Florida Department of Transportation’s Enhanced Hydroplaning Prediction Tool

2021 ◽  
pp. 036119812110114
Author(s):  
Hyung Suk Lee ◽  
Mateo Carvajal ◽  
Charles Holzschuher ◽  
Bouzid Choubane
Keyword(s):  
Water Film ◽  
Design Parameters ◽  
Prediction Tool ◽  
Design Phase ◽  
Department Of Transportation ◽  
Forensic Investigation ◽  
The Past ◽  
Florida Department ◽  
Roadway Design ◽  
Traveling Speed

Florida Department of Transportation (FDOT) recently developed and implemented a new hydroplaning prediction (HP) program for predicting the traveling speed at which a vehicle would start hydroplaning. The tool was developed as part of the effort to reduce hydroplaning accidents and is being used during the roadway design phase to evaluate the hydroplaning potential of Florida’s roadways. This paper presents an overview of FDOT’s HP program and demonstrates how it may be used. The tool incorporates a total of four water film thickness models and three hydroplaning speed models developed in the past, allowing for a total of 12 model combinations for the hydroplaning analysis. The tool also offers different analysis options that may be used to meet a variety of FDOT’s needs. As demonstrated in this paper, the primary use of the new HP tool is for checking the final geometric roadway design parameters for hydroplaning potential. In addition, the HP program can also be used as a forensic investigation tool for identifying specific locations that exhibit higher potential for hydroplaning.

Superpave Field Implementation: Florida’s Early Experience

1998 ◽  
Vol 1609 (1) ◽  
pp. 51-60 ◽  
Author(s):  
James A. Musselman ◽  
Bouzid Choubane ◽  
Gale C. Page ◽  
Patrick B. Upshaw
Keyword(s):  
Asphalt Pavement ◽  
Early Experience ◽  
Field Application ◽  
Pavement Performance ◽  
Department Of Transportation ◽  
Concerted Effort ◽  
The Past ◽  
Early Experiences ◽  
Florida Department ◽  
Current Loading

Over the past 10 to 15 years, Interstate pavements in northern Florida have experienced a significant number of failures, primarily due to rutting. It was believed that the present fine-graded, 50-blow Marshall-designed mixes were inadequate to withstand current loading conditions. The newly developed Superpave system represented an opportunity to address several of Florida’s asphalt pavement problems. Thus, the Florida Department of Transportation made a concerted effort to implement Superpave technology in 1996. During this period, eight projects were changed from the traditional Marshall mix designs to Superpave. Although the new procedure offers potential for improved pavement performance, there has been very little experience nationally with its field application. Florida’s early experiences with the field implementation of Superpave are documented.

Balancing Goods Movement and Livability with Freight Roadway Design Considerations

2017 ◽  
Vol 2609 (1) ◽  
pp. 46-54 ◽  
Author(s):  
Daniel Hardy ◽  
Brian Hunter
Keyword(s):  
Tampa Bay ◽  
Department Of Transportation ◽  
Design Strategies ◽  
Complete Streets ◽  
Context Sensitive ◽  
Interagency Coordination ◽  
Design Considerations ◽  
Goods Movement ◽  
Florida Department ◽  
Roadway Design

Freight Roadway Design Considerations (FRDC), the document described in this paper, was developed by the Florida Department of Transportation District 7 to provide guidance to transportation planning and engineering practitioners for balancing livability and the needs of goods movement in a context-sensitive manner. The FRDC implemented one recommended element of the 2012 Tampa Bay Regional Strategic Freight Plan to develop a new approach to the roadway design process. This approach takes into consideration the analysis of freight activity and land use compatibility in the Tampa Bay plan. The FRDC benefited from a literature review of current practices and guidance from an internal review group and interagency coordination and commentary on draft materials throughout its development. The FRDC provides guidance on identifying roadway context, understanding and clarifying design intent, and selecting from a series of design strategies to help integrate goods movement into the development of complete streets.

