Defining correctness conditions for concurrent objects in multicore architectures

Correctness of concurrent objects is defined in terms of conditions that determine allowable relationships between histories of a concurrent object and those of the corresponding sequential object. Numerous correctness conditions have been proposed over the years, and more have been proposed recently as the algorithms implementing concurrent objects have been adapted to cope with multicore processors with relaxed memory architectures. We present a formal framework for defining correctness conditions for multicore architectures, covering both standard conditions for totally ordered memory and newer conditions for relaxed memory, which allows them to be expressed in uniform manner, simplifying comparison. Our framework distinguishes between order and commitment properties, which in turn enables a hierarchy of correctness conditions to be established. We consider the Total Store Order (TSO) memory model in detail, formalise known conditions for TSO using our framework, and develop sequentially consistent variations of these. We present a work-stealing deque for TSO memory that is not linearizable, but is correct with respect to these new conditions. Using our framework, we identify a new non-blocking compositional condition, fence consistency, which lies between known conditions for TSO, and aims to capture the intention of a programmer-specified fence

Modelling the Pan-Spectral Energy Distributions of Starburst & Active Galaxies

We present results of a self-consistent model of the spectral energy distribution (SED) of starburst galaxies. Two parameters control the IR SED, the mean pressure in the ISM and the destruction timescale of molecular clouds. Adding a simplified AGN spectrum provides mixing lines on IRAS color : color diagrams. This reproduces the observed colors of both AGNs and starbursts.Comment: Poster Paper for IAU 222: The Interplay among Black Holes, Stars and ISM in Galactic Nucle

“Talking to Learn”: Focussing teacher education on dialogue as a core practice for teaching and learning.

Classroom interaction, as a core practice of teaching and learning, remains a ‘taken-for-granted’ and under-examined dimension of teacher education. This paper reports preliminary findings from an empirical investigation of pre-service teacher’s development of skills in classroom interaction as core educational practice. Specifically, the paper presents findings from a faculty-wide initiative involving first year Bachelor of Education students from one rural/regional university in NSW, Australia. The research investigated the impact that a focus on the role of dialogue for learning - both in university subjects and practising in classroom sites - has on 124 first year education pre-service teachers’ interaction practices with students in their professional experience placements. Findings show that if pre-service teachers experience classroom interactive practices as the object of overt focus during their undergraduate studies, understandings about effective pedagogy and teacher development will develop from beyond a ‘taken-for-granted’ dimension of teaching practice

Retirement Planning Model

This is a disparage in retirement planning between theory and practice. If a systems model can be developed to incorporate a theoretical, as well as a practical perspective, then new hypotheses or models can be developed to better understand the retirement process

Using coarse-grained abstractions to verify linearizability on TSO architectures

Most approaches to verifying linearizability assume a sequentially consistent memory model, which is not always realised in practice. In this paper we study correctness on a weak memory model: the TSO (Total Store Order) memory model, which is implemented in x86 multicore architectures. Our central result is a proof method that simplifies proofs of linearizability on TSO. This is necessary since the use of local buffers in TSO adds considerably to the verification overhead on top of the already subtle linearizability proofs. The proof method involves constructing a coarse-grained abstraction as an intermediate layer between an abstract description and the concurrent algorithm. This allows the linearizability proof to be split into two smaller components, where the effect of the local buffers in TSO is dealt with at a higher level of abstraction than it would have been otherwise

Accounting Hall of Fame 1999 induction: Ray J. Groves

For the induction of Ray J. Groves there were: Remarks by Dennis R. Beresford, University of Georgia; citation by Daniel L. Jensen, The Ohio State University; Response by Ray J. Groves, Ernst & Young, retired, and Legg Mason Merchant Banking, Inc

The Institute of Archaeology & Siegfried H. Horn Museum Newsletter Volume 27.3

Tent Dinner and Art Auction, Jennifer L. Green Younker Lecture, Carrie Rhodes Global Moments, Paul J. Ray, Jr. Al-Maktába: The Bookstore Random Surveyhttps://digitalcommons.andrews.edu/iaham-news/1027/thumbnail.jp