Feature extraction plays an important role in face recognition system as it can reduce dimensions and reserve the most significant features which need to be classified and recognized. Principal Component Analysis (PCA) has been one of the popular techniques that used in pattern recognition related research areas. Researches have been also carried out to improve the performance of this technique...

Two complementary methods for computing abstract factors are discussed. These two methods have a common theme of generating eigenvectors and abstract factors one at a time, thus allowing a specific number of abstract factors to be computed rather than being limited to computing all abstract factors for a given problem. Determination of only a limited number of abstract factors represents a sign...

this research has been done with the aim of explaining environmental and managerial factors that affects on rangeland vegetation distribution in saral rangelands of kurdistan province. after selecting plant types as working area were done sampling from plant types and determined some of plants parameters such as kind and number of plants and cover percentage. various environmental factors such ...

eight selected heavy metals (cu, zn, pb, cd, cr, mn, fe and al) in surface and sub-surfacesediments in the northern coast of sfax (tunisia) were studied in order to assess the sediment quality and tohighlight the anthropogenic contributions to heavy metal distributions in the two study sediment levels.multiple chemometric approaches based on geographic information system (gis), enrichment facto...

University of Tehran administers a test known as The University of Tehran English Proficiency Test (the UTEPT) to PhD candidates on a yearly basis. By definition, the test can be considered a high-stakes one. The validity of high stakes tests needs to be known (Roever, 2001). As Mesick (1988) maintains, if the validity of high stakes tests are not known, it might have some undesirable consequen...