33 research outputs found

    An LTE-Direct-Based Communication System for Safety Services in Vehicular Networks

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    With the expected introduction of fully autonomous vehicles, the long-term evolution (LTE)-based vehicle-to-everything (V2X) networking approach is gaining a lot of industry attention, to develop new strategies to enhance safety and telematics features. The vehicular and wireless industries are currently considering the development of an LTE-based system, which may co-exist, with the IEEE 802.11p-based systems for some time. In light of the above fact, our objective is to investigate the development of LTE Proximity Service (ProSe)-based V2X architecture for time-critical vehicular safety applications in an efficient and cost-effective manner. In this chapter, we present a new cluster-based LTE sidelink-based vehicle-to-vehicle (V2V) multicast/broadcast architecture to satisfy the latency and reliability requirements of V2V safety applications. Our proposed architecture combines a new ProSe discovery mechanism for sidelink peer discovery and a cluster-based round-robin scheduling technique to distribute the sidelink radio resources among the cluster members. Utilizing an OMNET++ based simulation model, the performance of the proposed network architecture is examined. Results of the simulation show that the proposed algorithms diminish the end-to-end delay and overhead signaling as well as improve the data packet delivery ratio (DPDR) compared with the existing 3GPP ProSe vehicle safety application technique

    ESAT6-Induced IFNγ and CXCL9 Can Differentiate Severity of Tuberculosis

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    BACKGROUND: Protective responses against Mycobacterium tuberculosis are dependent on appropriate T cell and macrophage activation. Mycobacterial antigen six kDa early secreted antigenic target (ESAT6) and culture filtrate protein 10 (CFP10) can detect M. tuberculosis specific IFNgamma responses. However, most studies have been performed in non-endemic regions and to study pulmonary tuberculosis (PTB). We have studied ESAT6 and CFP10 induced cytokine and chemokines responses in PTB and extrapulmonary (EPul) TB. METHODOLOGY: IFNgamma, IL10, CXCL9 and CCL2 responses were determined using an ex vivo whole blood assay system in PTB (n = 30) and EPulTB patients with limited (LNTB, n = 24) or severe (SevTB, n = 22) disease, and in healthy endemic controls (ECs). Responses to bacterial LPS were also determined. PRINCIPAL FINDINGS: ESAT6- and CFP10-induced IFNgamma was comparable between ECs and TB patients. Both ESAT6- and CFP10-induced IFNgamma secretion was greater in LNTB than PTB. ESAT6-induced CXCL9 was greater in EPulTB as compared with PTB, with an increase in SevTB as compared with LNTB. CFP10-induced CCL2 was higher in PTB than LNTB patients. LPS-stimulated CXCL9 was greatest in SevTB and LPS-induced CCL2 was increased in PTB as compared with LNTB patients. A positive correlation between ESAT6-induced IFNgamma and CXCL9 was present in all TB patients, but IFNgamma and CCL2 was only correlated in LNTB. ESAT-induced CCL2 and CXCL9 were significantly associated in LNTB while correlation in response to LPS was only present in SevTB. CONCLUSIONS: ESAT6 induced IFNgamma and CXCL9 can differentiate between limited and severe TB infections

    Accelerated surgery versus standard care in hip fracture (HIP ATTACK): an international, randomised, controlled trial

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    Effect of early tranexamic acid administration on mortality, hysterectomy, and other morbidities in women with post-partum haemorrhage (WOMAN): an international, randomised, double-blind, placebo-controlled trial

