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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.
71

Sensors, measurement fusion and missile trajectory optimisation

Moody, Leigh January 2003 (has links)
When considering advances in “smart” weapons it is clear that air-launched systems have adopted an integrated approach to meet rigorous requirements, whereas air-defence systems have not. The demands on sensors, state observation, missile guidance, and simulation for air-defence is the subject of this research. Historical reviews for each topic, justification of favoured techniques and algorithms are provided, using a nomenclature developed to unify these disciplines. Sensors selected for their enduring impact on future systems are described and simulation models provided. Complex internal systems are reduced to simpler models capable of replicating dominant features, particularly those that adversely effect state observers. Of the state observer architectures considered, a distributed system comprising ground based target and own-missile tracking, data up-link, and on-board missile measurement and track fusion is the natural choice for air-defence. An IMM is used to process radar measurements, combining the estimates from filters with different target dynamics. The remote missile state observer combines up-linked target tracks and missile plots with IMU and seeker data to provide optimal guidance information. The performance of traditional PN and CLOS missile guidance is the basis against which on-line trajectory optimisation is judged. Enhanced guidance laws are presented that demand more from the state observers, stressing the importance of time-to-go and transport delays in strap-down systems employing staring array technology. Algorithms for solving the guidance twopoint boundary value problems created from the missile state observer output using gradient projection in function space are presented. A simulation integrating these aspects was developed whose infrastructure, capable of supporting any dynamical model, is described in the air-defence context. MBDA have extended this work creating the Aircraft and Missile Integration Simulation (AMIS) for integrating different launchers and missiles. The maturity of the AMIS makes it a tool for developing pre-launch algorithms for modern air-launched missiles from modern military aircraft.
72

Sensors, measurement fusion and missile trajectory optimisation

Moody, Leigh 07 1900 (has links)
When considering advances in “smart” weapons it is clear that air-launched systems have adopted an integrated approach to meet rigorous requirements, whereas air-defence systems have not. The demands on sensors, state observation, missile guidance, and simulation for air-defence is the subject of this research. Historical reviews for each topic, justification of favoured techniques and algorithms are provided, using a nomenclature developed to unify these disciplines. Sensors selected for their enduring impact on future systems are described and simulation models provided. Complex internal systems are reduced to simpler models capable of replicating dominant features, particularly those that adversely effect state observers. Of the state observer architectures considered, a distributed system comprising ground based target and own-missile tracking, data up-link, and on-board missile measurement and track fusion is the natural choice for air-defence. An IMM is used to process radar measurements, combining the estimates from filters with different target dynamics. The remote missile state observer combines up-linked target tracks and missile plots with IMU and seeker data to provide optimal guidance information. The performance of traditional PN and CLOS missile guidance is the basis against which on-line trajectory optimisation is judged. Enhanced guidance laws are presented that demand more from the state observers, stressing the importance of time-to-go and transport delays in strap-down systems employing staring array technology. Algorithms for solving the guidance twopoint boundary value problems created from the missile state observer output using gradient projection in function space are presented. A simulation integrating these aspects was developed whose infrastructure, capable of supporting any dynamical model, is described in the air-defence context. MBDA have extended this work creating the Aircraft and Missile Integration Simulation (AMIS) for integrating different launchers and missiles. The maturity of the AMIS makes it a tool for developing pre-launch algorithms for modern air-launched missiles from modern military aircraft.
73

DIFFERENTIAL GPS APPLICATION FOR SEA-SKIMMING AERIAL TARGETS

Spadaro, Martin J. 10 1900 (has links)
International Telemetering Conference Proceedings / October 27-30, 1997 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Low cost, commercial off-the-shelf Global Positioning System (GPS) receivers can be used to provide real-time track of ground launched subsonic, sea-skimming missile targets when integrated with existing telemetry equipment and commercial radio modems. GPS reference stations can be deployed that are capable of generating, broadcasting and monitoring Differential GPS corrections that effectively eliminate the deliberate position errors imposed by the Department of Defense. Commercial GPS receivers are effective and provide contiguous position data even during the boost phase of flight when G forces exceed the receiver manufacturer’s published specifications.
74

Operational assessment of Target Acquisitions Weapons Software (TAWS) prediction performance at Nellis AFB, NV