scholarly journals Multi-stable composite twisting structure for morphing applications

2012 ◽  
Vol 468 (2141) ◽  
pp. 1230-1251 ◽  
Author(s):  
X. Lachenal ◽  
P. M. Weaver ◽  
S. Daynes
Keyword(s):  
Analytical Model ◽  
Material Properties ◽  
Degrees Of Freedom ◽  
Design Parameters ◽  
Engineering Structures ◽  
The Past ◽  
Wide Range ◽  
Morphing Structure ◽  
Low Mass ◽  
Unstable States

Conventional shape-changing engineering structures use discrete parts articulated around a number of linkages. Each part carries the loads, and the articulations provide the degrees of freedom of the system, leading to heavy and complex mechanisms. Consequently, there has been increased interest in morphing structures over the past decade owing to their potential to combine the conflicting requirements of strength, flexibility and low mass. This article presents a novel type of morphing structure capable of large deformations, simply consisting of two pre-stressed flanges joined to introduce two stable configurations. The bistability is analysed through a simple analytical model, predicting the positions of the stable and unstable states for different design parameters and material properties. Good correlation is found between experimental results, finite-element modelling and predictions from the analytical model for one particular example. A wide range of design parameters and material properties is also analytically investigated, yielding a remarkable structure with zero stiffness along the twisting axis.

Optimal design of a parallel robotic gripper using enhanced multi-objective ant lion optimizer with a sensitivity analysis approach

2020 ◽  
Vol 40 (5) ◽  
pp. 703-721
Author(s):  
Golak Bihari Mahanta ◽  
Deepak BBVL ◽  
Bibhuti B. Biswal ◽  
Amruta Rout
Keyword(s):  
Sensitivity Analysis ◽  
Distribution Function ◽  
Design Parameters ◽  
Objective Functions ◽  
Content Type ◽  
Multi Objective ◽  
The Past ◽  
Design Variables ◽  
Pick And Place ◽  
Ant Lion

Purpose From the past few decades, parallel grippers are used successfully in the automation industries for performing various pick and place jobs due to their simple design, reliable nature and its economic feasibility. So, the purpose of this paperis to design a suitable gripper with appropriate design parameters for better performance in the robotic production systems. Design/methodology/approach In this paper, an enhanced multi-objective ant lion algorithm is introduced to find the optimal geometric and design variables of a parallel gripper. The considered robotic gripper systems are evaluated by considering three objective functions while satisfying eight constraint equations. The beta distribution function is introduced for generating the initial random number at the initialization phase of the proposed algorithm as a replacement of uniform distribution function. A local search algorithm, namely, achievement scalarizing function with multi-criteria decision-making technique and beta distribution are used to enhance the existing optimizer to evaluate the optimal gripper design problem. In this study, the newly proposed enhanced optimizer to obtain the optimum design condition of the design variables is called enhanced multi-objective ant lion optimizer. Findings This study aims to obtain optimal design parameters of the parallel gripper with the help of the developed algorithms. The acquired results are investigated with the past research paper conducted in that field for comparison. It is observed that the suggested method to get the best gripper arrangement and variables of the parallel gripper mechanism outperform its counterparts. The effects of the design variables are needed to be studied for a better design approach concerning the objective functions, which is achieved by sensitivity analysis. Practical implications The developed gripper is feasible to use in the assembly operation, as well as in other pick and place operations in different industries. Originality/value In this study, the problem to find the optimum design parameter (i.e. geometric parameters such as length of the link and parallel gripper joint angles) is addressed as a multi-objective optimization. The obtained results from the execution of the algorithm are evaluated using the performance indicator algorithm and a sensitivity analysis is introduced to validate the effects of the design variables. The obtained optimal parameters are used to develop a gripper prototype, which will be used for the assembly process.

