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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.
21

Applying an Analytical Approach to Shop-Floor Scheduling: A Case Study

Swinehart, Kerry, Yasin, Mahmoud, Guimaraes, Eduardo 01 January 1996 (has links)
In the light of the complex and dynamic factors that exist in a typical production facility, manual development of an optimal shop-floor schedule is computationally impractical. This paper discusses the effective use of an heuristic algorithm approach to shop-floor scheduling at the TRW Rack and Pinion Division (RPD) Plant in Rogersville, Tennessee. The study documents the introduction of FAST, a computerised scheduling system that employs the Genetic Optimisation Algorithm. Results demonstrate a real potential advantage using this system for shop-floor scheduling, thus facilitating TRWs journey of continuous improvement.
22

System support for maintenance of production equipment and advanced test environment : Proposal for Saab’s Maintenance Operation

Gustafson, Jonathan January 2023 (has links)
In today’s industry, where manufacturing is fast and efficient, uptime for manufacturing machines plays a key role for companies to stay relevant with their competitors. Although manufacturing equipment today is very advanced and sometimes automated, they may still run into problems and wear out. By maintaining and servicing the equipment well, one can avoid unexpected equipment failure and unnecessary downtime. Keeping track and documenting maintenance can play a crucial role in how efficiently a manufacturer can produce their product. Maintenance management software exists on the market today, but they are large and expensive. As Saab, a manufacturer of highly advanced military technology, does not have a well-established system for managing their maintenance, there is a need for an evaluation and development of a customised option. In this thesis, the maintenance needs for Saab’s operations were analysed, and options for developing maintenance software that fits these needs were investigated. The result was a web application hosted on a Python-based web server, which uses MongoDB as a database to store data in an object-oriented manner, allowing flexibility within the system. The application is not fully developed but provides an overall picture of how a smaller software could serve the same purpose as the larger ones. After evaluating the developed application alongside the existing maintenance software, it is concluded that with further development, the application could serve the same function and be a competitive contender alongside the larger software. However, the safer and more reliable option for Saab would be to instead implement one of the existing software solutions. / I dagens industri, där tillverkning är snabb och effektiv, spelar drifttid för tillverkningsmaskiner en nyckelroll för att företag ska kunna hålla sig relevanta gentemot sina konkurrenter. Trots att tillverkningsutrustning idag är mycket avancerad och ibland automatiserad, kan de fortfarande stöta på problem och slitas ut. Genom att underhålla och serva utrustningen på rätt sätt kan man undvika oväntade maskinhaverier och onödig driftstopp. Att ha kontroll och dokumentera underhåll kan spela en avgörande roll för hur effektivt en tillverkare kan producera sin produkt. Underhållshanteringssystem finns på marknaden idag, men de är stora och dyra. Eftersom Saab, tillverkare av högteknologisk militärteknik, inte har ett väletablerat system för hur de hanterar sitt underhåll, finns det ett behov av en utvärdering och utveckling av ett anpassat alternativ. I denna avhandling analyserades underhållsbehoven för Saabs verksamhet, och alternativ för hur en underhållsprogramvara kunde utvecklas för att passa dessa behov undersöktes. Resultatet blev en webbapplikation som är värd på en Python-baserad webbserver och använder MongoDB som en databas för att lagra data på ett objektorienterat sätt, vilket ger flexibilitet inom systemet. Applikationen är inte fullt utvecklad men ger en övergripande bild av hur en mindre programvara kan tjäna samma syfte som de större. När den utvecklade applikationen utvärderas i förhållande till den befintliga underhållsprogramvaran dras slutsatsen att applikationen, med ytterligare utveckling, skulle kunna fylla samma funktion och vara en konkurrenskraftig utmanare till de större programvarorna. Dock skulle det säkrare och mer pålitliga alternativet för Saab vara att istället implementera en av de befintliga programvarorna.
23

Vztahy mezi motorickými testy a parametry dynamické posturální stability / The relationship between motor tests and dynamic postural stability parameters

Vrubelová, Lucie January 2019 (has links)
Title: The relationship between motor tests and dynamic postural stability parameters Objectives: The aim of this dissertation is to verify the relationship between motor performance and dynamic postural stability parameters in young individuals in the healthy population. To find out in addition whether there exists a significant relationship between motor tests and dynamic postural stability parameters, as well as to verify the differences between males and females within this relationship. Methods: This is a quantitative correlation study investigating the possible relationship between motor tests and dynamic postural stability parameters in young healthy individuals. The Smart EquiTest device from Neurocom was used to measure dynamic postural stability. The following tests were used for these measurements: Limits of Stability (LOS), Sensory Organisation Test (SOT), Motor Control Test (MTC), Adaptation Test (ADT), Weight Bearing/Squat (WBS), Unilateral stance (US) and Rhythmic Weight Shift (RWS). Motor performance was measured using 2 batteries of tests: UNIFIT 6-60 and EUROFIT for adults. In total, 24 healthy volunteers (9 males and 15 females) aged 21-29 years were deliberately enrolled for this study. Each volunteer undertook 8 motor performance tests, anthropometric measurements and 7 tests...
24

The physical and psychosocial environment associated with classrooms using new information technologies : a cross-national study.

