scholarly journals OPTIMIZING PHASE COMPRESSION FOR TRANSIT SIGNAL PRIORITY AT ISOLATED INTERSECTIONS

Transport ◽  
2017 ◽  
Vol 32 (4) ◽  
pp. 386-397 ◽  
Author(s):  
Xuedong Hua ◽  
Wei Wang ◽  
Yinhai Wang ◽  
Ziyuan Pu
Keyword(s):  
Low Cost ◽  
Fixed Time ◽  
Control Model ◽  
Transit Signal Priority ◽  
Bus Priority ◽  
Compression Process ◽  
Phase Selection ◽  
Time Control ◽  
Bus Delay ◽  
The Impact

Transit signal priority (TSP) is a promising low-cost strategy that gives preferential treatments for the buses to go through intersections with minimum delay time. In this paper, a new TSP control model was presented for isolated intersections to minimize bus delay and to reduce the impact of TSP on other vehicles by optimizing signal control phase selection and compression. This paper starts with the phase selection and compression strategies to provide treatments to bus priority requests. Then, two new features on phase selection and compression aspects are applied to TSP, i.e. the time that a bus priority request needs is provided by the phase(s) with the lowest traffic volume, and multi-phases can be selected to serve a bus request. Field data are collected from a major traffic corridor in Changzhou (China) and applied for VISSIM simulation. The proposed TSP control model as well as the fixed-time control and the conventional TSP control models are tested and compared under different traffic demands, headways and maximum saturation degrees. The comparative results showed that the proposed model outperformed the conventional TSP control model in terms of reducing bus delay, minimizing the impact on other vehicles and reducing the stop rate for buses. This paper reveals that, the proposed TSP strategy can significantly optimize the phase compression process and improve transit efficiency.

The impact of dwell time variability on transit signal priority performance

2014 ◽  
Vol 41 (2) ◽  
pp. 154-163 ◽  
Author(s):  
Mohammad S. Ghanim ◽  
Francois Dion ◽  
Ghassan Abu-Lebdeh
Keyword(s):  
Control Strategy ◽  
Dwell Time ◽  
Signalized Intersections ◽  
Time Variability ◽  
Transit Signal Priority ◽  
Operational Control ◽  
Priority Systems ◽  
Bus Delay ◽  
Transit Agencies ◽  
The Impact

Transit signal priority (TSP) is an operational control strategy that provides preferential treatments for transit vehicles at signalized intersections. Many transit agencies are currently considering the implementation of priority systems providing buses with preferential treatments at signalized intersections. While studies have demonstrated potential bus delay reductions, none has attempted to identify the problems posed by variable dwell times at bus stops. This study identifies the impacts of variable dwell times on the efficiency of transit signal priority systems. Results also show that, in general, variable dwell times negatively affect the TSP performance. However, and contrary to expectations, a number of scenarios with variable dwell times resulted in lower average bus delays than scenarios with fixed dwell times. These results are attributed to changes in progression and bus arrival patterns under variable dwell times resulting in an increasing number of buses arriving close enough to benefit from preferential treatments.

scholarly journals Event-driven NN adaptive fixed-time control for nonlinear systems with guaranteed performance

2021 ◽  
Author(s):  
Xiaona Song ◽  
Peng Sun ◽  
Shuai Song
Keyword(s):  
Neural Network ◽  
Nonlinear Systems ◽  
Tracking Error ◽  
Fixed Time ◽  
Dynamic Surface Control ◽  
Dynamic Surface ◽  
Filter Performance ◽  
Time Control ◽  
The Impact ◽  
Compensation Signal

Abstract This article investigates the adaptive neural network fixed-time tracking control for a class of strict-feedback nonlinear systems with prescribed performance demands, in which radial basis function neural network (RBFNN) is utilized to approximate the unknown items. First, an improved fractionalorder dynamic surface control (FODSC) technique is incorporated to address the issue of the iterative derivation, where a fractional-order filter is adopted to improve the filter performance. What's more, the error compensation signal is established to remove the impact of filter error. Furthermore, a fixed-time adaptive event-triggered controller is constructed to reduce the communication burden, where the Zeno-behavior can also be excluded. Stability results prove that the designed controller not only guarantees all the signals of the closedloop systems (CLS) are practically fixed-time bounded, but also the tracking error can be regulated to a predefined boundary. Finally, the feasibility and superiority of the designed control algorithm are verified by two simulation examples.

