A ϕ\phi-Competitive Algorithm for Scheduling Packets with Deadlines

In the online packet scheduling problem with deadlines (PacketScheduling, for short), the goal is to schedule transmissions of packets that arrive over time in a network switch and need to be sent across a link. Each packet has a deadline, representing its urgency, and a non-negative weight, that represents its priority. Only one packet can be transmitted in any time slot, so, if the system is overloaded, some packets will inevitably miss their deadlines and be dropped. In this scenario, the natural objective is to compute a transmission schedule that maximizes the total weight of packets which are successfully transmitted. The problem is inherently online, with the scheduling decisions made without the knowledge of future packet arrivals. The central problem concerning PacketScheduling, that has been a subject of intensive study since 2001, is to determine the optimal competitive ratio of online algorithms, namely the worst-case ratio between the optimum total weight of a schedule (computed by an offline algorithm) and the weight of a schedule computed by a (deterministic) online algorithm. We solve this open problem by presenting a $\phi$-competitive online algorithm for PacketScheduling (where $\phi\approx 1.618$ is the golden ratio), matching the previously established lower bound.Comment: Major revision of the analysis and some other parts of the paper. Another revision will follo

SRECMATs - an intelligent tutoring system to deliver online materials for student revision

The use of online course material is the approach adopted by most universities to support students’ revision, and teachers usually have the responsibility for designing or uploading online materials on their own course websites. However, some teachers might lack programming skills or motivation, and most current online materials are just uploaded in a static format (such as PDF) which is not suitable for all students. Moreover, during revision periods students may be faced with a lot of unorganised materials to be revised in a short period of time, and this can lead to an ineffective revision process. In order to address these issues, this paper proposes a software framework that aims to maximise the benefit of current online materials when used to support student revision. This framework is called SRECMATs (Self-Revision E-Course MATerials) and has been deployed as a tool that allows teachers to automatically create an intelligent tutoring system to manage online materials without any programming knowledge, and to support students to navigate easily through these online materials during their revision. This paper evaluates the proposed framework in order to understand students’ perceptions with regard to the use of the system prototype, and the results indicate which features are suitable for providing online revision materials as well as confirming the benefit of the revision framework

Increasing but levelling out risk of revision due to infection after total hip arthroplasty: a study on 108,854 primary THAs in the Norwegian Arthroplasty Register from 2005 to 2019

Background and purpose — Focus on prevention, surveillance, and treatment of infection after total hip arthroplasty (THA) in the last decade has resulted in new knowledge and guidelines. Previous publications have suggested an increased incidence of surgical revisions due to infection after THA. We assessed whether there have been changes in the risk of revision due to deep infection after primary THAs reported to the Norwegian Arthroplasty Register (NAR) over the period 2005–2019. Patients and methods — Primary THAs reported to the NAR from January 1, 2005 to December 31, 2019 were included. Adjusted Cox regression analyses with the first revision due to deep infection after primary THA were performed. We investigated changes in the risk of revision as a function of time of primary THA. Time was stratified into 5-year periods. We studied the whole population of THAs, and the subgroups: all-cemented, all-uncemented, reverse hybrid (cemented cup), and hybrid THAs (cemented stem). In addition, we investigated factors that were associated with the risk of revision, and changes in the time span from primary THA to revision. Results — Of the 108,854 primary THAs that met the inclusion criteria, 1,365 (1.3%) were revised due to deep infection. The risk of revision due to infection, at any time after primary surgery, increased through the period studied. Compared with THAs implanted in 2005–2009, the relative risk of revision due to infection was 1.4 (95% CI 1.2–1.7) for 2010–2014, and 1.6 (1.1–1.9) for 2015–2019. We found an increased risk for all types of implant fixation. Compared to 2005–2009, for all THAs, the risk of revision due to infection 0–30 days postoperatively was 2.2 (1.8–2.8) for 2010–2014 and 2.3 (1.8–2.9) for 2015–2019, 31–90 days postoperatively 1.0 (0.7–1.6) for 2010–2014 and 1.6 (1.0–2.5) for 2015–2019, and finally 91 days–1 year postoperatively 1.1 (0.7–1.8) for 2010–2014 and 1.6 (1.0–2.6) for 2015–2019. From 1 to 5 years postoperatively, the risk of revision due to infection was similar to 2005–2009 for both the subsequent time periods Interpretation — The risk of revision due to deep infection after THA increased throughout the period 2005–2019, but appears to have levelled out after 2010. The increase was mainly due to an increased risk of early revisions, and may partly have been caused by a change of practice rather than a change in the incidence of infection.publishedVersio