Zandvliet, David B. January 1999 (has links)
This research involved an in-depth and holistic investigation into the use of Internet technologies in high school classrooms. Specifically, it combined studies of the physical and psychosocial learning environments operating within these 'technological settings' and investigated interactions among the selected physical and psychosocial factors in influencing students' satisfaction with their learning. Further, the study described how both the physical and psychosocial domains may effectively enable, or alternatively, constrain the teaching methodologies used in these classrooms. The study involved two phases of investigation. The first phase involved a broad examination of the learning environment as measured with a questionnaire containing items measuring aspects of the psychosocial learning environment and with ergonomic site evaluations using a specially designed worksheet and inventory for computerised classrooms. In the second phase of the study, interactions among the physical and psychosocial variables in these measures were explored through the use of selected and detailed case studies from the original sample. Case studies included a more detailed assessment of the physical classroom environment in tandem with classroom observations and student/teacher interviews. The study was conducted in Australian and Canadian secondary schools and so, offers additional insights in the different approaches to technology implementation and teaching practice. The results of the study reveal a number of statistically significant and independent associations between physical and psychosocial factors and further, between psychosocial factors and students' satisfaction with learning. These findings were complemented by similar qualitative findings from the case studies. These quantitative and qualitative results were used to inform a model for educational productivity for ++ / computerised classrooms. The model includes a number of important physical and psychosocial factors which when considered together, may influence student attitudes (and potentially other outcomes) in emerging networked and computerised learning environments.
25

The organisational and communication implications of electronic ordering systems for hospital pathology services

Georgiou, Andrew January 2009 (has links)
Doctor of Philosophy / Computerised Provider Order Entry (CPOE) systems provide clinicians with the ability to electronically enter hospital orders for laboratory tests and services. CPOE is able to integrate with hospital information systems and provide point of care decision support to users thereby making a potentially significant contribution to the efficiency and effectiveness of care delivery. The evidence of the impact of CPOE systems on pathology services is not extensive and insufficient attention has been paid to their effect on organisational and communication processes. This thesis aimed to investigate the implications of CPOE systems for pathology laboratories, their work processes and relationships with other hospital departments, using comparative examinations to identify the tasks they are involved in and the particular needs the laboratories expect to be filled by the new system. This longitudinal study of a CPOE system was carried out over three years using multiple cases from a hospital pathology service based at a large Sydney teaching hospital. Multi-methods using quantitative and qualitative data were employed to achieve triangulation of data, theory and methods. The findings provide evidence of a significant 14.3% reduction of laboratory turnaround times from 42 to 36 minutes when laboratory data for two months were compared before and after CPOE implementation. The findings also reveal changes in the pattern and organisation of information communication, highlighting transformations in the way that work is planned, negotiated and synchronised. These findings are drawn together in a comprehensive organisational communication framework that is highly relevant for developing a contingent and situational understanding of the impact of CPOE on pathology services.
26

Three Essays on the Impact of Electronic Screen Trading in Futures Markets

Hill, Amelia Mary January 2001 (has links)
This dissertation consists of 3 essays that examine the impact of electronic screen trading in futures markets. The research provides empirical evidence on increasingly significant issues given the rapid global advances in technology used in securities markets. Each essay addresses the scarcity of conclusive research in order to aid researchers, regulators, exchange policy makers and systems builders as they confront issues related to electronic trading systems.
27

An investigation into the effectiveness of core muscle strengthening on cycling performance in asymptomatic cyclists