Development and Implementation of a Pavement Marking Management System in Florida

2018 ◽  
Vol 2672 (12) ◽  
pp. 209-219
Author(s):  
Bouzid Choubane ◽  
Joshua Sevearance ◽  
Charles Holzschuher ◽  
James Fletcher ◽  
Chieh (Ross) Wang
Keyword(s):  
Management System ◽  
Handheld Devices ◽  
Department Of Transportation ◽  
Pavement Markings ◽  
Lighting Conditions ◽  
Florida Department ◽  
Roadway Safety ◽  
Application Techniques ◽  
Effective Use ◽  
Pavement Marking

The visibility of pavement markings is an important aspect of a safe transportation system as the markings convey vital roadway warnings and guidance information to the traveling public. Therefore, it is beneficial to maintain acceptable visibility levels of markings on pavements under all weather and lighting conditions. To ensure the intended in-service visibility level is adequately maintained, the reflectivity must be monitored and quantified accordingly. Historically, visibility or retroreflectivity of in-service pavement markings has been measured with handheld devices and visual inspections. However, visual surveys are considered subjective and the handheld measurements are tedious and potentially hazardous. Consequently, the Florida Department of Transportation (FDOT) has focused on the use of a non-contact technology capable of assessing pavement markings continuously at highway speeds with improved safety and efficiency. The use of mobile technology for measuring reflectivity has allowed FDOT to develop and, subsequently, implement a Pavement Marking Management System (PMMS) to improve the safety and nighttime visibility of its roadways. Implementation of such a system provides an efficient and less subjective methodology to identify conditions that are detrimental to roadway safety, and strategize mitigating solutions including the selection of appropriate materials and application techniques. The system will ultimately result in an effective use of state funds while ensuring the safety of the traveling public. This paper presents a description of the Florida Pavement Markings Management System and its subsequent implementation including FDOT’s effort to ensure the quality, consistency, repeatability, and accessibility of statewide pavement marking retroreflectivity data.

Prevention of Historically Challenging Sustained Casing Pressure from Shallow Gas Through Re-Engineered Cement Design and Execution Methodology

2021 ◽  
Author(s):  
Farah Shakina Ezani ◽  
Myat Thuzar ◽  
Avinash Kishore Kumar ◽  
Chee Hen Lau
Keyword(s):  
Mitigation Measures ◽  
Design Parameters ◽  
Two Stage ◽  
Shallow Gas ◽  
Second Stage ◽  
The Past ◽  
Sustained Casing Pressure ◽  
Dual Stage ◽  
Casing Pressure ◽  
Selection Of

Abstract Sustained casing pressure (SCP) is a very costly event for any operator either at production phase or at the end of a well’s lifecycle. SCP is a result of incomplete hydraulic isolation across hydrocarbon bearing zone. In one of the gas fields in Malaysia, notoriously known for shallow gas hazard, drilled development wells which have reportedly been suffering SCP. In the past, various improvements in cement slurry design and placement methods were deployed in order to provide complete zonal isolation, especially at the shallow gas sand, yet SCP issue was encountered occasionally. In the current development campaign, different strategy to providing annulus sealing was adopted. This paper discusses proactive steps taken in the slurry design, fit together with the dual stage cementing approach, as a primary means of placing cement above the shallow hazard interval. During the design phase, essential key parameters that would lead to successful placement of cement in the annulus as well as unique slurry design that suits for two stage cementing methods were studied. Risk involved in first stage cementing is one of the most important steps that should be analyzed in detail and put mitigation measures in place to ensure the second stage cement job can be performed as planned. In addition to the slurry properties, such as fluid-loss value, gas-tightness, etc., thickening time and top of cement (TOC) of the lead slurry in the first stage cement job has become enormously critical in designing dual stage cementing job in order to assure cement ports in the stage collar are not covered with hard cement forcing the termination of second stage job prematurely. Besides cementing design, careful selection of the stage collar location and casing annulus packer in the string is also of significant importance in leading to successful two stage cement job. Two development wells with above approached has been delivered and no sustained casing pressure has been experienced. This proactive approach to use two stage cementing as primary plan has proven to successfully eliminate the risk of SCP, which was a frequent struggle in their sister wells drilled with primary cementing in the past in the same field. The risk analysis combined with careful considerations of critical cementing design parameters and selection of stage tool location have become a novel approach to combat against SCP in this gas field.

