Combination fluticasone and salmeterol versus fixed dose combination budesonide and formoterol for chronic asthma in adults and children

BackgroundCombination therapies are frequently recommended as maintenance therapy for people with asthma, whose disease is not adequately controlled with inhaled steroids. Fluticasone/salmeterol (FP/SAL) and budesonide/formoterol (BUD/F) have been assessed against their respective monocomponents, but there is a need to compare these two therapies on a head-to-head basis.ObjectivesTo estimate the relative effects of fluticasone/salmeterol and budesonide/formoterol in terms of asthma control, safety and lung function.Search strategyWe searched the Cochrane Airways Group register of trials with prespecified terms. We performed additional hand searching of manufacturers' web sites and online trial registries. Searches are current to May 2008.Selection criteriaRandomised studies comparing fixed dose FP/SAL and BUD/ F were eligible, for a minimum of 12 weeks. Crossover studies were excluded. Our primary outcomes were: i) exacerbations requiring oral steroid bursts, ii) hospital admission and iii) serious adverse events.Data collection and analysisTwo authors independently assessed studies for inclusion in the review. We combined continuous data outcomes with a mean difference (MD), and dichotomous data outcomes with an odds ratio (OR).Main resultsFive studies met the review entry criteria (5537 participants). Primary outcomes: The odds of an exacerbation requiring oral steroids did not differ significantly between treatments (OR 0.89; 95% CI 0.73 to 1.09, three studies, 4515 participants). The odds of an exacerbation leading hospital admission were also not significantly different (OR 1.29; 95% CI 0.68 to 2.47, four studies, 4879 participants). The odds of serious adverse events did not differ significantly between treatments (OR 1.47; 95% CI 0.75, 2.86, three studies, 4054 participants). Secondary outcomes: Lung function outcomes, symptoms, rescue medication, exacerbations leading ED visit/hospital admission and adverse events were not significantly different between treatments.Authors' conclusionsThe evidence in this review indicates that differences in the requirement for oral steroids and hospital admission between BUD/F and FP/SAL do not reach statistical significance. However, the confidence intervals do not exclude clinically important differences between treatments in reducing exacerbations or causing adverse events. The width of the confidence intervals for the primary outcomes justify further trials in order to better determine the relative effects of these drug combinations. Although this review sought to assess the effects of these drugs in both adults and children, no trials were identified in the under-12s and research in this area is of a high priority

Real-Time Motion Planning of Legged Robots: A Model Predictive Control Approach

We introduce a real-time, constrained, nonlinear Model Predictive Control for the motion planning of legged robots. The proposed approach uses a constrained optimal control algorithm known as SLQ. We improve the efficiency of this algorithm by introducing a multi-processing scheme for estimating value function in its backward pass. This pass has been often calculated as a single process. This parallel SLQ algorithm can optimize longer time horizons without proportional increase in its computation time. Thus, our MPC algorithm can generate optimized trajectories for the next few phases of the motion within only a few milliseconds. This outperforms the state of the art by at least one order of magnitude. The performance of the approach is validated on a quadruped robot for generating dynamic gaits such as trotting.Comment: 8 page

