Browsing by Subject "Risk assessment"

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Analysis of Unmanned Aerial Vehicles Concept of Operations in ITS Applications
(Center for Transportation Studies, 2011-03) Gebre-Egziabher, Demoz; Xing, Zhiqiang
The work described in this report is about developing a framework for the design of concept of operations (CONOP), which use small uninhabited aerial systems (SUAS) to support of intelligent transportation system (ITS) application of highway and transportation infrastructure monitoring. In these envisioned applications, these vehicles will be used for tasks such as remote collection of traffic data or inspection of roads and bridges. As such, a risk that has to be managed for these applications is that of vehicle-infrastructure collision. Various solutions to ensure safe separation between the unmanned aerial vehicle (UAV) and the object being inspected have been proposed. However, most, if not all, of these solutions rely on a multi-sensor approach, which combines digital maps of the infrastructure being inspected with an integrated GPS/Inertial navigator. While "turn key" solutions for such multi-sensor systems exist, the performance specifications provided by their manufactures does not provide sufficient information to allow precisely quantifying or bounding the collision risk. Furthermore, size, weight and power (or SWAP) constraints posed by these small aerial vehicles limits the use of redundant hardware and/or software as a risk mitigation strategy. The purpose of the work reported here was to develop a framework for the design of CONOPs, which take these SUAS limitations into account. The method outlined shows, in part, how these vehicle/infrastructure collision risks can be estimated or conservatively bounded.
College student persistence in the two-year setting: identifying risk early to guide early integration
(2013-05) Keys, Margo
College student persistence is examined. The unique nature of the students and environment of the two-year college setting warrant concentrated research effort. The purpose of the study is to examine student variables associated with persistence and program completion to develop a pre-entrance risk assessment in the two-year college setting. Identifying student risk early to triage students toward interventions such as counseling, tutoring and developmental education courses may lead to answers to student integration, eventually leading to improved student retention. Definitions and limitations of the study are outlined. A literature review includes the theoretical underpinnings surrounding the study of student persistence. Relevant research related to risk factors of attrition pre-matriculation and post-matriculation are included. Ex post facto research will be completed to examine entering students in the 2008-09 academic year at a two-year technical college in the Midwest who participated in the voluntary intake assessment program (n=1127). Student entrance variables readily available at the time of enrollment were used. Variables studied included: Placement exam scores, age, enrollment status, gender, financial aid as independent variables. Student persistence and program completion serves as the dependent variables. Binary logistic regression was used. The independent variables did not have a notable relationship with student persistence or program completion for this two-year college population.
Computational Techniques to Quantify Chemical Similarity: Tools for Risk Assessment
(University of Minnesota Duluth, 1995) Basak, Subhash C; Niemi, Gerald J; Host, George E
The principal goal of the cooperative agreement was to develop new molecular similarity methods and apply them to the risk assessment of environmental chemicals. To this end, our strategy had the following three-fold objectives: 1. Conduct an International workshop on " MOLECULAR SIMILARITY IN RISK ASSESSMENT " where internationally known experts in toxicology, computational chemistry, mathematical chemistry, structure-activity relationships and risk assessment of chemicals were brought together. These experts provided their opinions about how MOLECULAR SIMILARITY methods should be developed and used for risk assessment of chemicals. Ten experts were interviewed by the NRRI team and subsequently their input was summarized in a technical report submitted to USEPA. The workshop was part of QSAR ’92, an international conference held in Duluth, Minnesota jointly by the Natural Resources Research Institute-University of Minnesota and U S Environmental Protection Agency. The experts also submitted written manuscripts as part of the workshop. The workshop report reflected on different aspects of hazard assessment and molecular similarity. 2. Develop molecular similarity methodology by incorporating the inputs of the experts mentioned in item 1 above, along with our expertise in these methods. Special attention was given to the use of NONEMPIRICAL PARAMETERS (e.g., values calculated directly from the chemical structure) as opposed to empirical (or experimental) parameters because most chemicals used in the environment do not have experimental data necessary for detailed hazard assessment. 3. Apply the computational molecular similarity methods developed during the project in the selection of analogs and in estimation of environmentally important properties of these chemicals.
Design Tool for Controlling Runoff and Sediment from Highway Construction
(Minnesota Department of Transportation, 2008-08) Wilson, Bruce N.; Sheshukov, Aleksey; Mendez, Aida
Regulations require that stormwater pollution prevention plans be developed for construction activities that disturb an area that is equal to or greater than one acre. Different strategies, including a combination of practices, can be used to develop these plans. The WATER model was a tool developed from a previous project to assess the effectiveness of different on-site sediment control practices. This model is expanded in this study to consider offsite practices, to include processes at the watershed scale, and to allow spatial data sets to be integrated into the simulation framework. Routines to simulate the impact of off-site practices of rock check dams, vegetative filters, and detention ponds are added to the WATER model. The detention pond model has been modified to allow rock and gravel infiltration filters to be included as an off-site practice. Two different algorithms are used: (1) the Protocol Method based purely on empirical data and (2) the Process-Based Method using process-based relationships developed for porous media flow.