Computer simulation study about the dependence of amorphous silicon photonic waveguides efficiency on the material quality

2020 ◽  
Vol 90 (3) ◽  
pp. 30502
Author(s):  
Alessandro Fantoni ◽  
João Costa ◽  
Paulo Lourenço ◽  
Manuela Vieira
Keyword(s):  
Amorphous Silicon ◽  
High Throughput Screening ◽  
Simulation Analysis ◽  
Low Cost ◽  
Deposition Process ◽  
Large Area ◽  
Sidewall Roughness ◽  
Sensing Applications ◽  
Fabrication Defects ◽  
The Impact

Amorphous silicon PECVD photonic integrated devices are promising candidates for low cost sensing applications. This manuscript reports a simulation analysis about the impact on the overall efficiency caused by the lithography imperfections in the deposition process. The tolerance to the fabrication defects of a photonic sensor based on surface plasmonic resonance is analysed. The simulations are performed with FDTD and BPM algorithms. The device is a plasmonic interferometer composed by an a-Si:H waveguide covered by a thin gold layer. The sensing analysis is performed by equally splitting the input light into two arms, allowing the sensor to be calibrated by its reference arm. Two different 1 × 2 power splitter configurations are presented: a directional coupler and a multimode interference splitter. The waveguide sidewall roughness is considered as the major negative effect caused by deposition imperfections. The simulation results show that plasmonic effects can be excited in the interferometric waveguide structure, allowing a sensing device with enough sensitivity to support the functioning of a bio sensor for high throughput screening. In addition, the good tolerance to the waveguide wall roughness, points out the PECVD deposition technique as reliable method for the overall sensor system to be produced in a low-cost system. The large area deposition of photonics structures, allowed by the PECVD method, can be explored to design a multiplexed system for analysis of multiple biomarkers to further increase the tolerance to fabrication defects.

Advancing dairy farming profitability through research

2001 ◽  
pp. 17-22
Author(s):  
J.R. Caradus ◽  
D.A. Clark
Keyword(s):  
Research And Development ◽  
Dairy Cow ◽  
Low Cost ◽  
Pasture Management ◽  
Nitrogen Fertiliser ◽  
Grass Endophyte ◽  
Forage Species ◽  
Development Outcomes ◽  
Dairy Cow Nutrition ◽  
The Impact

The New Zealand dairy industry recognises that to remain competitive it must continue to invest in research and development. Outcomes from research have ensured year-round provision of low-cost feed from pasture while improving productivity. Some of these advances, discussed in this paper, include the use of white clover in pasture, understanding the impacts of grass endophyte, improved dairy cow nutrition, the use of alternative forage species and nitrogen fertiliser to improve productivity, demonstration of the impact of days-in-milk on profitability, and the use of feed budgeting and appropriate pasture management. Keywords: dairy, profitability, research and development

Optimisation and control of the inflow to a wastewater treatment plant using integrated modelling tools

1998 ◽  
Vol 37 (1) ◽  
pp. 347-354 ◽  
Author(s):  
Ole Mark ◽  
Claes Hernebring ◽  
Peter Magnusson
Keyword(s):  
Wastewater Treatment ◽  
Real Time ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Pilot Project ◽  
Integrated Modelling ◽  
Real Time Control ◽  
Sewer System ◽  
Time Control ◽  
The Impact

The present paper describes the Helsingborg Pilot Project, a part of the Technology Validation Project: “Integrated Wastewater” (TVP) under the EU Innovation Programme. The objective of the Helsingborg Pilot Project is to demonstrate implementation of integrated tools for the simulation of the sewer system and the wastewater treatment plant (WWTP), both in the analyses and the operational phases. The paper deals with the programme for investigating the impact of real time control (RTC) on the performance of the sewer system and wastewater treatment plant. As the project still is in a very early phase, this paper focuses on the modelling of the transport of pollutants and the evaluation of the effect on the sediment deposition pattern from the implementation of real time control in the sewer system.

