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Search Results: 1 - 10 of 19767 matches for " CHANG Chenghu "
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w-MPS Risk Aversion and the CAPM  [PDF]
Phelim P. Boyle, Chenghu Ma
Theoretical Economics Letters (TEL) , 2013, DOI: 10.4236/tel.2013.36052

This paper establishes general conditions for the validity of mutual fund separation and the equilibrium CAPM. We use partial preference orders that display weak form mean preserving spread (w-MPS) risk aversion in the sense of Ma (2011). We derive this result without imposing any distributional assumptions on asset returns. The results hold even when the market contains an infinite number of securities and a continuum number of traders, and when each investor is permitted to hold some (arbitrary) finite portfolios. A proof of existence of equilibrium CAPM is provided for finite economies by assuming that when preferences are constrained on the market subspace spanned by the risk free bond, the market portfolios admit continuous utility representations.


Medical colleges summary of biomedical engineering profession
—Luzhou Medical College in the perspective of biomedical engineering profession

Bangtao Liu, Min Luo, Minjun Li, Xiaoyu Kang, Chenghu Zhang
Journal of Biomedical Science and Engineering (JBiSE) , 2013, DOI: 10.4236/jbise.2013.63035
Abstract: This paper expounds professional characteristics of biomedical engineering in our school, and analyses some problems lying in it, emphatically discusses advantages and the problems combining biomedical engineering with the medical courses in order to offer targeted solutions. It summarizes the results and problems so as to provide reference value to a new major.
A partial least-squares regression approach to land use studies in the Suzhou-Wuxi-Changzhou region

ZHANG Yang,ZHOU Chenghu,

地理学报 , 2007,
Abstract: In several LUCC studies, statistical methods are being used to analyze land use data. A problem using conventional statistical methods in land use analysis is that these methods assume the data to be statistically independent. But in fact, they have the tendency to be dependent, a phenomenon known as multicollinearity, especially in the cases of few observations. In this paper, a Partial Least-Squares (PLS) regression approach is developed to study relationships between land use and its influencing factors through a case study of the Suzhou-Wuxi-Changzhou region in China. Multicollinearity exists in the dataset and the number of variables is high compared to the number of observations. Four PLS factors are selected through a preliminary analysis. The correlation analyses between land use and in-fluencing factors demonstrate the land use character of rural industrialization and urbaniza-tion in the Suzhou-Wuxi-Changzhou region, meanwhile illustrate that the first PLS factor has enough ability to best describe land use patterns quantitatively, and most of the statistical relations derived from it accord with the fact. By the decreasing capacity of the PLS factors, the reliability of model outcome decreases correspondingly.
Analysis and comparison of spatial interpolation methods for temperature data in Xinjiang Uygur Autonomous Region, China  [PDF]
Huixia Chai, Weiming Cheng, Chenghu Zhou, Xi Chen, Xiaoyi Ma, Shangming Zhao
Natural Science (NS) , 2011, DOI: 10.4236/ns.2011.312125
Abstract: Spatial interpolation methods are frequently used to estimate values of meteorological data in locations where they are not measured. However, very little research has been investigated the relative performance of different interpolation methods in meteorological data of Xinjiang Uygur Autonomous Region (Xinjiang). Actually, it has importantly practical significance to as far as possibly improve the accuracy of interpolation results for meteorological data, especially in mountainous Xinjiang. There- fore, this paper focuses on the performance of different spatial interpolation methods for monthly temperature data in Xinjiang. The daily observed data of temperature are collected from 38 meteorological stations for the period 1960- 2004. Inverse distance weighting (IDW), ordinary kriging (OK), temperature lapse rate method (TLR) and multiple linear regressions (MLR) are selected as interpolated methods. Two rasterized methods, multiple regression plus space residual error and directly interpolated observed temperature (DIOT) data, are used to analyze and compare the performance of these interpolation methods respectively. Moreover, cross-validation is used to evaluate the performance of different spatial interpolation methods. The results are as follows: 1) The method of DIOT is unsuitable for the study area in this paper. 2) It is important to process the observed data by local regression model before the spatial interpolation. 3) The MLR-IDW is the optimum spatial interpolation method for the monthly mean temperature based on cross-validation. For the authors, the reliability of results and the influence of measurement accuracy, density, distribution and spatial variability on the accuracy of the interpolation methods will be tested and analyzed in the future.
Stability of patches of oasis landscape in arid areas: A case study of Sangong River Watershed, Xinjiang, China
Geping Luo,Chenghu Zhou,Xi Chen
Chinese Science Bulletin , 2006, DOI: 10.1007/s11434-006-8212-1
Abstract: The stability of oases is one of the key scientific issues in the process of evolution and management of oases in arid areas. The stability of oases and its representation are also different at different scales. This paper deals with the stability of oases at the landscape patch scale with a case study in the Sangong River Watershed of Tianshan Mountains. We employed the remote sensing, geographic information system and mathematical statistical methods to process the remote sensing images of three periods in 1978, 1987 and 1998, and put forward the approaches for representing the oasis stability at the landscape patch scale. The landscape control capacity of oasis patches is a kind of natural driving forces of the dynamic landscape change. The control capacity of a certain patch type on landscape change increases with its area and shape complexity and contrasts between it and other patches, and reduces with its spatial distances between it and other patches. The patch type with the strongest control capacity should be the matrix of landscape. The conversion of oasis landscape patches results from both natural and anthropogenic driving forces, particularly the anthropogenic driving forces. The higher the conversion proportion is, the lower the stability of patch types is and the stronger the anthropogenic disturbance is. The patch type with the strongest net control capacity in the Sangong River Watershed in 1987 was the desert grassland, which was the matrix of landscapes; but the matrix of landscapes had been changed into the irrigated lands in 1987 and 1998. The control capacities of landscape patches on the oasis landscape evolution have gradually reduced with time in the Sangong River Watershed, and the change extents also have reduced gradually. This reveals that the interaction among the landscape patch types generally tends to reduce, and the natural stability of the oasis landscape patches generally tends to increase. However, the conversion among the landscape patches occurs more frequently due to the increase of intensive human activities, which probably causes the lower stability of environmental resources patch and higher stability of introduced patches in the oasis landscape.

