243 research outputs found

    Fibers are not (P)Threads: The Case for Loose Coupling of Asynchronous Programming Models and MPI Through Continuations

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    Asynchronous programming models (APM) are gaining more and more traction, allowing applications to expose the available concurrency to a runtime system tasked with coordinating the execution. While MPI has long provided support for multi-threaded communication and non-blocking operations, it falls short of adequately supporting APMs as correctly and efficiently handling MPI communication in different models is still a challenge. Meanwhile, new low-level implementations of light-weight, cooperatively scheduled execution contexts (fibers, aka user-level threads (ULT)) are meant to serve as a basis for higher-level APMs and their integration in MPI implementations has been proposed as a replacement for traditional POSIX thread support to alleviate these challenges. In this paper, we first establish a taxonomy in an attempt to clearly distinguish different concepts in the parallel software stack. We argue that the proposed tight integration of fiber implementations with MPI is neither warranted nor beneficial and instead is detrimental to the goal of MPI being a portable communication abstraction. We propose MPI Continuations as an extension to the MPI standard to provide callback-based notifications on completed operations, leading to a clear separation of concerns by providing a loose coupling mechanism between MPI and APMs. We show that this interface is flexible and interacts well with different APMs, namely OpenMP detached tasks, OmpSs-2, and Argobots.Comment: 12 pages, 7 figures Published in proceedings of EuroMPI/USA '20, September 21-24, 2020, Austin, TX, US

    Everything as a Resource: Foundations and Illustration through Internet-of-Things

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    This paper presents Everything-as-a-Resource (*aaR) as a paradigm for designing collaborative applications on the Web. Abstracting these applications’ various physical and logical entities, resources are defined in a way that permits their discovery, composition, and participation in business scenarios. Compared to Everything-as-a-Service (*aaS), resources are categorized into computational, consumed, and produced, have trackable lifecycles as per their respective category, and are customized in order to consider the characteristics of future resource-based collaborative applications to develop. From a capacity perspective, a computational resource processes data, a produced resource abstracts data, and a consumed resource captures data. Along with their capacities, resources expose methods that other resources and/or applications’ stakeholders call. The proper call of methods is ensured through restrictions like limited and non-shareable. This paper exemplifies the *aaR paradigm with a case study that revolves around the use of Internet-of-Things (IoT) in the healthcare domain. The case study is implemented in a RESTful fashion along with some standard Web technologies and protocols. The evaluation of IoTR4HealthCare system is benchmarked against two existing systems using cost and latency criteria

    Pre-operative oral nutritional supplementation with dietary advice versus dietary advice alone in weight-losing patients with colorectal cancer: single-blind randomized controlled trial.

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    BACKGROUND: Pre-operative weight loss has been consistently associated with increased post-operative morbidity. The study aims to determine if pre-operative oral nutritional supplements (ONSs) with dietary advice reduce post-operative complications. METHODS: Single-blinded randomized controlled trial. People with colorectal cancer scheduled for surgery with pre-operative weight loss >1 kg/3-6 months were randomized by using stratified blocks (1:1 ratio) in six hospitals (1 November 2013-28 February 2015). Intervention group was given 250 mL/day ONS (10.1 KJ and 0.096 g protein per mL) and dietary advice. Control group received dietary advice alone. Oral nutritional supplements were administered from diagnosis to the day preceding surgery. Research team was masked to group allocation. Primary outcome was patients with one or more surgical site infection (SSI) or chest infection; secondary outcomes included percentage weight loss, total complications, and body composition measurements. Intention-to-treat analysis was performed with both unadjusted and adjusted analyses. A sample size of 88 was required. RESULTS: Of 101 participants, (55 ONS, 46 controls) 97 had surgery. In intention-to-treat analysis, there were 21/45 (47%) patients with an infection-either an SSI or chest infection in the control group vs. 17/55 (30%) in the ONS group. The odds ratio of a patient incurring either an SSI or chest infection was 0.532 (P = 0.135 confidence interval 0.232 to 1.218) in the unadjusted analysis and when adjusted for random differences at baseline (age, gender, percentage weight loss, and cancer staging) was 0.341 (P = 0.031, confidence interval 0.128 to 0.909). Pre-operative percentage weight loss at the first time point after randomization was 4.1% [interquartile range (IQR) 1.7-7.0] in ONS group vs. 6.7% (IQR 2.6-10.8) in controls (Mann-Whitney U P = 0.021) and post-operatively was 7.4% (IQR 4.3-10.0) in ONS group vs. 10.2% (IQR 5.1-18.5) in controls (P = 0.016). CONCLUSIONS: Compared with dietary advice alone, ONS resulted in patients having fewer infections and less weight loss following surgery for colorectal cancer. We have demonstrated that pre-operative oral nutritional supplementation can improve clinical outcome in weight losing patients with colorectal cancer

