scholarly journals Capacity Estimation Model for Signalized Intersections under the Impact of Access Point

PLoS ONE ◽  
2016 ◽  
Vol 11 (1) ◽  
pp. e0145989 ◽  
Author(s):  
Jing Zhao ◽  
Peng Li ◽  
Xizhao Zhou
Keyword(s):  
Access Point ◽  
Signalized Intersections ◽  
Estimation Model ◽  
Capacity Estimation ◽  
The Impact

A Capacity Estimation Model for a Contraflow Left-Turn Pocket Lane at Signalized Intersections

2018 ◽  
Vol 2672 (17) ◽  
pp. 22-34 ◽  
Author(s):  
Yi Zhao ◽  
Rachel M. James ◽  
Lin Xiao ◽  
Joe Bared
Keyword(s):  
Signalized Intersections ◽  
Signalized Intersection ◽  
Traffic Operations ◽  
Estimation Model ◽  
Capacity Estimation ◽  
Average Delay ◽  
Left Turn ◽  
Traffic Demand ◽  
Key Characteristics ◽  
The Impact

Alternative intersection designs are increasingly proposed and adopted by different agencies to meet the needs of growing traffic demand and constrained transportation resources. The left turn (LT) is one of the most critical movements at signalized intersections from both a safety and operations perspective. Heavy LT volumes are especially impactful to the operational efficiency of a signalized intersection and often result in queue spillback. A contraflow left-turn pocket lane (CLPL) is proposed to mitigate congestion caused by heavy LT demand and has been shown in simulation to greatly mitigate the impact of queue spillback. The CLPL dynamically uses the opposing through lane (OTL) as an additional LT lane within the signal cycle on a temporary basis when the OTL is not occupied by through traffic. While geometric design schematics and analytical procedures for estimating delay have been proposed and discussed in existing literature, methodologies for estimating capacity benefits and traffic operations are not yet well defined. This paper has three primary contributions to the literature: development of a probabilistic capacity estimation model, exploration of the impact of key characteristics (e.g., cycle length, LT demand, lane selection preference) on estimated intersection capacity, and recommendations for the real-world implementation of a CLPL. The simulation results indicate that the CLPL treatment can increase a signalized intersection’s throughput up to 25% and decrease the intersection’s average delay by 35%.

scholarly journals Impact of Guideline Markings on Saturation Flow Rate at Signalized Intersections

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Zhengtao Qin ◽  
Jing Zhao ◽  
Shidong Liang ◽  
Jiao Yao
Keyword(s):  
Flow Rate ◽  
Signalized Intersections ◽  
Estimation Model ◽  
Left Turn ◽  
Proposed Model ◽  
Research Goal ◽  
Saturation Flow Rate ◽  
Saturation Flow ◽  
The Impact

Many intersections around the world are irregular crossings where the approach and exit lanes are offset or the two roads cross at oblique angles. These irregular intersections often confuse drivers and greatly affect operational efficiency. Although guideline markings are recommended in many design manuals and codes on traffic signs and markings to address these problems, the effectiveness and application conditions are ambiguous. The research goal was to analyze the impact of guideline markings on the saturation flow rate at signalized intersections. An adjustment estimation model was established based on field data collected at 33 intersections in Shanghai, China. The proposed model was validated using a before–after case study. The underlying reasons for the impact of intersection guideline markings on the saturation flow rate are discussed. The results reveal that the improvement in the saturation flow rate obtained from painting guide line markings is positively correlated with the number of traffic lanes, offset of through movement, and turning angle of left-turns. On average, improvements of 7.0% and 10.3% can be obtained for through and left-turn movements, respectively.

