We extend Post’s programme to finite levels of the Ershov hierarchy of ∆2 sets, and characterise, in the spirit of Post [9], the degrees of the immune and hyperimmune d.c.e. sets. We also show that no properly d.c.e. set can be hh-immune, and indicate how to generalise these results to n-c.e. sets, n > 2.

For optical studies of boiling heat transfer process, it is essential that the refractive index and its dependence on temperature for the test liquid be known. In this work a simple set-up was built to measure the refractive index of Fluorinert Liquid PF-5060 with temperature compensation and temperature control. The pinhole laser light beam was used for determining the refraction angle. The re...

Weprovide a simple set of sufficient conditions for theweak convergence of discrete-time, discrete-state Galton–Watson branching processes with immigration to continuous-time, continuous-state branching processes with immigration.

We show that in the c.e. weak truth table degrees if b < c then there is an a which contains no hypersimple set and b < a < c. We also show that for every w < c in the c.e. wtt degrees such that w is hypersimple, there is a hypersimple a such that w < a < c. On the other hand we know that there are intervals which contain no hypersimple set.

wars begin to supply some goals. they have many predictable and unpredictable costs. state leaders and military commanders try to find way to decries war damages and to choose suitable strategies to reach their objectives spending fewer costs. one of these strategies can be blitzkrieg. this essay tries to explain the way of using this strategy in 20th century wars describing its theoretical bas...

An incomplete degree is cuppable if it can be joined by an incomplete degree to a complete degree. For sets fulfilling some type of simplicity property one can now ask whether these sets are cuppable with respect to a certain type of reducibilities. Several such results are known. In this paper we settle all the remaining cases for the standard notions of simplicity and all the main strong redu...

This paper describes a representation of the dynamics of human walking action for the purpose of person identification and classification by gait appearance. Our gait representation is based on simple features such as moments extracted from video silhouettes of human walking motion. We claim that our gait dynamics representation is rich enough for the task of recognition and classification. The...

We present a new strategy for semantic paramodulation for Horn sets and prove its completeness The strategy requires for each paramoduiation that either both parents be false positive units or that one parent and the paramodulant both be false relative to an interpretation We also discuss some of the issues involved in choosing an interpretation that has a chance of giving better performance th...

Let R be a relation on the domain of a computable structure A. We establish that the existence of an isomorphic copy B ofA such that the image of R (¬R, resp.) is h-simple (h-immune, resp.) relative to B is equivalent to a syntactic condition, termed R is formally h-simple (formally h-immune, resp.) on A.