Traffic Signal Timing Optimization for Isolated Intersections Based on Differential Evolution Bacteria Foraging Algorithm

AbstractAiming at that the traffic congestion in urban often appears, the signal timing optimization model and method are researched. The signal control model is proposed considering the max throughput of intersection. The objective function of this model is to minimize the delay vehicles of a cycle time. The model has all kinds of constraint. A differential evolution bacteria foraging optimization algorithm is presented. The velocity of the traditional bacteria foraging optimization algorithm is slow. The bacterium position is revised by differential evolution in chemotaxis process to improve the convergence precision. Based on an intersection in Guangzhou City, the model is calculated and simulated through programming. As it shows, it can improve traffic capacity of intersections and especially works well in high demand

A General Maximum Progression Model to Concurrently Synchronize Left-Turn and through Traffic Flows on an Arterial

In the existing bandwidth-based methods, through traffic flows are considered as the coordination objects and offered progression bands accordingly. However, at certain times or nodes in the road network, when the left-turn traffic flows have a higher priority than the through traffic flows, it would be inappropriate to still provide the progression bands to the through traffic flows; the left-turn traffic flows should instead be considered as the coordination objects to potentially achieve better control. Considering this, a general maximum progression model to concurrently synchronize left-turn and through traffic flows is established by using a time-space diagram. The general model can deal with all the patterns of the left-turn phases by introducing two new binary variables into the constraints; that is, these variables allow all the patterns of the left-turn phases to deal with a single formulation. By using the measures of effectiveness (average delay time, average vehicle stops, and average travel time) acquired by a traffic simulation software, VISSIM, the validity of the general model is verified. The results show that, compared with the MULTIBAND, the proposed general model can effectively reduce the delay time, vehicle stops, and travel time and, thus, achieve better traffic control

Environmental circulations associated with tropical cyclones experiencing fast, slow and looping motion

May, 1982.Includes bibliographical references (pages 110-111).Sponsored by NOAA NA79RAD00002.Sponsored by NSF ATM-7923591

Microseisms generated by super typhoon Megi in the western Pacific Ocean

Author Posting. © American Geophysical Union, 2017. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Oceans 122 (2017): 9518–9529, doi:10.1002/2017JC013310.Microseisms generated by the super typhoon Megi (13–24 October 2010) were detected on both land-based and island-based seismic stations. We applied temporal frequency spectrum analysis to investigate the temporal evolution of the microseisms. When Megi was over the deep basins of the Philippine Sea, only weak microseisms with short-period double frequency (SPDF, ∼0.20–0.40 Hz) were observed. However, after Megi traveled into the shallower waters of the South China Sea, microseisms with both long-period double frequency (LPDF, ∼0.12–0.20 Hz) and SPDF were recorded. The excitation source regions of the microseisms were analyzed using seismic waveform records and synthetic modeling in frequency domain. Results reveal that part of the LPDF microseisms were excited in coastal source regions, while the intensity of both LPDF and SPDF microseisms correlated well with the distance from seismic stations to the typhoon center. Synthetic computations of equivalent surface pressure and corresponding microseisms show that the wave-to-wave interaction induced by coastal reflection has primary effects on microseismic frequency band of ∼0.10–0.20 Hz. The coastal generation of the dispersive LPDF microseisms is also supported by the observation of ocean swells induced by Megi through the images of C-band ENVISAT-ASAR satellite during its migration process. Two source regions of the microseisms during the life span of Megi are finally distinguished: One was mainly located in the left-rear quadrant of the typhoon center that generated both LPDF and SPDF microseisms at shallow seas, while the other one was near the coasts that generated mostly LPDF microseisms.National Natural Science Foundation of China Grant Numbers: 41104027, 91628301, U1606401, 41676044; Natural Science Foundation of Zhejiang Province Grant Number: LZ14D060001; Opening Fund of SKLGED Grant Number: SKLGED2013-1-7-E; Chinese Academy of Sciences Grant Numbers: Y4SL021001, Y6YB011001, QYZDY-SSW-DQC0052018-06-0

Biomass-derived three-dimensional porous N-doped carbonaceous aerogel for efficient supercapacitor electrodes

Functionalized carbonaceous materials with hierarchical structure and developed porosity are highly desired in energy storage and conversion fields. In this work, a facile and scalable hydrothermal methodology was established to synthesise three-dimensional (3D) N-doped carbonaceous aerogels using biomass-based starting materials and polypyrrole as N-source. The effect of different calcination temperatures on the structural properties, type and content of N-species and electrochemical performance of the 3D N-doped carbonaceous aerogels were uncovered. Thanks to the combinatorial effect of the appropriate N content and porous structure, the obtained samples exhibited excellent electrochemical performance, in particular, an outstanding specific capacitance of 281.0 F g-1 achieved on the sample calcined at 600 °C. This methodology offers a new fabrication strategy to prepare nanoscale carbonaceous materials with desirable morphology and hierarchical architecture of great potentials for the applications in energy fields

A practical method for predicting frequent use of emergency department care using routinely available electronic registration data.

Accurately predicting future frequent emergency department (ED) utilization can support a case management approach and ultimately reduce health care costs. This study assesses the feasibility of using routinely collected registration data to predict future frequent ED visits