Classification of road users detected and tracked with LiDAR at intersections

Data collection is a necessary component of transportation engineering. Manual data collection methods have proven to be inefficient and limited in terms of the data required for comprehensive traffic and safety studies. Automatic methods are being introduced to characterize the transportation system more accurately and are providing more information to better understand the dynamics between road users. Video data collection is an inexpensive and widely used automated method, but the accuracy of video-based algorithms is known to be affected by obstacles and shadows and the third dimension is lost with video camera data collection. The impressive progress in sensing technologies has encouraged development of new methods for measuring the movements of road users. The Center for Road Safety at Purdue University proposed application of a LiDAR-based algorithm for tracking vehicles at intersections from a roadside location. LiDAR provides a three-dimensional characterization of the sensed environment for better detection and tracking results. The feasibility of this system was analyzed in this thesis using an evaluation methodology to determine the accuracy of the algorithm when tracking vehicles at intersections. According to the implemented method, the LiDAR-based system provides successful detection and tracking of vehicles, and its accuracy is comparable to the results provided by frame-by-frame extraction of trajectory data using video images by human observers. After supporting the suitability of the system for tracking, the second component of this thesis focused on proposing a classification methodology to discriminate between vehicles, pedestrians, and two-wheelers. Four different methodologies were applied to identify the best method for implementation. The KNN algorithm, which is capable of creating adaptive decision boundaries based on the characteristics of similar observations, provided better performance when evaluating new locations. The multinomial logit model did not allow the inclusion of collinear variables into the model. Overfitting of the training data was indicated in the classification tree and boosting methodologies and produced lower performance when the models were applied to the test data. Despite ANOVA analysis not supporting superior performance by a competitor, the objective of classifying movements at intersections under diverse conditions was achieved with the KNN algorithm and was chosen as the method to implement with the existing algorithm

Estudio del efecto de diferentes líneas monospóricas de Rhizophagus irregularis en la respuesta del cacao al cadmio bajo condiciones de déficit hídrico en vivero

El creciente mercado mundial del cacao ha implicado una creciente preocupación por los daños en la salud de los consumidores debido a la presencia de cadmio proveniente de material parental del suelo, a la cercanía de los cultivos a zonas de extracción de minerales y a la utilización de fertilizantes fosforados o abonos orgánicos. El fitomejoramiento necesita un tiempo mayor al requerido por la Unión Europea. El estrés por déficit hídrico debido al cambio climático o a prácticas culturales, se constituye como otra amenaza para el cultivo del cacao en el mundo. Así, las acciones por alcanzar los requerimientos de inocuidad del cacao pueden dificultarse por cuenta del déficit hídrico. La fitoremediación asistida por HFMA, es una alternativa posible que ha demostrado la funcionalidad de los HFMA en la respuesta de las plantas hospederas frente al Cd y al déficit hídrico. No obstante, estas respuestas son muy variables entre otras, por la variabilidad funcional intra-específica de los HFMA limitando su aplicabilidad. Actualmente, no se conocen las respuestas del cacao inoculado con líneas monospóricas genéticamente diferentes de HFMA, frente al estrés por déficit hídrico y al Cd, que permitan identificar genotipos que induzcan respuestas fisiológicas indicadoras de potencial para la fito-remediación. En consecuencia, esta investigación se propuso estudiar el efecto de diferentes líneas monospóricas de Rhizophagus irregularis en la respuesta del cacao al cadmio bajo condiciones de déficit hídrico en condiciones de vivero. Se evaluaron múltiples parámetros para conocer las respuestas fisiológicas de las plantas a cada estrés de forma independiente y combinada. También se evaluó el efecto de la inoculación con un genotipo de HFMA comercial, así como de diferentes líneas monospóricas provenientes de cultivo monoxénico. Se encontraron diferencias funcionales entre las líneas monospóricas evaluadas y se identificaron las que indujeron las respuestas más y menos favorables de las plantas a estrés por déficit hídrico y por Cd, que de forma interesante fueron las mismas para cada estrés. Los resultados obtenidos revisten una alta relevancia porque hacen posible considerar oportunidades para estudios de mejoramiento genético para tolerancia a estrés a partir de búsqueda y selección de genotipos del hongo simbionte y no solamente de la planta hospedera.Abstract: The growing world market of cocoa has implied a growing concern about damages in the health of consumers due to cadmium coming from parental material of the soil, to the proximity of the crops to zones of extraction of minerals and to the use of fertilizers phosphorus or organic fertilizers. Plant breeding needs a longer time than that required by the European Union. Water deficit stress due to climate change or cultural practices constitutes another threat for cocoa cultivation in the world. Thus, actions to meet the requirements of cocoa safety can be complicated by the water deficit. The phytoremediation assisted by HFMA, is a possible alternative that has demonstrated the functionality of HFMA in the response of host plants against Cd and water deficit. However, these responses are very variable due to the intra-specific functional variability of HFMA among others, limiting its applicability. Currently, responses of cocoa inoculated with genetically different single spore lines of AMF fungi are not known, when subjected to water deficit and Cd stress, which allow the identification of genotypes that induce physiological responses with potential for phyto-remediation. Consequently, this research aimed to study the effect of different single spore lines of Rhizophagus irregularis on response of cocoa to cadmium under conditions of water deficit in nursery conditions. Multiple parameters were evaluated to know the physiological responses of plants to each stress independently and in combination. The effect of inoculation with a commercial HFMA genotype was also evaluated, as well as different single spore lines from monoxenic culture. Functional differences were found between the single spore lines evaluated and those that induced the most and least favourable responses of plants to water deficit and Cd stress were identified, which interestingly were the same for each stress. The results obtained are highly relevant because they make it possible to consider opportunities for studies on genetic improvement for tolerance to stress by searching and selecting genotypes from the symbiotic fungus and not only from the host plant.Doctorad

