Mentat/A: Medium grain parallel processing

The objective of this project is to support the Algorithm to Architecture Mapping Model (ATAMM) firing rules using the Mentat run-time system and the Mentat Programming Language (MPL). Specifically, this required changes to (1) modify the run-time system to control queue length and inhibit actor firing until required data tokens are available and space is available in the input queues of all of the direct descendent actors, (2) disallow the specification of persistent object classes in the MPL, and (3) permit only decision free graphs in the MPL. We have been successful in implementing the spirit of the plan, although some goals changed as we came to better understand the problem. Here, we report on what we accomplished and the lessons we learned. The Mentat/A runtime system, the compiler, results for three applications, and a summary and some observations are given. Appendix A contains a list of technical reports and published papers partially supported by the grant. Appendix B contains listings for the three applications

Mentat: An object-oriented macro data flow system

Mentat, an object-oriented macro data flow system designed to facilitate parallelism in distributed systems, is presented. The macro data flow model is a model of computation similar to the data flow model with two principal differences: the computational complexity of the actors is much greater than in traditional data flow systems, and there are persistent actors that maintain state information between executions. Mentat is a system that combines the object-oriented programming paradigm and the macro data flow model of computation. Mentat programs use a dynamic structure called a future list to represent the future of computations

Mentat/A: Medium grain parallel processing

The objective of this project is to test the Algorithm to Architecture Mapping Model (ATAMM) firing rules using the Mentat run-time system and the Mentat Programming Language (MPL). A special version of Mentat, Mentat/A (Mentat/ATAMM) was constructed. This required changes to: (1) modify the run-time system to control queue length and inhibit actor firing until required data tokens are available and space is available in the input queues of all of the direct descendent actors; (2) disallow the specification of persistent object classes in the MPL; and (3) permit only decision free graphs in the MPL. We were successful in implementing the spirit of the plan, although some goals changed as we came to better understand the problem. We report on what we accomplished and the lessons we learned. The Mentat/A run-time system is discussed, and we briefly present the compiler. We present results for three applications and conclude with a summary and some observations. Appendix A contains a list of technical reports and published papers partially supported by the grant. Appendix B contains listings for the three applications

Integrated Task And Data Parallel Programming: Language Design

his research investigates the combination of task and data parallel language constructs within a single programming language. There are an number of applications that exhibit properties which would be well served by such an integrated language. Examples include global climate models, aircraft design problems, and multidisciplinary design optimization problems. Our approach incorporates data parallel language constructs into an existing, object oriented, task parallel language. The language will support creation and manipulation of parallel classes and objects of both types (task parallel and data parallel). Ultimately, the language will allow data parallel and task parallel classes to be used either as building blocks or managers of parallel objects of either type, thus allowing the development of single and multi-paradigm parallel applications. 1995 Research Accomplishments In February I presented a paper at Frontiers '95 describing the design of the data parallel language subset. During the spring I wrote and defended my dissertation proposal. Since that time I have developed a runtime model for the language subset. I have begun implementing the model and hand-coding simple examples which demonstrate the language subset. I have identified an astrophysical fluid flow application which will validate the data parallel language subset. 1996 Research Agenda Milestones for the coming year include implementing a significant portion of the data parallel language subset over the Legion system. Using simple hand-coded methods, I plan to demonstrate (1) concurrent task and data parallel objects and (2) task parallel objects managing both task and data parallel objects. My next steps will focus on constructing a compiler and implementing the fluid flow application with the language. Concurrently, I will conduct a search for a real-world application exhibiting both task and data parallelism within the same program m. Additional 1995 Activities During the fall I collaborated with Andrew Grimshaw and Adam Ferrari to write a book chapter which will be included in Parallel Processing in C++ edited by Gregory Wilson. I also finished two courses, Compilers and Advanced Compilers, in 1995. These courses complete my class requirements at the University of Virginia. I have only my dissertation research and defense to complete

What's in a compound? Review article on Lieber and Štekauer (eds) 2009. 'The Oxford Handbook of Compounding'

