Dynamic multi-ramp metering control with simultaneous perturbation stochastic approximation (SPSA)

Ramp metering was proven to be a viable form of freeway traffic control strategy, which could eliminate, or at least reduce, freeway congestion. In this study, the development of ramp metering control strategies, models, and constraints (e.g., meter locations, ramp storage capacities, lower and upper bounds of ramp metering rates) are discussed in detail. The pre-timed and demand/capacity metering control strategies were first evaluated, while the potential metered ramps were determined. A Simultaneous Perturbation Stochastic Approximation (SPSA) algorithm is proposed to dynamically optimize multiple-ramp metering control by maximizing the total throughput subject to a number of constraints. The ramp metering rates subject to dynamic traffic conditions and capacity constraints are considered as decision variables in the SPSA algorithm. Based on the collected geometric and traffic data, a CORSIM model was developed to simulate traffic operation for the study site. The potential benefit of the dynamic multi-ramp metering control model under time varying traffic condition was simulated and evaluated. The increased total throughput and reduced total delay were observed, while the traffic conditions suitable for implementing ramp metering control were suggested. The developed dynamic multi-ramp metering control with SPSA algorithm has demonstrated its effectiveness to improve freeway operation

Player detection method based on scale attention and scale equalization algorithm

IntroductionObject detection methods for team ball games players often struggle due to their reliance on dataset scale statistics, resulting in missed detections for players with smaller bounding boxes and reduced accuracy for larger bounding boxes.MethodsThis study introduces a two-fold approach to address these challenges. Firstly, a novel multi-scale attention mechanism is proposed, aiming to reduce reliance on scale statistics by utilizing a specially created SIoU (Similar to Intersection over Union) label that explicitly represents multi-scale features. This label guides the training of multi-scale attention network modules at two granularity levels. Secondly, an integrated scale equalization algorithm within SIoU labels enhances the detection ability of multi-scale targets in imbalanced samples.Results and discussionComparative experiments conducted on basketball, volleyball, and ice hockey datasets validate the proposed method. The relative optimal approach demonstrated improvements in the detection accuracy of players with smaller and larger scale bounding boxes by 11%, 7%, 15%, 8%, 9%, and 4%, respectively

The President\u27s Emergency Plan for AIDS Relief and Adult Mortality: A Replication Study of HIV Development Assistance Effects in Sub-Saharan African Countries

The US budget for global health funding, which was by far the largest of similar funding in the world, increased from US $1.3 billion in 2001 to more than US$10 billion in recent years. More than 54% of this funding was allocated to the Global Fund to Fight HIV/AIDS through the US President\u27s Emergency Plan for AIDS Relief (PEPFAR) in Africa. However, recent studies indicate contradictory results regarding the effectiveness of PEPFAR. One by Bendavid, Holmes, Bhattacharya, and Miller shows positive effects of PEPFAR in reducing adult mortality in Africa, while another by Duber, Coates, Szekeras, Kaji, and Lewis finds that there are no significant differences in reducing adult mortality in countries that received PEPFAR funding vs countries that did not. Due to their potential impact on policy decisions regarding critical global health funding, we wanted to assess why the results are discrepant. To do this, we replicated the Bendavid study. The replication provides verification that the study replicable and that the analytic choices of the authors are robust to different assumptions or restrictions. This allows us to assess the different choices and data available to the two research groups and draw some conclusions about why the results may be different. Then, focusing on two of the prominently discrepant studies, i.e., the Bendavid study (1998-2008) and the Duber study (2000-2006), we establish why the two studies are in disagreement. We apply appropriate individual-level and country-level analytical methodology as used by Bendavid over the analytical time period used for the Duber study (2000-2006), which originally focused on nationally aggregated data and differed in some key focus countries. For our first objective, we replicated the original Bendavid study findings and our findings support their conclusion that between 1998-2008 all-cause mortality decreased significantly more (OR = 0.84, CI, 0.72-0.99) in countries that implemented PEPFAR. For our second objective (Bendavid\u27s data and methodology applied to Duber\u27s study period), we found reduction in all cause adult mortality to be borderline insignificant (OR = 0.87 CI, 0.75-1.01, p = 0.06), most possibly reflecting the abbreviated fewer number of events and sample size over a shorter period. Therefore, our overall analyses are consistent with the conclusion of positive impact of the PEPFAR program in reducing adult mortality. We believe that the discrepancy observed in the original studies mainly a reflection of shortcomings in the analytical approach necessitated by the Duber study\u27s nationally aggregated dataset or may reflect a lack of data quality in the Duber study (Duber, et al. 2010)

