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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.
421

VBS-RTK GPS輔助UAV影像自率光束法空三平差之研究 / VBS-RTK GPS Supported Self-Calibration Bundle Adjustment for Aerial Triangulation of Unmanned Aerial Vehicle Images

李敏瑜, Li, Min Yu Unknown Date (has links)
無人飛行載具(Unmanned Aerial Vehicle, UAV)於要求精度之圖資測製應用時,因飛行高度較低並可在雲下飛行取像,與大型載具相比可更機動性獲取空間解析度較高之影像,雖無法如大型載具酬載大像幅感測器供大區域圖資製作,但於小區域之圖資更新卻相當適合。但一般UAV因酬載重量限制,僅可酬載體積小且重量輕之感測器,如非量測型相機及低精度定位定向系統,即AHRS系統。因此,本研究嘗試在UAV上酬載Trimble BD970 GNSS OEM GPS接收模組,此GPS接收模組體積小且重量輕可安置於UAV上,並透過VBS-RTK GPS定位技術獲取UAV精確飛行軌跡資訊,再經時間內插相機曝光瞬時的GPS資訊供空中控制使用,輔助UAV影像空中三角測量(簡稱空三)平差,以降低地面控制點需求。 但欲引入GPS觀測量供空中控制使用必須考量GPS天線與相機投影中心偏移量之問題,但因UAV所酬載之非量測型相機,將造成此偏移量不易透過地面測量方式測得,於本研究將於空三平差時使用線性漂移參數克服此偏移量無法量測之問題;此外,UAV所酬載之非量測型相機,相機參數乃透過地面近景攝影測量以自率光束法平差方式率定所得,但率定所得相機參數無法完全描述相機在航拍取像時的情況,故本研究於空三平差將採用自率光束法克服相機參數率定不完全之問題。實驗中,首先確定GPS模組BD970在VBS-RTK GPS定位技術下在地面高速移動時可獲得高精度的定位成果;接續驗證線性漂移參數及自率光束法平差於此研究的適用性;最後亦探討不同地面控制點配置及來源對空三平差之精度探討,並提出1/5000基本圖圖資測製精度要求下,VBS-RTK GPS輔助UAV影像自率光束法空三平差的地面控制點最適配置。 / UAV(Unmanned Aerial Vehicle) is currently used in civil purpose such as mapping and disaster monitoring. One of UAV advantages is to collect images with high resolution for mapping demand. However, due to payload limitations of UAV, it is difficult to mount metric aerial camera and precise POS(Positioning and Orientation System) device. Instead, only the non-metric camera and the low accurate AHRS (Attitude and Heading Reference System) can be installed. For mapping demands, Trimble BD970 GNSS OEM board will be carried on the UAV to collect the high accurate flying trajectory as control information for AT (aerial triangulation) by VBS-RTK(Virtual Base Station - Real Time Kinematic) GPS technique. Meanwhile self-calibration bundle adjustment will be employed for AT(Aerial Triangulation) to overcome the imperfect calibration of non-metric camera by the close-range photogrammetric approach. The precise offset between image perspective center and GPS antenna center, called GPS antenna-camera offset, is hard to measure in centimenter level by terrestrial measurement approach. Therefore the drift parameters will be utilized to solve the problem of GPS antenna-camera offset while performing bundle adjustment with self-calibration for AT of UAV images. In the experiments of this study, the height positioning accuracy of BD970 by VBS-RTK GPS approach at high speed movement will be proved firstly. Then the adaptability of drift parameters and self-calibration for GPS supported AT of UAV images will be verified. Finally, the accuracy of AT by using different control information will be analized and appropriate configuration of GCPs(Ground Control Points) for VBS-RTK GPS supported self-calibration bundle adjustment for AT of UAV images will be proposed under the mapping demand with the scale of 1 : 5000.
422

Redesign av reduktionsutrustning i asselvalsverk inom stålindustri : Ett examensarbete utfört på konstruktionsbyrån BEKAB mot stålindustriföretaget Ovako / Redesign of Reduction Equipment in Assel mill within Steel Industry : A master thesis carried out at the design agency BEKAB towards the steel company Ovako

