Friday Seminar: A statistical process control framework to support health-monitoring

Overseas (Old) Highway Bridge, Missouri & Ohio  Key Channel

This week's TRANSOC Friday Seminar is all about infrastructure! Pablo L. Durango-Cohen from Northwestern University will talk about structural health-monitoring. 

In this talk, we describe development and field application of a process control framework to support structural health-monitoring and management of transportation infrastructure. The work is motivated by technological advances that allow for continuous, long-term, simultaneous collection of various response measurements, as well as the factors that contribute deterioration. The framework provides an integrated, generally-applicable (to various types of structural response data) statistical approach that links performance modeling and structural health monitoring. The framework consists of two parts: The first, estimation of statistical models to explain, predict, and control for common-cause variation, i.e., changes, including serial dependence that can be attributed to usual operating conditions. The ensuing standardized innovation series are analyzed in the second part of the framework, where we use single and multivariate control charts to detect special-cause or unusual events. We illustrate the proposed framework with analysis of strain and displacement data from the monitoring system on the Hurley Bridge (Wisconsin Structure B-26-7).

The seminar takes place Friday, November 8, 2013 in 534 Davis from 4:00-5:00 PM. Cookie Hour (of course) precedes in the library at 3:30. 

The California Greenhouse Gas Inventory Spreadsheet (GHGIS) Model

08-hollywood-HTF-3966

A new report from Lawrence Berkeley National Lab was issued last month that presents a new model for California's greenhouse gas emissions. Estimating Policy-Driven Greenhouse Gas Emissions Trajectories in California: The California Greenhouse Gas Inventory Spreadsheet (GHGIS) Model  by Jeffery Greenblatt presents and describes the model which was developed for the California Air Resources Board

A California Greenhouse Gas Inventory Spreadsheet (GHGIS) model was developed to explore the impact of combinations of state policies on state greenhouse gas (GHG) and regional criteria pollutant emissions. Starting from basic drivers such as population, numbers of households, gross state product, numbers of vehicles, etc., the model calculated energy demands by type (various types of liquid and gaseous hydrocarbon fuels, electricity and hydrogen), and finally calculated emissions of GHGs and three criteria pollutants: reactive organic gases (ROG), nitrogen oxides (NOx), and fine (2.5 µm) particulate matter (PM2.5). Calculations were generally statewide, but in some sectors, criteria pollutants were also calculated for two regional air basins: the South Coast Air Basin (SCAB) and the San Joaquin Valley (SJV). Three scenarios were developed that attempt to model: (1) all committed policies, (2) additional, uncommitted policy targets and (3) potential technology and market futures. Each scenario received extensive input from state energy planning agencies, in particular the California Air Resources Board. Results indicate that all three scenarios are able to meet the 2020 statewide GHG targets, and by 2030, statewide GHG emissions range from between 208 and 396 MtCO2/yr. However, none of the scenarios are able to meet the 2050 GHG target of 85 MtCO2/yr, with emissions ranging from 188 to 444 MtCO2/yr, so additional policies will need to be developed for California to meet this stringent future target. A full sensitivity study of major scenario assumptions was also performed. In terms of criteria pollutants, targets were less well-defined, but while all three scenarios were able to make significant reductions in ROG, NOx and PM2.5 both statewide and in the two regional air basins, they may nonetheless fall short of what will be required by future federal standards. Specifically, in Scenario 1, regional NOx emissions are approximately three times the estimated targets for both 2023 and 2032, and in Scenarios 2 and 3, NOx emissions are approximately twice the estimated targets. Further work is required in this area, including detailed regional air quality modeling, in order to determine likely pathways for attaining these stringent targets.

The full report can be found here

 

Friday Seminar: Transportation modeling: A practitioner’s perspective

View from the 33rd

Today's TRANSOC Friday Seminar is all about modeling. SFCTA's Deputy Director for Technological Services, Elizabeth Sall will present, "Transportation modeling: A practitioner’s perspective".  She will speak about the types of models commonly used in long-range transportation planning in the county of San Francisco and their role in the decision-making process, as well as give an overview of some research projects that have recently been conducted at the SFCTA.

The seminar will take place today! November 1, 2013 in 534 Davis from 4:00-5:00 PM. Don't forget about Cookie Hour at 3:30 in the library. See you then!

