Thesis (Ed.D.)--Boston University / PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / This study was designed to investigate student understanding of fundamental concepts in the engineering course, signals and systems. The aim of this study was threefold: (1) to identify faulty reasonings students invoke in their study of signals and systems; (2) to identify the reasoning resources that explain the origin of student faulty reasonings; and (3) to identify consistencies in students' invocation of reasoning resources across different signals and systems topics. Fifty-one undergraduate students majoring in aerospace engineering at the Massachusetts Institute of Technology participated in this study. Seven oral problems were designed to test student understanding of central topics in the study of continuous-time linear, time-invariant systems. Participants were divided into seven cohorts and each cohort was interviewed on a different problem. Interview transcriptions were analyzed based from a complex systems perspectiv to identify the knowledge elements of reasoning resources that characterize student reasoning in signals and systems. [TRUNCATED] / 2031-01-02

When a malfunction occurs in a traffic signal controller cabinet, the signal is automatically placed into malfunction flash mode as a safety precaution. During this event, drivers are presented with one of two possible scenarios: flashing yellow on the major street and flashing red on the minor street, or flashing red on all the approaches. Volumes and percentages of car stopping were collected at fifty-one study intersections in the Atlanta regions. By means of the VISSIM microsimulation software a sample of intersections was simulated under the two malfunction scenarios and the signalized one. Based on output data such as delay and queue, the performances of each simulated intersection is compared and recommendations on which mode of flash must be used in case of malfunction are provided.

The monitoring of traffic signal systems can be of great importance for identifying problems, self-assessment, budgeting, creating the strategy for future steps, etc. Monitoring procedure was developed through a set of dashboards with relevant signal performance and reliability measures. The dashboards were created to reflect performance and reliability of a specific signal system on a weekly or monthly level. The author used data from ATMS.now signal system central software to illustrate how similar dashboards could be developed from any central software to enable operators to promptly and efficiently monitor various parameters of traffic signals. The main outcome of the study is a pair of Excel dashboards accompanied with appropriate user manual. The dashboards represent the tool for monitoring which can be helpful in the process of evaluation for traffic signal systems. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2017. / FAU Electronic Theses and Dissertations Collection

When a traffic signals malfunction monitoring unit detects a problem with a traffic signal such as the simultaneous display of green indications to conflicting movements or loss of power to some signal heads, the signal is automatically placed into flash mode as a safety precaution. Signals can have either red/red malfunction flash mode or yellow/red malfunction flash mode, and the mode cannot change by time of day or day of week. This study analyzed traffic operation at 34 instances of yellow/red malfunction flash and 9 instances of red/red malfunction flash in the Atlanta, Georgia area. Many of these instances were during high volume periods. A high level of driver confusion exists at malfunction flash intersections. The rate at which through major street drivers (i.e. those facing a flashing yellow signal) stopped exceeded 75 percent at some yellow/red flash intersections. This creates a safety hazard for other major street drivers who are not expecting vehicles to stop, and for minor street drivers who cannot tell what type of control is being presented to cross traffic or do not understand that vehicles are not required to stop when approaching a flashing yellow indication. Furthermore, high stopping rates at a flashing yellow signal eliminate many of the operational benefits that yellow/red flash is assumed to have over red/red flash. Based on the findings of this study, the use of red/red flash should be the primary flash mode and possibly used exclusively. Requiring all vehicles to stop will improve safety conditions and not have large operational impacts at intersections where a majority of major street vehicles are already stopping at a flashing yellow signal. Yellow/red flash may be an acceptable malfunction flash mode at the intersection of a very large street and a very small street, but additional measures would be required at these intersections to address potential driver confusion.

Dissertation for the degree of Doctor of Science in Technology--Helsinki University of Technology, Espoo, 2002. / "ISSN 0781-5816." Includes bibliographical references (p. 65-71). Available online as a PDF file via the World Wide Web.

Lately, the attractiveness of cities has contributed to a rise in vehicle movements to and from cities. The growth of freight movements in cities predictably will be one of the critical issues of the near future. Congestion caused by the increased movements of freight impacts the flow of private and transit vehicles. Thus, it is crucial to reduce the congestion on multimodal corridors. Components of the Intelligent Transportation System (ITS) such as Freight Signal Priority (FSP) and Transit Signal Priority (TSP) that promote the freight and transit vehicles may not only help solve these conditions but may assist with the sustainability of the system. The primary objective of this research is to develop guidelines for traffic agencies to implement signal priorities based on identified decision factors on certain corridors. Besides, this study evaluates the efficiency of FSP and TSP in improving the performance of freight and transit systems. Finally, inclusive guidelines are drawn up based on the literature and the conducted simulation. The developed guidelines apply to corridors where freight delay plays a vital role in the assessment of corridor benefits. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2020. / FAU Electronic Theses and Dissertations Collection

The aim of this thesis is creation the appropriate multimedia support for signals and system with continuous time. The understanding of this issue is very important, because the obligatory subject Signals and systems, exactly BSIS, is taught at the EST bachelor degree. The understanding is also necessary prerequisite to successful understanding next topics in other related subjects. The next part of this thesis is focused on one dimension discrete signals. Concretely, the aim of this part is a realization of software system. Designed system has some basic operations (the signal energy, the number of signal zero crossing etc.) with sound files and also some advance functions e.g. vowel seeking and separating in fluent speech. The system is divided into two main parts. The first one analyzes sound files, creates the new sound file with wanted vowel and matrices with important parameters for other processing. The second program computes with given data, which statistically evaluates in other steps. The final system can be useful for speaker recognition, his emotional status etc.

Crashes resulting from automobiles running a red light are typically severe in nature. One way to try to reduce the number and severity of these types of crashes is by increasing the red clearance interval of a traffic signal. In Portland, Oregon, eight intersections received a variety of treatments including red extensions. Determining which treatment had what effect can be difficult to weed out. Using a combination of crash analysis and a model simulating an intersection with red extensions, this paper describes the estimated impact of red light running intersection upgrades and red extensions on crashes. By performing a variety of before and after crash analysis, a reduction of angle crashes after treatments was detected, with a crash modification factor of 0.64 +/- 0.28 using the Empirical-Bayes method. Output from the simple simulation also suggest that red light running crashes can be reduced with red extension technology and confirms crash modification values determined from the Empirical-Bayes method.

Today, the information (signal timings, detector extension, phase sequence, etc.) to install traffic lights on the street are obtained from traffic software simulations platforms, meaning that information from simulation is not tested on the field (intersection where it will be installed) before the installation. Many installed controllers on the street use time of day (TOD) patterns due to cheaper cost than adaptive traffic control systems, but that is not the best solution for traffic volume changes that can occur during the day or even a month. To improve traffic signal operation most of the traffic signal controllers in the same corridor or zone operate in coordination mode. Furthermore, phases need to be in coordination to achieve “green wave”. Green wave is term used when in corridor traffic lights allow continues flow of traffic through intersections that are coordinated. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2016. / FAU Electronic Theses and Dissertations Collection

Most U.S. urban traffic signal systems deploy multiple signal timing plans to account for daily variability of traffic demand (i.e. morning peak, midday, afternoon peak, off peak and night). Groups of signals (belonging to the one zone or section) along an urban arterial, usually operate in a coordinated manner. This essentially means that timing plans change at the same time for all the signals in the group, so as to facilitate vehicle progression of through a series of signals. Good traffic signal timing practices assume a certain level of monitoring and maintenance in order to guarantee that they are efficient in servicing current traffic conditions. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2015 / FAU Electronic Theses and Dissertations Collection