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Optimal Path Queries in Very Large Spatial DatabasesZhang, Jie January 2005 (has links)
Researchers have been investigating the optimal route query problem for a long time. Optimal route queries are categorized as either unconstrained or constrained queries. Many main memory based algorithms have been developed to deal with the optimal route query problem. Among these, Dijkstra's shortest path algorithm is one of the most popular algorithms for the unconstrained route query problem. The constrained route query problem is more complicated than the unconstrained one, and some constrained route query problems such as the Traveling Salesman Problem and Hamiltonian Path Problem are NP-hard. There are many algorithms dealing with the constrained route query problem, but most of them only solve a specific case. In addition, all of them require that the entire graph resides in the main memory. Recently, due to the need of applications in very large graphs, such as the digital maps managed by Geographic Information Systems (GIS), several disk-based algorithms have been derived by using divide-and-conquer techniques to solve the shortest path problem in a very large graph. However, until now little research has been conducted on the disk-based constrained problem. <br /><br /> This thesis presents two algorithms: 1) a new disk-based shortest path algorithm (DiskSPNN), and 2) a new disk-based optimal path algorithm (DiskOP) that answers an optimal route query without passing a set of forbidden edges in a very large graph. Both algorithms fit within the same divide-and-conquer framework as the existing disk-based shortest path algorithms proposed by Ning Zhang and Heechul Lim. Several techniques, including query super graph, successor fragment and open boundary node pruning are proposed to improve the performance of the previous disk-based shortest path algorithms. Furthermore, these techniques are applied to the DiskOP algorithm with minor changes. The proposed DiskOP algorithm depends on the concept of collecting a set of boundary vertices and simultaneously relaxing their adjacent super edges. Even if the forbidden edges are distributed in all the fragments of a graph, the DiskOP algorithm requires little memory. Our experimental results indicate that the DiskSPNN algorithm performs better than the original ones with respect to the I/O cost as well as the running time, and the DiskOP algorithm successfully solves a specific constrained route query problem in a very large graph.
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The Development and Deployment of a GIS tool for Transit Network DesignSimard, Stephanie January 2010 (has links)
Public transportation contributes to sustainable transportation in urban areas. Unfortunately, in some cases public transit systems have been underperforming. Over the years, factors such as urban sprawl and the increase in private vehicle ownership have led to challenges for public transportation providers. The lack of investment in transit infrastructure has resulted in transit agencies being under resourced which further limit the agencies’ ability to respond. Realizing the need to change and move towards a more sustainable and balanced transportation system, governments have begun to invest more and more in transportation infrastructure projects.
In order to encourage public transportation, focus has shifted to improving the quality of transit service being provided. There are many ways in which transit improvements can be made. The problem that describes the design of a public transportation network is referred to as the transit network design problem (TNDP). Much of the existing literature that addresses the TNDP describes methods that are rigorous and complex and have limited application in practice. Given the emergence of geographic information systems (GIS), there exists new opportunities to address the TNDP.
This thesis presents a customized GIS tool that assists transit network design. The approach utilizes GIS to identify desire lines or major travel demand corridors from which trunk transit routes are proposed and evaluated. The GIS tool is built using VBA scripting in ArcMap 9.3 part of ESRI’s general ArcGIS suite but the underlying GIS functionality needed by the tool is not limited to ESRI software. The tool offers a proven methodology for use within transit network design and evaluation at a level of resource requirement that is consistent with most transit agencies. The tool has been customized to minimize the need for GIS training and to maximize its adaptability for application in multiple cities. The analyst applying the tools must have substantial knowledge of local conditions.
The tool is applied to the Regional Municipality of Waterloo, Ontario, Canada, at the TAZ (traffic analysis zone) level using population and employment data. A street network with corresponding posted speeds on each link and the location of signalized intersections were also used in the analysis. The results of the analysis depicted major flows throughout Kitchener, Waterloo and Cambridge. Unique flows from students, major employers and an analysis of average income levels also provide input into the major demand corridors. From these results seven high order transit routes were designed to accommodate the major demand corridors.