Mini-Bikes Safety Fact Sheet

Speeed Shriners

We have several obscure items in our collection. One we stumbled across today was the Consumer Product Safety Commision's 1978 Fact Sheet on Mini-Bikes. They cite that at the time of writing, 31,000 people a year require hospital treatment for mini-bike incidents. Their exmaple accident is described:

DICK TRIED TO STOP HIS MINI-BIKE WHEN ANOTHER BOY RODE TOWARDS HIM, BUT HIS HANDBRAKES FAILED TO WORK. THEY COLLIDED, AND DICK FELL, HITTING HIS HEAD AND PINNING HIS RIGHT ARM AND LEG UNDER THE BIKE. HE SUFFERED A SLIGHT CEREBRAL HEMORRHAGE AND A SPRAINED RIGHT ARM.

Safety tipes include:

  • Look for a mini-bike with large wheels. Typically, mini-bikes with small wheels are unstable.
  • The rider should be able to conveniently reach all controls without exerting himself.
  • After buying a bike, don't modify its design.

They also warn riders of impromper use and rider error:

MICKEY WAS RIDING HIS MINI-BIKE WHEN HIS LEFT PANTS LEG CAUGHT IN THE CHAIN DRIVE AND SPROCKET MECHANISM. HE SUFFERED PUNCTURE WOUNDS ON HIS LEG.

The whole document, with several more tips on how to enjoy mini-bikes without a trip to the hospital, can be found here

 

 

Transportation mode recognition using GPS and accelerometer data

Cyclists

One of the big problems for smartphone travel diary apps is automatic mode detection. The split between walking and not is pretty easy, as is cycling, but what about separating cars from rail? Apps like Moves just dubs it "transport", but that doesn't help much with travel behavior research. A new paper in Transportarion Researc Part C examines using accelerometers and GPS to detect mode. Tao Feng and Harry J.P. Timmermans from Eindhoven University of Technology present their research in, "Transportation mode recognition using GPS and accelerometer data"

Potential advantages of global positioning systems (GPS) in collecting travel behavior data have been discussed in several publications and evidenced in many recent studies. Most applications depend on GPS information only. However, transportation mode detection that relies only on GPS information may be erroneous due to variance in device performance and settings, and the environment in which measurements are made. Accelerometers, being used mainly for identifying peoples’ physical activities, may offer new opportunities as these devices record data independent of exterior contexts. The purpose of this paper is therefore to examine the merits of employing accelerometer data in combination with GPS data in transportation mode identification. Three approaches (GPS data only, accelerometer data only and a combination of both accelerometer and GPS data) are examined. A Bayesian Belief Network model is used to infer transportation modes and activity episodes simultaneously. Results show that the use of accelerometer data can make a substantial contribution to successful imputation of transportation mode. The accelerometer only approach outperforms the GPS only approach in terms of the predictive accuracy. The approach which combines GPS and accelerometer data yields the best performance.

The full article can be found here

SafeTREC-UCTC Brown Bag Seminar: Transportation Policy in Oakland as It Is and as It Should Be

Latham square

This Friday, November 1 2013, the SafeTREC-UCTC Brown Bag Seminar features the City of Oakland's Senior Transportation Planner Jaime Parks. Parks will present, "Transportation Policy in Oakland as It Is and as It Should Be". 

Oakland has more BART stations than any other Bay Area jurisdiction, numerous mixed-use neighborhoods, and one of the highest bike-to-work mode shares in the country. Yet, the City has failed to fully take advantage of these natural advantages, partially due to the lack of a cohesive vision for the role transportation should play in the lives of Oaklanders. Oakland passed a Complete Streets Policy in 2013 that will allow the City to consider transportation decisions from a broader perspective. The presentation will share updates on several on-going complete streets initiatives, including analysis of crash trends Citywide, data management, CEQA reform, and experiments with green paint and temporary spaces. The presentation will also identify key knowledge gaps as suggested topics for future urban transportation research.

The seminar takes place from noon-1:00 PM SafeTREC 2nd Floor Conference Room, 2614 Dwight Way, Berkeley, CA
or via webcast

Friday Seminar: Decomposing connected vehicle dynamics: delay effects and nonlinearities

Interior: 2013 SRT Viper & SRT Viper GTS

Today's TRANSOC Friday seminar is about connected vehicles. University of Michigan's Gabor Orosz will present, "Decomposing connected vehicle dynamics: delay effects and nonlinearities".

Arising technologies related to vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communications can significantly improve the efficiency of connected vehicle systems. These allow cars to obtain detailed information about the motion of distant vehicles. Such information can be presented to the driver or incorporated in advanced vehicle control systems. In this talk I present some novel decomposition tools that allow us to untangle the infinite-dimensional dynamics of heterogeneous vehicular networks with V2V communication. These methods help us to understand the spatio-temporal complexity of large-scale multi-vehicle systems and redesign their dynamics by exploiting connectivity. Some similarities with flow oscillations on road networks equipped with V2I devices are also pointed out.

