In [CS-92] we studied the agreement of operators Plogi and ACi−1 acting on NP . In this article we extend this work to other classes of the polynomial time hierarchy. We show that on Σk , Π P k , ∆ P k and Θ P k -classes both operators have the same behaviour, but this coincidence does not seem to be true on other classes included in the PH hierarchy: we give a set A such that, relativized to A...

We show that some natural re nements of the Straubing and Brzozowski hierarchies correspond (via the so called leaf-languages) step by step to similar re nements of the polynomial-time hierarchy. This extends a result of H.-J. Burtschik and H. Vollmer on relationship between the Straubing and the polynomial hierarchies. In particular, this applies to the boolean hierarchy and the plus{hierarchy.

In this paper, I formally deene uncertainty, diiculty, and complexity both as measures of problems and environments and as analytic paradigms and discuss the importance of the diiculty and uncertainty paradigms in the study of institutions.

Two practical considerations concerning the use of computing machinery are the amount of information that must be given to the machine for it to perform a given task and the time it takes the machine to perform it. The size of programs and their running time are studied for mathematical models of computing machines. The study of the amount of information (i.e., number of bits) in a computer pro...

abstract the theory of hardship is a situation in which the implementation of contractual obligation, as a result of unpredictable events that are out of control, becomes economically difficult and expensive without being physically impossible and distorts the balance of the contract. in such a situation, the hardship theory is applied to restore the balance of the contract. this matter has var...

The objective of this study is to explore the challenges faced by Indian apparel supply chain in wake COVID-19 identify factors that are being affected and build a multilevel hierarchy model prioritize understand their inter-relationships. An intensive literature review was conducted many experts from were consulted. help survey sent these different echelons industry. data then analysed using T...

The heavy use of camera phones and other mobile devices all over the world has produced a market for mobile image analysis, including image segmentation to separate out objects of interest. Automatic image segmentation algorithms, when employed by many different users for multiple applications, cannot guarantee high quality results. Yet interactive algorithms require human effort that may becom...

Is the BELLE result for the cross section σ(e + e − → J/ψ + η c) a real difficulty for QCD ? Abstract It is shown that difficulties in reconciling the values of the cross section σ(e + e − → J/ψ + η c) measured at BELLE and calculated within non-relativistic QCD (NRQCD) are caused not by some misinterpretation of the data or other exotic explanations, but by poor applicability of NRQCD to such ...