The feasibility of underground space utilization in urban parks, the function and scale of underground space were explored, also the role, composition, quantification of the index system of underground space utilizati...The feasibility of underground space utilization in urban parks, the function and scale of underground space were explored, also the role, composition, quantification of the index system of underground space utilization in urban parks were analyzed, and the corresponding conceptual framework of index system were proposed.展开更多
The most significant changes of landscape in a certain period are landscape area changes and spatial changes of landscape patches.Based on transfer matrix and total amount change of landscape area,landscape space tran...The most significant changes of landscape in a certain period are landscape area changes and spatial changes of landscape patches.Based on transfer matrix and total amount change of landscape area,landscape space transfer index and landscape area change index were established,and then applied to analyze plain oasis and desert in Yutian County,Xinjiang Uyghur Nationality Autonomous Region,the results showed that landscape space transfer in this region was drastic,but total landscape area changed only slightly,thus space transfer index was much higher than area change index,which indicated that landscapes in arid area were given with particular spatial undulant features and sensitivity,while man-made landscapes(artificial oasis) are stable and expanding to some extent.With landscape space transfer index as the comprehensive indicator,space transfer intensity of landscape within a certain period can be demonstrated,which is favorable for the comparison of landscape change intensity among different types and within different periods,in addition,some macroscopic change features of landscapes can also be reflected by comprehensively analyzing landscape space transfer index and landscape area change index.展开更多
A harmonic condition that can distinguish whether the dimension of spline space S 1 3( △ ) depends on the geometrical character of triangulation is presented, then on a type of general triangulation the dimension...A harmonic condition that can distinguish whether the dimension of spline space S 1 3( △ ) depends on the geometrical character of triangulation is presented, then on a type of general triangulation the dimension is got.展开更多
For an operator on a Banach space , let be the collection of all its invariant subspaces. We consider the index function on and we show, amongst others, that if is a bounded below operator and if , , then If in additi...For an operator on a Banach space , let be the collection of all its invariant subspaces. We consider the index function on and we show, amongst others, that if is a bounded below operator and if , , then If in addition are index 1 invariant subspaces of , with nonzero intersection, we show that . Furthermore, using the index function, we provide an example where for some , holds .展开更多
Various index structures have recently been proposed to facilitate high-dimensional KNN queries, among which the techniques of approximate vector presentation and one-dimensional (1D) transformation can break the curs...Various index structures have recently been proposed to facilitate high-dimensional KNN queries, among which the techniques of approximate vector presentation and one-dimensional (1D) transformation can break the curse of dimensionality. Based on the two techniques above, a novel high-dimensional index is proposed, called Bit-code and Distance based index (BD). BD is based on a special partitioning strategy which is optimized for high-dimensional data. By the definitions of bit code and transformation function, a high-dimensional vector can be first approximately represented and then transformed into a 1D vector, the key managed by a B+-tree. A new KNN search algorithm is also proposed that exploits the bit code and distance to prune the search space more effectively. Results of extensive experiments using both synthetic and real data demonstrated that BD out- performs the existing index structures for KNN search in high-dimensional spaces.展开更多
Land use/land cover change (LUCC) mapping and analysis using multi-temporal normalize difference vegetation index (NDVI) data have been well documented. Recent empirical studies have documented that many new methods w...Land use/land cover change (LUCC) mapping and analysis using multi-temporal normalize difference vegetation index (NDVI) data have been well documented. Recent empirical studies have documented that many new methods with high accuracy of retrieved land surface temperature ( Ts) have been developed. Thus, the combination of land surface temperature and NDVI has the greatest potential to improve the surface vegetation dynamic monitoring. In this study, the following objectives are pursued to: (1) introduce the practical method to produce the Ts, NDVI and Ts/NDVI based on remotely sensed data; (2) investigate the different retrieved result of vegetation cover information from NDVI, Ts and Ts/NDVI data sets, and analyze the intra-annual time trajectories of different vegetation cover categories in the NDVI- Ts space for farming-pastoral zone in North China, and (3) quantitative analysis the difference in using NDVI, Ts and Ts/NDVI data sets to express information based on the indices (information entropy and averaged information grads), and evaluate the relative role of Ts/NDVI data set in the discrimination of different vegetation cover categories through comparison to traditional NDVI data set.展开更多
Eucalyptus forests are grown in many parts of the world for their commercial value and use in construction projects. Density management becomes im- portant as a means to attain the management goals in these forests. C...Eucalyptus forests are grown in many parts of the world for their commercial value and use in construction projects. Density management becomes im- portant as a means to attain the management goals in these forests. Changes in canopy and tree crown structure were quantified for Eucalyptus urophylla x E. grandis forests at different ages to determine when canopy closure occurs and the onset of competition begins. Site index was developed for these forests to determine whether site quality affects the canopy structure. Site index had little effect in the forests sampled, with the forest canopy on the better sites becoming slightly more elongated. Based upon crown projection ratio and crown diameter： dbh （diameter at breast height） ratio, it appears that crown closure occurs by age 4 years in these forests. The age at which this occurs was also checked and verified with the evaluation of relative spacing, RS （the ratio of the mean distance between trees to the average dominant height of the stand）. The RS value displayed a rapid decline until age 4 years, and then became relatively flat through age 21 years. The rapid height growth during the first 3 years with no change in density accounted for this rapid decrease. By age 4 years, reductions in the number of trees due to mortality began to have more of an influence on this value, resulting in a more gradual de- cline. The implications for management are discussed.展开更多
基金Supported by the 2008 Provincial Key Scientific Research Program of Anhui Science & Technology Department~~
文摘The feasibility of underground space utilization in urban parks, the function and scale of underground space were explored, also the role, composition, quantification of the index system of underground space utilization in urban parks were analyzed, and the corresponding conceptual framework of index system were proposed.
