نتایج جستجو برای: نرمافزار r

تعداد نتایج: 447189  

Journal: :Data Knowl. Eng. 2004
Wonik Choi Bongki Moon Sukho Lee

R-tree based access methods for moving objects are hardly applicable in practice, due mainly to excessive space requirements and high management costs. To overcome the limitations of such R-tree based access methods, we propose a new index structure called AIM (Adaptive cell-based Index for Moving objects). The AIM is a cell-based multiversion access structure adopting an overlapping technique....

Journal: :JCP 2011
Aiguo Li Chi Zhang Jiulong Zhang Zhenhai Zhang

A new dynamic multi-dimensional index structure called RSR-tree is proposed, in which splitting operations of leaf nodes and non-leaf nodes are performed separatively. RSR-tree retains the sequence ordering of index records in a leaf node of RS-tree and thus reduces the addressing time cost of disk access while reading data files. In addition, it integrates the characteristic of reducing the ov...

2001
Yufei Tao Dimitris Papadias

The Historical R-tree is a spatio-temporal access method aimed at the retrieval of window queries in the past. The concept behind the method is to keep an R-tree for each timestamp in history, but allow consecutive trees to share branches when the underlying objects do not change. New branches are only created to accommodate updates from the previous timestamp. Although existing implementations...

1994
Dimitris Papadias Yannis Theodoridis Timos K. Sellis

R-trees and related structures, like R-trees and R-trees, have been used to answer queries involving topological information about objects represented by their minimum bounding rectangles (MBRs). This paper describes how the R-tree method can be used for the storage and retrieval of direction relations. Direction relations deal with order in space, as for instance, left, above, north, southeast...

2013
Yiwei Chen Vivek F. Farias

We begin with establishing properties of the unit revenue function, g(·). Lemma 6. 1. g(·) is a non-negative, continuous, non-decreasing, and concave function on R+, with g(0) = 0. 2. yg(1/y) is non-decreasing and concave on R++. 3. g(y)/y is non-increasing on R+. 4. If u, v > 0, then g(u) g(v) ≥ min( u v , 1), 1 u ∫ u 0 g(v)dv ≤ g(u/2). Proof. 1. That g(·) is non-negative, continuous and non-d...

2011
Paul te Braak Richi Nayak

The R-Tree and variant indexes have been used for multidimensional indexing since 1984 and applied to temporal data since 1994. Despite this, there are few functional implementations of the index that can be applied directly to the temporal data. This paper explores the use of the index for temporal subsequence searches and identifies two implications that must be considered so the index can be...

Journal: :Acta Crystallographica Section E Structure Reports Online 2012

2012
A.S. Dayananda Grzegorz Dutkiewicz H. S. Yathirajan Maciej Kubicki

IN THE TITLE COMPOUND (SYSTEMATIC NAME (R)-dimeth-yl{2-[1-phenyl-1-(pyridin-2-yl)eth-oxy]eth-yl}aza-nium (R,R)-3-carb-oxy-2,3-dihy-droxy-propano-ate), C(17)H(23)N(2)O(+)·C(4)H(5)O(6) (-), the doxylaminium cation is protonated at the N atom. The tartrate monoanions are linked by short, almost linear O-H⋯O hydrogen bonds into chains extended along [100]. These chains are inter-linked by anion-pyr...

Journal: :British Journal of General Practice 2010

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید