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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Rotation Invariant Real-time Face Detection and Recognition System

Ho, Purdy 31 May 2001 (has links)
In this report, a face recognition system that is capable of detecting and recognizing frontal and rotated faces was developed. Two face recognition methods focusing on the aspect of pose invariance are presented and evaluated - the whole face approach and the component-based approach. The main challenge of this project is to develop a system that is able to identify faces under different viewing angles in realtime. The development of such a system will enhance the capability and robustness of current face recognition technology. The whole-face approach recognizes faces by classifying a single feature vector consisting of the gray values of the whole face image. The component-based approach first locates the facial components and extracts them. These components are normalized and combined into a single feature vector for classification. The Support Vector Machine (SVM) is used as the classifier for both approaches. Extensive tests with respect to the robustness against pose changes are performed on a database that includes faces rotated up to about 40 degrees in depth. The component-based approach clearly outperforms the whole-face approach on all tests. Although this approach isproven to be more reliable, it is still too slow for real-time applications. That is the reason why a real-time face recognition system using the whole-face approach is implemented to recognize people in color video sequences.
42

Aim for the Moon and you might reach the Stars

Elmers, Thor-Björn, Blanco Carlsson, Marcos January 2009 (has links)
The background to this paper is that that many new founded companies have a problem to achieve such a growth rate that they manage to stay alive their first five years. Only a few of the new started company is able to achieve a rapid growth rate in their early lives. Why is this? And can a vision be the answer? The answer to this is yes, a vision can be the answer. But how shall the vision be implemented in the organization in order to work? With this back ground a question were formulated: “How do small, high growth companies work with their vision?” The study is a case study of a small company in Sweden; company Alpha, who has had a growth rate of over 100 percent per year over the last six years. The company was chosen because of its size and its almost unique way of achieving a high growth rate. From several theoretical references a model were created. This model focuses on four different dimensions that are important in order to work and use a vision within a company. These four aspects were; vision development, vision articulation, and vision communication and vision implementation. The conclusion of the paper is that rapid growth companies work with visions as a tool to attract personal, and stakeholders. They also work with it in a way that the vision becomes a management tool, used for controlling and showing the direction to the employees, making their work, and decision-taking easier. This is a way to make the employees more secure in both their own actions and what to expect of the company. The paper also shows that companies’ works with smaller visions, department visions, in order to easier implement the vision in the day-to-day work.
43

Three dimensional dynamic video position sensing

Jansky, L. Andrew 17 December 1993 (has links)
A comprehensive system to locate and track objects in two or three dimensional space, using non-contact video sensing techniques is described. The need exists to be able to quantify range and proximity of objects that would be difficult or impossible to measure using standard contact based sensor technology. Available video technology is surveyed and classified. Then, a hardware system is assembled that fulfills the project goal, within given budgetary constraints. The individual components of the system are described in detail. The theoretical solution for single camera, 2-D positioning, is developed. A device dependent computer algorithm is developed to perform the object location. An accurate multi-camera, 3-D positioning algorithm is also developed. A method to calibrate the cameras is also described and applied. Computer algorithms to perform calibration and solve the multiple view, 3-D location geometry are presented. The theoretical equations and most of the algorithms are transferable, not hardware specific. Examples using the 2-D model are presented. The first test is a submerged, single degree of freedom model that was subjected to wave action. Video tracking data is compared with available positioning data from string potentiometers. The second test is a surface float application where contact sensing methods were not possible. The 3-D algorithm is demonstrated in an above water test. The longitudinal motion of a linear constrained target is measured with a string potentiometer and compared with a two-camera, 3-D video interpretation of the motion. The calibration method is verified with the 3-D algorithm. / Graduation date: 1994
44

The relationship of expressed vision and instructional supervision in a selected school district