Mobility aware of WDM-based CMO OFDM communication system

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Saad M. Hardan ◽  
Ayad A. Abdulkafi ◽  
Saadi Hamad Thalij ◽  
Sherine S. Jumaah
Keyword(s):  
Wavelength Division Multiplexing ◽  
Orthogonal Frequency Division Multiplexing ◽  
High Speed ◽  
Light Emitting Diode ◽  
Access Point ◽  
Mobile Users ◽  
Visible Light Communications ◽  
Optical Wireless Communications ◽  
High Data ◽  
The Impact

Abstract The continued increase in several mobile applications forces to replace existing limited spectrum indoor radio frequency wireless connections with high-speed ones. Visible light communications (VLC) technology has gained prominence in the development of high data rate transmission for fifth-generation networks. In optical wireless communications, light-emitting diode (LED) transmitters are used in applications that desire mobility as LED divergence enables larger coverage. Since each VLC access point covers a small area, handovers of mobile users are inevitable. Wavelength division multiplexing (WDM) can be used in VLC systems to tackle the above issue and to meet the increasing demand for indoor connectivity with high bit rates. In this paper, a new system architecture for WDM with coded modulated optical in orthogonal frequency division multiplexing (OFDM) VLC system in conjunction with red, green, blue, and yellow (RGBY) LEDs is proposed to reduce the impact of random receiver orientation of indoor mobile users over VLC downlink channels and improves the system’s bit-error-rate (BER) performance. Simulation results show that the proposed method is not affected by the user’s mobility and hence it performs better than other approaches, in terms of BER for all scenarios and at all positions. This study reveals that using WDM-OFDM-VLC with RGBY LEDs to construct a VLC system is very promising.

scholarly journals Attributes of turnaround rural hospitals: Case study findings and research opportunities

2017 ◽  
Vol 6 (6) ◽  
pp. 8
Author(s):  
Asa B. Wilson
Keyword(s):  
Theory Of The Firm ◽  
Access Point ◽  
Hospital Performance ◽  
Rural Hospitals ◽  
Rural Hospital ◽  
Classical Economics ◽  
The Status ◽  
History Of ◽  
Closure Conversion ◽  
The Impact

Background: Rural and Critical Access Hospitals (CAHs) have a history of operating challenges and closure-conversion threats. The history is reviewed including the supportive public policy provisions and administrative tactics designed to maintain a community’s hospital as the hub and access point for health services. Limited research indicates that rural facilities are not strategic in their responses to challenges. A question emerges regarding the enduring nature of operating difficulties for these facilities, i.e., no understanding with explanatory value.Objective: The author, as the CEO in six rural hospitals designated as turnaround facilities, used inductive participant-observer involvement to identify operating attributes characteristic of these organizations. An objective description of each facility is provided. While implementing a turnaround intervention, fifteen behaviors or outcomes were found to be consistent across all six entities. This information is used to posit factors associated with or accounting for identified performance weaknesses.Conclusions: It is conceptualization that observed organizational behaviors can be explained as remnants of an agrarian ideology. Such a mindset is focused on preserving the status quo despite challenges that would require strategic positioning of the organization. In addition, emerging studies on community types indicates that follow-up research is needed that assesses the impact of community attributes on rural hospital performance. Also, this study shows that a theory of the rural hospital firm based on neo-classical economics has no explanatory value. Thus, a theory of the firm can be developed that includes behavioral economic principles.

scholarly journals The impact of boundary conditions on CO2 storage capacity estimation in aquifers

2011 ◽  
Vol 4 ◽  
pp. 4828-4834 ◽  
Author(s):  
D.J. Smith ◽  
D.J. Noy ◽  
S. Holloway ◽  
R.A. Chadwick
Keyword(s):  
Boundary Conditions ◽  
Storage Capacity ◽  
Co2 Storage ◽  
Capacity Estimation ◽  
The Impact

The Impact of Structural Reforms and Regulations on the Demand Side in the Railway Industry

2019 ◽  
Vol 18 (1) ◽  
pp. 1-33
Author(s):  
Fumitoshi Mizutani
Keyword(s):  
Market Structure ◽  
Vertical Integration ◽  
High Speed ◽  
Fixed Effect Model ◽  
Structural Reform ◽  
Estimation Methods ◽  
Public Ownership ◽  
Estimation Model ◽  
Passenger Demand ◽  
The Impact

