9 research outputs found

    A Methodology for Eliciting and Ranking Control Points for Adaptive Systems

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    Designing an adaptive system to meet its quality constraints in the face of environmental uncertainties, such as variable demands, can be a challenging task. In cloud environment, a designer has to also consider and evaluate different control points, i.e., those variables that affect the quality of the software system. This thesis presents a method for eliciting, evaluating and ranking control points for web applications deployed in cloud environments. The proposed method consists of several phases that take a high-level stakeholders' adaptation goal and transform it into lower level MAPE-K loop control points. The MAPE-K loop is then activated at runtime using an adaptation algorithm. We conducted several experiments to evaluate the different phases of the methodology and we report the results and the lesson learnt

    Dynamic Adaptation of Software-defined Networks for IoT Systems: A Search-based Approach

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    The concept of Internet of Things (IoT) has led to the development of many complex and critical systems such as smart emergency management systems. IoT-enabled applications typically depend on a communication network for transmitting large volumes of data in unpredictable and changing environments. These networks are prone to congestion when there is a burst in demand, e.g., as an emergency situation is unfolding, and therefore rely on configurable software-defined networks (SDN). In this paper, we propose a dynamic adaptive SDN configuration approach for IoT systems. The approach enables resolving congestion in real time while minimizing network utilization, data transmission delays and adaptation costs. Our approach builds on existing work in dynamic adaptive search-based software engineering (SBSE) to reconfigure an SDN while simultaneously ensuring multiple quality of service criteria. We evaluate our approach on an industrial national emergency management system, which is aimed at detecting disasters and emergencies, and facilitating recovery and rescue operations by providing first responders with a reliable communication infrastructure. Our results indicate that (1) our approach is able to efficiently and effectively adapt an SDN to dynamically resolve congestion, and (2) compared to two baseline data forwarding algorithms that are static and non-adaptive, our approach increases data transmission rate by a factor of at least 3 and decreases data loss by at least 70%

    Effect of Intermediate-Dose vs Standard-Dose Prophylactic Anticoagulation on Thrombotic Events, Extracorporeal Membrane Oxygenation Treatment, or Mortality among Patients with COVID-19 Admitted to the Intensive Care Unit: The INSPIRATION Randomized Clinical Trial

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    Importance: Thrombotic events are commonly reported in critically ill patients with COVID-19. Limited data exist to guide the intensity of antithrombotic prophylaxis. Objective: To evaluate the effects of intermediate-dose vs standard-dose prophylactic anticoagulation among patients with COVID-19 admitted to the intensive care unit (ICU). Design, Setting, and Participants: Multicenter randomized trial with a 2 � 2 factorial design performed in 10 academic centers in Iran comparing intermediate-dose vs standard-dose prophylactic anticoagulation (first hypothesis) and statin therapy vs matching placebo (second hypothesis; not reported in this article) among adult patients admitted to the ICU with COVID-19. Patients were recruited between July 29, 2020, and November 19, 2020. The final follow-up date for the 30-day primary outcome was December 19, 2020. Interventions: Intermediate-dose (enoxaparin, 1 mg/kg daily) (n = 276) vs standard prophylactic anticoagulation (enoxaparin, 40 mg daily) (n = 286), with modification according to body weight and creatinine clearance. The assigned treatments were planned to be continued until completion of 30-day follow-up. Main Outcomes and Measures: The primary efficacy outcome was a composite of venous or arterial thrombosis, treatment with extracorporeal membrane oxygenation, or mortality within 30 days, assessed in randomized patients who met the eligibility criteria and received at least 1 dose of the assigned treatment. Prespecified safety outcomes included major bleeding according to the Bleeding Academic Research Consortium (type 3 or 5 definition), powered for noninferiority (a noninferiority margin of 1.8 based on odds ratio), and severe thrombocytopenia (platelet count <20 �103/µL). All outcomes were blindly adjudicated. Results: Among 600 randomized patients, 562 (93.7) were included in the primary analysis (median interquartile range age, 62 50-71 years; 237 42.2% women). The primary efficacy outcome occurred in 126 patients (45.7%) in the intermediate-dose group and 126 patients (44.1%) in the standard-dose prophylaxis group (absolute risk difference, 1.5% 95% CI,-6.6% to 9.8%; odds ratio, 1.06 95% CI, 0.76-1.48; P =.70). Major bleeding occurred in 7 patients (2.5%) in the intermediate-dose group and 4 patients (1.4%) in the standard-dose prophylaxis group (risk difference, 1.1% 1-sided 97.5% CI,-� to 3.4%; odds ratio, 1.83 1-sided 97.5% CI, 0.00-5.93), not meeting the noninferiority criteria (P for noninferiority >.99). Severe thrombocytopenia occurred only in patients assigned to the intermediate-dose group (6 vs 0 patients; risk difference, 2.2% 95% CI, 0.4%-3.8%; P =.01). Conclusions and Relevance: Among patients admitted to the ICU with COVID-19, intermediate-dose prophylactic anticoagulation, compared with standard-dose prophylactic anticoagulation, did not result in a significant difference in the primary outcome of a composite of adjudicated venous or arterial thrombosis, treatment with extracorporeal membrane oxygenation, or mortality within 30 days. These results do not support the routine empirical use of intermediate-dose prophylactic anticoagulation in unselected patients admitted to the ICU with COVID-19. Trial Registration: ClinicalTrials.gov Identifier: NCT04486508. © 2021 American Medical Association. All rights reserved