Andersson, Tommy January 2014 (has links)
Intresset för sömlösa stålrör med stora ytterdiametrar i förhållande till tunna väggtjocklekar har ökat tillsammans med att högre hållfasthet i olika stålsorter tillkommit. Detta gör det möjligt att tillverka lättare, billigare och mer materialeffektiva stålprodukter med samma eller högre hållfasthet som tidigare. Denna nya utvecklingsriktning medför förändringar och utmaningar i en av företaget Ovakos produktionslinor i Rörverk 5 Hofors, vilket de har behov av att samarbeta med maskinkonstruktionsföretaget BEKAB för att utvärdera och utveckla. I Ovakos produktionslina i Rörverk 5 finns en del av ett asselvalsverk som kallas för "förreducerare". Denna del av asselvalsverket ser Ovako ett stort intresse i att utvärdera och utveckla för att bättre anpassas till den nya utvecklingsriktningen.  En känd utmaning hos förreduceraren sen tidigare är att den från början är framtagen för att reducera ner ett kvalitetsproblem hos rörprodukterna som kallas för trattbildning. Projektet fördjupar sig därför inom trattbildning för att bättre förstå grunden till förreducerarens nuvarande design för att därefter genomföra en redesign av förreduceraren. I en nulägesanalys av nuvarande förreducerare framkommer ett flertal olika produktionsutrustningsproblem med tillhörande kvalitetsproblem hos rörprodukterna. Projektet väljer därmed att fokusera på de produktionsutrustningsproblem som ger störst effekt för förreduceraren om de löstes. Detta resulterar i ett nytt produktkoncept av förreduceraren i form av en visuell 3D-CAD-modell med tillhörande hållfasthetsberäkningar och materialoptimering. Studien behandlar ämnen som design, konstruktion, produktutveckling, hållfasthet samt materialoptimering. / The interest in seamless steel tubes with large outside diameters in relation to thin wall thickness has increased along with the strength improvements in various steel grades. This makes it possible to produce lighter, cheaper and more material-efficient steel products with the same or greater strength as before. These new development directions bring changes and challenges in one of the company Ovako's production lines in Tube Mill 5 Hofors, which they need to cooperate with the design agency BEKAB to evaluate and develop. In Ovako's production line in Tube Mill 5 there is a part of an assel mill called "förreducerare". Ovako sees a lot of interest in evaluating and developing this part of the assel mill in order to better adapt to the new development directions. A well-known challenge of the existing reduction equipment is that it was initially developed to reduce a quality issue with the tube products called funnel formation. The project therefore immerses itself into the funnel formation in order to better understand the foundations of the current design of the reduction equipment and to then implement a redesign of the reduction equipment. A situation analysis of the current reduction equipment reveals a number of different production issues with their accompanying quality issues in the tube products. The project thus chooses to focus on the production issues that would have the greatest impact on the reduction equipment if they were resolved. This results in a new product concept of the reduction equipment in the form of a visual 3D-CAD-model with associated strength calculations and material optimization. The study covers topics such as design, engineering, product development, material strength calculations and material optimization.
423

Truth-telling in aged care: a qualitative study

Tuckett, Anthony Gerrard January 2003 (has links)
This thesis argues that truth-telling in high level (nursing home) aged care is a undamentally important aspect of care that ought to reside equally alongside instrumental care. The health of the resident in a nursing home, as with individuals in other care contexts, is directly linked to care provision that allows the resident to be self determining about their care and thus allows them to make reasonable choices and decisions. This qualitative study explores the meaning of truth-telling in the care providerresident dyad in high level (nursing home) aged care. Grounded within the epistemology of social constructionism and the theoretical stance of symbolic interactionism, this study relied on oral and written text from care providers (personal care assistants and registered nurses) and residents. Thematic analysis of data relied on practices within grounded theory to determine their understanding and the conditions and consequences of their understanding about truth-telling in the nursing home. Through an understanding of the relationship-role-residency trinity, truth-telling in high level (nursing home) care comes to be understood. It has been determined that the link between truth-telling and the nature of the care provider-resident (and residents' families) relationship is that both personal carers and nurses in this study premise their understanding of truth disclosure on knowing a resident's (and resident's family's) capacity for coping with the truth and therefore catering for the resident's or family's best interests. The breadth and depth of this knowing and how the relationship is perceived and described determine what care providers will or will not tell. That is, the perceptions both personal carers and nurses have about the relationship - how they describe themselves as 'family like', 'friend' and 'stranger', has implications for the way disclosure operates and is described. Additionally, how care providers perceive and understand their role determines what care providers will or will not tell. That is, the perceptions both carers and nurses have about their own and each other's role - how they describe themselves for example as 'hands-on' carer and 'happy good nurse' has implications for the way disclosure operates and is described. Furthermore, care providers' meaning and understanding of truth-telling in aged care is not possible in the absence of an appreciation of how the care providers give meaning to and come to understand the care circumstance - residency, the aged care facility, the nursing home. That is, the perceptions both personal carers and nurses have about the aged care facility - how they describe residency as 'Home away from Home' (and what this means), as a place of little time and a plethora of situations have implications for the operation of truth-telling as a whole. Recommendations from the study include the implementation of a telling audit to better serve the truth-telling preferences of residents and the reorientation of care practices to emphasise affective care (talk rather than tasks). Furthermore, it is recommended that changes occur to the care provider roles, that care providers define themselves as facilitators rather than protectors, and education be ongoing to improve communication with and care of residents with dementia and those dying. Finally, the language of residency as 'home' needs to capture an alternate philosophy and attendant practices for improved open communication.
424

