A Unified Scheduler for Recursive and Task Dataflow Parallelism

Task dataflow languages simplify the specification of parallel programs by dynamically detecting and enforcing dependencies between tasks. These languages are, however, often restricted to a single level of parallelism. This language design is reflected in the runtime system, where a master thread explicitly generates a task graph and worker threads execute ready tasks and wake-up their dependents. Such an approach is incompatible with state-of-the-art schedulers such as the Cilk scheduler, that minimize the creation of idle tasks (work-first principle) and place all task creation and scheduling off the critical path. This paper proposes an extension to the Cilk scheduler in order to reconcile task dependencies with the work-first principle. We discuss the impact of task dependencies on the properties of the Cilk scheduler. Furthermore, we propose a low-overhead ticket-based technique for dependency tracking and enforcement at the object level. Our scheduler also supports renaming of objects in order to increase task-level parallelism. Renaming is implemented using versioned objects, a new type of hyper object. Experimental evaluation shows that the unified scheduler is as efficient as the Cilk scheduler when tasks have no dependencies. Moreover, the unified scheduler is more efficient than SMPSS, a particular implementation of a task dataflow language.

Efficient FPGA Hardware Development: A Multi-Language Approach

This paper presents a multi-language framework to FPGA hardware development which aims to satisfy the dual requirement of high-level hardware design and efficient hardware implementation. The central idea of this framework is the integration of different hardware languages in a way that harnesses the best features of each language. This is illustrated in this paper by the integration of two hardware languages in the form of HIDE: a structured hardware language which provides more abstract and elegant hardware descriptions and compositions than are possible in traditional hardware description languages such as VHDL or Verilog, and Handel-C: an ANSI C-like hardware language which allows software and hardware engineers alike to target FPGAs from high-level algorithmic descriptions. On the one hand, HIDE has proven to be very successful in the description and generation of highly optimised parameterisable FPGA circuits from geometric descriptions. On the other hand, Handel-C has also proven to be very successful in the rapid design and prototyping of FPGA circuits from algorithmic application descriptions. The proposed integrated framework hence harnesses HIDE for the generation of highly optimised circuits for regular parts of algorithms, while Handel-C is used as a top-level design language from which HIDE functionality is dynamically invoked. The overall message of this paper posits that there need not be an exclusive choice between different hardware design flows. Rather, an integrated framework where different design flows can seamlessly interoperate should be adopted. Although the idea might seem simple prima facie, it could have serious implications on the design of future generations of hardware languages.

Development of a Java-based Unified and Flexible Natural Language Discourse System

This paper outlines the design and development of a Java-based, unified and flexible natural language dialogue system that enables users to interact using natural language, e.g. speech. A number of software development issues are considered with the aim of designing an architecture that enables different discourse components to be readily and flexibly combined in a manner that permits information to be easily shared. Use of XML schemas assists this component interaction. The paper describes how a range of Java language features were employed to support the development of the architecture, providing an illustration of how a modern programming language makes tractable the development of a complex dialogue system.

A design model: the Autism Spectrum Disorder Classroom Design Kit

Architects and designers have a responsibility to provide an inclusive built environment. However for those with a diagnosis of Autism Spectrum Disorder (ASD), the built environment can be a frightening and confusing place, difficult to negotiate and tolerate. The challenge of integrating more fully into society is denied by an alienating built environment. For ASD pupils in a poorly designed school, their environment can distance them from learning. Instead, if more at ease in their surroundings, in an ASD-friendly environment, the ASD pupil stands a greater chance of doing better.

However a difficulty exists in that most architects are not knowledgeable in designing for those with ASD. Any available design guidelines for architects tend, because of the inherent difficulties associated with a spectrum, to be general in their information. Therefore, if wanting to provide an ASD-friendly learning environment, there is a need to ensure that teachers, as the experts, can most clearly and effectively impart their knowledge and requirements to architects.