Wiseman, Kate 08 April 2014 (has links)
Dissertation submitted in partial compliance with the requirements for the Masters’ Degree in Technology: Chiropractic, Durban University of Technology, 2013. / Background : Core strengthening may improve athletic ability by providing stability to the trunk, and as a result, stabilising the pelvis. The leverage from which cyclists generate power may be enhanced as a result of a stable pelvis, thereby improving the cyclist’s performance. In the popular, highly competitive sport of cycling, performance enhancement is much sought after. Despite its widespread use, research involving core strengthening in sporting situations is lacking, with studies investigating the effect of a core strengthening programme on cycling performance yet to be investigated. Objectives : To determine the participants’ cycling speed, power, cadence and completion time, and core strength in terms of objective findings, pre- and post- core strengthening intervention, in the whole sample and within the two age strata. To determine the participants’ heart rate in terms of objective findings, and the rate of perceived exertion in terms of subjective findings, pre- and post- core strengthening intervention, in the whole sample and within the two age strata. To determine the participants’ perception of change in speed, power and cadence post- intervention, in the whole sample and within the two age strata. Method : Forty-two asymptomatic cyclists performed two 1.5 km time trials, pre- and post- core strengthening intervention. Core strength assessments were performed pre- and post- intervention, using the Pressure Biofeedback Unit, and the maximum and average speed (km/hr), power (w) and cadence (rpm), and completion time (s) were recorded pre- and post- intervention, using the Computerised Electromagnetic Roller resistance Ergometer (Tacx Trainer). Heart rate and rate of perceived exertion (RPE) were recorded pre- and post- intervention, as well as the participant’s perception of change in speed, power, and cadence post- intervention. SPSS version 20 (SPSS Inc) was used to analyse the data, in the whole sample and stratified into two age strata. Results : ll cycling performance indicators, speed, power, cadence and completion time showed a significant improvement post- intervention, in the whole sample, and within the two age strata. Core strength indicators showed a significant improvement post- intervention, in the whole sample and within the two age strata. A significant decrease in rate of perceived exertion and corresponding heart rate measurements post- intervention was observed in the whole sample. Similarly, the younger age strata reflected a significant decrease in rate of perceived exertion, however heart rate measurements were not significant. In contrast, the older age strata showed significant changes in heart rate measurements, with no significance in rate of perceived exertion measurements. The majority of participants experienced an increased perception in all outcomes post- intervention. Conclusions: The results of this study found that core strengthening had a statistically significant effect (p < 0.001) on cycling performance, both in terms of objective and subjective findings. Future studies could address the effect of core strengthening in an endurance setting.
28

Radiation from curved (conical) frequency selective surfaces

Chia, Yan Wah January 1993 (has links)
The thesis deals with the analysis of a microwave Frequency Selective Surface (FSS) on a conical dielectric radome illuminated by a feed hom located at the base. Two approaches have been adopted to solve this problem. The first approach is to calculate the element currents under the assumption that the surface is locally flat. Consequently, the element current at that locality can be determined by employing Floquet modal analysis. The local incidence has been modelled from the radiation pattern of the source or the aperture fields of the feed. Three types of feed model were used to account for the field illumination on the radome. The transmitted fields from the curved surface are obtained from the sum of the radiated fields due to the equivalent magnetic and electric current sources distributed in each local unit cell of the conical surface. This method treats the interaction of neighbouring FSS elements only. In the second approach the curvature is taken into account by dividing the each element into segments which conform to the curved surface. An integral formulation is used to take into account the interaction of all the elements. The current source in each FSS element from the formulation is solved using the method of moments (MOM) technique. A linear system of simultaneous equations is obtained from the MOM and has been solved using elimination method and an iterative method which employs conjugate gradients. The performance of both methods has been compared with regard to the speed of computations and the memory storage capability. New formulations using quasi static approximations have been derived to account for thin dielectric backing in the curved aperture FSS analysis. Computer models have been developed to predict the radiation performance of the curved(conical) FSS. Experiments were performed in an anechoic chamber where the FSS cone was mounted on a jig resting on a turntable. The measuring setup contained a sweep oscillator that supplied power to a transmitting feed placed at the base of the cone. Amplitude and phase values of the far field radiation pattern of the cone were measured with the aid of a vector network analyser. Cones with different dimensions and FSS element geometries were constructed and the measured transmission losses and radiation patterns compared with predictions.
29

Three Essays on the Impact of Electronic Screen Trading in Futures Markets

Hill, Amelia Mary January 2001 (has links)
This dissertation consists of 3 essays that examine the impact of electronic screen trading in futures markets. The research provides empirical evidence on increasingly significant issues given the rapid global advances in technology used in securities markets. Each essay addresses the scarcity of conclusive research in order to aid researchers, regulators, exchange policy makers and systems builders as they confront issues related to electronic trading systems.
30

The organisational and communication implications of electronic ordering systems for hospital pathology services

Georgiou, Andrew January 2009 (has links)
Doctor of Philosophy / Computerised Provider Order Entry (CPOE) systems provide clinicians with the ability to electronically enter hospital orders for laboratory tests and services. CPOE is able to integrate with hospital information systems and provide point of care decision support to users thereby making a potentially significant contribution to the efficiency and effectiveness of care delivery. The evidence of the impact of CPOE systems on pathology services is not extensive and insufficient attention has been paid to their effect on organisational and communication processes. This thesis aimed to investigate the implications of CPOE systems for pathology laboratories, their work processes and relationships with other hospital departments, using comparative examinations to identify the tasks they are involved in and the particular needs the laboratories expect to be filled by the new system. This longitudinal study of a CPOE system was carried out over three years using multiple cases from a hospital pathology service based at a large Sydney teaching hospital. Multi-methods using quantitative and qualitative data were employed to achieve triangulation of data, theory and methods. The findings provide evidence of a significant 14.3% reduction of laboratory turnaround times from 42 to 36 minutes when laboratory data for two months were compared before and after CPOE implementation. The findings also reveal changes in the pattern and organisation of information communication, highlighting transformations in the way that work is planned, negotiated and synchronised. These findings are drawn together in a comprehensive organisational communication framework that is highly relevant for developing a contingent and situational understanding of the impact of CPOE on pathology services.

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