Robot navigation in sensor space

Keeratipranon, Narongdech January 2009 (has links)
This thesis investigates the problem of robot navigation using only landmark bearings. The proposed system allows a robot to move to a ground target location specified by the sensor values observed at this ground target posi- tion. The control actions are computed based on the difference between the current landmark bearings and the target landmark bearings. No Cartesian coordinates with respect to the ground are computed by the control system. The robot navigates using solely information from the bearing sensor space. Most existing robot navigation systems require a ground frame (2D Cartesian coordinate system) in order to navigate from a ground point A to a ground point B. The commonly used sensors such as laser range scanner, sonar, infrared, and vision do not directly provide the 2D ground coordi- nates of the robot. The existing systems use the sensor measurements to localise the robot with respect to a map, a set of 2D coordinates of the objects of interest. It is more natural to navigate between the points in the sensor space corresponding to A and B without requiring the Cartesian map and the localisation process. Research on animals has revealed how insects are able to exploit very limited computational and memory resources to successfully navigate to a desired destination without computing Cartesian positions. For example, a honeybee balances the left and right optical flows to navigate in a nar- row corridor. Unlike many other ants, Cataglyphis bicolor does not secrete pheromone trails in order to find its way home but instead uses the sun as a compass to keep track of its home direction vector. The home vector can be inaccurate, so the ant also uses landmark recognition. More precisely, it takes snapshots and compass headings of some landmarks. To return home, the ant tries to line up the landmarks exactly as they were before it started wandering. This thesis introduces a navigation method based on reflex actions in sensor space. The sensor vector is made of the bearings of some landmarks, and the reflex action is a gradient descent with respect to the distance in sensor space between the current sensor vector and the target sensor vec- tor. Our theoretical analysis shows that except for some fully characterized pathological cases, any point is reachable from any other point by reflex action in the bearing sensor space provided the environment contains three landmarks and is free of obstacles. The trajectories of a robot using reflex navigation, like other image- based visual control strategies, do not correspond necessarily to the shortest paths on the ground, because the sensor error is minimized, not the moving distance on the ground. However, we show that the use of a sequence of waypoints in sensor space can address this problem. In order to identify relevant waypoints, we train a Self Organising Map (SOM) from a set of observations uniformly distributed with respect to the ground. This SOM provides a sense of location to the robot, and allows a form of path planning in sensor space. The navigation proposed system is analysed theoretically, and evaluated both in simulation and with experiments on a real robot.
425

Generic inhibitors to conserve and transform traditional technologies : the case of Ethiopia

Negassi Yosseph G-Egziabher 12 1900 (has links)
Traditional technologies are revelations of knowledge, skill, and wisdom of ancestors that have been used to facilitate and enhance the performance of socio-economic activities, overcome environmental challenges, and magnify symbolic presentations of cultural and spiritual engagements. Traditional technologies are still practiced in many communities despite the strides made in the advancement of modern technologies. The socio-economic significance of traditional technologies in the context of Ethiopia is even more profound. There are hardly social, economic, and spiritual activities that are not, directly or indirectly, influenced by the application of traditional technologies. The irony is, however, they are not appreciated and conserved in spite that they have been proving a sustained significance across generations while, to the contrary, modern technologies are even staggering to outlive the stage of product introduction. Although still proving to be useful, traditional technologies have been marginalized as if they are symbols of backwardness belonging to the past as irrelevant to the modern day settings. It was, therefore, the urge to look into this dilemma that became the basis for the initiation to conduct a research on the captioned topic. The study has endeavored to address how traditional technologies, specifically that of Ethiopia, are able to sustain contrary to extant theoretical predictions of technologies, and investigate why they have been deterred from getting the conservation and transformation they deserve in spite of the socio-economic significant role they have continued to play as capitulated in the statement of the problem. In addressing the statement of the problem, the paradigm of the world outlook within which the research was situated is found to be related to the Critical Theory paradigm. As a result, a qualitative research methodology based on a case study design was framed and a longitudinal field study on the sampled cases was conducted. The data generated from the study were ix filtered, coded, organized, categorized, and ultimately analyzed and interpreted using apparent analytic models until saturated and triangulated findings were established. Accordingly, the core constructs that has been defining the fate of traditional technologies were induced and their impact in deterring or promoting the conservation and transformation of traditional technologies were synthesized. Based on the outcomes of data analysis and interpretation, appropriate methods of reshaping the societal attitude and orientation in terms of conserving and transforming traditional practices are proposed as induced recommendations ultimately requiring a timely intervention. / Business Management / D. Litt. et Phil. (Business Leadership)
426

