we study algebraic properties of categories of merotopic, nearness, and filter algebras. we show that the category of filter torsion free abelian groups is an epireflective subcategory of the category of filter abelian groups. the forgetful functor from the category of filter rings to filter monoids is essentially algebraic and the forgetful functor from the category of filter groups to the cat...

Cognitive radio technology gets much attention of wireless network research environments as a new way to utilize the precious spectrum efficiently. IEEE 802.22, Wireless Regional Area Network, is the first international standard based on cognitive radio technology which intends to provide broadband access by utilizing unused TV channels, also known as TV white spaces. This standard provides PHY...

Human’s disregard to nature and consequently his living environment’s distance from natural endowments and potentials have caused many problems. Human’s living spaces are less desirable for him, and have destroyed his comfort in many cases, as man-made things. In this regard, public open spaces in residential areas can be mentioned because they are usually considered among the most vulnerable s...

Undoubtedly, public spaces can be considered as an essential factor, which could contribute to urban arrangement, create and maintain a strong local center and enhance the quality of superior environment and the sense of citizenship. Moreover, integrity has always been the most basic structural qualities and one of the key principles of cities. Integrated urban spaces exhibit the integrated str...

We will give a combinatorial description of the homotopy groups for the suspension ofK(π, 1) and wedges of 2-spheres. In particular, all of the homotopy groups of the 2-sphere are given as the centers of certain combinatorially described groups.

The level of satisfaction and effectiveness of 3D virtual learning environments were examined. Additionally, 3D virtual learning environments were compared with face-to-face learning environments. Students that experienced higher levels of flow and presence also experienced more satisfaction but not necessarily more effectiveness with 3D virtual learning environments. There were no significant ...

This paper has three main aims. The first is to ground the subject in current literature. Reference will then be made to two research studies conducted at Dubai Men's College where the use of e-portfolios was proposed and in one case implemented. The barriers identified around e-portfolios are described, along with an overview of current attitudes expressed at Unitec NZ during small-scale trial...