the fao penman - monteith (f-p-m) method is now broadly accepted as the standard for estimating the reference evapotranspiration (et0). the method is also now used for evaluating the temperature-based [blaney-criddle (b-c) and hargreaves-samani (h-s)] and radiation-based [jensen-haise (j-h) and turc (tc)] methods. the objective was to compare the et0 estimated by the b-c, h-s, j-h, tc methods w...

In group theory, it is a fundamental question to determine what information about a group is necessary and sufficient tomake a group finitely presented. In this paper, we develop the theory of Σ-invariants due to Robert Bieri and Ralph Strebel [Bieri] whi provides an answer to this question for the class of metabelian groups. We begin our study of Σ-invariants with a digression on group extens...

Novel species are introduced into a network of interacting replicators either (i) as mutants of members of the network or (ii) as unrelated immigrants. We consider the meta-population dynamics of such a system. In the rst case the appearance of mutants leads to a slow growth of the replicator network, proportional to the logarithm of the number of mutation events. Surprisingly, replicator evolv...

The g o a l o f t h e NLG p r o j e c t i s t o enhance p e r s o n c o m p u t e r i n t e r a c t i o n b y u s i n g more t h a n one mode o f c o m m u n i c a t i o n . The p r o j e c t uses a c o m b i n a t i o n o f n a t u r a l l anguage and g r a p h i c s f o r b o t h i n p u t and o u t p u t . T h i s a l l o w s deve lopmen t o f p r a c t i c a l , h a b i t a b l e sys tems s...

Let I be a set and let A, f be functions. The functor f↾IA yielding a many sorted function indexed by I is defined by: (Def. 1) For every set i such that i ∈ I holds (f↾IA)(i) = f↾A(i). One can prove the following propositions: (1) For every set I and for every many sorted set A indexed by I holds idUnionA↾IA = idA. (2) Let I be a set, A, B be many sorted sets indexed by I, and f , g be functio...

Let p be a prime > 3 and consider the Tate algebra A := Q p z defined to be the Banach algebra of formal power series over Q p that converge on the closed unit disk B[0, 1] ⊆ C p with the supremum norm ||f || := sup z∈B[0,1] |f (z)| for f ∈ A. Equivalently, we have (0.1) A = f (z) = ∞ k=0 a k z k a k ∈ Q p and lim k→∞ a k = 0 and the norm is given by (0.2) ||f || = sup k |a k |, for f = ∞ k=0 a...

When studying certain class of structures (e.g., sets of reals) one frequently enters the following situation. We are given an element A of the class and a mapping f defined on some cube A r o r [ A ] r of A and we need to find a large B _ A where the behaviour of f is as simple as possible. Here is a sample of results of this sort. There is c: [Q]2 ~ {0, 1} such that c"[P] 2 = {0, 1} for every...

restored by adjustment of sensitivity controls in the normal fashion. Continuous recording of two echoes by time-position is not important because respiratory activity is continuously monitored by chart recorder. The time-position signals are merely used to verify the respiratory origin of the recorded signals. The recording of fetal chest wall velocity provides additional information which may...

We define when a linear-time temporal property is a fairness property with respect to a given system. This captures the essence that is shared by most fairness assumptions that are used in the specification and verification of reactive concurrent systems, such as weak fairness, strong fairness, kfairness, and many others. We give three characterisations for the family of all fairness properties...