Erosion Risk Assessment Tool for Construction Sites
(2006-07-01) Wilson, Bruce N.; Sheshukov, Aleksey; Pulley, Reid
The impact of erosion and sediment from construction sites can be reduced by using a variety of onsite and offsite practices. The WATER model was developed to be a tool to assess the effectiveness of different sediment control practices. The WATER model evaluates risk by performing many simulations of a construction site response for different weather conditions. A particularly important component of the WATER model is the prediction of daily climate variables and storm characteristics called WINDS. This model uses the statistics for the analyzed data to predict many years of possible weather conditions. Predicted weather and storm characteristics are in very good agreement with those observed. The WATER model simulates surface runoff, plant processes, and erosion and sediment transport as major hillslope processes. Four runoff events (spring dry run, spring wet run, fall dry run, and fall wet run) from artificial rainfall conditions were measured.
Modeling Bicyclist Exposure to Risk and Crash Risk: Some Exploratory Studies
(Center for Transportation Studies, University of Minnesota, 2018-07) Lindsey, Greg; Wang, Jueyu; Hankey, Steven; Pterka, Michael
This report presents models for estimating bicyclist exposure to risk and crash risk. Direct demand models for estimating weekday PM peak-period bicyclist exposure to risk are estimated from a database of PM peak-period bicycle counts in Minneapolis and used to estimate exposure for the street network. Bicycle crashes in Minneapolis are described and crash risk is assessed. Probability models to assess crash risk at both intersections and along segments show that both bicyclist exposure and vehicular exposure are associated with the likelihood of a bicycle crash. Estimates of exposure at 184 roadway-trail crossings are used to apply warrants for traffic controls. The results show that warrants for traffic signals and pedestrian hybrid beacons are most likely to be met using weekend peak-hour traffic flows. Most locations that meet warrants already have controls, but site specific safety investigations may be warranted at 9% of all crossings. Count-based models of bicyclist exposure are estimated for Duluth using origin-destination centrality indices as explanatory variables. Although these indices correlate positively and significantly with bicyclist volumes, estimates of exposure do not correlate with bicycle crashes. Together, these analyses illustrate how measures of bicyclist exposure to risk can be used in assessments of safety and crash risk. The approaches can be used in planning-level studies where consistent measures of exposure or risk are needed. These results underscore the need to continue bicycle traffic monitoring and make available estimates of exposure for safety assessments.
Report of the Internal Workshop on Molecular Similarity in Risk Assessment
(University of Minnesota Duluth, 1993) Basak, Subhash C; Hunter, Bob; Niemi, Gerald J; Host, George E
In an attempt to adequately capture the different aspects of molecular similarity, our group thought it would be appropriate to solicit, a variety of opinions regarding chemical similarity and its uses in different situations. While we have some experience and expertise in this field, we felt it important to consider a variety of opinions of internationally known experts about the concept of chemical similarity and its uses. Along those lines, we were fortunate enough to be able to access many researchers and regulators who had intended to participate in the QSAR 92 Conference held in Duluth, MN during July 19-23, 1992. In fact, we felt it essential that we take advantage of the collective body of expertise. To that end, we, in conjunction with United States Environmental Protection Agency (USEPA), sponsored nine key speakers and presenters who, we felt, had broad background in their area of expertise and could share with us their perspectives of what it means for two chemicals to be similar. After selecting our key speakers, we. arranged for many of them to be present at QSAR 92. During the course of the conference, we made arrangements to meet and have open discussions regrading chemical similarity with these speakers. The participants were questioned about what they thought were the critical elements or processes relevant to their subject area and the relevancy or uses of chemical similarity in their field of expertise. Many of these participants provided papers, which were reviewed for content relevant to chemical similarity and are provided in Appendix A. The goal of this exercise was to distill the common elements critical to operationalizing a method or system of components to formulate, implement, test, and validate chemical similarity models. This would lead to the development of a computer system design that incorporates many of the essential elements together under a common interface. We felt that it was essential that regulatory, toxicological, and computational perspectives of chemical similarity be taken into account during the course of this project. The remainder of this report will detail these different perspectives, and then discuss and review the common features to be used, with the hope that this will facilitate a computer software system design to accomplish the objectives of this project.
Risk Evaluation for In-Vehicle Sign Information
(Minnesota Department of Transportation, 2016-05) Schlicht, Erik J.; Morris, Nichole L.
