Collective dynamics of pedestrians interacting with attractions

In order to investigate collective effects of interactions between pedestrians and attractions, this study extends the social force model. Such interactions lead pedestrians to form stable clusters around attractions, or even to rush into attractions if the interaction becomes stronger. It is also found that for high pedestrian density and intermediate interaction strength, some pedestrians rush into attractions while others move to neighboring attractions. These collective patterns of pedestrian movements or phases and transitions between them are systematically presented in a phase diagram. The results suggest that safe and efficient use of pedestrian areas can be achieved by moderating the pedestrian density and the strength of attractive interaction, for example, in order to avoid situations involving extreme desire for limited resources.Peer reviewe

Effects on the Design of Transport Systems of Pedestrian Dynamics

In the study, transportation-architecture-people-focused triple, urban transportation, design of transportation systems, pedestrian-oriented design and pedestrian walkable spaces will be emphasized. However, by analyzing the effects of pedestrian dynamics, transport systems aim to present a mechanism with an improved model that will define dynamics for the first time to explain the processes underlying design decisions. Four hundred and twelve healthy volunteers were selected from 18–65 years of age. First, three-dimensional (3D) virtual city is designed to understand the experiences of the pedestrians. Later, it was provided to navigate the three-dimensional virtual glasses in the city where the broadcasts were designed. During this navigation, pedestrian dynamics were observed, and spaces where pedestrians cautioned were identified. Following this determination, the “attractive” locations will be shown on the macroscale, with the eye-tracking method, it has been in both virtual city navigation and analysis with eye-tracking technology, the cognitive activities of the broadcasts were tested with electroencephalogram (EEG). This approach will in general bridge an empirical and theoretical link between transport-architectural literature in understanding pedestrian movements/behaviors and combining architectural-pedestrian interactions with transport research. However, by analyzing the way-finding behavior, the study interprets its effects on the spatial area

Adaptive pedestrian behaviour for the preservation of group cohesion

A crowd of pedestrians is a complex system in which individuals exhibit conflicting behavioural mechanisms leading to self-organisation phenomena. Computer models for the simulation of crowds represent a consolidated type of application, employed on a day-to-day basis to support designers and decision makers. Most state of the art models, however, generally do not consider the explicit representation of pedestrians aggregations (groups) and their implications on the overall system dynamics. This work is aimed at discussing a research effort systematically exploring the potential implication of the presence of groups of pedestrians in different situations (e.g. changing density, spatial configurations of the environment). The paper describes an agent-based model encompassing both traditional individual motivations (i.e. tendency to stay away from other pedestrians while moving towards the goal) and an adaptive mechanism representing the influence of group presence in the simulated population. The mechanism is designed to preserve the cohesion of specific types of groups (e.g. families and friends) even in high density and turbulent situations. The model is tested in simplified scenarios to evaluate the implications of modelling choices and the presence of groups. The model produces results in tune with available evidences from the literature, both from the perspective of pedestrian flows and space utilisation, in scenarios not comprising groups; when groups are present, the model is able to preserve their cohesion even in challenging situations (i.e. high density, presence of a counterflow), and it produces interesting results in high density situations that call for further observations and experiments to gather empirical data. The introduced adaptive model for group cohesion is effective in qualitatively reproducing group related phenomena and it stimulates further research efforts aimed at gathering empirical evidences, on one hand, and modelling efforts aimed at reproducing additional related phenomena (e.g. leader-follower movement patterns)

