221 |
Artificial neural networks and map-matching for GPS navigationWinter, Marylin January 2006 (has links)
Global navigation satellite systems (GNSS), such as the Global Positioning System (GPS) have been increasingly used in navigation and tracking of vehicles. Using GPS, certain positioning errors and limitations, such as multipath effects and the geometric position of the satellites (DOP) or signal obstructions by high buildings, trees and terrain, have to be considered. Generally travel on road or footpath, map-matching algorithms can be used to correlate the computed system location with a digital map network. Map Matched GPS (MMGPS) is a test-bed simulator for researching algorithms and techniques to reduce the error in position provided by a low cost stand-alone GPS receiver. In order to correctly map-match the GPS positions, a decision about the correct road can be difficult, especially at road junctions, slip roads or almost parallel roads. Investigations into the use of artificial neural networks (ANNs) for reliability and accuracy improvement of map-matched GPS positioning was initiated in previous research [Winter, 2002]. However, there are generally strong interference effects that lead to slow learning and poor generalization when a single ANN is trained to perform different subtasks on different occasions [Jacobs et al., 1991], e.g. correct transport network (TN) segment selection considering different TN geometry. Interference can be reduced by training a system composed of several different "expert" ANNs using a TN geometry indicator to decide which of the experts should be used for each training case. An aim of this research was the design, development and implementation of such a modular neural network (MNN). This work uses a new measure for indicating TN geometry, directly derived from GPS positions in MMGPS. An improvement of more than 50% to traditional map-matching techniques was achieved using the proposed MNN approach, when the correct road could not be uniquely identified by map-matching.
|
222 |
GPS augmentation using digital spatial dataLi, Jing January 2006 (has links)
The primary aim of this research is to develop and assess the innovative methods and techniques which are used to augment GPS using a variety of digital spatial data. It is well known that the use of GPS can be severely compromised by various error sources such as signal obstructions, multipath and poor satellite geometry etc., especially in highly built-up areas. In order to improve the accuracy and reliability of GPS, complementary data is often combined with GPS data for enhancing the performance of a standalone GPS receiver. Spatial data is one type of complementary data that can be used to augment GPS. However, the potential of using various types of existing and newly acquired spatial data for enhancing GPS performance has not been fully realised. This is particularly true due to the fact that higher accuracy digital surface models (DSMs), which include buildings and vegetation, and digital maps, have only been made widely available in recent years. This thesis will report on a number of experiments that used spatial data of various complexity and accuracy for enhancing GPS performance. These experiments include height aiding with different scale digital terrain models (DTMs); map-matching using odometer data, DTM and road centrelines; modelling and prediction of GPS satellite visibility using DSMs; and prediction of GPS multipath effect using DSMs and building footprints. These experiments are closely related to each other in the sense that GPS and spatial data are combined to provide value-added information for improved modelling and prediction of GPS positioning accuracy and reliability, for applications such as transport navigation and tracking ... Extensive fieldwork has been carried out to verify the developed techniques and methods. The results show that the accuracy of a standalone GPS receiver can be improved by height aiding using a higher resolution DTM and map-matching especially when the satellite geometry is poor. The mean error of single receiver GPS positioning for one particular dataset, on which the described map-matching algorithm was developed, is 8.8m compared with 53.7m for GPS alone. This work was carried out in collaboration with London Transport. In terms of satellite visibility analysis, the results obtained from the fieldwork indicate that greater modelling accuracy has been achieved when using higher resolution DSMs. Furthermore, a ray tracing model was implemented in a 3D GIS environment in order to model reflected and diffracted GPS signals. The Double Differencing (DD) residuals were used to give an indication of the magnitude of the possible pseudorange multipath error caused by diffraction. A single-knife diffraction model was first implemented on 1m Light Detection And Ranging (LiDAR) DSMs, and verified by post-processing (i.e. large DD residuals occurred when the satellites are partially masked and unmasked by buildings), which indicate that GPS multipath prediction with LiDAR data and building footprints is feasible, and has the potential to offer greater modelling accuracy.
|
223 |
Nano-satellite GPS receiver design and Implementation : a software-to-firmware approachBayendang, Nganyang Paul January 2015 (has links)
Thesis submitted in partial fulfilment of the requirements for the degree
Master of Technology: Electrical Engineering
in the Faculty of Engineering
at the Cape Peninsula University of Technology
2015 / Space-borne GPS receivers designed for nano-satellites are faced with various challenges. This research is undertaken to address the problems of inefficiency and high-costs associated with space-borne GPS receivers. The problem of inefficiency relates to poor performances of the GPS receiver in terms of the algorithmic models, execution speed, memory usage and errors proness. The problem of high-costs relates to the spacegrade hardware cost, implementation complexity, development time, as well as the manufacturing, production and the testing processes involved.