Motivating Compliance: Firm Response to Mandatory Disclosure Policies

2018 ◽  
Vol 32 (2) ◽  
pp. 103-119
Author(s):  
Colleen M. Boland ◽  
Chris E. Hogan ◽  
Marilyn F. Johnson
Keyword(s):  
Conflict Of Interest ◽  
Low Cost ◽  
Cost Effective ◽  
Data Availability ◽  
Policy Adoption ◽  
Future Research ◽  
Regulated Firms ◽  
Firm Response ◽  
Disclosure Rules ◽  
The Impact

SYNOPSIS Mandatory existence disclosure rules require an organization to disclose a policy's existence, but not its content. We examine policy adoption frequencies in the year immediately after the IRS required mandatory existence disclosure by nonprofits of various governance policies. We also examine adoption frequencies in the year of the subsequent change from mandatory existence disclosure to a disclose-and-explain regime that required supplemental disclosures about the content and implementation of conflict of interest policies. Our results suggest that in areas where there is unclear regulatory authority, mandatory existence disclosure is an effective and low cost regulatory device for encouraging the adoption of policies desired by regulators, provided those policies are cost-effective for regulated firms to implement. In addition, we find that disclose-and-explain regulatory regimes provide stronger incentives for policy adoption than do mandatory existence disclosure regimes and also discourage “check the box” behavior. Future research should examine the impact of mandatory existence disclosure rules in the year that the regulation is implemented. Data Availability: Data are available from sources cited in the text.

scholarly journals Ears in the Sky: Potential of Drones for the Bioacoustic Monitoring of Birds and Bats

Drones ◽  
2021 ◽  
Vol 5 (1) ◽  
pp. 9
Author(s):  
Adrien Michez ◽  
Stéphane Broset ◽  
Philippe Lejeune
Keyword(s):  
Forest Canopy ◽  
Low Cost ◽  
Population Monitoring ◽  
Biodiversity Loss ◽  
Active Species ◽  
Terrestrial Mammals ◽  
Technical Developments ◽  
High Resolution Imagery ◽  
Human Operators ◽  
The Impact

In the context of global biodiversity loss, wildlife population monitoring is a major challenge. Some innovative techniques such as the use of drones—also called unmanned aerial vehicle/system (UAV/UAS)—offer promising opportunities. The potential of UAS-based wildlife census using high-resolution imagery is now well established for terrestrial mammals or birds that can be seen on images. Nevertheless, the ability of UASs to detect non-conspicuous species, such as small birds below the forest canopy, remains an open question. This issue can be solved with bioacoustics for acoustically active species such as bats and birds. In this context, UASs represent an interesting solution that could be deployed on a larger scale, at lower risk for the operator, and over hard-to-reach locations, such as forest canopies or complex topographies, when compared with traditional protocols (fixed location recorders placed or handled by human operators). In this context, this study proposes a methodological framework to assess the potential of UASs in bioacoustic surveys for birds and bats, using low-cost audible and ultrasound recorders mounted on a low-cost quadcopter UAS (DJI Phantom 3 Pro). The proposed methodological workflow can be straightforwardly replicated in other contexts to test the impact of other UAS bioacoustic recording platforms in relation to the targeted species and the specific UAS design. This protocol allows one to evaluate the sensitivity of UAS approaches through the estimate of the effective detection radius for the different species investigated at several flight heights. The results of this study suggest a strong potential for the bioacoustic monitoring of birds but are more contrasted for bat recordings, mainly due to quadcopter noise (i.e., electronic speed controller (ESC) noise) but also, in a certain manner, to the experimental design (use of a directional speaker with limited call intensity). Technical developments, such as the use of a winch to safely extent the distance between the UAS and the recorder during UAS sound recordings or the development of an innovative platform, such as a plane–blimp hybrid UAS, should make it possible to solve these issues.

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