    The post-2015 debate and the place of education in development thinking

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    As the end date for the Millennium Development Goals approaches so the focus on goals, visions and policies for development after 2015 becomes ever heightened. However, there has been relatively little engagement by educational research community in these debates. What then is being written about education in the key post-2015 documents? How is education's role in development conceptualised by those most central to shaping new accounts? I explore these issues through an analysis of a key text on post-2015, the High Level Panel Report of May 2013 (UN-HLP 2013), and an exploration of a year's worth of posts on 30 prominent blogs and websites discussing post-2015 matters. This leads me to two further, interlinked questions: what are the implications of potential marginalisation and irrelevance from these debates for the field of international education and development research? What are the potential dangers for the field of closer engagement in these debates and their growing use of social media? The academic international education and development community may be more comfortable in keeping these policy debates at a distance, but this may play against the strong educational research drive to engage in social science that makes a difference. If there is to be engagement with post-2015 then alternative ways of developing practices of research, action and dialogue need further strengthened. This may include interdisciplinary dialogues around such issues as early childhood development, the role of professions in development or environmental sustainability. Engagement with the post-2015 debate would also require a careful analysis of how best to engage with the instrumentalised accounts of education that are dominant in the policy-advocacy arena. This would entail more strategic positions on the uses and dangers of social media. At the same time, engagement with development studies as well as the development policy community requires a reappraisal of epistemological and methodological stances

    OT Modeling: The Enterprise Beyond IT

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    Enterprises are composed of an enormous number of elements (e.g., organizational units, human resources, production processes, and IT systems) typically classified in the business or the IT domain. However, some crucial elements do not belong in either group: they are directly responsible for producing and delivering the company’s goods and services and include all the elements that support day to day operations. Collectively, these elements have been called operational technologies (OT) and have been conspicuously excluded from enterprise modeling (EM) approaches which traditionally have focused on the business and IT dimensions. Evidence of this is the absence of OT elements in languages and metamodels for EM. This is in line with the historical division between IT and OT in organizations that has led to information silos, independent teams, and disparate tech- nologies that only recently have started to be reconciled. Considering that OT is critical to most productive organi- zations, and the benefits that EM brings to its understand- ing and improvement, it makes sense to expand EM to include OT. For that purpose, this paper proposes an extension to ArchiMate 3.0 which includes crucial OT elements. On top of that, this paper also proposes an approach to further expand ArchiMate to address specific industries where more specific OT elements are required. This is illustrated in the paper with an extension for the Oil and Gas case that was validated with experts belonging to five companies in the sector

    Self-archiving and the Copyright Transfer Agreements of ISI-ranked library and information science journals

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    A study of Thomson-Scientific ISI ranked Library and Information Science (LIS) journals (n = 52) is reported. The study examined the stances of publishers as expressed in the Copyright Transfer Agreements (CTAs) of the journals toward self-archiving, the practice of depositing digital copies of one\u27s works in an Open Archives Initiative (OAI)-compliant open access repository. Sixty-two percent (32) do not make their CTAs available on the open Web; 38% (20) do. Of the 38% that do make CTAs available, two are open access journals. Of the 62% that do not have a publicly available CTA, 40% are silent about self-archiving. Even among the 20 journal CTAs publicly available there is a high level of ambiguity. Closer examination augmented by publisher policy documents on copyright, self-archiving, and instructions to authors reveals that only five, 10% of the ISI-ranked LIS journals in the study, actually prohibit self-archiving by publisher rule. Copyright is a moving target, but publishers appear to be acknowledging that copyright and open access can co-exist in scholarly journal publishing. The ambivalence of LIS journal publishers provides unique opportunities to members of the community. Authors can self-archive in open access archives. A society-led, global scholarly communication consortium can engage in the strategic building of the LIS information commons. Aggregating OAI-compliant archives and developing disciplinary-specific library services for an LIS commons has the potential to increase the field\u27s research impact and visibility. It may also ameliorate its own scholarly communication and publishing systems and serve as a model for others
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