The paper is a continuation of work initiated by the first two authors in [K–M]. Section 1 is introductory. In Section 2 we give new proofs of results of Scheiderer in [S1] [S2] in the compact case; see Corollaries 2.3, 2.4 and 2.5. The main tool in Section 2, Lemma 2.1, is also used in Section 3 where we continue the examination of the case n = 1 initiated in [K–M], concentrating on the compac...

The class of Church-Rosser congruential languages has been introduced by McNaughton, Narendran, and Otto in 1988. A language L is Church-Rosser congruential (belongs to CRCL), if there is a finite, confluent, and length-reducing semi-Thue system S such that L is a finite union of congruence classes modulo S. To date, it is still open whether every regular language is in CRCL. In this paper, we ...

In the ideal topological spaces (X, ?, I) and (Y, J, ?), we define (I, J)-irresolute function, weakly-(I, J)-irresolute, strongly-(I, functions, semi-I-open sets quasi-H-closed modulo I. We discuss properties of function mapping connected, closed, compact I semi-I-isolated points. J)-Homeomorphisim on presemi-I-open closure subsets are explored in this paper.

In this Paper we report on optical spectroscopic observations of the low-mass X-ray binary 2S 0921–630 obtained with the Very Large Telescope. We found sinusoidal radial velocity variations of the companion star with a semi–amplitude of 99.1±3.1 km s modulated on a period of 9.006±0.007 days, consistent with the orbital period found before for this source, and a systemic velocity of 44.4±2.4 km...

A novel technique for obtaining a single-layer single-feed dual frequency rectangular microstrip antenna with protruding semi ellipse for s-band communication is proposed and demonstrated. By protruding semi ellipse of appropriate dimension close to one of the edge, the rectangular patch has been shown to realize dual-frequency broadside radiations. This dual frequency operation increases its a...