A New Materials and Design Approach for Roads, Bridges, Pavement, and Concrete

Increased understanding of demand for transport energy and how to improve road pavement materials would enable decision makers to make environmental, financial, and other positive changes in future planning and design of roads, bridges, and other important transportation structures. This research comprises three studies focused on pavement materials and a fourth study that examines energy demand within the road transportation sector. These studies are as follows: 1. A techno-economic study of ground tire rubber as an asphalt modifier; 2. A computational fluid dynamics analysis comparing the urban heat island effect of two different pavement materials – asphalt and Portland Cement Concrete; 3. A new approach that modifies the surface of ground tire rubber using low-cost chemicals and treatment methods to be used in asphalt applications; and 4. Analysis of road transport energy demand in California and the United States. The findings of these studies include that 1. GTR is an effective and economically suitable additive for modified asphalt, 2. the suitability of PCC pavements in urban settings should be reexamined, 3. Surface modification of GTR materials can improve compatibilization of particles for the manufacture of asphalt materials, and 4. gasoline sales are generally price inelastic in both the U.S. and California. Ultimately, these four studies improve understanding of road pavement materials and transport energy demand. They lay out important information about the future of the relationship between materials and design in the transportation industry. These findings may be used by engineers, policymakers, and others in the industry to better consider implications of decisions involved in design, creation, and modification of structures using pavement and concrete, including roads, bridges, etc

Computational Study of Social Interactions and Collective Behavior During Human Emergency Egress.

Egress of occupants from a facility is normally straightforward. Problems arise when an emergency is present and many occupants are attempting to egress as quickly as possible, at which point egress can become life threatening. There are many reported events in history where emergency egress resulted in extensive loss of life and injuries. Egress research depends heavily on computational modeling because ethical and safety concerns preclude running experiments involving emergency crowd evacuations. However, to date, existing egress models rarely take into account meaningful social interactions and adherence to cultural norms, both of which are commonly present among egressing occupants and have significant influence on their egress response. The objective of this study is to develop a new methodology to address this gap using an Agent-Based computational platform. A novel method, termed Scalar Field Method (SFM), is proposed to accomplish this goal. The new technique draws on an analogy to a charged particle in an electromagnetic field to simulate the decision making process of an agent as it navigates through a facility and considers social interactions in its quest to egress. Two categories of social interactions are accounted for: 1) pre-existing social relationships associated with social identities, and 2) informal relations in collective behaviors such as lining up in counter-flow, queuing, and collective mobility. The latter is achieved by requiring an agent to establish informal and transient leader-follower relationships with others while adjusting its behavioral patterns as warranted by the situation. Simulation results demonstrate the model’s capabilities of handling social interactions, modeling reasonable egress behavior, and mimicking self-organized social gathering and collective behavior during egress. Comparisons with field studies show that the computational results correlate realistically with experimental data. A case study of the Station Nightclub fire that occurred in Rhode Island in 2003 and killed 100 occupants demonstrates that the proposed computational tools have strong potential for quantitatively exploring the influence of social level traits on egress situations.PhDCivil EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/113381/1/calcite_1.pd

Division of Research and Economic Development Annual Report for FY2004

Annual report for the Division of Research and Economic Development of the University of Rhode Island for the year 2003-2004. Includes statistics of project proposals, expenditures, URI Foundation Awards, previous annual report summaries and awards received by individual academic and administrative departments