scholarly journals 186. Risk Factors for Extended Spectrum β-Lactamase Bacteremia and External Application of a Clinical Prediction Tool

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S113-S114
Author(s):  
Jacqueline Burnell ◽  
Rebecca Fallis ◽  
Peter Axelrod ◽  
Daniel Mueller
Keyword(s):  
Risk Factors ◽  
Antibiotic Therapy ◽  
Klebsiella Oxytoca ◽  
Significant Risk ◽  
University Hospital ◽  
Prediction Tool ◽  
External Application ◽  
The Past ◽  
Extended Spectrum ◽  
History Of

Abstract Background Extended spectrum β-lactamase (ESBL) bacteria are resistant to many antibiotics, which increases the risk of inadequate early antibiotic therapy. A previous single-center study had created a prediction tool to assist clinicians in identifying patients at risk for ESBL bloodstream infections. The purpose of our research project was to assess validity of this tool while also identifying risk factors for ESBL bacteremia within our own institution, which would allow for assessment of alternative prediction tools. Methods We performed a retrospective chart review of adult patients admitted to an urban university hospital who were found to have bacteremia with Escherichia coli, Klebsiella pneumoniae, and/or Klebsiella oxytoca between October 2016 and April 2018. Demographics and comorbidities were assessed, along with other potential risk factors including exposure to antibiotics and hospitalizations within the past 6 months. Results A total of 214 instances of bacteremia were identified and 14% were due to ESBL organisms. Risk factors for ESBL bacteremia in our cohort included history of positive culture for ESBL (RR = 5.9) or MRSA (RR = 3.5) and antibiotic usage in the past 6 months (RR = 2.3). Patients with ESBL bacteremia were hospitalized longer (mean 16 days vs. 6 days for non-ESBL), received longer durations of antibiotic therapy (11.7 days vs. 5.3 days), and were exposed to greater numbers of different antibiotics (1.9 vs. 0.7) in the previous 6 months. Multivariate logistic regression showed that history of prior ESBL infection (OR 14.7, CI 1.8–120) and increasing number of different antibiotic classes administered in the prior 6 months (OR 4.3, CI 1.7–11.2) were significant risk factors for ESBL bacteremia. The previously created prediction tool did not sufficiently differentiate higher and lower risk for ESBL bacteremia in our cohort. Conclusion Although risk factors were similar, the previously derived stepwise prediction tool did not predict ESBL bacteremia in our external cohort. Point-based prediction modeling might better assess risk across institutions. Additionally, the number of different antibiotics received was associated with risk for ESBL bacteremia and should be investigated further. Disclosures All authors: No reported disclosures.

scholarly journals Understanding Computational Methods for Solar Envelopes Based on Design Parameters, Tools, and Case Studies: A Review

Energies ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3302 ◽  
Author(s):  
Miktha Farid Alkadri ◽  
Francesco De Luca ◽  
Michela Turrin ◽  
Sevil Sariyildiz
Keyword(s):  
Case Studies ◽  
Urban Areas ◽  
Urban Infrastructure ◽  
Digital Tools ◽  
Design Stage ◽  
Design Parameters ◽  
Design Strategies ◽  
The Past ◽  
Local Contexts ◽  
Urban Heat