Abstract The main purpose of this study is to evaluate factors affecting passenger rail demand, with special attention to the effects of structural reform/regulation and competition. In order to do this, we use data obtained from 30 OECD countries for the 24 years from 1990 to 2013. As structural reform/regulation and competition variables, we take the OECD’s five kinds of regulatory indices: (i) overall, (ii) entry, (iii) public ownership, (iv) vertical integration, and (v) market structure; and for competition variables, we take (vi) rail passenger-freight ratio, (vii) rail share, and (viii) high-speed train ratio. As estimation methods, both the fixed effect model and the Hausman-Taylor estimation model are used. The major findings are as follows. First, competition as competitiveness (i.e. the share of rail, passenger over freight ratio) increases passenger demand. And the existence of high-speed trains increases passenger demand. Second, overall, entry regulation, and market structure have no significant effect on demand. Third, public ownership affects passenger demand positively. Last, vertical integration reduces passenger demand.

Performance of Wireless Magnetometers for Stop Bar Detection at Signalized Intersections

2018 ◽  
Vol 2672 (45) ◽  
pp. 55-63 ◽  
Author(s):  
Jidong J. Yang ◽  
Bashan Zuo
Keyword(s):  
Environmental Conditions ◽  
Access Point ◽  
Signalized Intersections ◽  
Conditional Inference ◽  
Professional Judgment ◽  
Heavy Vehicles ◽  
Study Results ◽  
Adverse Weather ◽  
Reliable Detection ◽  
Conditional Inference Trees

Wireless magnetometers have been considered as a practical alternative to inductive loops and suitable for large intersections, where span wire is generally used for traffic signal support. In this paper, wireless magnetometers are evaluated for stop bar vehicle detection at signalized intersections. High-resolution detector data were collected in the field subjected to various weather and environmental conditions. Conditional inference trees were used to correlate detection errors with weather and environmental factors that potentially affect the performance of wireless magnetometers. The study results indicated that the wireless magnetometers are fairly robust to various environmental conditions, such as wind, lighting, and visibility. Frequent passing of heavy vehicles, common at large intersections, can cause communication interruption between in-pavement sensors and the access point. This likely increases false and stuck-on call errors, which could be aggravated by adverse weather (e.g., rain, fog, or snow). This communication interruption issue can be mitigated by proper installation of additional repeaters. Provided the interruption issues are site-specific, professional judgment and field test are required for proper system setup, which is critical to delivering accurate and reliable detection for the wireless magnetometer system.

scholarly journals Revenue diversification and financial sustainability of microfinance institutions

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Peter Nderitu Githaiga
Keyword(s):  
Generalized Method Of Moments ◽  
Financial Sustainability ◽  
Microfinance Institutions ◽  
Revenue Diversification ◽  
Estimation Model ◽  
Data Set ◽  
Content Type ◽  
Method Of Moments Estimation ◽  
The Impact ◽  
Positive Effect

PurposeThis paper aims to investigate whether revenue diversification affects the financial sustainability of microfinance institutions (MFIs).Design/methodology/approachThe study uses a worldwide panel data set of 443 MFIs in 108 countries for the period 2013–2018 and two-step system Generalized Method of Moments estimation model.FindingsThe study finds that revenue diversification has a significant and positive effect on the financial sustainability of MFIs.Practical implicationsThe findings of this study actually offer important managerial and policy lessons on MFIs’ financial sustainability. Microfinance managers and policymakers should consider revenue diversification as a strategy through which MFIs can attain financial sustainability instead of overreliance on donations and government subsidiesOriginality/valueUnlike previous studies that examined revenue diversification in the context of banking firms, this study contributes to literature by examining the impact of revenue diversification of the financial sustainability of MFIs.

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