Zhou Chenghu,

地理研究 , 1990,
Abstract: Existing landuse database system (DBS) in the area between two fjood-control dykes of the lower yellow River from Huayuankou to sunkou, based on ARC/INFO geographical information system software, was developed by using landuse interpretation maps of air infrared photos taken in June, 1988, and other thematic maps such as topographical maps. DBS is comprised of database and database management system (DBMS).The database consists of existing landuse, floodland distribution, digital elevation model. The data model is a hybrid of relational and topological models. Locational data may be represented explicitly, or topologically, as a series of x,y coordinate, Attribute data, discribing feature names, symbols and classification, are stored in feature attribute tables.Polygon overlay and isomorphic buffer operation are used to study the landuse structure and the landuse difference among three kinds of floodland. Landuse data were traped on digital elevation model (DEM), showing the spatial distribution of existing landuse and floodland.GIS-based analysis of existing landuse is featured by use of multisources information and information integration through ARC/INFO, powerful analsis functions such as spatial retrieval and query, statictical calculation and space modelling .

Zhou Chenghu,

地理研究 , 1993,
Abstract: Flood hazard is one of the major natural hazards which threaten mankind. Besides the flood control construction, it is also important to the disaster deduction to establish a flood monitoring system. This paper focused on the application of Landsat satellite, meteorological satellite and air-born side-looking radar to flood disaster investigation and evaluation. Based on the analysis of the thematic flood information characteristics of the remotely sensed data, flood inundation area calculation model was developed.This model included digital image processing sub-model, water boundary extraction sub-model, flooding-area calculation sub-model and flood mapping sub-model. The last part of the papsr showed a successful application of the technology to the investigation and evaluation of "the 1991's flooding in Taihu basin.
Dynamic analysis of evapotranspiration based on remote sensing in Yellow River Delta

PAN Zhiqiang,LIU Gaohuan,ZHOU Chenghu,

地理学报 , 2003,
Abstract: Evapotranspiration (ET) is an important parameter for water resource management. Compared to the traditional ET computation and measurement methods, the ET computation method based on remote sensing has the advantages of quickness, precision, raster mapping and regional scale. SEBAL, an ET computation model using remote sensing method is based on the surface energy balance equation which is a function of net radiance flux, soil heat flux, sensible heat flux and latent heat flux. The former three fluxes can be computed through the parameters retrieved from remote sensing image, then the latent heat flux can be obtained to provide energy for ET. Finally we can obtain the daily ET. In this study SEBAL was applied to compute ET in the Yellow River Delta of China where water resource faces a rigorous situation. Three Landsat TM images and meteorology data of 1999 were used for ET computation, and spatial and temporal change patterns of ET in the Yellow River Delta were analysed.

Zhou Chenghu,

地理学报 , 1993,
Abstract: Remote sensing and geographic information system provide important technical supports for the modernization of flood control and prevention. This paper discussed the design, development and application of the flood hazard evaluation information system. Firstly, the author explicated the method and strategies of the system design from the point of view of users investigation, database design, model base design, and system definition and building-up under the direction of structural analysis and design theory. Then, one example system, flood hazard evaluation information system in the Lower Yellow Rver which is composed of large database and complicated model base, was established, based on ARC/INFO GIS software system. Its database consists of 11 geographical environmental background and socio-economic elements, and the computer storage reaches 70MB. The model base includes basic mathematical model, statistical and spatial analysis model, and profession 1 applied models, At last, two case studies were discussed.
Streamflow trends and hydrological response to climatic change in Tarim headwater basin

JIANG Yan,ZHOU Chenghu,CHENG Weiming,

地理学报 , 2007,
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