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Estimation of aboveground biomass using in situ hyperspectral measurements in five major grassland ecosystems on the Tibetan Plateau

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Journal of Plant Ecology 2008年第4期1卷 247-257页

作者： Miaogen Shen Yanhong Tang Julia Klein Pengcheng Zhang Song Gu Ayako Shimono Jin Chen State Key Laboratory of Earth Surface Processes and Resource Ecology Academy of Disaster Reduction and Emergency ManagementBeijing Normal UniversityBeijing 100875China National Institute for Environmental Studies TsukubaIbaraki 305-8569Japan Colorado State University Fort CollinsCO 80523USA Terrestrial Ecology Lab Graduate School of Life and Environment ScienceUniversity of TsukubaTennodai 1-1-1TsukubaIbaraki 305-8577Japan Northwest Plateau Institute of Biology Chinese Academy of ScienceXining 810001China

Aims There are numerous grassland ecosystem types on the Tibetan *** include the alpine meadow and steppe and degraded alpine meadow and *** study aimed at developing a method to estimate aboveground biomass(AGB)for these grasslands from hyperspectral data and to explore the feasibility of applying air/satellite-borne remote sensing techniques to AGB estimation at larger *** We carried out a field survey to collect hyperspectral reflectance and AGB for five major grassland ecosystems on the Tibetan Plateau and calculated seven narrow-band vegetation indices and the vegetation index based on universal pattern decomposition(VIUPD)from the spectra to estimate ***,we investigated correlations between AGB and each of these vegetation indices to identify the best estimator of AGB for each ecosystem ***,we estimated AGB for the five pooled ecosystem types by developing models containing dummy *** last,we compared the predictions of simple regression models and the models containing dummy variables to seek an ecosystem type-independent model to improve prediction of AGB for these various grassland ecosystems from hyperspectral *** findings When we considered each ecosystem type separately,all eight vegetation indices provided good estimates of AGB,with the best predictor of AGB varying among different *** AGB of all the five ecosystems was estimated together using a simple linear model,VIUPD showed the lowest prediction error among the eight vegetation *** regression models containing dummy variables predicted AGB with higher accuracy than the simple models,which could be attributed to the dummy variables accounting for the effects of ecosystem type on the relationship between AGB and vegetation index(VI).These results suggest that VIUPD is the best predictor of AGB among simple regression ***,both VIUPD and the soil-adjusted VI could provide accurate estimates of AGB with d

关键词： biomass estimation dummy variable hyperspectral remote sensing Tibetan Plateau regression analysis vegetation index VIUPD

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Cointegration analysis with structural changes between consumption and economic growth in China

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Journal of Southeast University(English Edition) 2006年第2期22卷 238-241页

作者：郭建平何建敏东南大学经济管理学院南京210096

In order to investigate the existence of a stable long-run equilibrium relationship between economic growth and consumption in China, the relationship between the gross domestic product （GDP） and consumption in China was investigated by the cointegration analysis method. Using the Engle-Granger （EG） test and considering the possibility of structural changes, the impact of external economic shocks on the long-run equilibrium relationship between economic growth and consumption in China was analyzed. Analysis results show that without considering structural changes, the EG test cannot detect cointegration in the series subjected to structural changes; in considering structural changes, cointegration is successfully detected by specifying the dummy variable. In addition, the error correction models were constructed in different periods. This study verifies the existence of a long-run equilibrium relationship between economic growth and consumption in China, and this relationship has significantly changed in 1989 and 1997, respectively.

关键词： cointegration with structural changes economic growth dummy variable consumption error correction model

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Regression Analysis on the Causes of the International Gold Prices Rising

Regression Analysis on the Causes of the International Gold ...

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第三届教学管理与课程建设学术会议

作者： Xiaoxue Wang 1 , Zhiqiang Luan 2 1 International College Beijing, China Agricultural University, Beijing, China, 100083 2 : International College Beijing, China Agricultural University, Beijing, China, 100083

Gold has experienced appreciation for nine years since 2001. This paper analyzes the causes of the international gold price rise. From the data of gold prices for recent years, the causes are summaried: political cause and economic causes which include the price of the silver, the price of oil, S&P500 (stock market), inflation of the U.S. and the federal interest rate. And illustrate what different with widely accepted outcomes of the relationships with the trend of dollar exchange rate, supply of gold.

关键词： gold price regression model dummy variable financial analysis

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泰国对华烟胶片出口贸易影响因素研究

泰国对华烟胶片出口贸易影响因素研究

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作者： SIRINYA SUWANNAWONG 南京农业大学

学位级别：硕士

This study was conducted with two main objectives:firstly, to study and analyze for factors that have some impact on the export of Thailand in exporting RSS3 to China;and secondly, to study about adaptation of rubber farmers when there are changes in such factors. For the second objective, a case study method was conducted with the "Bungkan Para Rubber Group" Agriculture Lovers Community Enterprise, Kokkong sub-district, Muang district, Bungkan *** analyzing for influences of relevant factors on Ribbed Smoked Sheets Grade 3 export of Thailand to China, the study employed the technique of multiple regression models, which were solved by the method of ordinary least square (OLS). Trimester time-series data from 2001 to 2010 were used for the analysis, which was based on the theory of Learner and Sterne (1970) and some other reviewed literature. The analysis result revealed that factors affecting Ribbed Smoked Sheets Grade 3 export of Thailand to China included 1)price of Block Rubber or STR20 (which is a substitute good of RSS3 for producing car tires in the motor vehicular industry);2) price of Tyre Cord Fabric (which is a complementary good of Ribbed Smoked Sheets Grade 3 for producing car tires);3) a dummy variable that represents an impact from the opening of the R3A route that connects China-Laos-Thailand;and 4) a dummy variable that represents impact from the ASEAN-China *** adaptation of rubber farmers when there are changes in factors influencing RSS3 export from Thailand to China, the case study was conducted by employing the adaptation framework of John W. Bennet (1969) together with the facts as obtained from the in-depth interviews. Without using a questionnaire, the in-depth interviews were conducted with 2 groups of stakeholders namely:1) the Ribbed Smoked Sheets Grade 3 export association of Thailand, the Ribbed Smoked Sheets Grade 3 factory association of Thailand, and the Ribbed Smoked Sheets Grade 3 factory association of Northeas

关键词： export Ribbed Smoked Sheets Grade 3 multiple regression models ordinary least square Trimester time-series data factors affecting dummy variable the in- depth interviews

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