Let S be a nonempty bounded set in R2. Then S is staxshaped if and only if every 3 or fewer boundary points of S are clearly visible via S from a common point of S. The number 3 is best possible.

Let Γ be a topological semigroup acting on a topological space X, and let Γ0 be a subsemigroup of Γ. We give general conditions ensuring that Γ and Γ0 have the same transitive points.

The transfer of council estates into housing association (HA) ownership has transformed the structure of social housing provision across Britain; in half of English local authorities council housing is a thing of the past. From 1997, stock transfer extended beyond rural shire districts, with urban estates accounting for the majority of properties being handed to new social landlords. This study...

in this paper, the unified power flow controller (upfc) is enhanced with a chaotic particle swarm optimization (cpso) damping controller in order to mitigate the low frequency oscillations (lfo) in a single machine infinite bus (smib) power system. the designed damping controller is an optimized lead-lag controller, which extracts the speed deviation of the generator rotor and generates the out...

concurrency control is one of the important problems in operation systems. various studies have been reported to present different algorithms to address this problem, although a few attempts have been made to represent an overall view of the characteristics of these algorithms and comparison of their capabilities to each other. this paper presents a survey of the current methods for controlling...

chemical vapor deposition (cvd) is one of the most popular methods for producing carbon nanotubes (cnts). the growth rate of cnts based on cvd technique is investigated by using a numerical model based on finite volume method. inlet gas mixture, including xylene as carbon source and mixture of argon and hydrogen as carrier gas enters into a horizontal cvd reactor at atmospheric pressure. in thi...

Speaker transitions in conversation are often brief, with minimal vocal overlap. Signed languages appear to defy this pattern with frequent, long spans of simultaneous signing. But recent evidence suggests that turn boundaries in signed language may only include the content-bearing parts of the turn (from the first stroke to the last), and not all turn-related movement (from first preparation t...

[MISSING]

This paper presents a Genetic Algorithms (GA) based rule generation method for Fuzzy Power System Stabilizer (FPSS) to enhance damping of the power system low frequency oscillations. This proposed controller is more efficient because it cope with oscillations and different operating points. There is no doubt that fuzzy controller is tuned on line from the knowledge base and fuzzy interference. ...

STUDY DESIGN  Retrospective study. OBJECTIVE  To assess the learning curve of microendoscopic decompression surgery for lumbar spinal canal stenosis (LSCS). METHODS  Four hundred eighty LSCS cases involving 753 stenotic lesions limited to the intraspinal canal were treated with microendoscopic decompression by a single surgeon at an institution between November 2006 and January 2015. They w...