For every pattern p over the alphabet {x, y, x, y}, we specify the least k such that p is k-avoidable.

Document retrieval and web search engines index large quantities of text. The static costs associated with storing the index can be traded against dynamic costs associated with using it during query evaluation. Typically, index representations that are effective and obtain good compression tend not to be efficient, in that they require more operations during query processing. In this paper we d...

A binary word u is f -free if it does not contain f as a factor. A word f is d-good if for any f -free words u and v of length d, v can be obtained from u by complementing one by one the bits of u on which u and v differ, such that all intermediate words are f -free. We say that f is good if it is d-good for any d ≥ 1. A word is bad if it is not good. The index β(f) of f is the smallest integer...

index tracking is the process of developing a portfolio that reproduces the performance of an index. the tracker portfolio has relatively good diversity and low turnover and low transaction costs. in this paper we applied a binary programming model for index tracking problem. in this model the number of assets for portfolio construction is defined by portfolio manager. the robust optimization f...

A Non-Binary Snow Index for Multi-Component Surfaces (NBSI-MS) is proposed to map snow/ice cover. The NBSI-MS based on the spectral characteristics of different Land Cover Types (LCTs), such as snow, water, vegetation, bare land, impervious, and shadow surfaces. This index can increase separability between values corresponding snow from other LCTs accurately delineate cover in non-binary maps. ...

A total of 1099 data points consisting of alcohol-alcohol, alcohol-alkane, alkane-alkane, alcohol-amine and acid-acid binary solutions were collected from scientific literature to develop an appropriate artificial neural network (ANN) model. Temperature, molecular weight of the pure components, mole fraction of one component and the structural groups of the components were used as input paramet...

A desired P2P file sharing system is expected to achieve the following design goals: scalability, routing efficiency and complex query support. In this paper, we propose a powerful P2P file sharing system, PSON, which can satisfy all the three desired properties. PSON is essentially a semantic overlay network of logical nodes. Each logical node represents a cluster of peers that are close to ea...