Dray, Norman William 31 July 2007
The purpose of the study was to examine the relationship between the vision of a selected school district and practices it has undertaken in the area of instructional supervision in two schools. The school district was identified through a reputational survey process as one having exemplary instructional supervision practices. This case study used qualitative techniques drawing upon principles of naturalistic inquiry. Semi-structured interviews, document analysis, and observation, with accompanying field-notes, represented the major forms of data collection. <p>Interviews were conducted with the Superintendent, the Director of Education Services, the Board Chair, the Coordinator of Human Resources, an Area Supervisor, two principals, and seven teachers (representing the two schools). Observations were conducted at the school sites and district office. District level and school-based documents were analyzed. The data collection process began in the schools and subsequently moved to system-level investigation.<p>A conceptual framework based upon the policy perspectives of Guba (1984) guided the study. Vision as meta-policy (Downey, 1988), policy-in-intention, policy-in-action, and policy-in-experience were used as a frame for the analysis of policy and practice.<p>There was a low level of awareness of the expressed vision of the district among the respondents. Most of the respondents identified only one or two elements in their description of the vision. Paradoxically, all respondents seemed to feel that they were working in harmony with the vision of the Board. Implied vision was used to describe the interpretations placed by school personnel on the actions and words of the board and senior staff. This phenomenon presented a vision different from the expressed vision of the system. The implied vision seemed to suggest a clear direction to those in the organization, but it was not necessarily consistent with the expressed vision. An examination of the relationship between the elements of the vision and the formal instructional supervision program (the PPP) revealed congruency on four of six elements. The examination of policy-in-experience showed that the PPP was operationalized as it was espoused in the policy, but from different perspectives, and with different levels of detail from school to school. More important, the implementation of the PPP seemed to depend on the actions and the direction of the principals, who had adapted the formal policy to their own styles and to current trends. The leadership provided by the principal emerged from the data as critical to the success of the supervision process in both schools. The term policy-alive was suggested to describe the impact on student learning and professional growth that a principal can have through the instructional supervision process. <p>The findings highlighted the need for communication and ongoing dialogue to maximize congruence among vision, policy, and practice. This process should be planned to avoid the drift to multiple interpretations or implied vision.<p>A heuristic was presented, integrating vision, policy, and outcomes. The heuristic tied together some of the learnings from the study and gave a visual representation of the systemic functions of vision and instructional supervision.
45

Use of OCT and Oculus Pentacam HR as Aids to Semi-Scleral Contact Lens Fitting

Otchere, Heinz January 2013 (has links)
Purpose: To determine whether semi-scleral contact lenses (sSCL) can be appropriately fitted using corneal sagittal depth measurements, and to determine the impact of fit on visual acuity, effect of time on topographic corneal clearance and comfort ratings. Method: Three sSCL (Jupiter 15mm; Essilor) were fit to 20 subjects who had previous diagnoses of KC (n=18) or PMD (n=2). The fitting of the sSCL were based on the CSD measured with the Visante™ OCT at a 15mm chord on the horizontal meridian. To select the sSCL from the diagnostic trial lens set, values of 325 (lens 1), 375 (lens 2) and 425 (lens 3) μm were randomly added in sequence to the CSD. Subjects were allowed to wear each of the sSCL for 1hour. After this time, the central corneal clearance (CCC) was assessed using an UL-OCT, high contrast visual acuity (HCVA) and low contrast visual acuity (LCVA) were measured using a LogMAR VA chart and comfort ratings were obtained using a comfort rating scale (0-100). Results: The mean CSD in the horizontal meridian was 3.78±0.53 (range: 3.33-4.17) mm at a 15mm chord. The mean CCC was 190±100, 360±120 and 450±170 µm for each lens respectively (p=0.001). The mean CCC loss was 30.00±40.00, 30±60.00 and 40.00±50 µm for each lens respectively (p>0.05). The mean HCVA for lenses 1, 2 and 3 were 0.05±0.12, 0.07±0.11 and 0.11±0.08 respectively, which were significantly different (p=0.02). Tukey post hoc analysis demonstrated that this difference was only significant between lenses 1 and 3 (p=0.01). Similar findings were found for LCVA. The overall comfort rating for all three sSCL was 77.7±10.6. The comfort ratings for lenses 1, 2 and 3 were 74.9±9.2, 79.7 ±11.6 and 78.6±10.8 respectively. These differences were not significantly different (p=0.24). Conclusion: Evaluation of CSD can be used effectively to select which sSCL to fit on the eye. The results of this study suggest that lens 2 (adding 375 μm to the CSD) gave the best combination of VA and comfort ratings. However, evaluation of the fluorescein pattern must be balanced with the VA and comfort ratings for successful fitting of sSCL in a clinical setting. There was also a likelihood of topographic corneal loss after 1 hour of sSCL wear; however, this may vary depending on many factors such as scleral zone and its relationship with the scleral conjunctiva. Eyelid force, design of the contact lens and other unknown factors may play a part in the contact lens settling time and amount.
46

