检索结果-南通市图书馆

Remote sensing based shrub above-ground biomass and carbon storage mapping in Mu Us desert,china

Science china(Technological sciences) 2010年第S1期53卷 176-183页

作者： XU Min 1,2,CAO ChunXiang 1,TONG QingXi 1,LI ZengYuan 3,ZHANG Hao 1,HE QiSheng 1,2,GAO MengXu 1,2,ZHAO Jian 1,2,ZHENG Sheng 1,2,CHEN Wei 1,2 & ZHENG LanFen 1 1state key laboratory of Remote Sensing Science,Jointly Sponsored by the Institute of Remote Sensing Applications of chinese academy of sciences and beijing Normal university,beijing 100101,china 2 graduate School of the chinese academy of sciences,beijing 100049,china 3 Research Institute of Forest Resources and information Techniques,chinese academy of Forestry,beijing 10009,china state key laboratory of Remote Sensing Science Jointly Sponsored by the Institute of Remote Sensing Applications of Chinese Academy of Sciences and Beijing Normal University Beijing China graduate School of the chinese academy of sciences Beijing China Research Institute of Forest Resources and information Techniques Chinese Academy of Forestry Beijing China

The estimation of above-ground biomass(AGB) and carbon storage is very important for arid and semi-arid ***-1A/B satellite data combined with field measurement data was used for the estimation of shrub AGB and carbon storage in the Mu Us desert,*** correlations of shrub AGB and spectral reflectance of four bands as well as their combined vegetation indexes were respectively analyzed and stepwise regression analysis was employed to establish AGB prediction *** prediction equation based on ratio vegetation index(RVI)was proved to be more suitable for shrub AGB estimation in the Mu Us desert than *** AGB and carbon storage were mapped using the RVI based prediction model in *** statistics showed the western Mu Us desert has relatively high AGB and carbon storage,and that the gross shrub carton storage in Mu Us desert reaches 16 799 200 t,which has greatly contributed to the carbon fixation in northern china.

关键词： above-ground biomass carbon storage Mu Us desert HJ-1A/B remote sensing

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

A prototype auto-human support system for spatial analysis

引用

Progress in Natural Science:Materials International 2006年第9期16卷 954-966页

作者： LI Lianfa and WANG Jinfeng (state key laboratory of Resources & Environmental information System, Institute of Geographical sciences & Natural Resources Research, chinese academy of sciences, beijing 100101, china) state key laboratory of Resources and Environmental information System Institute of Geographical Sciences and Natural Resources Re-search Chinese Academy of Sciences Beijing 100101 China

Spatial analysis is a multidisciplinary field that involves multiple influential factors, variation and uncertainty, and modeling of geospatial data is a complex procedure affected by spatial context, mechanism and assumptions. In order to make spatial modeling easier, some scholars have suggested a lot of knowledge from exploratory data analysis (EDA), specification of the model, fitness and diagnosis of the model, to interpretation of the model. Also an amount of software has improved some functionalities of spatial analysis, e. g. EDA by the dynamic link (GeoDa) and robust statistical calculation (R). However, there are few programs for spatial analysis that can automatically deal with unstructured declarative issues and uncertainty in machine modeling using the domain knowledge. Under this context, this paper suggests a prototype support system for spatial analysis that can automatically use experience and knowledge from the experts to deal with complexity and uncertainty in modeling. The knowledge base component, as the major contribution of the system, in support of the expert system shell, codes and stores declarative modeling knowledge, e.g. spatial context, mechanisms and prior knowledge to deal with declarative issues during the modeling procedure. With the open architecture, the system integrates functionalities of other components, e.g. GIS’ visualization, DBMS, and robust calculation in an interactive environment. An application case of spatial sampling, design and implementation of spatial modeling with such a system is demonstrated.

关键词： spatial analysis automatic support system modeling of spatial data artificial inference for modeling.

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

The roles of a decision support system in applying forest ecosystem management in Northeast china

引用

Science china(Technological sciences) 2006年第Z1期49卷 9-18页

作者： DAI Limin, ZHENG Bofu, Guofan Shao & ZHOU Li state key Lab of Systems Ecology, Research Center for Eco-Environmental sciences, chinese academy of sciences, beijing 100085, china Institute of Applied Ecology, chinese academy of sciences, Shenyang 110016, china Department of Forestry and Natural Resources, Purdue university, West Lafayette, IN 47907, USA graduate university of chinese academy of sciences, beijing 100101, china state key Lab of Systems Ecology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing China Institute of Applied Ecology Chinese Academy of Sciences Shenyang China Department of Forestry and Natural Resources Purdue University West Lafayette USA graduate university of chinese academy of sciences Beijing China

Forest ecosystems provide a variety of services and forest ecosystem management (FEM) is an effective approach to maximize the services. Because of the complexity of forest ecosystems, the applications of FEM can be facilitated with decision support systems (DSS) that recognize and incorporate ecological and socio-economic variables. With the rapid development of computation and information technologies, DSS have been advanced in many ways. Traditional forest management within a forestry unit in china is planned on a yearly basis. The planning itself remains primarily a verbal concept as there are no quantitative decision-support tools available to translate the concept into forest management actions. For the purposes of FEM at the management level, a forest management DFF, FORESTAR, has been developed under a framework of geographic information system (GIS) and forest models. The paper explained the intelligent modeling mechanisms and demonstrated how the applications of FEM can be strengthened with the applications of FORESTAR.