Statistical Analysis of Safety Improvements and Integration into Project Design Process

RoadHAT is a tool developed by the Center for Road Safety and implemented for the INDOT safety management practice to help identify both safety needs and relevant road improvements. This study has modified the tool to facilitate a quick and convenient comparison of various design alternatives in the preliminary design stage for scoping small and medium safety-improvement projects. The modified RoadHAT 4D incorporates a statistical estimation of the Crash Reduction Factors based on a before-and-after analysis of multiple treated and control sites with EB correction for the regression-to-mean effect. The new version also includes the updated Safety Performance Functions, revised average costs of crashes, and the comprehensive table of Crash Modification Factors—all updated to reflect current Indiana conditions. The documentation includes updated Guidelines for Roadway Safety Improvements. The improved tool will be implemented at a sequence of workshops for the final end users and preceded with a beta-testing phase involving a small group of INDOT engineers

Speed Management in Small Cities and Towns—Guidelines for Indiana

Many small cities and towns in rural states such as Indiana are crossed by arterial highways. The local traffic on these roads, particularly vulnerable road users, face the excessive risk of injury and death. This danger is amplified with local land development, driveways, and on-street parking in town centers. This report presents an Indiana study of the speeding problem on arterial roads passing through small communities. Past research on various countermeasures suitable for the studied conditions were identified and the connection between speed reduction and safety improvements was investigated in a sample of Indiana small towns. Promising speed-reduction measures include speed feedback signs and converging chevrons with speed limit legends marked on the pavement. Point-to-point enforcement is a modern and highly effective alternative that may be applicable on highways passing small towns if the through traffic prevails with limited interruptions. This report provides a method of evaluating the benefits of speed reduction in the studied conditions where the risk of severe injury and fatality is excessive to road users while the frequency of crashes is low. The method includes the proactive estimation of the economic benefit. The results indicate that both the local and through traffic on highways passing a small town benefit considerably from speed reduction even after accounting for the loss of time. An Excel spreadsheet developed in the study facilitates the calculations

TScan–Stationary LiDAR for Traffic and Safety Applications: Vehicle Interpretation and Tracking

To improve traffic performance and safety, the ability to measure traffic accurately and effectively, including motorists and other vulnerable road users, at road intersections is needed. A past study conducted by the Center for Road Safety has demonstrated that it is feasible to detect and track various types of road users using a LiDAR-based system called TScan. This project aimed to progress towards a real-world implementation of TScan by building two trailer-based prototypes with full end-user documentation. The previously developed detection and tracking algorithms have been modified and converted from the research code to its implementational version written in the C++ programming language. Two trailer-based TScan units have been built. The design of the prototype was iterated multiple times to account for component placement, ease of maintenance, etc. The expansion of the TScan system from a one single-sensor unit to multiple units with multiple LiDAR sensors necessitated transforming all the measurements into a common spatial and temporal reference frame. Engineering applications for performing traffic counts, analyzing speeds at intersections, and visualizing pedestrian presence data were developed. The limitations of the existing SSAM for traffic conflicts analysis with computer simulation prompted the research team to develop and implement their own traffic conflicts detection and analysis technique that is applicable to real-world data. Efficient use of the development system requires proper training of its end users. An INDOT-CRS collaborative process was developed and its execution planned to gradually transfer the two TScan prototypes to INDOT’s full control. This period will be also an opportunity for collecting feedback from the end user and making limited modifications to the system and documentation as needed

Evaluation of Alternative Intersections and Interchanges: Volume I—Roundabout Capacity and Rollover Analysis for Heavy Vehicles