Hernandez, Jerome H. 03 1900 (has links)
Target Acquisition Weapons Software (TAWS) Version 3.4 is a joint Tactical Decision Aid (TDA) used to predict performance of electro-optic and electro-magnetic (EM/EO) munitions and navigation systems. TAWS is the USAF and USN mission-planning standard for laser-guided, infrared, and TV munitions and navigation systems TDAs. As TAWS continues to deploy through the mission planning community there is a need to establish a systematic approach to assessing TAWS accuracy. This study was an operational assessment of TAWS Infrared (IR) model performance and consisted of two parts: a comparison of model predictions to pilot observations of IR detection range of a static tank target and an assessment of physical temperature predictions. Limiting factors of this project are similar to those encountered in real world utilization of TAWS mission planning TDAs. This evaluation found TAWS predicted detection ranges and target scene model output were representative forecasts of observed values. The TDA provided a good description of background thermal behavior and highlighted the necessity of careful evaluation of the target scene because of component facet complexity and the geometry of facets exposed to the sensor view. The resulting component analysis illuminated the benefit of focusing new TAWS development on improving the target physical model.
75

The research of target costing that applies to constructional investment companies

Yang, Bo-Wen 10 July 2000 (has links)
The real-estate faced serious recession recently in Taiwan, it caused several famous listed constructional investment companies to result in financial crisis. The constructional investment companies made high profit due to real-estate¡¦s prosperity in the past. Currently, it, however, faces heavy pressure on business operation due to recession in the real-estate. The auto-makers in Japan accepts target costing, because it helps companies to combine the cost management and strategic goals to enhance the companies¡¦ competition. The key point of this thesis, therefore, tries to analyze the target costing that applies to constructional investment companies; and ultimately attempts to provide a conceptual system that helps the companies to make decision. The research makes some propositions based on literatures, and other sources. Secondly, the difference between the current operations and target costing is understood. The final step attempts to modify the propositions according to company interviews; and as a result, contributions are made when the constructional investment companies evaluate and implement the target costing.
76

Codeswitching in Swedish ESL Teaching / Kodväxlingi Svenska Skolors Engelskaundervisning

Berg, Niklas January 2013 (has links)
Many studies have shown that use of the target language second and/ or foreign language (in this case English) teaching has greatly improved students' learning, albeit, not all teachers use the target language exclusively but rather switch between the first and target language. This particular study has shown that the teacher in compulsory school does alternate between the target language and the first language for various reasons, while teachers in upper secondary school exclusively use the target language both within and outside the classroom and there are rarely any occurrences of codeswitching among students and teachers. The reasons for this are, because the content which has been taught has been too difficult for the students to understand, or the students have refused to interact in English with both their teacher and fellow students. The teachers' view on the matter tells us that even though they have tried to exclusively use the target language in the English classroom, it has not been working in the manner they wanted it to have. In order to gather data for this research, seven classroom observations have been carried out and to complement them interviews with three teachers have been conducted to get their view on the use of English in their own teaching and why they think codeswitching occurs among students and themselves.
77

An investigation of aiming point strategies for field artillery against area targets

Petersen, Lawrence Carl 08 1900 (has links)
No description available.
78

Is thinking worthwhile? A comparison of corporate segment choice strategies.

Buchta, Christian, Dolnicar, Sara, Freitag, Roman, Leisch, Friedrich, Meyer, David, Mild, Andreas, Ossinger, Martina January 2003 (has links) (PDF)
The field of strategic marketing has long been identified as fruitful ground for gaining competitive advantage. Ever since the market segmentation concept was introduced in the late sixties, research interest steadily increased, covering issues as e.g. which fundamental segmentation strategy is most appropriate, in which ways can segments be identified or constructed, which algorithm provides optimal data-driven segmentation solutions, which number of segments should be constructed etc.. Interestingly, the issue of segment evaluation and choice has not been emphasised very strongly in the past, although this is of primary interest as soon as it comes to practical implementation. This article tries to fill this gap in an experimental manner: the consequences of different corporate segment choice strategies based on different segment evaluation criteria are investigated under different environmental conditions formalised in a complex artificial consumer market. The results indicate that complex decision models for segment choice do not turn out to be superior in general. Both mass marketers and firms concentrating on particular segments based on an a priori logic can be just as successful under "favourable" market conditions, the most influential condition being the available advertising budget. (author's abstract) / Series: Working Papers SFB "Adaptive Information Systems and Modelling in Economics and Management Science"
79

Identification of Downstream Target Genes of the T-cell Oncoprotein HOX11 by Global Gene Expression Profiling