Signal Phasing Strategies for Intersections with an Exclusive Bicycle Path

Over the past few years in the United States, there has been a gradual increase among many public agencies installing experimental exclusive bicycle traffic signals in conjunction with vehicular traffic signals. These signals, mostly found at intersections with protected two-way bicycle paths, may cause operational inefficiencies if unsatisfactory phasing strategies are used. The source of the issue stems from difficulty in developing a phasing strategy where simultaneous vehicular movement is to not come into conflict with any concurrent bicycle movement, particularly the vehicular right-turn movement adjacent to a bicycle path. Additionally, as a new signal type, there has been a lack of general guidelines on how to develop an efficient strategy that not only accommodate bicycle traffic signals, but also pedestrian signals. The goal of this research was to develop different strategies to accommodate bicycle traffic signals. The strategies are based on a case study intersection where a bicycle signal has been installed and is causing operational inefficiencies. Three strategies was developed for each split and lead-lag phasing using a combination of overlaps, dummy phases, and phase modifiers. Using the simulation software VISSIM, a model was developed based on the case study's intersection roadway geometry and signal timing. Each strategy is then implemented and evaluated for the capacity and delay of the right-turn lane by varying bicycle and pedestrian volumes. Analytical models based on Poisson distribution were developed for the capacity and delay of the right-turn lane and checked with simulation results for validation. The current intersection operation was also evaluated using current traffic volumes, and implementing all three split design strategies.The results from simulation showed low delays and high capacity for the vehicular right-turn lane at low bicycle and pedestrian volumes. Vice versa, higher delay and lower capacity for the vehicular right-turn lane at higher bicycle and pedestrian volumes resulted, which is expected. A reduction of the current operation's right-turn lane average delay was observed with the implementation of all three solutions. And finally, the results from simulation indicate that each strategy will be advantageous at different bicycle and pedestrian demands

USING CONNECTED VEHICLE TECHNOLOGY TO IMPLEMENT A PAY FOR PRIORITY SYSTEM AT SIGNALIZED INTERSECTIONS

This research evaluated a mixed vehicle environment that included connected and non-connected vehicles in which connected vehicles (CV) were allowed to pay a small fee to request priority at a signalized intersection, similar to a transit signal priority system. Connected vehicles with signal priority were simulated with penetration levels ranging from 10% to 100% as well as with various priority directions (all directions, major street movements in both directions, and major street movements in the direction of highest flow) being allowed to request priority. These scenarios were compared to optimized signal timings to determine the effectiveness of the technology in terms of average delay and benefit-cost analysis was performed to assess the viability of this strategy that allows connected vehicles to receive signal priority for a fee. It was discovered that connected vehicles with signal priority experience less delay than non-connected vehicles for all priority direction scenarios studied up to a certain point. When all directions and major street movements in both directions are allowed to request priority, the advantage for CV was statistically significant up to 20% CV penetration. When priority was only allowed to be requested in the direction of highest flow, CVs experienced lower delay at a statistically significant level up to 40% CV penetration levels. Above these thresholds connected and non-connected vehicles experience similar delay. Average delay for all vehicles on the network, including connected and non-connected vehicle types, was also analyzed and revealed that average delay tended to increase as the CV penetration levels increased. When priority was permitted in only the major direction of travel the average delay for all vehicles on the network was significantly less than the base scenario for up to 50% CV penetration levels. Delay for all vehicles types was higher than the base scenario when priority was permitted in all directions and in both directions on the main corridors. A benefit-cost analysis was performed for the major flow direction priority scenario because it was the only scenario that outperformed the optimized signal timing scenario with no CV. A benefit-cost analysis based solely on revenue generated from CV requesting priority at intersections and the system cost resulted in a benefit-cost ratio greater than 1 at as low as 20% CV penetration levels. When the benefit-cost analysis added the benefit of decreased network delay for all vehicles, benefit-cost ratios as high as 3 were observed at 10% CV penetration levels

Real-world research and its importance in respiratory medicine

Peer reviewedPublisher PD

A simplified software architecture for self-updating Building Information Models (BIM)