Induction and professional development support of newly qualified professional nurses during community service

Makua, Memme Girly 06 1900 (has links)
Text in English / In South Africa, retention of newly qualified professional nurses in public health institutions upon completion of their year of compulsory remunerated community service remains a challenge that exacerbates the shortage of professional nurses in these institutions. The literature indicates that many newly qualified professional nurses leave the public health institutions due to lack of professional development support and heavy workloads while they are still finding their feet. A mixed-methods design of concurrent triangulation approach was used to answer the question: How are the newly qualified professional nurses supported in terms of induction and professional development during community service in South Africa? Triangulation was achieved by using both quantitative and qualitative methods. Induction/orientation documents from public health institutions were analysed using a checklist. A survey questionnaire with mixed quantitative closed items (1–43) and qualitative open-ended questions (43–46) was sent to newly qualified professional nurses who had recently completed community service. Focus groups held with operational nurse managers and individual interviews with coordinators of community service for nurses yielded rich qualitative data. Descriptive and inferential statistics were used to describe and synthesise data. The qualitative findings confirmed the quantitative findings. Findings were lack of professional development support in some public health institutions, informal, non-comprehensive support where given, shortage of experienced professional nurses, reluctance by some professional nurses and operational nurse managers to supervise newly qualified nurses, and increased workload due to the shortage of experienced professional nurses in the public health institutions. Inadequate clinical skills, poor discipline and lack of professionalism in the newly qualified professional nurses also played a part. Respondents suggested constructive recommendations for the induction and professional development support of the newly qualified professional nurses, and these were incorporated in the recommended guidelines for the induction and professional development support of newly qualified professional nurses during community service. / Health Studies / D. Litt. et Phil. (Health Studies)
427

Information communication technologies as a support mechanism for learners experiencing reading difficulties in full-service schools

Mphahlele, Ramashego Shila Shorty 01 1900 (has links)
Reading is an important skill that forms part of acquiring knowledge. It improves literacy levels, social skills, personal wellbeing and provides a sense of purpose. However, there are majority of learners experiencing reading difficulties around the world. The purpose of this study revolves around recent trends in academic underperformance that have led to a proliferation of studies which suggest that one of the greatest causes is reading difficulties. The Full-Service Schools (FSS) being part of the support strategy as denoted by Education White Paper 6 are primary schools that are equipped with most resources including Information Communication Technologies (ICTs). For this reason, they were selected so that the perceptions and experiences of their School-Based Support Team (SBST) members and Learning Support Educators (LSEs) can be explored, described and be explained when supporting learners experiencing reading difficulties. Through the concurrent triangulation mixed methods design data was collected using both quantitative and qualitative methods (that is the structured questionnaire, focus group interviews and official documents). The collected data was analysed through mixed analysis and merged to corroborate the findings from quantitative and qualitative data. Findings indicated that there was a small statistically significant difference in the reading performance of participants who were exposed to ICTs as a support mechanism for learners experiencing reading difficulties in the FSS. The slight improvement can be attributed to lack of ICTs guidelines for supporting learners experiencing reading difficulties, limited teacher training on ICTs and the limited use of the ICTs. In conclusion, the ICTs scaffolding guideline for teachers to support leaners experiencing reading difficulties was developed. The guideline incorporated the three theories that unpinned this study namely the social interaction part of Vygotsky’s sociocultural theory, the readers-response theory and e-reading theory. Throughout the ICTs scaffolding guideline, electronic text feature as part of the e-reading theory. It is the eradication of reading difficulties that can improve the learners’ confidence which in turn will have a positive effect on their academic performance on some or all of the subjects. / Psychology of Education / D. Ed. (Psychology of Education)
428