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    Background Post-partum haemorrhage is the leading cause of maternal death worldwide. Early administration of tranexamic acid reduces deaths due to bleeding in trauma patients. We aimed to assess the effects of early administration of tranexamic acid on death, hysterectomy, and other relevant outcomes in women with post-partum haemorrhage. Methods In this randomised, double-blind, placebo-controlled trial, we recruited women aged 16 years and older with a clinical diagnosis of post-partum haemorrhage after a vaginal birth or caesarean section from 193 hospitals in 21 countries. We randomly assigned women to receive either 1 g intravenous tranexamic acid or matching placebo in addition to usual care. If bleeding continued after 30 min, or stopped and restarted within 24 h of the first dose, a second dose of 1 g of tranexamic acid or placebo could be given. Patients were assigned by selection of a numbered treatment pack from a box containing eight numbered packs that were identical apart from the pack number. Participants, care givers, and those assessing outcomes were masked to allocation. We originally planned to enrol 15 000 women with a composite primary endpoint of death from all-causes or hysterectomy within 42 days of giving birth. However, during the trial it became apparent that the decision to conduct a hysterectomy was often made at the same time as randomisation. Although tranexamic acid could influence the risk of death in these cases, it could not affect the risk of hysterectomy. We therefore increased the sample size from 15 000 to 20 000 women in order to estimate the effect of tranexamic acid on the risk of death from post-partum haemorrhage. All analyses were done on an intention-to-treat basis. This trial is registered with ISRCTN76912190 (Dec 8, 2008); ClinicalTrials.gov, number NCT00872469; and PACTR201007000192283. Findings Between March, 2010, and April, 2016, 20 060 women were enrolled and randomly assigned to receive tranexamic acid (n=10 051) or placebo (n=10 009), of whom 10 036 and 9985, respectively, were included in the analysis. Death due to bleeding was significantly reduced in women given tranexamic acid (155 [1·5%] of 10 036 patients vs 191 [1·9%] of 9985 in the placebo group, risk ratio [RR] 0·81, 95% CI 0·65–1·00; p=0·045), especially in women given treatment within 3 h of giving birth (89 [1·2%] in the tranexamic acid group vs 127 [1·7%] in the placebo group, RR 0·69, 95% CI 0·52–0·91; p=0·008). All other causes of death did not differ significantly by group. Hysterectomy was not reduced with tranexamic acid (358 [3·6%] patients in the tranexamic acid group vs 351 [3·5%] in the placebo group, RR 1·02, 95% CI 0·88–1·07; p=0·84). The composite primary endpoint of death from all causes or hysterectomy was not reduced with tranexamic acid (534 [5·3%] deaths or hysterectomies in the tranexamic acid group vs 546 [5·5%] in the placebo group, RR 0·97, 95% CI 0·87-1·09; p=0·65). Adverse events (including thromboembolic events) did not differ significantly in the tranexamic acid versus placebo group. Interpretation Tranexamic acid reduces death due to bleeding in women with post-partum haemorrhage with no adverse effects. When used as a treatment for postpartum haemorrhage, tranexamic acid should be given as soon as possible after bleeding onset. Funding London School of Hygiene & Tropical Medicine, Pfizer, UK Department of Health, Wellcome Trust, and Bill & Melinda Gates Foundation

    The development and validation of a scoring tool to predict the operative duration of elective laparoscopic cholecystectomy

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    Background: The ability to accurately predict operative duration has the potential to optimise theatre efficiency and utilisation, thus reducing costs and increasing staff and patient satisfaction. With laparoscopic cholecystectomy being one of the most commonly performed procedures worldwide, a tool to predict operative duration could be extremely beneficial to healthcare organisations. Methods: Data collected from the CholeS study on patients undergoing cholecystectomy in UK and Irish hospitals between 04/2014 and 05/2014 were used to study operative duration. A multivariable binary logistic regression model was produced in order to identify significant independent predictors of long (> 90 min) operations. The resulting model was converted to a risk score, which was subsequently validated on second cohort of patients using ROC curves. Results: After exclusions, data were available for 7227 patients in the derivation (CholeS) cohort. The median operative duration was 60 min (interquartile range 45–85), with 17.7% of operations lasting longer than 90 min. Ten factors were found to be significant independent predictors of operative durations > 90 min, including ASA, age, previous surgical admissions, BMI, gallbladder wall thickness and CBD diameter. A risk score was then produced from these factors, and applied to a cohort of 2405 patients from a tertiary centre for external validation. This returned an area under the ROC curve of 0.708 (SE = 0.013, p  90 min increasing more than eightfold from 5.1 to 41.8% in the extremes of the score. Conclusion: The scoring tool produced in this study was found to be significantly predictive of long operative durations on validation in an external cohort. As such, the tool may have the potential to enable organisations to better organise theatre lists and deliver greater efficiencies in care

    Real-time load scheduling and storage management for solar powered network connected EVs

