Zoekresultaten

On the Automation of Periodic HardReal-time Processes: a Graph-Theoretical Approach

In bepaalde single-core configuraties met één processor, b.v. embedded control systems zoals robotic applications die uit vele korte processen bestaan, kunnen de context switches van een proces een aanzienlijke hoeveelheid van de beschikbare processing power verbruiken. Het verminderen van het aantal context switches vermindert de executietijd en verhoogt daardoor de prestaties van de toepassing. Bovendien is de end-to-end executietijd van de processen langer dan strict noodzakelijk, b.v. omdat de processen moeten wachten op controllers die een taak uitvoeren. Door de regels voor synchrone communicatie via kanalen in de procesalgebraïsche specificatietaal Communicating Sequential Processes te versoepelen, kunnen we de end-to-end executietijd verkorten. In ons onderzoek definiëren we verschillende graafproducten, bewijzen we dat deze producten een prestatiewinst opleveren (onder bepaalde voorwaarden) en we werken de numerieke en combinatorische aspecten van deze graafproducten uit.

Education as community affair : Digitally designing knowledge⁠

Asynchronous mHealth interventions in rheumatoid arthritis

BACKGROUND: Mobile devices such as smartphones and tablets have surged in popularity in recent years, generating numerous possibilities for their use in health care as mobile health (mHealth) tools. One advantage of mHealth is that it can be provided asynchronously, signifying that health care providers and patients are not communicating in real time. The integration of asynchronous mHealth into daily clinical practice might therefore help to make health care more efficient for patients with rheumatoid arthritis (RA). The benefits have been reviewed in various medical conditions, such as diabetes and asthma, with promising results. However, to date, it is unclear what evidence exists for the use of asynchronous mHealth in the field of RA.OBJECTIVE: The objective of this study was to map the different asynchronous mHealth interventions tested in clinical trials in patients with RA and to summarize the effects of the interventions.METHODS: A systematic search of Pubmed, Scopus, Cochrane, and PsycINFO was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Studies were initially screened and later assessed by two independent researchers. Disagreements on inclusion or exclusion of studies were resolved by discussion.RESULTS: The literature search yielded 1752 abstracts. After deduplication and screening, 10 controlled intervention studies were included. All studies were assessed to be at risk for bias in at least one domain of the Cochrane risk-of-bias tool. In the 10 selected studies, 4 different types of mHealth interventions were used: SMS reminders (to increase medication adherence or physical activity; n=3), web apps (for disease monitoring and/or to provide medical information; n=5), smartphone apps (for disease monitoring; n=1), and pedometers (to increase and track steps; n=1). Measured outcomes varied widely between studies; improvements were seen in terms of medication compliance (SMS reminders), reaching rapid remission (web app), various domains of physical activity (pedometer, SMS reminders, and web apps), patient-physician interaction (web apps), and self-efficacy (smartphone app).CONCLUSIONS: SMS reminders, web apps, smartphone apps, and pedometers have been evaluated in intervention studies in patients with RA. These interventions have been used to monitor patients or to support them in their health behavior. The use of asynchronous mHealth led to desirable outcomes in nearly all studies. However, since all studies were at risk of bias and methods used were very heterogeneous, high-quality research is warranted to corroborate these promising results.

Asynchronous Readers and Writers

Reading and writing is modelled in CSP using actions containing the sym- bols ? and !. These reading and writing actions are synchronous and there is a one- to-one relationship between occurrences of pairs of these actions. It is cumbersome to ease the restriction of synchronous execution of the read and write actions. For this reason we introduce the half-asynchronous parallel operator that acts on actions con- taining the symbols ¿ and ¡ and study the impact on a Vertex Removing Synchronised Product.

A Majority Vote, Modelled by Asynchronous Readers and Asynchronous Writers

Reading and writing is modelled in CSP using actions containing the symbols ? and !. These reading actions and writing actions are synchronous, and there is a one-to-one relationship between occurrences of pairs of these actions. In the CPA conference 2017, we introduced the extended half-synchronous al- phabetised parallel operator X ⇕ Y , which disconnects the writing to and reading from a channel in time; the reading processes are divided into sets which are set-wise asynchronous, but intra-set-wise synchronous, giving full flexibility to the reads. In this paper, we allow multiple writers to write to the same channel set-wise asynchronously, but intra-set-wise synchronously and we study the impact on our (Extended) Vertex Removing Synchronised Product. The advantages we accomplish are that the extension of X ⇕ Y gives more flexibility by indexing the writing actions and the reading actions, leading to a straightforward majority vote design. Furthermore, the extension of X ⇕ Y preserves the advantages of the X ⇕ Y operator.

Asynchronous Readers and Asynchronous Writers

Reading and writing is modelled in CSP using actions containing the symbols ? and !. These reading actions and writing actions are synchronous, and there is a one-to-one relationship between occurrences of pairs of these actions. In the CPA conference 2016, we introduced the half-synchronous alphabetised parallel operator X ⇓ Y , which disconnects the writing to and reading from a channel in time. We introduce in this paper an extension of X ⇓ Y , where the definition of X ⇓ Y is relaxed; the reading processes are divided into sets which are set-wise asynchronous, but intra-set-wise synchronous, giving full flexibility to the asynchronous writes and reads. Furthermore, we allow multiple writers to the same channel and we study the impact on a Vertex Removing Synchronised Product. The advantages we accomplish are that the extension of X ⇓ Y gives more flexibility by indexing the reading actions and allowing multiple write actions to the same channel. Furthermore, the extension of X ⇓Y reduces the end-to-end processing time of the processor or coprocessor in a distributed computing system. We show the effects of these advantages in a case study describing a Controlled Emergency Stop for a processor-coprocessor combination.