchical visualization database performance Space Tree Tree-maps

来源：评论

学校读者我要写书评

暂无评论

Social evolutionary games

Social evolutionary games

引用

International Conference on Game Theory for networks, GameNets

作者： Jianye Yu Yuanzhuo Wang Xiao!ong Jin Xueqi Cheng CAS Key Laboratory of Network Data Science and Technology Institute of Computing Technology Chinese Academy of Sciences University of Chinese Academy of Sciences Beijing China

In this paper, we introduce a framework of social evolutionary games (SEG) for investigating the evolution of social networks. In a SEG, a coevolutionary mechanism is adopted by agents who aim to improve his short-term utility and long-term reputation. Two examples are presented to demonstrate SEG, prisoner's dilemma game for pairwise interaction and public goods game for group interaction. Numerical simulations are performed on the two examples with different parameter settings, and the results indicates that SEG can be used as a metaphor for investigating the evolution of social networks in some scenarios.

关键词： Microscopy

来源：评论

学校读者我要写书评

暂无评论

Sequential and adaptive sampling for matrix completion in network monitoring systems

Sequential and adaptive sampling for matrix completion in ne...

引用

IEEE Annual Joint Conference: INFOCOM, IEEE Computer and Communications Societies

作者： Kun Xie Lele Wang Xin Wang Gaogang Xie Guangxing Zhang Dongliang Xie Jigang Wen College of Computer Science and Electronics Engineering Hunan University Changsha China State Key Lab of Networking & Switching Tech. Beijing Univ. of Posts and Telecomm. China Department of Electrical and Computer Engineering State University of New York at Stony Brook USA Institute of Computing Technology Chinese Academy of Sciences Beijing China DNSLAB China Internet Network Information Center Beijing China

End-to-end network monitoring is essential to ensure transmission quality for Internet applications. However, in large-scale networks, full-mesh measurement of network performance between all transmission pairs is infeasible. As a newly emerging sparsity representation technique, matrix completion allows the recovery of a low-rank matrix using only a small number of random samples. Existing schemes often fix the number of samples assuming the rank of the matrix is known, while the data features thus the matrix rank vary over time. In this paper, we propose to exploit the matrix completion techniques to derive the end-to-end network performance among all node pairs by only measuring a small subset of end-to-end paths. To address the challenge of rank change in the practical system, we propose a sequential and information-based adaptive sampling scheme, along with a novel sampling stopping condition. Our scheme is based only on the data observed without relying on the reconstruction method or the knowledge on the sparsity of unknown data. We have performed extensive simulations based on real-world trace data, and the results demonstrate that our scheme can significantly reduce the measurement cost while ensuring high accuracy in obtaining the whole network performance data.

关键词： Monitoring Sparse matrices Matrix decomposition Computers Accuracy Conferences Internet

来源：评论

学校读者我要写书评

暂无评论

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

请选择保存的检索档案：

请选择收藏分类：

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

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

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：