• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 489
  • 206
  • 173
  • 135
  • 91
  • 52
  • 38
  • 16
  • 10
  • 8
  • 8
  • 7
  • 6
  • 5
  • 5
  • Tagged with
  • 1472
  • 222
  • 171
  • 132
  • 106
  • 105
  • 97
  • 86
  • 82
  • 80
  • 75
  • 67
  • 64
  • 62
  • 61
  • 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.
291

The effect of the activator adjusting instrument in the treatment of chronic sacroiliac joint syndrome

Coetzee, Natasha 20 May 2014 (has links)
Objective : Low back pain (LBP), and in particular sacroiliac joint syndrome, is a significant health concern for both patient and their chiropractor with regards to quality of life and work related musculoskeletal disorders. Therefore, chiropractors often utilise mechanical aids to reduce the impact on the chiropractor’s health. It is, however, important to establish whether these mechanical aids are indeed clinically effective, therefore, this study evaluated the Activator Adjusting Instrument (AAI) against an AAI placebo to determine whether this adjusting instrument is an effective aid for both the chiropractor and the patient. Method : This randomised, placebo controlled clinical trial consisted of 40 patients (20 per group), screened by stringent inclusion criteria assessed through a telephonic and clinical assessment screen. Post receipt of informed consent from the patients, measurements (NRS, Revised Oswestry Disability Questionnaire, algometer) were taken at baseline, prior to consultation three and at the follow consultation. This procedure occurred with four interventions over a two week period. Results: The AAI group showed clinical significance for all clinical measures as compared to the AAI placebo group which attained clinical significance only for the Revised Oswestry Disability Questionnaire. By comparison there was only a statistically significant difference between the groups in terms of the algometer readings (p= 0.037). Conclusion : Therefore, it is evident that the AAI seems to have clinical benefit beyond a placebo. However this is not reflected in the statistical analysis. It is, therefore, suggested that this study be repeated with a larger sample size in order to verify the effect on the statistical analysis outcomes.
292

The cross-cultural application of the adapted Schwartz values instrument in South Africa / G.C. Welthagen

Welthagen, Gerrit Cornelius January 2005 (has links)
Different value systems are a major source of diversity between people and culture groups. A better understanding of these differences can be a valuable tool when a diverse work force, as found in South Africa, has to be managed. Values can act as a unifying theory for the field of human motivation, as a way of organising the different needs, motives and goals proposed in other theories. The values theory describes aspects of the human psychological structure that are fundamental, aspects presumably common to all humankind. The objective of this study was to investigate the construct equivalence of the values as measured by the Work and Organizational Values Scale for new applicants from different language groups in the South African Police Service (SAPS), and to investigate the relationship between the value patterns of the different language and gender groups. A cross-sectional survey design was used. The study population consisted of two groups who applied for jobs in the South African Police Services (SAPS). The first group consisted of civilians (N=3 400), while the second group consisted of police applicants (N=1 800). The Work and Organizational Values Scale was administered. Descriptive statistics, exploratory factor analyses, and multivariate analysis of variance were used to analyse the results. Principal component analysis with a direct oblimin rotation resulted in two factors. The first factor was interpreted as self-enhancement (power, materialism and prestige) versus conservation (conformity and security). The second factor was interpreted as collectivism (social commitment, relations, and environment) versus individualism (goal-orientedness. stimulation and self-direction). These factors were found to be equivalent for four language groups. Statistically significant differences were found between the value priorities of different language groups as well as genders. However, larger practically significant differences were found between males and females than between different language groups. Recommendations for future research were made. / Thesis (M.A. (Industrial Psychology))--North-West University, Potchefstroom Campus, 2006.
293