This paper sets out the challenges and difficulties inherent in the design process when designing for ASD. It then sets out an alternative strategy to the usual method of drawing-centric dialogue between teacher and architect by using models instead as a basis for a more common language. An ASD Classroom Design Kit was designed and developed by Queen’s University of Belfast Architecture students. It was then used by ASD teaching staff from the Southern Education and Library Board in Northern Ireland as a case study to trial its effectiveness. The paper outlines how the study was carried out before concluding with reflections by both teaching staff and architect on using the ASD Classroom Design Kit.

It is hoped that this paper will firstly highlight the need for better dialogue between expert and architect when considering ASD and the Built Environment and secondly, that it may encourage others to consider using models to convey their ideas and knowledge when designing, not just for ASD, but for other Special Educational Needs and disabilities.

Integrating textual analysis and evidential reasoning for decision making in Engineering design

Decision making is an important element throughout the life-cycle of large-scale projects. Decisions are critical as they have a direct impact upon the success/outcome of a project and are affected by many factors including the certainty and precision of information. In this paper we present an evidential reasoning framework which applies Dempster-Shafer Theory and its variant Dezert-Smarandache Theory to aid decision makers in making decisions where the knowledge available may be imprecise, conflicting and uncertain. This conceptual framework is novel as natural language based information extraction techniques are utilized in the extraction and estimation of beliefs from diverse textual information sources, rather than assuming these estimations as already given. Furthermore we describe an algorithm to define a set of maximal consistent subsets before fusion occurs in the reasoning framework. This is important as inconsistencies between subsets may produce results which are incorrect/adverse in the decision making process. The proposed framework can be applied to problems involving material selection and a Use Case based in the Engineering domain is presented to illustrate the approach. © 2013 Elsevier B.V. All rights reserved.

A language-independent parallel refactoring framework

Recent trends towards increasingly parallel computers mean that there needs to be a seismic shift in programming practice. The time is rapidly approaching when most programming will be for parallel systems. However, most programming techniques in use today are geared towards sequential, or occasionally small-scale parallel, programming. While refactoring has so far mainly been applied to sequential programs, it is our contention that refactoring can play a key role in significantly improving the programmability of parallel systems, by allowing the programmer to apply a set of well-defined transformations in order to parallelise their programs. In this paper, we describe a new language-independent refactoring approach that helps introduce and tune parallelism through high-level design patterns targeting a set of well-specified parallel skeletons. We believe this new refactoring process is the key to allowing programmers to truly start thinking in parallel. © 2012 ACM.

Doing Focus Groups and Interviews with Recent Migrants to Northern Ireland: A Dynamic Interplay of Ethics, Language and Access

This case describes a qualitative social science research project that was conducted in 2009 and that examined the experiences of recent migrants to Northern Ireland. While background to the research and key findings are presented, the topic forms a backdrop to the case. The following aspects of the study are presented: the theoretical context; formulating the research question, design and methodology; key methodological issues; data collection and analysis; project dissemination; and research funding and reporting. The case pays particular attention to the needs and impact of different groups including the researcher, the funding body, the researcher’s employer and the researched. The significance of access, language and ethics to this study are examined. Finally, the way in which the research unfolded in an often-unpredictable way throughout the implementation process is highlighted in the narrative.

Neural basis of language switching in the brain: fMRI evidence from Korean-Chinese early bilinguals

Using fMRI, we conducted two types of property generation task that involved language switching, with early bilingual speakers of Korean and Chinese. The first is a more conventional task in which a single language (L1 or L2) was used within each trial, but switched randomly from trial to trial. The other consists of a novel experimental design where language switching happens within each trial, alternating in the direction of the L1/L2 translation required. Our findings support a recently introduced cognitive model, the 'hodological' view of language switching proposed by Moritz-Gasser and Duffau. The nodes of a distributed neural network that this model proposes are consistent with the informative regions that we extracted in this study, using both GLM methods and Multivariate Pattern Analyses: the supplementary motor area, caudate, supramarginal gyrus and fusiform gyrus and other cortical areas.