Isolated prehospital hypotension correlates with injury severity and outcomes in patients with trauma

Objective Patients normotensive in the trauma bay despite documented prehospital hypotension may not be recognized as significantly injured. The purpose of this study was to determine whether isolated prehospital hypotension portends poor outcomes and correlates with injury severity. Methods Prospective cohort study conducted at a level 1 university trauma center. The lowest recorded prehospital systolic blood pressure (SBP) and the first recorded SBP on hospital arrival were used to divide patients into either the normotensive (NP) or hypotensive (HP) group. Patients who failed to achieve normotension on hospital arrival were excluded. Hypotension was defined as SBP≤110 mmHg. Results Compared to NP (n=206), HP (n=81) had lower Glasgow Coma Scores both prehospital (12.81±0.44 vs 14.38±0.13) and at hospital admission (12.78±0.47 vs 14.37±0.14). Injury Severity Score positively correlated with prehospital hypotension (HP 12.27±1.12 vs NP 9.22±0.49). Prehospital hypotension positively correlated with intensive care unit (ICU) admission (HP 56.79% vs NP 22.82%), ICU length of stay (LOS) (HP 3.23±0.71 vs NP 0.71±0.17), hospital LOS (HP 8.58±1.39 vs NP 4.86±0.33), ventilator days (HP 3.38±1.20 vs NP 0.27±0.08 days), and repeat hypotensive episodes during their hospital stay (HP 81.71% vs NP 38.16%). HP also required more packed red blood cells in the first 24 hours after admission (22% vs 6%). Significance was set at p\u3c0.05. Conclusions Isolated prehospital hypotension in patients in the trauma and emergency department correlates with increased injury severity and portends worse outcomes despite a normal blood pressure reading at admission. Prehospital hypotension must be given heavy consideration in triage, as these patients may be transiently hypotensive and appear less critical than their true status. Level of Evidence Level II, Prognostic study

Second-Harmonic Generation and Spectrum Modulation by Active Nonlinear Metamaterial

The nonlinear properties of a metamaterial sample composed of double-layer metallic patterns and voltage controllable diodes are experimentally investigated. Second harmonics and spectrum modulations are clearly observed in a wide band of microwave frequencies, showing that this kind of metamaterial is not only tunable by low DC bias voltage, but also behaves strong nonlinear property under a small power incidence. These properties are difficult to be found in normal, naturally occurring materials.Comment: 14 pages, 4 figure

Optimal Design of a High Temperature Superconducting Homopolar Inductor Machine

A high temperature superconducting homopolar inductor machine (HTS-HIM) is optimally designed considering the effect of magnetic field on HTS coil in this paper. Firstly, the structure and operation principle of HTS-HIM are presented. The three-dimensional HTS-HIM finite element analysis model and two-dimensional axisymmetric direct coupling model of HTS-HIM based on T-A formulation are established. Secondly, the excitation window parameters, the excitation current and number of turns of HTS coil are optimized, taking into account the HTS-HIM performance and the safety of HTS coil. Thirdly, the magnetic field weakening capabilities of the U-shaped flux diverter and copper layer are analyzed and their parameters are optimized. Finally, the optimal design scheme and the critical current of HTS coil in HTS-HIM are obtained

Exome-based Variant Detection in Core Promoters.

Core promoter controls the initiation of transcription. Core promoter sequence change can disrupt transcriptional regulation, lead to impairment of gene expression and ultimately diseases. Therefore, comprehensive characterization of core promoters is essential to understand normal and abnormal gene expression in biomedical studies. Here we report the development of EVDC (Exome-based Variant Detection in Core promoters) method for genome-scale analysis of core-promoter sequence variation. This method is based on the fact that exome sequences contain the sequences not only from coding exons but also from non-coding region including core promoters generated by random fragmentation in exome sequencing process. Using exome data from three cell types of CD4+ T cells, CD19+ B cells and neutrophils of a single individual, we characterized the features of core promoter-mapped exome sequences, and analysed core-promoter variation in this individual genome. We also compared the core promoters between YRI (Yoruba in Ibadan, Nigeria) and the CEU (Utah residents of European decedent) populations using the exome data generated by the 1000 Genome project, and observed much higher variation in YRI population than in CEU population. Our study demonstrates that the EVDC method provides a simple but powerful means for genome-wile de novo characterization of core promoter sequence variation