There is a recent trend of building roundabouts on high-speed roads, often with the considerable presence of heavy vehicles. With the increased presence of trucks on roundabouts, the issue of overturning has become a concern. Although some geometric, vehicle, and loading factors have been connected to rollover, the safety performance of roundabouts built on high-speed roads is not well understood due to their relative novelty. In addition, other concerns related to geometry, driver behavior, and environmental considerations may exist at roundabouts. This study examined roundabout circulatory superelevation, aggressive driver behavior, roundabout readability, and nighttime conditions in the context of heavy vehicle rollover. Moreover, the critical and follow-up headways were estimated for trucks and other vehicles at roundabouts located on the low- and high–speed roads and during daytime and nighttime conditions. This research developed a methodology which may be used to examine truck overturning at roundabouts. A generalized rollover model suitable for application to heavy vehicles was applied to field-observed semi-trailer speeds and paths to estimate their proximity to rollover at newly-built Indiana roundabouts. This was done by introducing delta v - the difference between the critical rollover speed determined from the model and the actual speed. This report revealed that heavy vehicles increased the critical headway, and in turn reduced the entry capacity of roundabouts. Drivers of heavy vehicles, on average, accepted a 1.1 sec longer critical headway than drivers of passenger cars. The effects of nighttime/twilight conditions indicated additional capacity reduction caused by a 0.6 sec longer critical headway compared to daylight conditions. Likewise, drivers on dual-lane roundabouts in rural areas accepted a 0.6 sec longer critical headway than drivers on single-lane roundabouts in urban areas. It was determined that the gap-acceptance parameters for a single-lane roundabout on a low-speed state road were shorter than the national values, resulting on average in 30% higher capacity for Indiana conditions. In contrast, the estimated critical headway was larger for dual-lane roundabouts on high-speed state roads, resulting in 15% reduced capacity for Indiana conditions. The findings of this report are based on low and medium traffic volumes presently observed on high-speed rural and suburban roads. Heavy traffic flow may affect driver behavior; therefore, studying such roundabouts in heavier traffic conditions might improve the results

Clasificación de Errores en una Red de Comunicación Industrial (Modbus TCP/IP)

Este artículo consiste en el desarrollo de una metodología aplicada a la clasificación de errores en una red de comunicación industrial (Modbus TCP/IP), a través de un método de reconocimiento de patrones. Las pruebas se realizaron con la programación de un PLC TWIDO TWDLCAE40DRF, y fue sometido a perturbaciones o fallos generados en la red. Los datos fueron adquiridos y monitoreados por la herramienta ModScan32 y posteriormente fueron procesados a través del Análisis de Componentes Principales (PCA), obteniendo una tasa de acierto en la discriminación de 100%. En este estudio fue posible clasificar de manera fácil y rápida algunos factores o errores generados en una comunicación Modbus

Significados, obstáculos y formas de construcción: la paz desde los estudiantes universitarios

The present article includes the findings of the research entitled "Social representations on the peace of the students of the University Francisco de Paula Santander, headquarter"; for this purpose, the theoretical basis and methodology to be followed are presented. The study inquired on the meaning of peace, construction and obstacles to peace from the different visions of young students belonging to different academic programs. It is essential to recognize each student's perspective against what they consider a peace scenario in their social dynamics, and consider the pedagogical role of education to strengthen these scenarios and build a more equitable and human social fabric.El presente artículo comprende los hallazgos de la investigación titulada “Representaciones sociales sobre la paz de los estudiantes de la Universidad Francisco de Paula Santander, sede central”; para tal fin, se exponen los sustentos teóricos y la metodología a seguir. El estudio indagó sobre el significado de paz, la construcción y los obstáculos para la paz desde las distintas visiones de jóvenes estudiantes pertenecientes a diferentes programas académicos. Es fundamental reconocer la perspectiva de cada estudiante frente a lo que considera un escenario de paz en su dinámica social, y considerar el papel pedagógico que tiene la educación para fortalecer estos escenarios y construir un tejido social más equitativo y humano

Estimation of Safety Performance Functions (SPF) at signalized intersections in Medellín, Colombia •

