Recall that hyperbolic 3-manifolds M and N are said to be commensurable if they have a common finite sheeted covering. This is equivalent to the fundamental groups having subgroups of finite index which are conjugate in PSL(2,C). In general it is very difficult to determine if two manifolds are commensurable or not, once the most obvious invariants of commensurability (for example, the invarian...

By a tournament we mean a directed graph (T,→) such that whenever x, y are two distinct elements of T , then precisely one of the two cases, either x→ y or y → x, takes place. There is a one-to-one correspondence between tournaments and commutative groupoids satisfying ab ∈ {a, b} for all a and b: set ab = a if and only if a→ b. This makes it possible to identify tournaments with their correspo...

Consumers are often observed to purchase more than one variety of a product on a given shopping trip. The simultaneous demand for varieties is observed not only for packaged goods such as yogurt or soft drinks, but in many other product categories such as movies, music compact disks, and apparel. Multinomial (MN) choice models cannot be applied to data exhibiting the simultaneous choice of more...

Beginning with a review of some optimization problems in RKHS, and going on to a model selection problem via Likelihood Basis Pursuit (LBP).

nowadays, potato is one of the most important foods in the people¢s diet. daily consumption of potato is increasing in iran significantly; therefore the study and research on this product is essential. in order to the components of potato, three varieties of potato (diamant, aola and draga) were chosen from thirty six fields in north of khorasan province. each variety was harvested from 12 fiel...

The most important tool for classifying recognizable languages is Eilenberg’s variety theorem [1], which gives a one-to-one correspondence between (pseudo)-varieties of finite semigroups and varieties of recognizable languages. Varieties of recognizable languages are classes of recognizable languages closed under union, intersection, complement, left and right quotients and inverse morphisms. R...

The selective advantages of using light as a source of information are reflected in the diverse types of extant eyes. The physical properties of light restrict how it can be collected and processed, resulting in only eight known optical systems found in animals. Eyes develop through tissue rearrangement and differentiation. Our understanding of the source of genetic information used in developm...

Seaports are key locations within value chains and production networks. Port policies of national and local governments seek higher rents through strategies of specialisation or diversification. Elaborating on longstanding research about urban and regional development, this paper proposes an empirical investigation of the interplay between traffic variety and port performance. The analysis of t...

Both annual biomass production and biodiversity at any locality on earth are continually under threat as the population of Homo sapiens steadily increases, with the resultant pollution of atmosphere, soil and water. Today, environmental degradation and global warming (with its effect on evaporative aerodynamics and cellular respiration) have increased at an alarming rate. The ABP of all terrest...

We investigate how differences in set-up costs of various types affect the trade-off between global efficiency and spatial equity and show that the standard assumption of symmetry in fixed costs masks the existence of an interesting effect: the range of available varieties varies depends on the spatial distribution of firms. In such a setting, even when the market outcome leads to excessive agg...