Lightweight Design of Vehicle Side Door

Due to increasing environmental concern about emission of Green House Gas and government regulations on vehicle safety, vehicle manufacturers, and their suppliers, must turn to new technologies. This is the main way to help them to achieve the goals of making vehicles lighter and safer. These two targets seem to be in deep contrast one with the other as increasing expectations from car consumers and the crashworthiness requirements. Nowadays a lot of innovative vehicle technologies are being considered in order to reduce emissions of GHG, such as engine with increased efficiency, less drag losses, regenerative braking systems, lower weight and so on. Lightweight design is becoming an effective way to get higher fuel efficiency and less vehicle emissions in recent years. Some vehicle weight reduction techniques such as vehicle redesign and vehicle downsizing are playing a negative role on both customer comfort and vehicle safety, since vehicle size and safety are linked together. Consequently, research work and car makers design departments are willing to find advanced materials with excellent performances to substitute traditional materials, such as high strength steel, aluminum, magnesium, composite and so on. Composite have many advantages comparing to traditional materials, such as their relatively higher strength and lower weight, better corrosion resistance, better energy absorption in case of impact and so on. But many difficulties are encountered on the way of successful incorporation of huge quantities of composites, which could be divided into some categories: production cost, production volume, design methodologies, joining technology, repair and recycling issues. Also vehicle safety should be discussed when lighter materials are adopted into automobiles. The research activity in this PhD thesis is motivated and drawn from the above stated problems. Vehicle lateral door substructure is the focus point of this study. Vehicle side door is not a simple panel but rather a substructure system which satisfies many different functions. This structure is traditionally built with steel material traditionally. Basically, the door is composed by an outer panel supported by an inner panel where different additional components are placed. Furthermore, nowadays car doors usually have a reinforcing element (side impact beam) placed longitudinally between outer and inner panels which protects the driver and passengers in case of a side impact event. This thesis has developed several composite side door structures for vehicle model Toyota Yaris 2010, considering static design requirements, NVH design criteria and crashworthiness. All the composite models are simulated with numerical tools ABAQUS and LS-DYNA. The original Yaris steel door structure is considered as reference solution in this study and its performance compared with all composite solutions. The first chapter is dedicated to vehicle fuel consumption and emissions in Europe during recent years. Then the chapter discusses the CO_2 emission limitations from Euro 1 to Euro 6 for gasoline and diesel passenger cars. The second chapter covers technological strategies adopted by car manufacturers in order to reach vehicle noxious gas emissions and fuel consumption reduction. Lightweight design is the main way considered in this thesis and then advanced materials used to substitute traditional material are summarized. Both advantages and disadvantages of composite materials are discussed in detail; also safety of lighter vehicles is covered briefly in the end. The third chapter introduces the particular application of the vehicle lateral door in the past. In this activity, the differences between finite element model of Yaris and real car are investigated. Active safety and passive safety of vehicle is discussed, usually the passive safety includes frontal crash, side crash and rear crash. Every vehicle fleet must pass not only legislation safety tests before they are permitted to be sold in market but also “New car Assessment Program”, all the NCAP established in different countries are summarized. The Federal Motor Vehicle Safety Standard 214 is the reference normative in the study, which is discussed in deepth. Biomechanical response of instrumented dummy is used to assess injury risk of body part, including Head Injury Criteria (HIC), thorax, abdomen and pelvis. At the end, three composite door solutions developed in this study are briefly described. The fourth chapter covers composite characterization; types of fiber and matrix common in use are summarized at first. The selection of composite for vehicle side door should consider bending stiffness, strength and capacity to absorb energy. As a response, several composite materials are considered because of their own advantages, they are carbon fiber reinforced plastic (CFRP), E-Glass/epoxy composite (GFRP), glass mat thermoplastic (GMT), GMT-UD, GMT-TEX and semi impregnated micro sandwich material (SIMS). The fifth chapter introduces composite door solutions in detail, such as sizes of models, types of element and so on. The first composite door solution is framed by composite thin-walled beams based on the size of Yaris door. The composite beams are connected by aluminum joint through epoxy adhesives. In this case, outer panel and inner panel of door structure are not considered, so it is not possible to integrate this solution into Yaris vehicle directly. The second solution is to substitute traditional materials using composite, interesting parts are outer panel, inner panel and impact beam. In third solution, one innovative side door reinforcing structure is presented, the proposal is that traditional impact beam and some particular reinforcements are replaced by an innovative composite reinforcing panel, and this innovative panel could be bonded with outer surface panel and inner surface panel together. The sixth chapter is covering numerical simulation results for first and second solutions under static loading cases, including vertical, horizontal, lateral stiffness, sagging and quasi static intrusion simulation test. At the end the modal analysis is done for second solution. All the numerical results of composite solutions are compared with Yaris reference solution. The crashworthiness evaluation is in chapter seven, including intrusion displacements of compartment and biomechanical response of instrumented dummy which is placed at driver’s seat. Acceleration of head, rib deflection, abdominal force and pubic symphysis force are used to assess the injury risk of body parts. All the biomechanical response of composite solutions are compared with steel reference solution and limitation value required in regulation FMVSS214. Finally in chapter eight the main conclusions of this research activity are briefly summarized