Observations of the Crab Nebula at 850 µm made with the Submillimetre Common-User Bolometer Array (SCUBA) on the James Clerk Maxwell Telescope are presented. A variety of chop-throws and scanning directions was used in these observations, to well sample structure over a range of scales and directions. The resulting image, which was restored using a MEM algorithm, has a resolution of 17 arcsec, ...

We describe, axiomatize, and implement, a new method for identifying community structures (groups of structurally equivalent nodes) from network data. The method is based on maximum likelihood estimation, a standard statistical tool. μ Copiμc and Jackson are at the Division of the Humanities and Social Sciences, California Institute of Technology, Pasadena, California 91125, USA, emails: jackso...

Sea water samples were collected from 32 stations in the southern part of the Persian Gulf and the Gulf of Oman during winter of 1987. Surface water of the Persian Gulf exhibited wide range and higher values of salinity (37.15-43.95, mean 40.02%) compared with lower values and narrow range (36.58-36.95, mean 36.74%) in the Gulf of Oman. Surface salinity did not reflect any significant relations...

This paper considers when one can invert general recursive operators which map a class of functions F to F . In this regard, we study four different notions of inversion. We additionally consider enumeration of operators which cover all general recursive operators which map F to F in the sense that for every general recursive operator Ψ mapping F to F , there is a general recursive operator in ...

Klaimullin, Melnikov and Ng [KMNa] have recently suggested a new systematic approach to algorithms in algebra which is intermediate between computationally feasible algebra [CR91, KNRS07] and abstract computable structure theory [AK00, EG00]. In this short survey we discuss some of the key results and ideas of this new topic [KMNa, KMNc, KMNb, Ala]. We also suggest several open problems.