Darcelle@gmail.com, Darcelle Natalie Dixon January 2004 (has links)
HOX11 is a homeodomain transcription factor that has been implicated in leukaemic transformation associated with T-cell acute lymphoblastic leukaemia (T-ALL). Its role in leukaemogenesis remains enigmatic, nevertheless, in vitro and in vivo studies have provided additional evidence supporting the role of HOX11 as an oncogene. The mechanism by which HOX11 transforms cells is yet to be elucidated, however, HOX11 has been postulated to function by binding regulatory elements within the promoter regions of specific target genes in order to control gene transcription. The identification of transcriptional targets is thus thought to be critical to our understanding of the pathways controlled by this master gene regulator. To date, only three candidate HOX11 target genes have been reported and given that HOX11 overexpression can have a profound impact on cell behaviour, it is likely that many more exist. In this study, we sought to further understand the role of HOX11 in tumorigenesis by: 1) The identification of novel putative HOX11 target genes by profiling gene expression in response to HOX11 in a number of cell lines using a combination of RDA, cDNA microarray and GeneChip approaches and 2) confirming target gene status by assessing whether the proximal promoters of the leading candidates identified are transcriptionally regulated by HOX11. To identify genes whose expression was altered by HOX11, three techniques were employed, namely representational difference analysis, cDNA microarray and Affymetrix GeneChip array. Because of the relative novelty of these technologies, all three methods were employed in a complementary manner. While representational difference analysis did not require dedicated equipment and enabled the identification of novel genes, the technique was labour-intensive and also exhibited a number of problems including high levels of background. Emphasis was therefore placed on the more systematic microarray approaches that enabled a global investigation of expression patterns and thus the identification of a range of candidate target genes. Initially, this involved cDNA microarray experiments, however, during the course of this work Affymetrix GeneChip technology became available. The latter was identified as the most appropriate technology for the identification of candidate target genes because of its relative ease of use, as well as its employment of multiple independent probe pairs which greatly improved background noise, increased the range and accuracy of detection, minimized the effects of cross hybridization and drastically reduced the rate of false positives and miscalls. Using these combined approaches, several genes of interest were identified which were differentially regulated in the presence of HOX11 and thus may represent oncogenically or physiologically relevant target genes. These included OSTEOPONTIN, PAG, GUANOSINE DIPHOSPHATE DISSOCIATION INHIBITOR 3, SUR8, GAS3, C-KIT, VEGFC, NOR1 and SMARCD3. In order to confirm their role as target genes, four candidates (C-KIT, VEGFC, NOR1 and SMARCD3) were characterized in terms of the ability of their proximal promoters to be transcriptionally regulated by HOX11 using luciferase reporter assays. Significant repression of the proximal promoters of C-KIT and VEGFC by HOX11 was observed, which provided further evidence for their status as target genes. This repression was, however, in stark contrast to the transcriptional activation seen when the C-KIT and VEGFC proximal promoters were co-transfected with a HOX11 mutant lacking the third helix of the DNA-binding homeodomain. This unexpected finding suggested that the transcriptional activity of HOX11 is complex and highly context-dependent, and in particular, highlighted the importance of an intact homeodomain for HOX11 function. C-KIT and VEGFC are both involved in tyrosine kinase signal transduction pathways, as a receptor tyrosine kinase and tyrosine kinase ligand, respectively. C-KIT plays an important role in the survival and self-renewal of haematopoietic cells. It is a previously identified and relatively well characterized oncogene known to be regulated by other transcription factors (SCL/TAL1 and LMO) implicated in the pathogenesis of T-ALL. VEGFC is a member of the vascular endothelial growth factor family that functions in angiogenesis and lymphangiogenesis. A paracrine loop involving VEGFC and its receptor VEGFR-3 has previously been implicated in leukaemic cell survival. While further work is required in order to confirm the status of VEGFC and C-KIT as oncogenically-relevant HOX11 target genes and to characterize their exact mode of regulation, these findings implicate receptor tyrosine kinases in HOX11-mediated tumorigenesis and underscore their potential importance as therapeutic targets in haematological malignancies.
80

The wrong target : the problem of mistargeting resulting in fratricide and civilian casualties /

Rasmussen, Robert E. January 1900 (has links)
Thesis (M.S. in Joint Campaign Planning and Strategy)--Joint Forces Staff College, Joint Advanced Warfighting School, 2007. / Vita. "National Defense Univ Norfolk VA"--DTIC cover. "13 May 2007." Includes bibliographical references (p. 66-70). Also available via the Internet.

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