The goal of the study was to examine the influence of in-vehicle signing (IVS) pertaining to four types of changing driving conditions and determine the utility and potential safety costs associated with the IVS information. Signage displayed on a personal navigation device was presented for specific zones within the simulation to assist drivers’ preparation for transitioning to new driving conditions ahead. These zones included: speed zone changes within the same roadway, notification of school zones, notification of work zones, and notification of curves. Driving performance measures known to be related to distraction as well as subjective usability and workload measures were used to help identify potential distraction associated with the IVS information. Moreover, risk analysis was conducted to evaluate the safety associated with IVS technology compared to the known safety levels with standard roadside signage. The objective measures collected in this study (both driving performance and risk analysis) indicated that implementing IVS technology would impact driving performance in the following manner: When IVS was deployed in the absence of external signs, speeding behavior significantly increased relative to baseline levels. IVS technology was not observed to impact speeding behavior when external signs were also present. Risk analysis suggested that IVS technology (when used in conjunction with external signs) can improve the safety associated with frontal-impact crashes; however, risk analysis proved that safety across all crash types was significantly reduced below baseline levels when IVS was used without external signs. Moreover, subjective usability results reinforced the driving performance findings.
Risk-Based Evaluation Of The Public Health Impact Of Food Safety Interventions For The Control Of Salmonella Spp. In The Chicken Meat Production Chain
(2017-05) Gonzalez, Rolando
The aim of this work was to develop a risk-based decision analysis framework of farm to table food safety interventions for the control of Salmonella spp. in the chicken meat production chain, using chicken breasts and ground chicken as the model food systems. This framework should assist chicken producers, processors and policy makers when evaluating and selecting the most cost-effective and feasible pre-harvest and post-harvest interventions to control Salmonella spp. The approach included defining the risk factors for Salmonella spp. contamination in the chicken meat production chain, identifying existing and proposed pre- and post-harvest interventions for controlling Salmonella spp., prioritizing pre- and post-harvest interventions based on the reduction of the overall public health risk, developing a quantitative risk assessment to predict the number of Salmonella cases in the US population per year and the impact of individual and combined intervention strategies in reducing the Salmonella public health burden, and finally, applying cost-benefit analysis to identify the most cost-effective measures. The results suggest that the use of peroxyacetic acid as a single intervention applied at post-chill is the most cost-effective intervention to both control Salmonella spp. and meet regulatory performance standards in chicken meat production. It also became evident that there is a need to update the body of published literature to better understand the impact of all stages of the chicken meat production chain, from pre- and post-harvest through consumer handling and cooking, particularly on levels of Salmonella spp.
Septic System Evaluation at MnDOT Rest Stops, Truck Stations and Weigh Scales
(Center for Transportation Studies, University of Minnesota, 2016-01) Heger, Sara; Wheeler, Dan; Gustafson, Dave; Szmorlo, Mike
The University of Minnesota (UM) and the Minnesota Department of Transportation (MnDOT) performed a unique evaluation of the 52 existing subsurface sewage treatment systems at safety rest areas (SRA) travel information centers, truck stations and weigh scales at MnDOT facilities across Minnesota. This three year partnership brought together the septic expertise of the UM with the MnDOT wastewater unit’s agency and site knowledge. The goal of the assessments was to evaluate risk and provide a risk analysis ranking system. The project began with an extensive record search where many documents were digitized and a database of information created. The next step was development of a draft assessment protocol. This draft protocol was pilot tested on five systems and refined based on those experiences. The full assessment included a preliminary review of the site, a facility assessment, effluent sampling, septic tank inspections, evaluation of advanced treatment units when present and an assessment of the soil treatment system. The information from the assessment was used to develop a risk ranking of all systems. The risk assessment created can be used for planning purposes to prioritize capital upgrades, but only if a sustainable process is created and incorporated into the day to day workload.
Stereo-electronic Factors in Molecular Similarity and Risk Assessment
(University of Minnesota Duluth, 1994) Basak, Subhash C; Hunter, Bob; Niemi, Gerald J; Host, George E
Three strategic tasks for the risk assessment of the chemicals can be defined nowadays. The first one is related to the critical evaluation of the existing test data. For example, in the area of industrial chemicals, after exploration the availability of toxicity endpoints, the National Research Council concluded that for many of these chemicals minimum of tests or, in many cases, no tests at all are performed [1]. On the other hand, the available test data mostly consist of acute toxicity and eye/skin irritation tests. Recently, an analysis of an environmental database of more than 30,000 chemicals showed [2] that the total number of chemicals possessing measured values of either boiling/melting points or vapor pressure is only 3,692. The second task should handle the identification problem of potential analogues of chemicals. An effective solution of this problem based on similarity methods can allow the selection of analogues of a query chemical possessing similar (hazardous) properties. The third task is closely related with the second one and is directed to estimating the properties of chemicals by using quantitative structure-activity relationships (QSAR) models.

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