From the results it was found that GIS can be used to depict major demand corridors and inform transit network design. GIS is an excellent tool that can display complex information and visually identify spatial patterns. Further research includes the development of a model that evaluates network alternatives or the development of quantitative methods by which limits on aggregation can be automated.
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A behavioural and neurobiological investigation of basic reading processesCummine, Jacqueline 15 September 2009 (has links)
There are competing theories in the literature regarding the extent to which the translation of print to speech involves single or multiple routes. Regardless of the number of routes in a model, all models of reading must account for both sight vocabulary (SV) processing, which specializes in mapping whole-word representations, and phonetic decoding (PD) processing, which specializes in mapping sub-word representations. The purpose of the present work was to examine two hypotheses regarding the relationship between SV and PD: independence versus redundancy. Both behavioural and functional Magnetic Resonance Imaging (fMRI) experiments were conducted and the results supported the hypothesis that SV and PD are behaviourally and neurobiologically independent processes. Furthermore, in the interest of advancing all models of basic word recognition, the neurobiological representations of some of the sub-systems within SV and PD routes were explored and the contribution that particular brain regions make to the completion of naming particular stimuli was evaluated. Finally, basic and applied areas of research were integrated to demonstrate how diagnostic stimuli developed from basic reading research can inform us about impaired reading performance following traumatic brain injury.
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The study of career development and decision for non-traditional route teachers.Tsai, Ya-fang 09 July 2010 (has links)
The purpose of this study is to explore the process of career development experience of non-traditional route teachers serving in junior high schools. Depth of interview method which is expected to make this study closer to the respondents¡¦ life experiences is used to collect the participants¡¦ courses of choosing teaching and presented by the patterns of life stories.
The researcher explores the mood changes from these teachers¡¦ courses including growth background, integrating with the road of education, practice stage, exam participation, and future career plans to comprehend why they choose teaching as a career.
The researcher concludes the following results according to the collection analysis and induction from these six respondents.
1.Internal personal factors and external environmental factors can affect the career choice from the non-traditional route teachers.
2.The information and learning process are the foundation of choosing teaching as career.
3.The process of exam participation and mental adjustment is the critical period to choose teaching as career.
4.The problems which the non-traditional route teachers face with in reality can provide development for the future researches.
It is expected that the study can be the reference for the teacher training institutions and for the non-traditional route students and plan to choose teaching as career in the future. It is also expected that the suggestions according to research conclusions can be the reference for follow-up researches.
1.The suggestion to the non-traditional route students.
2.The suggestion to the teacher training institutions.
3.The suggestion for the researches in the future.
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Locating and tracking assets using RFIDKim, Gak Gyu 15 May 2009 (has links)
Being able to quickly locate equipment is critical inside buildings, including hospitals, manufacturing floors and warehouses. In order to utilize limited budget and resources efficiently, accurate locating or tracking is required in many fields. In this research, we will focus on how to find the location of an item by using RFID in real time indoors to track equipment.
When an item needs to be located, the purpose of using RFID is to minimize the searching time, effort, and investment cost. Thus, this research presents a math¬ematical model of using RFID (both handheld readers and stationary readers) for efficient asset location. We derive the expected cost of locating RFID¬tagged objects in a multi¬area environment where hand¬held RF readers are used. We then discuss where to deploy stationary RF readers in order to maximize the efficiency of the search process.
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An Implementation of a Placement and Routing Tool for the Fine-grain Multi-context Reconfigurable Processing UnitHuang, Tzu-che 22 August 2005 (has links)
Reconfigurable computing systems require supports from powerful computer aided design tools to help users developing the interactions between software programs and hardware circuits. The placement and routing support for reconfigurable processing units is also the key to the efficiency of the computing system. In this thesis, we implemented the placement and routing tool for the FMRPU (Fine-grain Multi-context Reconfigurable Processing Unit). The routing resource among the Logic Arrays supports only 8-bit aligned data width, so the routing of the FMRPU can¡¦t completely imitate from the pattern used by LUT-based routing. Thus we proposed an operation-based design model which accepts a data flow graph that describes the operations of the circuit. After compressing the graph, the tool uses Simulated Annealing algorithm with either Maze Route or Center-of-Gravity Route to map the compressed graph into FMRPU. Through the placement and routing tool we implemented, we have successfully mapped several algorithms used in multi-media applications, such as FFT and DCT, into FMRPU.