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    In this paper, we investigate a joint real-time load scheduling and energy storage management at a grid-connected solar powered electric vehicle. Without any a priori knowledge, we consider a finite time approach with arbitrary dynamics of system inputs. Our aim is to minimize an average aggregated system cost through joint optimization of electric vehicle's energy procurement price, load scheduling delays, photovoltaic sufficiency in terms of locally generated renewable energy mix, and battery degradation. Through subsequent modification and reformulation of the joint optimization problem, we utilize the concept of one-slot look-ahead queue stability to solve the problem by employing the Lyapunov optimization technique. We show that the joint optimization problem is separable into sub-problems, which are sequentially solved with asymptotic optimality and a bounded performance guarantee. Simulations are carried in different scenarios and under varying weather conditions. Results show that our proposed algorithm can achieve a daily electric vehicle's photovoltaic sufficiency up to 50.50%, a monthly bill reduction up to 72.61%, and a yearly reduced CO_2 emission level up to 6.06 kg, while meeting electric vehicle user's energy and delay requirements

    A Joint Real Time Optimization of Household Loads, Energy Storage and Peak Generator for Stand-Alone Distributed PV Systems

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    We investigate a real time (RT) communication and control technique for a user centric stand-alone distributed photovoltaic (PV) system. The current user centric RT techniques for grid-connected systems may not be directly employed in stand- alone systems due to contradiction in their objectives. In this paper, we propose a user centric RT control algorithm for stand-alone PV systems and investigate its communication requirements. Our aim is to minimize an average aggregate system cost considering a joint optimization problem of load scheduling, energy procurement from a peak generator (PG) and battery energy storage (BES) management. By subsequent relaxation and reformulation of the problem, we employ the Lyapunov optimization technique (LOT). Simulation results show the effectiveness of the proposed RT solution in terms of the selected performance metrics

    Real-time load scheduling, energy storage control and comfort management for grid-connected solar integrated smart buildings

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    Energy storage control, load scheduling, and indoor user comfort management are perceived as key management solutions for electric industry in the building sector. Nevertheless, requirement of a-priori knowledge on system inputs (i.e., renewable energy generation process, load arrival process, and dynamic price signals) raises concerns about the ability of existing building energy management solutions to accurately adapt to real-time needs in energy generation, demand, storage, and indoor comfort feel. Conversely, with the consideration of unknown dynamics of system inputs, a one-slot-look-ahead virtual queue stability based Lyapunov optimization technique is employed in this article for a real-time energy and comfort optimization in grid-connected solar integrated smart buildings. The goal is to minimize an average aggregated system cost through a real-time joint optimization of electrical and thermal load scheduling delays, energy procurement cost from controllable generators and external grid, electrical and thermal energy storage degradation, and indoor user comfort feel. It is also shown that the joint optimization problem is separable into subproblems which are sequentially solved to obtain all solutions in closed-forms. The solutions are proved as asymptotically optimal, and can be easily implemented in real-time building energy and comfort management scenarios especially when the statistics of system inputs are unknown and arbitrary. The proposed algorithm is validated through simulations where it is tested in different weather conditions. Results show that the proposed algorithm can achieve an average monthly energy procurement-and-operations cost reduction up to 16.37%, while meeting building’s energy and comfort requirements

    Roof-top stand-alone PV micro-grid: A joint real-time BES management, load scheduling and energy procurement from a peaker generator

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    In this paper, we propose a user centric real-time (RT) technique for an optimal control of a distributed photovoltaic stand-alone micro-grid. Our objective is to minimize an average aggregated system cost over a finite time period considering a joint optimization problem of battery energy storage (BES) management, load scheduling, and energy procurement process from a peaker generator (PG). Due to online decision making, the dynamic control actions of the state of energy of the storage battery are correlated over time. Thus, we impose a constraint on the BES state of energy over the considered time period and eliminate the finite BES capacity constraint. In the load scheduling process, we account for the temporal variability and spatial uncertainty of each household load explicitly. We introduce the concept of block duration to optimize the energy procurement cost from a PG. We modify and then transform the problem to utilize the Lyapunov optimization technique. We show that the proposed solution to the joint optimization problem is asymptotically optimal with a bounded performance guarantee and is easy to implement. Simulations in different weather conditions show the effectiveness of our proposed user centric RT solution in terms of the selected performance metrics
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