The increasing population density in urban areas simultaneously impacts the trend of energy consumption in building sectors and the urban heat island (UHI) effects of urban infrastructure. Accordingly, passive design strategies to create sustainable buildings play a major role in addressing these issues, while solar envelopes prove to be a relevant concept that specifically considers the environmental performance aspects of a proposed building given their local contexts. As significant advances have been made over the past decades regarding the development and implementation of computational solar envelopes, this study presents a comprehensive review of solar envelopes while specifically taking into account design parameters, digital tools, and the implementation of case studies in various contextual settings. This extensive review is conducted in several stages. First, an investigation of the scope and procedural steps of the review is conducted to frame the boundary of the topic to be analyzed within the conceptual framework of solar envelopes. Second, comparative analyses between categorized design methods in parallel with a database of design parameters are conducted, followed by an in-depth discussion of the criteria for the digital tools and case studies extracted from the selected references. Third, knowledge gaps are identified, and the future development of solar envelopes is discussed to complete the review. This study ultimately provides an inclusive understanding for designers and architects regarding the progressive methods of the development of solar envelopes during the conceptual design stage.

Results from Phase I of a Pilot Study on Dynamic Ramp Metering in Houston

2020 ◽  
Vol 2674 (11) ◽  
pp. 478-489
Author(s):  
Hongmin “Tracy” Zhou ◽  
Magdy Kozman
Keyword(s):  
Pilot Study ◽  
Phase I ◽  
Ramp Metering ◽  
Cost Ratio ◽  
Department Of Transportation ◽  
Benefit Cost Ratio ◽  
The Past ◽  
Texas Department ◽  
The Right ◽  
Benefit Cost

Traffic in Houston, U.S., has continued growing over the past decade. The Houston District of the Texas Department of Transportation (TxDOT) recently began a pilot study to evaluate a dynamic ramp metering system. The project is aimed to convert ramp metering from local control to system-wide dynamic operation. In Phase I of the project, major control parameters and different metering strategies were tested and evaluated in simulation and field settings for a study corridor installed with six ramp meters. The study identified a base metering plan that overall worked well for sites without restrictive queue conditions. This base plan was that average speed of 50 mph or lower in the right-most two mainlanes will call for metering at a constant metering rate of 850 vehicles per hour for at least 4 min, and that queue occupancy of 50% or higher will call for meter shutdown for at least 1 min. Ramp metering coordinated with the downstream intersection performed well by accommodating diverted traffic caused by ramp metering. When operating ramp meters in a group, metering the immediately upstream meter performed best compared with metering further upstream meters. It is evident that ramp metering caused traffic diversion to the frontage road and also caused reduced queue-jumping behaviors on the frontage road at ramp meters with an immediately upstream exit ramp. The coordinated ramp metering strategy can potentially generate a benefit/cost ratio of 117:1 compared with local metering in the District.

Effect of Speed, Flow, and Geometric Characteristics on Crash Frequency for Two-Lane Highways

2000 ◽  
Vol 1717 (1) ◽  
pp. 76-83 ◽  
Author(s):  
Nicholas J. Garber ◽  
Angela A. Ehrhart
Keyword(s):  
Department Of Transportation ◽  
Deterministic Models ◽  
Crash Frequency ◽  
Crash Rates ◽  
The Past ◽  
Speed Flow ◽  
Lane Width ◽  
The Mean ◽  
Virginia Department ◽  
Made In

Although during the past several years significant progress has been made in improving safety on U.S. highways, the frequency and severity of crashes continue to be of concern. A better understanding of the factors associated with crashes will facilitate the identification of suitable countermeasures that could further reduce the occurrence of crashes. Results are presented from a study that determines how the characteristics of speed, flow, and geometry affect the crash rates for two-lane highways. Deterministic models that relate the crash rate with the mean speed, standard deviation of speed, flow per lane, lane width, and shoulder width are presented. The multivariate ratio of polynomials method was used to develop the models. Research was limited to two-lane roadways in Virginia with speed limits of 89 km/h (55 mph). The data were obtained from speed-monitoring stations established by the Virginia Department of Transportation and from police accident reports from January 1993 to September 1995.

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