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2009.Cataloged from PDF version of thesis.Includes bibliographical references (p. 61-63).Building Information Modeling (BIM) is an emerging software technology that is revolutionizing the architecture, engineering, and construction (A/E/C) industry. BIM technology employs "object-based 3D models-containing the physical and functional characteristics of a facility-that serve as a repository for lifecycle information in an open, interoperable format" [1]. The major difference between BIM and Computer-Aided Design/Drafting (CADD) is that the former includes geometry and a plethora of building information while the latter includes only geometry. BIM utilization in the AEC industry has increased due to 1) BIM tools increasing productivity in design tasks; 2) the increasing number of private and government agencies that have instituted BIM requirements; 3) the pervasive use of computer analysis and simulations models; 4) the benefits of BIM as lifecycle management tool. Current literature shows trends of a transition from a "passive"-static model-based-approach to an "active"-dynamic model-based-approach. The active approach requires the integration of BIM with sensors to create "self-updating" building models. Previous research introduces the concept of a self-updating building model ([2], [31, [41). These systems involve complex software architecture and may perpetuate the problem of software interoperability. This thesis explores the following question: May a similar system be created to synthesize dynamic sensor data while improving upon previous research and simplifying the software architecture? The author describes a prototype system, called LiveBuild, which integrates commercial BIM software with other off-the-shelf software components to create a self-updating building model. LiveBuild is the first self-updating building model that operates as an extension to existing commercial BIM software. Therefore, the transition from static to active building models is as simple as installing a plug-in. LiveBuild may serve as the basis for future research in self-updating building by providing simplified system that is well integrated with state-of-the art commercial design software. Likewise, the prototype is applicable for professional practice by allowing firms to use their existing BIM software to perform "pilot projects" with self-updating technology. The current prototype supports an interface with single commercial BIM software (Autodesk Revit 2009) product however future prototypes may extend both the functions and interfaces for other BIM software.by Pierre Fuller.S.M

A self-learning intersection control system for connected and automated vehicles

This study proposes a Decentralized Sparse Coordination Learning System (DSCLS) based on Deep Reinforcement Learning (DRL) to control intersections under the Connected and Automated Vehicles (CAVs) environment. In this approach, roadway sections are divided into small areas; vehicles try to reserve their desired area ahead of time, based on having a common desired area with other CAVs; the vehicles would be in an independent or coordinated state. Individual CAVs are set accountable for decision-making at each step in both coordinated and independent states. In the training process, CAVs learn to minimize the overall delay at the intersection. Due to the chain impact of taking random actions in the training course, the trained model can deal with unprecedented volume circumstances, the main challenge in intersection management. Application of the model to a single-lane intersection with no turning movement as a proof-of-concept test reveals noticeable improvements in traffic measures compared to three other intersection control systems. A Spring Mass Damper (SMD) model is developed to control platooning behavior of CAVs. In the SMD model, each vehicle is assumed as a mass, coupled with its preceding vehicle with a spring and a damper. The spring constant and damper coefficient control the interaction between vehicles. Limitations on communication range and the number of vehicles in each platoon are applied in this model, and the SMD model controls intra-platoon and inter-platoon interactions. The simulation result for a regular highway section reveals that the proposed platooning algorithm increases the maximum throughput by 29% and 63% under 50% and 100% market penetration rate of CAVs. A merging section with different volume combinations on the main section and merging section and different market penetration rates of CAVs is also modeled to test inter-platoon spacing performance in accommodating merging vehicles. Noticeable travel time reduction is observed in both mainline and merging lanes and under all volume combinations in 80% and higher MPR of CAVs. For a more reliable assessment of the DSCLS, the model is applied to a more realistic intersection, including three approaching lanes in each direction and turning movements. The proposed algorithm decreases delay by 58%, 19%, and 13% in moderate, high, and extreme volume regimes, improving travel time accordingly. Comparison of safety measures reveals 28% improvement in Post Encroachment Time (PET) in the extreme volume regime and minor improvements in high and moderate volume regimes. Due to the limited acceleration and deceleration rates, the proposed model does not show a better performance in environmental measures, including fuel consumption and CO2 emission, compared to the conventional control systems. However, the DSCLS noticeably outperforms the other pixel-reservation counterpart control system, with limited acceleration and deceleration rates. The application of the model to a corridor of four interactions shows the same trends in traffic, safety, and environmental measures as the single intersection experiment. An automated intersection control system for platooning CAVs is developed by combining the two proposed models, which remarkably improves traffic and safety measures, specifically in extreme volume regimes compared to the regular DSCLS model

Decision Support For Demand Response Triggers: Methodology Development and Proof of Concept Demonstration

Project Final Report prepared for CIEE and California Energy Commissio