Revision Processes in First Language and Foreign Language Writing: Differences and Similarities in the Success of Revision Processes

Writing academic texts in one’s native language (L1) and – even more – in a foreign language (FL) places high cognitive demands on students. In order to cope with these demands, writers should learn to adapt their writing methods flexibly to their tasks, depending on the language and the genre they are writing in. Crucial aspects here are the methods of revising because the need for linguistic revision will be higher in the FL text than in the L1 text; at the same time, it should not be the main or only focus of the revision process. In order to analyse the differences in L1 and FL revision, a study was set up in which ten L1 German students wrote academic essays in German and in English. The production process was protocolled with the help of keylogging, so that the revising processes could be analysed. The results show that the participants revised similarly in both the L1 and the FL. They focussed on the same aspects (content, typing mistakes, and language errors that were not L1 related). At the same time, there are differences in finer grades. These differences in revision do not seem to be a conscious decision, however, but are rather the result of the higher cognitive demands in FL academic writing and the lower degree of language knowledge. Additionally, the analysis of the final FL texts showed that most of the errors that were not corrected were L1 induced. When one looks at the revisions, however, one sees that hardly any revisions were made in these aspects: the L1 influence went more or less unnoticed. For writing pedagogy, this means that one has to put a higher focus on revision strategies during teaching, in order to give students the tools to write successfully in L1 and in FL, and to motivate them in enhancing their papers

Optimizing Sepsis Management Through Enhanced Protocol Compliance in the Emergency Department

Problem: This quality improvement (QI) project aims to optimize early sepsis management and sepsis bundle compliance among Emergency Department (ED) registered nurses in order to reduce the risk of sepsis-related deaths and associated hospital length of stay. Context: Clinical Nurse Leader (CNL) students conducted a microsystem assessment on the ED at Hospital A, located within the greater San Francisco Bay Area. This microsystem, equipped with 115 nurses and 44 rooms, consists of an acuity of care for urgent to life-threatening medical conditions, including sepsis. Intervention: Following time constraints, and limitations, implementation of an intervention was not feasible; however, CNL students provided recommendations so stakeholders may further investigate and pursue. The recommended interventions include: increasing sepsis bundle training frequency, refining intravenous placement skills through technologically driven training and readily available resources, badge buddy sepsis cards, and revision of the current charting system. Measures: CNL students collected data to assess the nurses\u27 knowledge of the sepsis bundle and Hospital A’s sepsis policy. The data also served to identify frequency of training, debriefings, and any barriers nurses experienced while implementing the bundle. Due to time constraints, a post-intervention survey was not conducted. Results: 41 of the 115 ED registered nurses responded. Pre-intervention questionnaire responses revealed that 42% of ED nursing staff recommend protocol revision, 24.4% claim to not have attended any sepsis training with another 4.9% reporting rarely attending, and 46.3% reported there is no debriefing, or follow-up training, when sepsis bundle compliance is failed to be met. Additionally, nurses identified various barriers, prolonging sepsis bundle compliance. Conclusions: Analysis of the pre-intervention questionnaire responses from Hospital A’s ED registered nurses revealed knowledge gaps and barriers to timely sepsis management and bundle compliance. CNL students identified evidence-based recommendations, which stakeholders may implement to yield anticipated outcomes. Keywords: sepsis, sepsis management, sepsis bundle, sepsis bundle compliance, SIRS, emergency department, and quality improvemen