关键词： forest functions, forested landscapes, forest services, forest models, geographic information systems.

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

Accountable authority key policy attribute-based encryption

引用

Science china(information sciences) 2012年第7期55卷 1631-1638页

作者： WANG YongTao 1,2 ,CHEN KeFei 1,3 ,LONG Yu 1,4 & LIU ZhaoHui 2 1 Department of Computer Science and Engineering,Shanghai Jiao Tong university,Shanghai 200240,china 2 china information Technology security Evaluation Center,beijing 100085,china 3 Shanghai key laboratory of Scalable Computing and Systems,Shanghai Jiao Tong university,Shanghai,200240,china 4 state key laboratory of information security,graduate School of chinese academy of sciences,100039,china Department of Computer Science and Engineering Shanghai Jiao Tong University Shanghai China china information Technology security Evaluation Center Beijing China Shanghai key laboratory of Scalable Computing and Systems Shanghai Jiao Tong University Shanghai China state key laboratory of information security Graduate School of Chinese Academy of Sciences Beijing China

We present an accountable authority key policy attribute-based encryption (A-KPABE) *** this paper,we extend Goyal's work to key policy attribute-based encryption *** first generalize the notion of accountable authority in key policy attribute-based encryption scenario,and then give a *** addition,our scheme is shown to be secure in the standard model under the modified Bilinear Decisional Diffie-Hellman (mBDDH) assumption.

关键词： accountable authority key policy attribute-based encryption standard model access structure

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Induction of chromosomal inversion by integration of T-DNA in the rice genome

引用

Journal of Genetics and Genomics 2010年第3期37卷 189-196页

作者： Chuanfeng Zhu,Jiahe Wu,Chaozu He state key laboratory of Plant Genomics,Institute of Microbiology,chinese academy of sciences,beijing 100101,china state key laboratory of Plant Genomics Institute of Microbiology Chinese Academy of Sciences Beijing 100101 China

Transfer DNA （T-DNA） of Agrobacterium tumefaciens integration in the plant genome may lead to rearrangements of host plant chromosomal fragments, including inversions. However, there is very little information concerning the inversion. The present study re- ports a transgenic rice line selected from a T-DNA tagged population, which displays a semi-dwarf phenotype. Molecular analysis of this mutant indicated an insertion of two tandem copies of T-DNA into a locus on the rice genome in a head to tail mode. This insertion of T-DNA resulted in the inversion of a 4.9 Mb chromosomal segment. Results of sequence analysis suggest that the chromosomal inversion resulted from the insertion of T-DNA with the help of sequence microhomology between insertion region of T-DNA and target sequence of the host plant.

关键词： Agrobacterium tumefaciens-mediated transformation (ATMT) T-DNA chromosomal inversion

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

Instantiate Random Oracles in OAEP with Pseudorandom Functions

引用

Wuhan university Journal of Natural sciences 2008年第6期13卷 651-656页

作者： JIA Xiaoying LI Hongda LI Bao state key laboratory of information security/graduate university of chinese academy of sciences Beijing 100049 China

This paper focuses on the instantiation of random oracles in public key encryption schemes. A misunderstanding in the former instantiations is pointed out and analyzed. A method of using this primitive as a substitution of random oracles is also proposed. The partial and full instantiations of random oracles in optimal asymmetric encryption padding （OAEP） implemented by pseudorandom functions are described and the resulted schemes are proven to be indistinguishable secure against adaptive chosen ciphertext attack （IND-CCA2） secure. Using this method, one can transform a practical public key encryption scheme secure in the random oracle model into a standard-model secure scheme. The security of the scheme is based on computational assumptions, which is weaker than decisional assumptions used in Cramer- Shoup like schemes.

关键词： random oracle(RO) model instantiation optimal asymmetric encryption padding(OAEP) indistinguishable securitity against adaptive chosen ciphertext attack (IND-CCA2)

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

New application methods for word-oriented cryptographic primitives

引用

Science china(information sciences) 2012年第9期55卷 2149-2160页

作者： YANG Yang 1,2,ZENG Guang 1,2,JIN ChengHui 1 & QU YunYing 1 1 Zhengzhou information Science and Technology Institute,Zhengzhou 450002,china 2.state key laboratory of information security,Institute of Software,chinese academy of sciences,beijing 100190,china Zhengzhou information Science and Technology Institute Zhengzhou China state key laboratory of information security Institute of Software Chinese Academy of Sciences Beijing China

Modern software oriented symmetric ciphers have become a key feature in utilizing word-oriented cryptographic *** the output sequence,in the order of its generation,of a word-oriented cryptographic primitive in the same way as traditional bit-oriented primitives,we can expose the intrinsic weakness of these primitives,especially for word-oriented linear feedback shift registers,T-functions,and so *** new methods for using word-oriented cryptographic primitives are presented in this paper,that is,the extracted state method and cascading extracted coordinate *** a T-function as an example,we research the different cryptographic properties of the output sequences of the original method and the two proposed methods,focusing mainly on period,linear complexity,and k-error linear *** conclusions show that the proposed methods could enhance at low cost the cryptographic properties of the output *** a result,since the new methods are simple and easy to implement,they could be used to design new word-oriented cryptographic primitives.