Investigating good usability consistency within and across the South African super 14 rugby franchise web sites

Howard, Grant Royd 08 1900 (has links)
This study investigates the usability of the South African Super 14 Rugby franchise web sites. Web site usability is a measure of a web site user’s experience when visiting a web site. A web site user’s experience will determine how well a web site’s goals are achieved. The relevant web site goals are, having as many visitors as possible, both unique visitors and repeat visitors, and ensuring that those visitors stay on the web site for as long as possible. This study uses data generation method triangulation to enhance the validity of the findings. The data generation methods are an e-mail questionnaire survey and an expert group consensus method called the Delphi Method. This study shows that within each web site and across all five web sites, there is poor usability consistency. Management guidelines and recommendations for improvements to these web sites are presented, so that the web site goals can be achieved. / Computer Science / M.Sc. (Information Systems)
429

Knowledge management practices at the Department of Defence in South Africa

Ramohlale, Molatelo Paul 06 1900 (has links)
Defence organisations have now significantly developed and in the process they have applied various measures to sustain their progresses and encourage innovation. One of those measures is by embarking on KM programs. KM in military is seen as a strategic approach to achieving defense objectives by leveraging the value of collective knowledge through the process of creating, gathering, organizing, sharing and transferring knowledge into action. It is through proper knowledge management practices that an organisation embraces and manages its knowledge generation, knowledge acquisition, knowledge organisation, knowledge storage, transfer, knowledge sharing, and knowledge retention. The purpose of this study was to investigate knowledge management practices in the Department of Defence (RSA). The objective of the study was to find out how the department appreciates, understands, interprets and handles its knowledge. This study employed triangulation method to present trustworthiness of both qualitative and quantitative research approaches using positivist research design. Questionnaires, interviews and document analysis were employed to collect data. In order to arrive at the number of participants who received the questionnaires, a probability sampling method called stratified random sampling was used as well as purposive sampling. When setting up a study, it was essential to review the research identified in the literature review and to determine whether there is anything relevant to the research design of the proposed study. The study found that knowledge management was hardly understood generally in the department and was not an approach used and institutionalised for the benefit of the organisation. However there was embedded knowledge management appreciation from a few staff members in the department, only managing their own knowledge regarding learning, capturing and storage. Additionally there is a significant number of staff members who believe knowledge management is a way to go in the future and strongly believe their Defence Department needs to adopt a comprehensive and inclusive KM approach. / Information Science / M.A. (Information Science)
430

An evaluation of the "Life Skills Train the Trainer Programme"

Baloyi, Lydia Tsakane 11 1900 (has links)
Summaries in English and Afrikaans / Life skills are coping skills taught to learners, with the purpose of developing self-reliant and confident people with skills, to cope with important life's challenges in times of change. Where life skill education initiatives are being set up, much time and resources are channelled into training teachers, promoting, disseminating and implementing life skill education. For life skill education to be effective and continue to be relevant, research needs to be undertaken as an integral part of the whole process. This study focuses on the 'Life Skills Train the Trainer Programme'. The aim being to evaluate the success of this programme in empowering teachers to teach life skills. It was found that although life skill education has been found to be an important area in every learner's life, there are obstacles that may affect an effective implementation of life skill education in schools. These obstacles need to be attended to. / ewensvaardighede word aan leerlinge onderrig met die doe! om selfstandigheid en selfversekerdheid te ontwikkel, sodat hulle in staat is om lewenseise te midde van veranderende tye te kan hanteer Wanneer lewensvaardighede-onderrig gelnisieer word, word baie tyd en hulpbronne gekanaliseer in die opleiding van onderwysers, asook in die promovering, verspreiding en implementering van sodanige onderwys. Vir lewensvaardighede-onderrig om effektief te wees en relevant te bly, moet navorsing 'n integrale dee! van die hele prose vorm. Hierdie studie is gerig op die "Life Skills Train the Trainer Programme". Die doe! was om vas te stel tot watter mate hierdie program bydra tot die bemagtiging van onderwysers in die onderrig van lewensvaardighede. Die bevinding was dat alhoewel erkenning gegee word aan die belangrikheid van lewensvaardighede-onderrig, daar tog struikelblokke is wat effektiewe implementering in skole kan belemmer Hierdie struikelblokke moet aangespreek word. / Educational Studies / M.Ed.

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