Our interest in this paper is to define and study the concept of a fuzzy hypergroup, which depends on the concept of a fuzzy space. Indeed, the paper is a continuation of ideas presented by Davvaz [Fuzzy Sets and Systems, 101 (1999) 191-195]. A relation between a fuzzy hypergroup based on a fuzzy space and a fuzzy hypergroup in the sense of Davvaz is obtained 2010 AMS Classification: 20N20

Using mid-infrared and radio criteria, we select a sample of candidate z ∼ 2 obscured quasars. Optical spectroscopy confirms about half of these as type-2 quasars, and modelling the population suggests 50-80% of the quasars are obscured. We find some flat radio spectrum type-2 quasars, and tentative evidence for obscuration unrelated to the torus. Using a similar sample, we also find evidence f...

T is my great pleasure to welcome you to the inaugural I issue of the IEEE TRANSACTIONS ON FUZZY SYSTEMS. Many of you are probably quite familiar with the basic ideas underlying fuzzy sets and systems that utilize fuzzy models. However, there will also be readers who are looking at the contents of this issue, wondering what it’s all about. For this latter group, the papers in this first issue m...

The concepts of fuzzy e-open sets and fuzzy e-continuous are introduced and studied in fuzzifying topology and by making use of these concepts, we introduce and study T e 0 -, R e 0-, T e 1 -, R e 1-, T e 2 -, T e 3 -, T e 4 -, strong T e 3 and strong T e 4 separation axioms in fuzzifying topology and give some of their characterizations as well as the relations of these axioms and other separa...

RZ Psc is a young Sun-like star, long associated with the UXor class of variable stars, which is partially or wholly dimmed by dust clumps several times each year. The system has a bright and variable infrared excess, which has been interpreted as evidence that the dimming events are the passage of asteroidal fragments in front of the host star. Here, we present a decade of optical photometry o...

Since the inception of the Diffie-Hellman protocol in 1976, it has been an elusive open problem to construct a one-round group key exchange (GKE) protocol. In this paper, we investigate the open problem and answer it in a modular way. We first revisit the GKE definition and distinguish the conventional (symmetric) group key exchange from asymmetric group key exchange (ASGKE) protocols. In the l...