The high/low hierarchy respects the ordering of degrees, and so we can expect to find properties of order which are possessed by all degrees in a given hierarchy class. Such properties can also be found for classes of the generalized high/low hierarchy even though that hierarchy does not respect the ordering of the degrees. For example, Jockusch and Posner [4], extending a result of Cooper [l],...

We show that over the base system P− + Σ2-bounding, the existence of a 1-generic degree < 0′′ bounding a minimal degree is equivalent to Σ2-induction.

Universities are increasingly turning to ‘fashionable’ education programs to attract bright, high-quality students to both under-graduate and post-graduate degree programs. Traditional offerings in technology areas, such as Information Systems and Information Technology are being augmented by newer, more marketable degrees in areas such as eCommerce/eBusiness. This paper analyses the eCommerce/...

The expertise of academic librarians in the area of using and teaching with information technology provides a solid foundation for increasing their level of collaboration with teaching faculty. Of course, differing degrees of collaboration exist in every university system depending upon status of the librarians and faculty culture. Many approaches have been taken by librarians to encourage and ...

In this work we characterize different types of solutions of a vector optimization problem by means of a scalarization procedure. Usually different scalarizing functions are used in order to obtain the various solutions of the vector problem. Here we consider different kinds of solutions of the same scalarized problem. Our results allow us to establish a parallelism between the solutions of the...

A computable structure A is x-computably categorical for some Turing degree x, if for every computable structure B ∼= A there is an isomorphism f : B → A with f ≤T x. A degree x is a degree of categoricity if there is a computable structure A such that A is x-computably categorical, and for all y, if A is y-computably categorical then x ≤T y. We construct a Σ2 set whose degree is not a degree o...

In this paper I recall the reasons in favour of extending the classical conception of truth to include degrees of truth as well as truth value gaps and gluts, then provide a sketch of a new system of logic that provides all of these simultaneously. Despite its power, the resulting system is quite simple, combining degrees of truth and degrees of falsity to provide a very flexible and elegant co...

This paper deals with the topic of robots dynamics identification. In this paper, we focus on the instrumental variable (IV) technique. For robots, the set of instruments is the inverse dynamic model built from simulated data which are calculated from the integration of the direct dynamic model, assuming the same reference trajectories and the same control law structure for both actual and simu...

Volume 14, Number 2 284 that live under some of the harshest conditions on the planet invigorating. Understanding how the structural and physiological adaptations of these microorganisms allow them to live under these harsh conditions provides insight into what life had to endure when our own world was a much more inhospitable place. The new text Polar Microbiology: Life in a Deep Freeze by Rob...