关键词： stream cipher single cycle T-function linear complexity k-error linear complexity

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Estimation of forest volumes by integrating Landsat TM imagery and forest inventory data

引用

Science china(Technological sciences) 2006年第Z1期49卷 54-62页

作者： GU Huiyan, DAI Limin, WU Gang, XU Dong, WANG Shunzhong &WANG Hui Institute of Applied Ecology, chinese academy of sciences, Shenyang 110016, china School of Forestry, Northeast Forestry university, Harbin 150040, china state key Lab of Systems Ecology, Research Center for Eco-Environmental sciences, chinese academy of sciences, beijing 100085, china graduate university of chinese academy of sciences, beijing 100039, china Institute of Applied Ecology Chinese Academy of Sciences Shenyang China School of Forestry Northeast Forestry University Harbin China state key Lab of Systems Ecology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing China graduate university of chinese academy of sciences Beijing China

Accurate information about forest volumes is essential for forest management planning. The survey interval of the Forest Resource Inventory of china (FRIC) is too long to meet the demand for timely decision-making required for forest protection, management, and utilization. Analysis of satellite imagery provides good potential for more frequent reporting of forest parameters. In this study, we describe an application of the k-nearest neighbors (kNN) method to Landsat TM imagery for improving estimation of forest volumes. Several spectral features were tested and compared in forest volume estimations, including normalized difference vegetation index, environmental vegetation index, and the combination of the spectral features. The combined index resulted in the most accurate volume estimations. The kNN estimator and the combined index were then used in forest volume estimation. The estimation error (RMSE) of the total volume was44.2%, much lower than those for Larix forest (the RMSE was 51.7%) and those for the Korean pine and broadleaved forests (the estimation errors were over 71.7% and 88.19%,respectively). This preliminary study demonstrates the potential of forest volume estimations with remote sensing data to provide useful information for forest management if only limited ground information is available.

关键词： forest inventory, landsat TM, k-nearest neighbors, spectral extraction.

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

Seasonal patterns of spatial differentiation of landcover change in china

引用

chinese Science Bulletin 1999年第4期44卷 362-364页

作者： CHEN Yufengstate key laboratory of Resource and Environment information System , Institute of Geography, chinese academy of sciences, beijing 100101, china state key laboratory of Resource and Environment information System Institute of Geography Chinese Academy of Sciences Beijing China

Using the 1°×1° NOAA AVHRR NDVI data set in china, an index on the spatial different gradient of landcover is created. Then based on the index and supported by the geographical information system, it is revealed through principal component and factor analyses methods that there exist four types of seasonal patterns of spatial differentiation of landcover change in china, i.e. November to next March type, June to September type, May or October type and April type.

关键词： landcover spatial differentiation seasonal pattern.

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

Monitoring of rice crop using ENVISAT ASAR data

引用

Science china Earth sciences 2006年第7期49卷 755-763页

作者： DONG Yanfang1, 2, SUN Guoqing1,3 & PANG Yong4 1. state key laboratory of Remote Sensing Science, Institute of Remote Sensing Applications, chinese academy of sciences, beijing 100101, china 2. graduate university of chinese academy of sciences, beijing 100039, china 3. Department of Geography, university of Maryland, College Park, MD 20742, USA 4. Forest Remote Sensing Lab, Research Institute of Forest Resource and information Technology, chinese academy of For-estry, beijing 100091, china state key laboratory of Remote Sensing Science Institute of Remote Sensing Applications Chinese Academy of Sciences Beijing China graduate university of chinese academy of sciences Beijing China Department of Geography University of Maryland College Park USA Forest Remote Sensing Lab Research Institute of Forest Resource and Information Technology Chinese Academy of Forestry Beijing China

Because of the cloudy conditions during the rice growth period, rice is one of the agri-cultural crops most suited to monitoring with the SAR instruments. Backscatter response measured by SAR is correlated with rice conditions, including height, density, biomass and structure, which are variable at different growing stages. In this paper, multi-date ENVISAT ASAR Alternating Polarization Mode (APMode) imageries were acquired during the rice crop growing cycle. At the same time, the rice parameters were measured in field. A continuous canopy model was used to compute the back-scattering from rice fields during the growth cycle, and the relationship between rice parameters and radar backscattering coefficients from both ASAR and modeling was analyzed. The effects of polari-zation, incidence angle and polarization on radar backscattering coefficients were analyzed. It was found that simulated radar backscatter has similar trends as ASAR data. This will be meaningful for the further research of rice parameters estimation from ASAR data. Different features show signifi-cantly different signatures in ASAR images and they follow some certain laws, so rice area can be accurately mapped by using multi-temporal SAR images, then rice yield can be estimated.

关键词： rice, ASAR, radar backscattering, model.

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：