The seminar will take place at the usual time today, October 25, 2013 from 4:00-5:00 PM in 534 Davis. Cookie Hour will kick off in the library at 3:30 PM. 

Open Access Article: Spatial modeling of bicycle activity at signalized intersections

Biking at Grand/Halsted/Milwaukee (3 of 4)

This week is Open Access Week. What's Open Access? Here is a not very brief overview by Peter Suber. UC Berkeley also has an Open Access Initiative to help open up your research and data. 

In the spirit of Open Access Week, here's an interesting article from an open access journal - The Journal of Transport and Land Use. Go check it out and peruse the articles. No need to depend on your institution's sibscription because it's free to the public! (Thanks open access!)

In "Spatial modeling of bicycle activity at signalized intersections", Jillian Strauss and Luis F Miranda-Moreno look at the built-environment and cycling. 

This paper presents a methodology to investigate the link between bicycle activity and built environment, road and transit network characteristics, and bicycle facilities while also accounting for spatial autocorrelation between intersections. The methodology includes the normalization of manual cyclist counts to average seasonal daily volumes (ASDV), taking into account temporal variations and using hourly, daily, and monthly expansion factors obtained from automatic bicycle count data. To correct for weather conditions, two approaches were used. In the first approach, a relative weather ridership model was generated using the automatic bicycle count and weather data. In the second approach, weather variables were introduced directly into the model. For each approach, the effects of built environment, road and transit characteristics, and bicycle facilities on cyclist volumes were determined. It was found that employment, schools, metro stations, bus stops, parks, land mix, mean income, bicycle facility type (bicycle lanes and cycle tracks), length of bicycle facilities, average street length, and presence of parking entrances were associated with bicycle activity. From these, it was found that the main factors associated with bicycle activity were land-use mix, cycle track presence, and employment density. For instance, intersections with cycle tracks have on average 61 percent more cyclists than intersections without. An increase of 10 percent in land-use mix or employment density would cause an increase of 8 percent or 5.3 percent, respectively, in bicycle flows. The methods and results proposed in this research are helpful for planning bicycle facilities and analyzing cyclist safety. Limitations and future work are discussed at the end of this paper.

The full article can be found here

Special Friday Seminar: Marco Nie "From Pricing to Cap-and-Trade"

MTA-Slides_0106

This week's TRANSOC Friday Seminar is at a special time - 11:00am - noon in 534 Davis. This week Northwestern University Associate Professor Yu (Marco) Nie will present on a cap-and-trade approach to congesiton management in "From Pricing to Cap-and-Trade: Analysis and Design of Quantity-based Approach to Congestion Management."

Traffic congestion continues to threaten economic prosperity and quality of life around the world. It is widely acknowledged that demand management is an indispensable ingredient in the recipe for solving the traffic congestion puzzle, and likely to be one of the more effective and cost-efficient if properly implemented. This research will explore a new and promising travel demand management strategy, inspired by various cap-and-trade schemes aiming to reduce greenhouse gas and air pollutant emissions. The cap-and-trade schemes considered in this research seek to couple direct travel demand restriction with a trading mechanism. Because such a scheme typically involves creating mobility credits and trading them in a market, it is also known as tradable credit scheme. In this talk we will examine a few key design issues involved in building such credit markets, including how to account for the effects of transaction cost and how to initially allocate credits, using various analytical models.

As noted above, the seminar is happening this Friday, October 25 2013, from 11:00am to noon in 534 Davis. We'll keep you posted about Cookie Hour. 

Great California Shake Out! Are you ready?

Oct. 18 1989 Cypruss Overpass Collapse

Today is the Great California Shake Out, a statewide earthquake drill.  Do you know what to do when the Big One comes? 

Ever since the 1989 earthquake and its effects on transportation infrastructure, such as the collapse of the Cypress Freeway (which of course was replaced) or the structural failure of a portion of the San Francisco-Oakland Bay Bridge, there has been considerable research on seismic safety and stability. Are aerial BART stations safe? What are the optimal risk-based maintenance procedures to earthquake safety for bridges and highways?

Of course the Los Angeles region has its own concerns about the Big One, such as the disruption of freight logistics for the mega-region. How will the region's highways be affected? There were lots of lessons learned from the 1994 Northridge earthquake, which help inform projections for future risks.

If you want more research about earthquakes and California transportation, of course turn to TRID. For today, think about what you'd do when the Big One hits and how you prepare for such an event. 

Stay safe. 

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