The relationship of expressed vision and instructional supervision in a selected school district

Dray, Norman William 31 July 2007 (has links)
The purpose of the study was to examine the relationship between the vision of a selected school district and practices it has undertaken in the area of instructional supervision in two schools. The school district was identified through a reputational survey process as one having exemplary instructional supervision practices. This case study used qualitative techniques drawing upon principles of naturalistic inquiry. Semi-structured interviews, document analysis, and observation, with accompanying field-notes, represented the major forms of data collection. <p>Interviews were conducted with the Superintendent, the Director of Education Services, the Board Chair, the Coordinator of Human Resources, an Area Supervisor, two principals, and seven teachers (representing the two schools). Observations were conducted at the school sites and district office. District level and school-based documents were analyzed. The data collection process began in the schools and subsequently moved to system-level investigation.<p>A conceptual framework based upon the policy perspectives of Guba (1984) guided the study. Vision as meta-policy (Downey, 1988), policy-in-intention, policy-in-action, and policy-in-experience were used as a frame for the analysis of policy and practice.<p>There was a low level of awareness of the expressed vision of the district among the respondents. Most of the respondents identified only one or two elements in their description of the vision. Paradoxically, all respondents seemed to feel that they were working in harmony with the vision of the Board. Implied vision was used to describe the interpretations placed by school personnel on the actions and words of the board and senior staff. This phenomenon presented a vision different from the expressed vision of the system. The implied vision seemed to suggest a clear direction to those in the organization, but it was not necessarily consistent with the expressed vision. An examination of the relationship between the elements of the vision and the formal instructional supervision program (the PPP) revealed congruency on four of six elements. The examination of policy-in-experience showed that the PPP was operationalized as it was espoused in the policy, but from different perspectives, and with different levels of detail from school to school. More important, the implementation of the PPP seemed to depend on the actions and the direction of the principals, who had adapted the formal policy to their own styles and to current trends. The leadership provided by the principal emerged from the data as critical to the success of the supervision process in both schools. The term policy-alive was suggested to describe the impact on student learning and professional growth that a principal can have through the instructional supervision process. <p>The findings highlighted the need for communication and ongoing dialogue to maximize congruence among vision, policy, and practice. This process should be planned to avoid the drift to multiple interpretations or implied vision.<p>A heuristic was presented, integrating vision, policy, and outcomes. The heuristic tied together some of the learnings from the study and gave a visual representation of the systemic functions of vision and instructional supervision.
47

3D Shape Measurements Using Stereo Vision Method

Song, Chia-Ming 27 November 2007 (has links)
This paper presents a novel technique which actually restructures the 3D image profiled by stereovision method. Correspondence between two images is addressed by projecting a 2D fringe pattern. These projected patterns fix their positions to the tested object during two segmented measurements. Finding two matched surface points becomes a problem of searching for two identical phases in the fused data sets. The proposed method is superior to the other methods because of the following reasons: (1)We successfully designed a 2-D fringe pattern whose the transmittance is sinusoidal and the accuracy of the sinusoidal fringe pattern was of the order of sub-microns. (2)By using the 2-D fringe pattern, image registration was achieved more easily. (3)By using the optical spot method, the 3d image profiled was restructured such that the computational time was reduced and the crabwise accuracy was better than that of a single CCD system.
48

Activations cérébrales liées à l'intégration des indices locaux lors de la perception de la transparence investigation basée sur l'imagerie fonctionnelle cérébrale /

Bouet, Romain Knoblauch, Kenneth. Dojat, Michel. January 2007 (has links)
Reproduction de : Thèse de doctorat : Sciences cognitives : Lyon 2 : 2007. / Titre provenant de l'écran-titre. Bibliogr.
49

An adaptive feature-based tracking system /

Pretorius, Eugene. January 2008 (has links)
Thesis (MSc)--University of Stellenbosch, 2008. / Bibliography. Also available via the Internet.
50

Whiteness constancy as a function of difference in illumination

Hsia, Yün, January 1943 (has links)
Issued also as Thesis (Ph. D.)--Columbia University. / Bibliography: p. 63.

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