The Oxford Handbook of Compounding surveys a variety of theoretical and descriptive issues, presenting overviews of compounding in a number of frameworks and sketches of compounding in a number of languages. Much of the book deals with Germanic noun–noun compounding. I take up some of the theoretical questions raised surrounding such constructions, in particular, the notion of attributive modification in noun-headed compounds. I focus on two issues. The first is the semantic relation between the head noun and its nominal modifier. Several authors repeat the argument that there is a small(-ish) fixed number of general semantic relations in noun–noun compounds (‘Lees's solution’), but I argue that the correct way to look at such compounds is what I call ‘Downing's solution’, in which we assume that the relation is specified pragmatically, and hence could be any relation at all. The second issue is the way that adjectives modify nouns inside compounds. Although there are languages in which compounded adjectives modify just as they do in phrases (Chukchee, Arleplog Swedish), in general the adjective has a classifier role and not that of a compositional attributive modifier. Thus, even if an English (or German) adjective–noun compound looks compositional, it isn't

Adventures of punctuated equilibria : a struggle for authority in the evolutionary sciences

The theory of ‘punctuated equilibria’ was formulated by two paleontologists, Niles Eldredge and Stephen Gould, in 1972 and has been the focus of considerable controversy within the evolutionary sciences ever since. The primary intentions of this thesis are to relate the history of punctuated equilibria and to examine how it has affected evolutionary science. Several modes of analysis have been used to illuminate the history: The sociological perspectives of Pierre Bourdieu and Bruno Latour (who see scientific debate as a ‘struggle for authority’); Rhetorical analysis of some of the key documents; Communication with practising scientists via questionnaires and correspondence; Citation Analysis. Chapter 1 gives a short summary of the history and introduces the methods and socio-philosophical perspectives used to illuminate the history. Chapters 3 and 4 examine the rhetorical process by which Eldredge and Gould constructed the ‘punctuationist revolution’. Chapters 2, 3, 5 and 6 relate the history of punctuated equilibria

Energetics of linear geostrophic adjustment in stratified rotating fluids

The energy conversion ratio, γ, is shown to be bounded below by 0 and above by 1/2 in the two-dimensional linear geostrophic adjustment of a continuously stably stratified, incompressible, inviscid non-Boussinesq fluid. \u27\u27Two-dimensional\u27\u27 refers to problems in which the initial isopycnal displacement field is an arbitrary function of the vertical (parallel to the rotation axis) and a single horizontal coordinate. By using Fourier analysis techniques, the paper also identified classes of initial isopycnal displacement profiles for which the adjustment process leads to γ \u3e 1/3. Finally, an expression for γ is derived when the initial isopycnal displacement profile is three dimensional

Predicting Execution Readiness of MPI Binaries with FEAM, a Framework for Efficient Application Migration

Abstract-As computational science becomes increasingly relevant for performing research, shared computing resources made accessible by cyberinfrastructures emerge as especially valuable for the majority of scientists who have not traditionally been the dominant users of such resources. However, in order to provide these newer computational scientists the opportunities to do great research, the ease-of-use of shared computing resources needs to be increased. In this paper, we present techniques that aim to make the migration to (and between) shared computing resources more efficient. Specifically, we focus on determining whether a computing site is a good fit for running an MPI binary. We present our methods and a Linux-based implementation called FEAM (a Framework for Efficient Application Migration). FEAM predicts execution readiness, resolves missing shared libraries, and composes site-specific configurations. We show that FEAM is more than 90% accurate at predicting execution readiness of MPI application binaries from the NAS Parallel and SPEC MPI2007 benchmark suites. In our evaluation, only half of the migrated binaries execute successfully at sites only configured with a matching MPI implementation. We show that by automatically resolving shared libraries requirements, FEAM is able to increase the number of successful executions by a third

Predicting Execution Readiness of MPI Binaries with FEAM, a Framework for Efficient Application Migration

Abstract-Today's scientific computing infrastructures provide scientists with easy access to a wide variety of computing resources. However, migrating applications to new computing sites can be tedious and time consuming. When optimal performance is not a concern, scientists can benefit by moving binaries instead of source code. Our work aims to make migration of MPI application binaries more efficient by automation. We present general methods that assess if binaries are a good match for execution at computing sites. We also present methods for increasing execution readiness by resolving missing shared libraries. Our work aims to free scientists from extensive manual preparation at new sites. To evaluate the effectiveness of our methods, we present an automated Linux-based implementation called FEAM, a Framework for Efficient Application Migration. We show that FEAM is more than 90% accurate at predicting execution readiness of MPI application binaries from the NAS Parallel and SPEC MPI2007 benchmark suites. In our evaluation, only half of the migrated binaries execute successfully at sites configured with a matching MPI implementation. We show that by automatically resolving shared libraries requirements, FEAM is able to increase the number of successful executions by a third

Inadequate reporting of research ethics review and informed consent in cluster randomized trials : review of random sample of published trials

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