Employee Engagement Construct and Instrument Validation

Witemeyer, Hazen A 11 May 2013 (has links)
Employee engagement is a relatively new construct in academic literature and an increasingly popular idea in practice. Proponents of employee engagement claim a strong positive relationship between engagement and business success, both at the firm and individual levels, and outcomes including retention, productivity, profitability, and customer loyalty and satisfaction. Despite numerous academic and practitioner publications on employee engagement, no consistently-accepted conceptualization of the construct or its sub-dimensions exists, and there is an ongoing debate regarding whether the employee engagement construct is a new idea or a re-hashing of old ideas. Similarly, no consistently-accepted tool to measure employee engagement exists. In the absence of consistent conceptualization and measurement, relationships between employee engagement and its antecedents and outcomes cannot be empirically tested. Drawing on prior literature and practitioner interviews, the present study defines employee engagement as an attitude towards one’s work at one’s company, comprising feelings of vigor, dedication, and absorption; cognitive appraisals of psychological empowerment; and motivation to act, both within role and extra role, in the service of the organization’s goals. In addition, the present study validates a self-report instrument to measure this conceptualization of employee engagement, using construct and scale validation procedures accepted in marketing and information systems literature.
294

Optimizing the Optical Calibration Performance of a Multi-Object Adaptive Optics Instrument

Pham, Laurie Nhu An 17 December 2013 (has links)
Multi-Object Adaptive Optics (MOAO) is an adaptive optics technique being developed for Extremely Large Telescopes that will allow simultaneous observation of approximately 20 targets in a several arc-minute field of regard. Raven is an MOAO pathfinder developed by the Adaptive Optics Laboratory of the University of Victoria, in collaboration with the National Research Council of Canada and the Subaru Telescope. It will be the first MOAO instrument on a 8-m class telescope, will demonstrate that MOAO technical challenges such as open-loop control and calibration are achievable on-sky and will deliver science results using three natural guide stars and two science arms on ∼ 3.5′ field-of-regard. The open-loop approach makes the need for calibration even more crucial. An important part of the calibration process resides in the misregistration of the wavefront sensors (WFSs) with the deformable mirrors (DMs) because the sensing elements are located before the correcting ones. This problem is solved using a cal- ibration DM seen by all WFSs in the system that permits the open-loop WFS to be registered to the science DMs. The method developed in this thesis registers the position of the DM actuators to the WFSs and gives misregistration values. These results are then used to better align the instrument, to have a better knowledge of the positions of the different optical components and generate new ways to perform the AO correction. Using the registration parameters results, synthetic interaction matrices are created in order to improve the AO correction. Calibration tests are also presented in this thesis. They show complementary tests to the expected requirements to expand the knowledge of the calibration unit behaviour. / Graduate / 0548 / 0752 / lpham@uvic.ca
295

Giovanni Puzzi : his life and work : a view of horn playing and musical life in England from 1817 into the Victorian era (c.1855)

Strauchen, Elizabeth Bradley January 2000 (has links)
The focus of this dissertation is a comprehensive study of the life and work of Giovanni Puzzi, nineteenth-century Britain's most celebrated virtuoso of the horn. In his hands, the horn -- hitherto largely known to England's aristocracy as an obstreperous member of the orchestra or popular form of pleasure garden entertainment became a sought-after attraction at London's most fashionable and exclusive concerts. An examination of Puzzi's activities as an orchestral player and as a soloist in a wide variety of public and private concerts chronicles his rise to celebrity and establishes his position in London's concert life. Equally impressive was Puzzi's sustained prosperity in a notoriously difficult business. Key to this triumph was his multifaceted exploitation of the Italian opera. Through his activities as an agent, impresario and arranger he allied himself as a fixer and performer with his era's most lucrative musical commodity: the singers of the Italian opera. In the large body of music that he arranged and composed to capitalise on audience fascination with virtuosity and opera, Puzzi has provided the only substantial record of horn playing in Britain during the nineteenth century. The majority of fhe manuscripts considered in this dissertation are drawn from a private collection and have not been previously studied or published. This material, in conjunction with Puzzi's surviving instruments and critical accounts of his playing, has been utilised to reconstruct and assess the main attributes of his virtuosity. This dissertation shows that Puzzi was responsible for establishing the preference for French style instruments and performance technique in England and that he was the first exponent of the British school of horn playing that reached its culmination in Dennis Brain. While virtuoso string players, pianists and singers have attracted much attention from scholars and biographers, this dissertation is the first full length historical study of a nineteenth-century horn virtuoso to be written.
296

