6,072 research outputs found

    The development of a mathematical programming technique as a design tool for traffic management

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    In urban areas, competition for road space at junctions is one of the major causes of congestion and accidents. Routes chosen to avoid conflict at junctions have a mutually beneficial effect which should improve circulation and reduce accidents. A prototype design tool has been developed to provide for traffic management based on such routes. The mathematical model behind the design tool works with a given road network and a given O-D demand matrix to produce feasible routes for all drivers in such a way that the weighted sum of potential conflicts is minimised. The result is a route selection in which all journeys from origin i to destination j follow the same route. The method which works best splits the problem into single commodity problems and solves these repeatedly by the Out-of-Kilter algorithm. Good locally optimal solutions can be produced by this method, even though global optimality cannot be guaranteed. Software for a microcomputer presented here as part of the design tool is capable of solving problems on realistic networks in a reasonable time. This method is embedded in a suite of computer programs which makes the input and output straightforward. Used as a design tool in the early stages of network design it gives a network-wide view of the possibilities for reducing conflict and indicates a coherent set of traffic management measures. The ideal measure would be automatic route guidance, such as the pilot scheme currently being developed for London. Other measures include a set of one-way streets and banned turns. The resulting turning flows could be used as input to the signal optimiser TRANSYT to determine signal settings favouring the routeing pattern. The project was funded by the S. E. R. C. and carried out at Middlesex Polytechnic in collaboration with MVA Systematica

    Sketchmate: A Computer-Aided Sketching and Simulation Tool for Teaching Graph Algorithms

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    In this dissertation, we developed and tested a sketching, visualization, and simulation tool called Sketchmate for demonstrating graph algorithms commonly taught in undergraduate computer science courses. For this research, we chose to focus on shortest path and network flow algorithms. Two versions of this tool have been implemented: 1) an instructor tool that supports computer-aided manual simulations of algorithms that augment traditional whiteboard presentations, allowing lectures to be more dynamic and interactive, and 2) a student tool that supports computer-aided manual practice of algorithms that enables students to work through homework problems more quickly while providing detailed incremental feedback about their performance and about how to solve a problem when they get stuck. Previous algorithm simulation systems have essentially forced instructors to narrate an algorithm as though they were describing an automated set of slides. In contrast, our tool allows instructors to manually manipulate attributes of a graph as they demonstrate an algorithm. A set of experiments was conducted using the tools. The results for the student tool showed that there was no statistically significant difference in test score improvement between Sketchmate and paper and pencil students, although they did show that Sketchmate students scored roughly one letter grade higher than paper and pencil students. Based on survey data, the students preferred using the tool to using paper and pencil. The results of the experiment involving the instructor tool showed that although there was no statistically significant difference in learning between Sketchmate and the whiteboard, both the instructor and the students preferred a Sketchmate lecture to a whiteboard lecture

    Exploiting UML dynamic object modeling for the visualization of C++ programs

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    In this paper we present an approach to modeling and visualizing the dynamic interactions among objects in a C++ application. We exploit UML diagrams to expressively visualize both the static and dynamic properties of the application. We make use of a class diagram and call graph of the application to select the parts of the application to be modeled, thereby reducing the number of objects and methods under consideration with a concomitant reduction in the cognitive burden on the user of our system. We use aspects to insert probes into the application to enable profiling of the interactions of objects and methods and we visualize these interactions by providing sequence and communication diagrams for the parts of the program under consideration. We complement our static selectors with dynamic selectors that enable the user to further filter objects and methods from the sequence and communication diagrams, further enhancing the cognitive economy of our system. A key feature of our approach is the provision for dynamic interaction with both the profiler and the application. Interaction with the profiler enables filtering of methods and objects. Interaction with the application enables the user to supply input to the application to provide direction and enhance comprehension or debugging

    Safe data structure visualisation

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    Automated Academic Planning System

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    Planning and Scheduling of classes in an institute is of pivotal importance. Classes which have to be rescheduled must be immediately notied to the students so that they do not miss the classes and later blame the authorities for not notifying them.Same is the case for classes which are cancelled. Assignments given by faculties must be immediately relayed to the students since the students have to plan their everyday schedule according to the academic workload. Many a times classes are cancelled or rescheduled on a short notice or extra classes are scheduled prior to any information. This leads to students missing a number of classes or wasting their time and energy to attend a class which was already cancelled. Assignments on the other hand fail to get submitted on time due to misinformation by the intermediaries. The general method used to relay such information is taking the help of the class representative of the class, who either sends SMS or emails to every student,which have an history of failing. All the various information about the timing of classes cancelled or rescheduled, submission of assignments and other important notices is handled by one human which increases the chances of failure from time to time.If the class representative is not available then the problem aggravates to a higher level. In this project, we have tried to replace the manual labour involved in the aforementioned issues and created an automated system which eliminates the work of the class representative to some extent. Also a scheduler is made for students to schedule their daily activities along with the classes so that any change in the academic schedule or any pending assignments or other issues will be re ected and they can plan their day accordingly

    Investigation of Leading Indicators for Systems Engineering Effectiveness in Model-Centric Programs

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    Acquisition Research Program Sponsored Report SeriesSponsored Acquisition Research & Technical ReportsThis technical report summarizes the research conducted by Massachusetts Institute of Technology under contract award HQ0034-19-1-0002 during July 22, 2019 – August 31, 2021. Involved research team members include: Dr. Donna H. Rhodes, Principal Investigator; Dr. Eric Rebentisch, Research Associate; and Mr. Allen Moulton, Research Scientist. Systems engineering practice is evolving under the digital engineering paradigm, including use of model-based systems engineering and newer approaches such as agile. This drives a need to re-examine the existing use of metrics and leading indicators. Early engineering metrics were primarily lagging measures, whereas more recent leading indicators draw on trend information to provide more predictive analysis of technical and programmatic performance of the engineering effort. The existing systems engineering leading indicators were developed under the assumption of paper-based (traditional) systems engineering practice. This research investigates the model-based implications relevant to the existing leading indicators. It aims to support program leaders, transitioning to model-based engineering on their programs, in continued use of leading indicators. It provides guiding insights for how current leading indicators can be adapted for model-based engineering. The study elicited knowledge from subject matter experts and performed literature review in identifying these implications. An illustrative case was used to investigate how four leading indicators could be generated directly from a model-based toolset. Several recommendations for future research are proposed extending from the study. A companion research study (“phase 2”) under contract HQ0034-20-1-0008 provides insights for the art of the possible for future systems engineering leading indicators and their use in decision-making on model-centric programs. For completeness, selected background information and illustrative case are included in the technical reports in both studies. This research aims to provide insights for current practice within programs transforming to digital engineering, for continued use of systems engineering leading indicators. Several recommendations for future research are proposed extending from results of the study.Approved for public release; distribution is unlimited.Approved for public release; distribution is unlimited
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