The research objectives are to i) establish an efficient high-dynamics software-defined GPS receiver, ii) demonstrate a firmware approach and then iii) postulate a low-cost hardware implementation roadmap. The research methodology employed to address the problems and to attain the objectives is based-on using Matlab computing platform to i) implement a software-defined GPS receiver using free open-source GPS receiver algorithms, ii) further develop the software GPS receiver and lastly iii) convert the improved GPS receiver algorithms to firmware.
The GPS receiver was successfully implemented in Matlab floating-point algorithms with a ±100kHz Doppler search bins and was used to post-process a pre-captured real GPS L1 C/A signal dataset. The pre-captured GPS signal was acquired, tracked, decoded and post-processed to extract the navigation message; use to compute the GPS receiver position, UTC date and time.
Attempt to convert the entire Matlab floating-point GPS receiver algorithms to equivalent VHDL implementations failed; however, three of the Matlab floating-point algorithms (check_t.m, deg2dms.m and findUtmZone.m), were successfully converted to equivalent fixed-point formats in Matlab, Simulink and finally VHDL. These three algorithms, now created and optimised to fixed-point formats (efficient and enable implementation unto a low-cost microcontroller), set the basis for the firmware implementation. They were simulated and verified in Matlab, Simulink and VHDL using the Matlab HDL Coder workflow. Altera Quartus II software was then used to compile (synthesise, place & route and generate programming files) the three converted generic VHDL algorithms to embedded firmware, suitable for a FPGA programming.
The Matlab HDL Coder workflow used in this research is feasible and can be used to accurately design and implement an improved GPS receiver and furthermore achieve it in three equivalent algorithms. This conclusion was drawn and the proposed recommendations are to address the conversion issues in the other Matlab floating-point GPS receiver algorithms that failed in the conversion process and to further develop and implement the GPS receiver as a fully functional unit, based-on the Xilinx space-grade, radiation hardened and low-cost Virtex 5QV FPGA.
|
224 |
Treatment of global positioning system signals by softwareDuchateau, Laurent M. January 2002 (has links)
Doctorat en sciences appliquées / info:eu-repo/semantics/nonPublished
|
225 |
Develoment of a navigation system for an autonomous guided vehicle using android technologySnyman, Christo Johannes Unknown Date (has links)
Modern cell phone hardware, due to its integrated peripherals, provides a low cost intelligent controller for use in the navigation of an Automated Guided Vehicle (AGV). Most commercial AGV’s use proprietary hardware which is expensive to replace and also difficult to maintain. Using industrial hardware components combined with Android mobile platforms could provide a low-cost alternative. This would be easier to maintain, using existing in-house factory maintenance knowledge. A prototype AGV was designed and developed based on an integrated system between an industrial Programmable Logic Controller (PLC) and an Android operating system mobile platform. This system utilises the mobile platforms integrated Global Position System (GPS) or video camera as tools for navigation. Experimental tests were performed to determine whether the prototype can navigate a predefined course by making use of GPS and camera line following algorithms. The accuracy of the line following algorithm was influenced by the speed at which the research AGV moved. Mounting the Android camera higher above the ground improved the vision and therefore accuracy of the algorithm. The GPS algorithm successfully navigated to various waypoints. The accuracy of the implemented GPS unit on the Android device is its limitation. The research unit was only capable of reaching a waypoint consistently within a three-metre radius.
|
226 |
Komparace positioningu jednotlivých produktových řad značky Concha y Toro / Positioning comparison of Concha y Toro product linesTopol, Jindřich January 2009 (has links)
The theoretical part of this paper (chapters 1 to 3) explained the main relevant terms such as marketing, marketing mix, segmentation, targeting, positioning, brand, brand value and brand management. The practical part in its fourth chapter described the charakteristics of wine market in the world and also in the conditions of Czech republic. It also describes the chilean wines market in Czech republic and the local market competition environment. The fifth chapter introduces Concha y Toro winemaking company and also Bacchus company which is importing the Concha y Toro product into Czech republic. Sixth chapter analyses the Concha y Toro product portfolio and introduces the product lines and their role in context of the whole portfolio. This chapter also explains the influence of price and wine specific origin on the product positioning. Chapter seven focuses on more detailed analysis of the offtrade brands. It describes differences in communication activities, product characteristics and distribution channels. It also includes survey on chilean wines offered in some of the chain stores which illustrates the position of Concha y Toro wines on the czech market. Proposal of strategy to increase the sales volume in offtrade is presented as well.