Preservice Teachers’ Content Knowledge of Function Concept within a Contextual Environment

Brown, Irving 2011 August 1900 (has links)
The overarching goal of this dissertation research was to develop and measure the psychometric properties of an instrument to assess preservice teachers’ content knowledge of the function concept embedded in contextual problems. This goal was accomplished through two research projects described in two central chapters. Chapter II reports on the collective case study that was used to pilot test the instrument and Chapter III details the rationale used in item selection and the psychometric properties of the new instrument. Unlike existing research studies that examine a broad range of function related topics using various forms of symbolic, tabular, and graphical representations as the basis for questions and problems, this study focused solely on function problems immersed in various real world contexts. Since this is not a common approach to measuring content knowledge of the function concept, the existing instruments in published studies were not found to be suitable for this specialized purpose. The psychometric measurements of the instrument did not suggest that the instrument was valid or reliable so more research will be required to validate the instrument. However, based on the preliminary results from testing, several potential suggestions can be made to teacher educations programs. Inferences drawn from the mathematical problem-solving cognition will aid in the development and validation of future instruments to assess preservice mathematics teachers’ knowledge of how to connect their knowledge mathematical concept of function to a contextual setting.
297

Numerical Techniques for Acoustic Modelling and Design of Brass Wind Instruments

Noreland, Daniel January 2003 (has links)
Acoustic horns are used in musical instruments and loudspeakers in order to provide an impedance match between an acoustic source and the surrounding air. The aim of this study is to develop numerical tools for the analysis and optimisation of such horns, with respect to their input impedance spectra. Important effects such as visco-thermal damping and modal conversion are shown to be localised to different parts of a typical brass instrument. This makes it possible to construct hybrid methods that apply different numerical techniques in different parts of the instrument. Narrow and slowly flaring parts are modelled using a one-dimensional transmission line analogy, and the rapidly flaring bell is modelled using a two-dimensional finite-difference method. The connection between the different regions is done by the aid of impedance boundary conditions. The use of such boundary conditions is investigated with respect to the required number of degrees of freedom. Numerical shape optimisation is employed in order to design horns with desired impedance characteristics throughout a design frequency band. A loudspeaker horn is optimised with respect to its sound power output, and a brass instrument is optimised with respect to its intonation. The horns are modelled using the finite-element method and a transmission line analogy. In order to achieve rapid convergence of the optimisation, gradient based minimisation algorithms are used. A prerequisite for success is the ability to accurately and inexpensively compute the gradient of the objective function. The gradient for the finite-element method is computed by an adjoint equation technique, whereas for the transmission line analogy, it is derived by formal differentiation of the model. In order to find smooth solutions, a smoothing technique is used, where optimisation is done with respect to the right hand side of a Poisson type equation.
298

On the characterization of multipath errors in satellite-based precision approach and landing systems

Braasch, Michael S. January 1992 (has links)
Thesis (Ph. D.)--Ohio University, June, 1992. / Title from PDF t.p.
299

Der Einfluss ökologischer Direktzahlungen auf das Grünland der Schweizer Alpen eine Untersuchung der multifunktionalen Kulturlandschaft unter Berücksichtigung sozioökonomischer und landwirtschaftlicher Gemeindestrukturen sowie landschaftsökologischer Gesichtspunkte

Kampmann, Dorothea January 2006 (has links)
Zugl.: Freiburg (Breisgau), Univ., Diss., 2006
300

Investigation of the deleterious effects on an instrument landing system localizer produced by scattering of radio frequency energy for a bi-fold hanger door

Huntwork, Matthew E. January 1999 (has links)
Thesis (M.S.)--Ohio University, March, 1999. / Title from PDF t.p.

Page generated in 0.0885 seconds