One of the objectives of road infrastructure sustainability is to ensure that users are treated equally and their quality of life is improved by providing better mobility and traffic safety. When designing roads, it is important to evaluate different design criteria alternatives - in this case, we look at traffic safety principles. For this, we used the Safety Performance Functions (SPF) tool to obtain the expected crash frequency. The data used were Medellín’s crash records from 2012 to 2016, as well as the geometric features and traffic conditions at signalized intersections. A negative binomial model was fitted to estimate the SPF. Exposure, geometry, and traffic volume were found to be statistically significant in determining the expected crash frequency for collisions where there was property damage only (PDO) and fatal or injury (FI). It was found that accidents were less likely on T-junctions compared to four-leg junctions, one-way approaches were found to be safer whereas right turns were found to increase collisions causing FIUno de los propósitos respecto de la sostenibilidad de las infraestructuras viales es lograr la equidad social en los usuarios mejorando la calidad de vida proveyendo mejor movilidad y seguridad vial. En el diseño de carreteras, es importante evaluar múltiples alternativas basadas en criterios de diseño, el presente trabajo se centra en los principios de seguridad vial. Para lograr este objetivo, se usaron herramientas como las Funciones de Desempeño de Seguridad Vial (SPF) para obtener la frecuencia esperada de accidentes. Se utilizaron los registros de accidentes en Medellín de 2012 hasta 2016, además, se incluyeron características geométricas y condiciones de tránsito en las intersecciones semaforizadas. Se ajustó un modelo binomial negativo para estimar el SPF. Se descubrió que la exposición, la geometría y el volumen de transito son estadísticamente significativos para determinar la frecuencia de accidentes esperada para accidentes de solo daños (PDO) y accidentes fatales o con heridos (FI); las intersecciones en T fueron encontradas menos propensas a colisiones en comparación con las intersecciones de cuatro accesos, se encontró que los accesos unidireccionales son más seguros, contrariamente, se encontró que los giros a la derecha aumentan las colisiones FI

TScan: Stationary LiDAR for Traffic and Safety Studies—Object Detection and Tracking

The ability to accurately measure and cost-effectively collect traffic data at road intersections is needed to improve their safety and operations. This study investigates the feasibility of using laser ranging technology (LiDAR) for this purpose. The proposed technology does not experience some of the problems of the current video-based technology but less expensive low-end sensors have limited density of points where measurements are collected that may bring new challenges. A novel LiDAR-based portable traffic scanner (TScan) is introduced in this report to detect and track various types of road users (e.g., trucks, cars, pedestrians, and bicycles). The scope of this study included the development of a signal processing algorithm and a user interface, their implementation on a TScan research unit, and evaluation of the unit performance to confirm its practicality for safety and traffic engineering applications. The TScan research unit was developed by integrating a Velodyne HDL-64E laser scanner within the existing Purdue University Mobile Traffic Laboratory which has a telescoping mast, video cameras, a computer, and an internal communications network. The low-end LiDAR sensor’s limited resolution of data points was further reduced by the distance, the light beam absorption on dark objects, and the reflection away from the sensor on oblique surfaces. The motion of the LiDAR sensor located at the top of the mast caused by wind and passing vehicles was accounted for with the readings from an inertial sensor atop the LiDAR. These challenges increased the need for an effective signal processing method to extract the maximum useful information. The developed TScan method identifies and extracts the background with a method applied in both the spherical and orthogonal coordinates. The moving objects are detected by clustering them; then the data points are tracked, first as clusters and then as rectangles fit to these clusters. After tracking, the individual moving objects are classified in categories, such as heavy and non-heavy vehicles, bicycles, and pedestrians. The resulting trajectories of the moving objects are stored for future processing with engineering applications. The developed signal-processing algorithm is supplemented with a convenient user interface for setting and running and inspecting the results during and after the data collection. In addition, one engineering application was developed in this study for counting moving objects at intersections. Another existing application, the Surrogate Safety Analysis Model (SSAM), was interfaced with the TScan method to allow extracting traffic conflicts and collisions from the TScan results. A user manual also was developed to explain the operation of the system and the application of the two engineering applications. Experimentation with the computational load and execution speed of the algorithm implemented on the MATLAB platform indicated that the use of a standard GPU for processing would permit real-time running of the algorithms during data collection. Thus, the post-processing phase of this method is less time consuming and more practical. Evaluation of the TScan performance was evaluated by comparing to the best available method: video frame-by-frame analysis with human observers. The results comparison included counting moving objects; estimating the positions of the objects, their speed, and direction of travel; and counting interactions between moving objects. The evaluation indicated that the benchmark method measured the vehicle positions and speeds at the accuracy comparable to the TScan performance. It was concluded that the TScan performance is sufficient for measuring traffic volumes, speeds, classifications, and traffic conflicts. The traffic interactions extracted by SSAM required automatic post-processing to eliminate vehicle interactions at too low speed and between pedestrians – events that could not be recognized by SSAM. It should be stressed that this post processing does not require human involvement. Nighttime conditions, light rain, and fog did not reduce the quality of the results. Several improvements of this new method are recommended and discussed in this report. The recommendations include implementing two TScan units at large intersections and adding the ability to collect traffic signal indications during data collection