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Finding The Optimum Route For Transmission Lines Within GisOzturk, Tunay 01 May 2007 (has links) (PDF)
This study defines the optimum route planning for Electric Transmission Lines by
Multicriteria Decision Analysis which is based on Geographic Information Systems (GIS).
Determination of the optimum route is performed by using both the spatial and Euclidean
distances between two points located on the Earth&rsquo / s surface.
The criteria needed to be taken into account to define the route of the Electrical Transmission
Lines were evaluated with help of the experts who are doing this business in the available
system and for this study the decision about the usage of needed data such as landuse map,
landuse capability map, geology map, road map, zone plan and digital elevation models is
also made with their knowledge.
A Matlab code, which computes the optimum distance between two transformers by using
real distance (spatial distance) method and by considering materials mentioned above is
written. The results are compared with the ones found from the Euclidian distance, which is
the common distance finding method in the available commercial GIS softwares.
The spatial resolution effect in finding the spatial distance is also analyzed. The routes
obtained by two different distance computation methods are compared with the existing route.
The economical expectations in finding the optimum route are also discussed.
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Pedestrian Safety Around Elementary SchoolsCicek, Bunyamin Erkan 01 September 2009 (has links) (PDF)
This study establishes pedestrian safety focused environment around elementary schools. In order to reach this objective 3 consecutive goals are fulfilled / firstly / proposing, a newly designed black spot analysis, &ldquo / Behavioral Black Spot Analysis&rdquo / , secondly / documenting pedestrian behavior around black spots, and finally stimulating effective interventions around elementary schools. This study proposes a newly designed methodology / &ldquo / Behavioral Black Spot Analysis&rdquo / which is namely based upon pedestrians&rsquo / route choice and risk perception statements. Additionally it is observed that students choose the shortest route on their way. &ldquo / Behavioral Black Spot Analysis&rdquo / reveals that traffic flows, pedestrian visibility, vehicle visibility, waiting time, road width are most important parameters of pedestrians&rsquo / perception of traffic safety. Results of unobtrusive observations indicate that interventions have significant effect on vehicle speed, number of conflicts, yielding behavior of drivers, total number of cars forming a queue, number of pedestrians stopping on the curb, head movements, crossing angles, crossing tempos, and crossing distances of pedestrians. Behind this interventions affects pedestrians&rsquo / waiting time in negative manner. Recommendations for pedestrian safety interventions are suggested.
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Route Planning For Unmanned Air VehiclesTulum, Kamil 01 September 2009 (has links) (PDF)
In this thesis, automatic routing technologies for unmanned air vehicles are investigated. A route planner that minimizes the fuel consumption and maximizes the survivability is developed. While planning the route, using more than one objective entails the auto-routing problem to multi-objective optimization considerations. In this work, these considerations are handled with search algorithms.
In order to assess the route options, a fuel consumption model and a survivability model are utilized for the route planner. As the assessment models are established, required computational time is taken into account without deteriorating the fidelity.
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A Parallel Algorithm For Flight Route Planning On Gpu Using CudaSanci, Seckin 01 May 2010 (has links) (PDF)
Aerial surveillance missions require a geographical region known as the area of interest to be inspected. The route that the aerial reconnaissance vehicle will follow is known as the flight route. Flight route planning operation has to be done before the actual mission is executed. A flight route may consist of hundreds of pre-defined geographical positions called waypoints. The optimal flight route planning manages to find a tour passing through all of the waypoints by covering the minimum possible distance. Due to the combinatorial nature of the problem it is impractical to devise a solution using brute force approaches. This study presents a strategy to find a cost effective and near-optimal solution to the flight route planning problem. The proposed approach is implemented on GPU using CUDA.
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