基金Supported by National Natural Science Foundation(40661002)Project of National Natural Science Youth Foundation(40701188)Highlevel Talents Initiation Project of Shihezi University(RCZX200693)~~
文摘The most significant changes of landscape in a certain period are landscape area changes and spatial changes of landscape patches.Based on transfer matrix and total amount change of landscape area,landscape space transfer index and landscape area change index were established,and then applied to analyze plain oasis and desert in Yutian County,Xinjiang Uyghur Nationality Autonomous Region,the results showed that landscape space transfer in this region was drastic,but total landscape area changed only slightly,thus space transfer index was much higher than area change index,which indicated that landscapes in arid area were given with particular spatial undulant features and sensitivity,while man-made landscapes(artificial oasis) are stable and expanding to some extent.With landscape space transfer index as the comprehensive indicator,space transfer intensity of landscape within a certain period can be demonstrated,which is favorable for the comparison of landscape change intensity among different types and within different periods,in addition,some macroscopic change features of landscapes can also be reflected by comprehensively analyzing landscape space transfer index and landscape area change index.
文摘A harmonic condition that can distinguish whether the dimension of spline space S 1 3( △ ) depends on the geometrical character of triangulation is presented, then on a type of general triangulation the dimension is got.
文摘For an operator on a Banach space , let be the collection of all its invariant subspaces. We consider the index function on and we show, amongst others, that if is a bounded below operator and if , , then If in addition are index 1 invariant subspaces of , with nonzero intersection, we show that . Furthermore, using the index function, we provide an example where for some , holds .
基金Project (No. [2005]555) supported by the Hi-Tech Research and De-velopment Program (863) of China
文摘Various index structures have recently been proposed to facilitate high-dimensional KNN queries, among which the techniques of approximate vector presentation and one-dimensional (1D) transformation can break the curse of dimensionality. Based on the two techniques above, a novel high-dimensional index is proposed, called Bit-code and Distance based index (BD). BD is based on a special partitioning strategy which is optimized for high-dimensional data. By the definitions of bit code and transformation function, a high-dimensional vector can be first approximately represented and then transformed into a 1D vector, the key managed by a B+-tree. A new KNN search algorithm is also proposed that exploits the bit code and distance to prune the search space more effectively. Results of extensive experiments using both synthetic and real data demonstrated that BD out- performs the existing index structures for KNN search in high-dimensional spaces.
文摘Land use/land cover change (LUCC) mapping and analysis using multi-temporal normalize difference vegetation index (NDVI) data have been well documented. Recent empirical studies have documented that many new methods with high accuracy of retrieved land surface temperature ( Ts) have been developed. Thus, the combination of land surface temperature and NDVI has the greatest potential to improve the surface vegetation dynamic monitoring. In this study, the following objectives are pursued to: (1) introduce the practical method to produce the Ts, NDVI and Ts/NDVI based on remotely sensed data; (2) investigate the different retrieved result of vegetation cover information from NDVI, Ts and Ts/NDVI data sets, and analyze the intra-annual time trajectories of different vegetation cover categories in the NDVI- Ts space for farming-pastoral zone in North China, and (3) quantitative analysis the difference in using NDVI, Ts and Ts/NDVI data sets to express information based on the indices (information entropy and averaged information grads), and evaluate the relative role of Ts/NDVI data set in the discrimination of different vegetation cover categories through comparison to traditional NDVI data set.
基金Supported by Undergraduate Research Abroad Program,Ohio State University,USA(11731-011000)~~
文摘Eucalyptus forests are grown in many parts of the world for their commercial value and use in construction projects. Density management becomes im- portant as a means to attain the management goals in these forests. Changes in canopy and tree crown structure were quantified for Eucalyptus urophylla x E. grandis forests at different ages to determine when canopy closure occurs and the onset of competition begins. Site index was developed for these forests to determine whether site quality affects the canopy structure. Site index had little effect in the forests sampled, with the forest canopy on the better sites becoming slightly more elongated. Based upon crown projection ratio and crown diameter： dbh （diameter at breast height） ratio, it appears that crown closure occurs by age 4 years in these forests. The age at which this occurs was also checked and verified with the evaluation of relative spacing, RS （the ratio of the mean distance between trees to the average dominant height of the stand）. The RS value displayed a rapid decline until age 4 years, and then became relatively flat through age 21 years. The rapid height growth during the first 3 years with no change in density accounted for this rapid decrease. By age 4 years, reductions in the number of trees due to mortality began to have more of an influence on this value, resulting in a more gradual de- cline. The implications for management are discussed.