|
227 |
Analýza potenciálu positioningu značky Stará myslivecká / Analysis of potencial positioning brand Stará mysliveckáPribilová, Petronela January 2013 (has links)
Stará Myslivecká is a traditional Czech brand occurring on the market since 1847. The label was one of the premium products during the period of socialism. However, there was a boom of new international brands on the market after 1989, which caused a downfall of Stará Myslivecká that lost its post. Diploma thesis contains an analysis of current brand position based on secondary and primary data obtained from online questionnaire. The aim of diploma thesis is to determine objectives that should be reached by the brand in next three years and to propose a marketing strategy based on the analysis of obtained data that would help to meet the objectives. To sum up, after reviewing all aspects is there the recommendation which one of the strategies is more preferable for the company.
|
228 |
Analýza marketingová strategie GE Money Bank na českém trhu / The Analysis of Marketing Strategy of GE Money Bank in the Czech MarketŠvástová, Magda January 2011 (has links)
The objective of my thesis is the analysis of GE Money Bank's marketing strategy in the Czech market and proposal of measures to reduce its weaknesses. Theoretic part of the thesis describes concept of strategic management and particular parts of marketing strategy. Analytic part evaluates external environment in which GE Money Bank operates and subsequently describes marketing strategy of GE Money Bank -- goals of the company, segmentation and targeting, marketing objectives, corporate identity and so on. In the final part of the thesis, there is an SWOT analysis of the marketing strategy and proposed measures to reduce weaknesses of the marketing strategy.
|
229 |
Marketingová strategie značky Grom pro český trh / Marketing strategy of the brand Grom for the Czech marketPawlasová, Veronika January 2012 (has links)
The thesis introduces theory of marketing strategy of a brand in an international environment with focus on brand positioning. The theoretical knowledge is then applied on Grom -- brand of Italian company Gromart S.p.A., producer of Italian premium ice-cream. The main objective of the thesis is to create a draft of marketing strategy for the brand to enter Czech market.
|
230 |
" I See it All, but I Don't Have the Power": Exploring Institutional Change Talk and Subject Positioning in the Context of Higher Education AdministrationOlle, Chad D. January 2019 (has links)
Thesis advisor: David L. Blustein / Critical studies have developed a tendency to schematically neglect the ways in which individuals actively participate in social and self-construction, even while constrained by the systems in which they are embedded. The current study explores discursive forms of self-construction embedded in an organizational hierarchy. Under critical analysis are 13 interviews with individuals employed as mid-level administrators by a large, private Catholic university in the United States (heretofore referred to as “PC University”). As mid-level university employees, most administrators are structurally bound to institutional priorities to some degree, regardless of any personal interpretation of supporting and competing discourses. In the context of this “middle ground,” people may be situated at intersections of overlapping and competing discourses, feeling pulled to position themselves differently depending on the context and its perceived stakes and expectations. How and why they make sense of, (re)constitute, and resist this positionality (in the context of a research interview situation) are the topics of interest. This study utilizes Foucauldian discourse analysis (FDA; Arribas-Ayllon & Walkerdine, 2017), a translation of critical discourse analysis (CDA; Martínez-Alemán, 2015). To aid in establishing empirical rigor, I enlisted principles from constructivist grounded theory (CGA; Charmaz, 2017). The shifts and innovations to the original grounded theory (Glaser & Strauss, 1967) that Charmaz evokes make the method an ideal match for studying subject formation from a critical (Foucauldian) discourse-analytic perspective. Results eventually took the form of 12 recurrent patterns grouped into 3 coherent groups. These groups corresponded to the categorical ways in which participants explained or justified their beliefs and actions related to institutional change. Generally, participants justified statements in three ways: in terms of morality, rationality, and fear. In terms of self-construction, how participants constructed change often related to group identification and outgroup orientation and ultimately, whether or not participants identified with the institution or as an outsider. These identifications were fluid in conjunction with changing circumstances including how groups were constructed and described in any given moment. / Thesis (PhD) — Boston College, 2019. / Submitted to: Boston College. Lynch School of Education. / Discipline: Counseling, Developmental and Educational Psychology.
|
Page generated in 0.123 seconds