Achieving Asynchronous Speedup While Preserving Synchronous Semantics: An Implementation of Instructional Footprinting in Linda

Linda is a coordination language designed to support process creation and inter-process communication within conventional computational languages. Although the Linda paradigm touts architectural and language independence, it often suffers performance penalties, particularly on local area network platforms. Instructional Footprinting is an optimization technique with the primary goal of enhancing the execution speed of Linda programs. The two main aspects of Instructional Footprinting are instructional decomposition and code motion. This paper addresses the semantic issues encountered when the Linda primitives, IN and RD, are decomposed and moved past other Linda operations. Formal semantics are given as well as results showing significant speedup (as high as 64%) when Instructional Footprinting is used

Comparison of Unix Communication Facilities Used In Linda

This report presents the results of an investigative effort that focuses on a first step toward providing a distributed framework for Linda system processes. In particular, we discuss the restructuring of the kernel "process" to support Tuple Space access through UNIX socket calls, rather than through shared memory primitives based on semaphore usage. A description of the restructured system and the rationale for such restructuring is presented first. Most intriguing, however, are the latter sections that discuss the ramifications and insights gained from our particular approach to system redesign, i.e., the unnecessary serialization of Tuple Space access, redundant memory copies, being victimized by the UNIX scheduler

A Distributed Parallel Processing Environment Based upon the Linda Paradigm: A Research Prospectus

As the computing capacity of the uniprocessor is being taxed, and the high cost of parallel and super-computers is still prevalent, alternative methods of achieving parallel performance at an economical price are desired. This proposed research effort offers one such alternative, focusing on the idle CPU cycles existing on local area networks. With the increase in the computing power of workstations and their declining costs, one can effectively transform the unused computing power attached to a local area network into a parallel processing environment. Effectively exploiting such an environment, however, requires a specification and operational framework that is portable, easy to use, and efficient. The environment is constructed around the Linda parallel programming paradigm which provides an effective parallel computational framework

Instructional Footprinting: A Model for Exploiting Concurrency through Instructional Decomposition and Code Motion

In many languages, the programmer is provided the capability of communicating, through the use of function calls, with other separate, independent processes. This capability can be as simple as a service request made to the operating system, or more advanced as Tuple Space operations specific to a Linda programming system. The problem with such calls, however, is that they block while waiting for data or information to be returned. This synchronous nature and lack of concurrency can be avoided by initiating the request for data earlier in the code and retrieving the returned data later when it is needed. In order to facilitate this concurrency of processing, an instructional footprint model is developed which formally describes movement of instructions. This paper presents research findings that entail the development of the instructional footprint model, an algorithmic framework in which to exploit concurrency in programming languages, and some preliminary results from applying the instructional footprint model

Instructional Footprinting: A Basis for Exploiting Concurrency Through Instructional Decomposition and Code Motion: A Research Prospectus

In many languages, the programmer is provided the capability of communicating, through the use of function calls, with other, separate, independent processes. This capability can be simple, as a service request made to the operating system, or more advanced, as Tuple space operations specific to a Linda programming system. The problem with such calls, however, is that they block while waiting for data of information to be returned. This synchronous nature and lack of concurrency can be avoided by initiating the request for data earlier in the code and retrieving the returned data later when it is needed. In order to facilitate this concurrency of processing, an instructional footprint model is developed which formally describes movement of instruction. This paper presents a proposal for research that involves the development of the instructional footprint model and an algorithmic framework in which to exploit concurrency in programming languages

Instructional Footprinting and Semantic Preservation in Linda

Linda is a coordination language designed to support process creation and inter-process communication within conventional computational languages. Although the Linda paradigm touts architectural and language independence, it often suffers performance penalties, particularly on local area network platforms. Instructional Footprinting is an optimization technique with the primary goal of enhancing the execution speed of Linda programs. The two main aspects of Instructional Footprinting are instructional decomposition and code motion. This paper addresses the semantic issues encountered when the Linda primitive, IN and RD, are decomposed and moved past other Linda operations. Formal semantics are given as well as results showing significant speedup (as high as 64%) when Instructional Footprinting is used

Control Systems’ Effect on Attributional Processes and Sales Outcomes: A Cybernetic Information-Processing Perspective

Built upon a cybernetic information-processing framework, this article advances and empirically tests a conceptual model proposing the relationships between sales controls (outcome, activity, capability), salespeople’s attributional ascriptions (effort, strategy, ability), attributional dimensions (internal/external, stable/unstable), and psychological consequences (job satisfaction, performance expectation). The study challenges the assumption in the sales literature that attributional dimensions cleanly map onto attributional ascriptions. Findings support that sales control systems affect salespeople’s attribution processes in ways suggesting that the processes are more malleable than heretofore theorized in the marketing literature. Furthermore, the study demonstrates that control systems differentially affect attribution processes across two cultures: the United States and China. The article concludes with a discussion of research and managerial implications.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

Upper limits on the strength of periodic gravitational waves from PSR J1939+2134

The first science run of the LIGO and GEO gravitational wave detectors presented the opportunity to test methods of searching for gravitational waves from known pulsars. Here we present new direct upper limits on the strength of waves from the pulsar PSR J1939+2134 using two independent analysis methods, one in the frequency domain using frequentist statistics and one in the time domain using Bayesian inference. Both methods show that the strain amplitude at Earth from this pulsar is less than a few times $10^{-22}$.Comment: 7 pages, 1 figure, to appear in the Proceedings of the 5th Edoardo Amaldi Conference on Gravitational Waves, Tirrenia, Pisa, Italy, 6-11 July 200

Improving the sensitivity to gravitational-wave sources by modifying the input-output optics of advanced interferometers

We study frequency dependent (FD) input-output schemes for signal-recycling interferometers, the baseline design of Advanced LIGO and the current configuration of GEO 600. Complementary to a recent proposal by Harms et al. to use FD input squeezing and ordinary homodyne detection, we explore a scheme which uses ordinary squeezed vacuum, but FD readout. Both schemes, which are sub-optimal among all possible input-output schemes, provide a global noise suppression by the power squeeze factor, while being realizable by using detuned Fabry-Perot cavities as input/output filters. At high frequencies, the two schemes are shown to be equivalent, while at low frequencies our scheme gives better performance than that of Harms et al., and is nearly fully optimal. We then study the sensitivity improvement achievable by these schemes in Advanced LIGO era (with 30-m filter cavities and current estimates of filter-mirror losses and thermal noise), for neutron star binary inspirals, and for narrowband GW sources such as low-mass X-ray binaries and known radio pulsars. Optical losses are shown to be a major obstacle for the actual implementation of these techniques in Advanced LIGO. On time scales of third-generation interferometers, like EURO/LIGO-III (~2012), with kilometer-scale filter cavities, a signal-recycling interferometer with the FD readout scheme explored in this paper can have performances comparable to existing proposals. [abridged]Comment: Figs. 9 and 12 corrected; Appendix added for narrowband data analysi

Search for gravitational wave bursts in LIGO's third science run

We report on a search for gravitational wave bursts in data from the three LIGO interferometric detectors during their third science run. The search targets subsecond bursts in the frequency range 100-1100 Hz for which no waveform model is assumed, and has a sensitivity in terms of the root-sum-square (rss) strain amplitude of hrss ~ 10^{-20} / sqrt(Hz). No gravitational wave signals were detected in the 8 days of analyzed data.Comment: 12 pages, 6 figures. Amaldi-6 conference proceedings to be published in Classical and Quantum Gravit