    Atorvastatin versus Placebo in ICU Patients with COVID-19: Ninety-day Results of the INSPIRATION-S Trial

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    BACKGROUND: In the INSPIRATION-S trial, atorvastatin versus placebo was associated with a nonsignificant 16% reduction in 30-day composite of venous/arterial thrombosis or death in intensive care unit (ICU) patients with COVID-19. Thrombo-inflammatory response in coronavirus disease 2019 (COVID-19) may last beyond the first 30 days. METHODS: This article reports the effects of atorvastatin 20 mg daily versus placebo on 90-day clinical and functional outcomes from INSPIRATION-S, a double-blind multicenter randomized trial of adult ICU patients with COVID-19. The main outcome for this prespecified study was a composite of adjudicated venous/arterial thrombosis, treatment with extracorporeal membrane oxygenation (ECMO), or all-cause mortality. Functional status was assessed with the Post-COVID-19 Functional Scale. RESULTS: In the primary analysis, 587 patients were included (age: 57 [Q1-Q3: 45-68] years; 44% women). By 90-day follow-up, the main outcome occurred in 96 (33.1%) patients assigned to atorvastatin and 113 (38.0%) assigned to placebo (hazard ratio [HR]: 0.80, 95% confidence interval [CI]: 0.60-1.05, p = 0.11). Atorvastatin in patients who presented within 7 days of symptom onset was associated with reduced 90-day hazard for the main outcome (HR: 0.60, 95% CI: 0.42-0.86, p interaction_{interaction} = 0.02). Atorvastatin use was associated with improved 90-day functional status, although the upper bound CI crossed 1.0 (ORordinal_{ordinal}: 0.64, 95% CI: 0.41-1.01, p = 0.05). CONCLUSION: Atorvastatin 20 mg compared with placebo did not significantly reduce the 90-day composite of death, treatment with ECMO, or venous/arterial thrombosis. However, the point estimates do not exclude a potential clinically meaningful treatment effect, especially among patients who presented within 7 days of symptom onset (NCT04486508)

    Tools to Support SMEs to Migrate to the Cloud: Opportunities and Challenges

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    The first author of this paper thanks for the Scholarship (T.O.B)-No BOL0731/2016 provided by the Research Foundation State of Bahia (FAPESB).The cloud computing paradigm represents a shift in the way companies deal with customizable and resourceful platforms to deploy software. It has been receiving increasing attention, partly due to its claimed financial and functional benefits. Cloud computing providers provide organizations with access to computing services without the need for those organizations to own the providing infrastructure. However, migration of legacy information systems to the cloud is not simple. This field is very dynamic and related technologies are rapidly evolving. For instance, Small and Medium Enterprises (SMEs) may not necessarily be well prepared to deal with issues such as multi-tenancy, elasticity, interoperability, and cloud services. With such issues in view, we searched for different types of tools referenced in the literature to support migration to the cloud and discussed related challenges and advantages of their use by SMEs.publishe
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