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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.
441

Assessment of software measurement

Berry, Michael, CSE, UNSW January 2006 (has links)
Background and purpose. This thesis documents a program of five studies concerned with the assessment of software measurement. The goal of this program is to assist the software industry to improve the information support for managers, analysts and software engineers by providing evidence of where opportunities for improving measurement and analysis exist. Methods. The first study examined the assessment of software measurement frameworks using models of best practice based on performance/success factors. The software measurement frameworks of thirteen organisations were surveyed. The association between a factor and the outcome experienced with the organisations' frameworks was then evaluated. The subsequent studies were more info-centric and investigated using models of information quality to assess the support provided for software processes. For these studies, information quality models targeting specific software processes were developed using practitioner focus groups. The models were instantiated in survey instruments and the responses were analysed to identify opportunities to improve the information support provided. The final study compared the use of two different information quality models for the assessing and improving information support. Assessments of the same quantum of information were made using a targeted model and a generic model. The assessments were then evaluated by an expert panel in order to identify which information quality model was more effective for improvement purposes. Results. The study of performance factors for software measurement frameworks confirmed the association of some factors with success and quantified that association. In particular, it demonstrated the importance of evaluating contextual factors. The conclusion is that factor-based models may be appropriately used for risk analysis and for identifying constraints on measurement performance. Note, however, that a follow-up study showed that some initially successful frameworks subsequently failed. This implied an instability in the dependent variable, success, that could reduce the value of factor-based models for predicting success. The studies of targeted information quality models demonstrated the effectiveness of targeted assessments for identifying improvement opportunities and suggest that they are likely to be more effective for improvement purposes than using generic information quality models. The studies also showed the effectiveness of importance-performance analysis for prioritizing improvement opportunities.
442

Jauge conforme des espaces métriques compacts

Carrasco Piaggio, Matias 25 October 2011 (has links) (PDF)
L'objet principal de cette thèse est l'étude de la dimension conforme Ahlfors régulière ($\dim_{AR}X$) d'un espace métrique $X$. C'est un invariant numérique par quasisymétrie, introduit par P.\,Pansu, permettant la classification à quasi-isométrie près des espaces homogénes de courbure négative. Elle joue actuellement un rôle important en théorie géométrique des groupes et en dynamique conforme. A partir d'une suite de recouvrements d'un espace métrique compact $\left(X,d\right)$, on construit des distances de dimension contrôlée appartenant à la jauge conforme (Ahlfors régulière). On peut ainsi caractériser toutes les métriques de la jauge á homéomorphismes bi-Lipschitz prés. On montre comment calculer $\dim_{AR}X$ á partir de modules combinatoires en considérant un exposant critique $Q_N$. Comme conséquence de l'égalité $\dim_{AR}X=Q_N$, on obtient un critère général de dimension $1$. Les conditions sont données en termes de points de coupure locale de $X$. On donne par ailleurs des applications de ces résultats aux bords des groupes hyperboliques et aux ensembles de Julia des fractions rationnelles semihyperboliques.
443

Körperbau, Gelenkbeweglichkeit und Handkräfte Erwachsener im Generationenvergleich / Body type, joint flexibility and hand forces of adults in generation comparism

Voigt, Andrea January 2008 (has links)
Die ergonomische Anpassung von Produkten der körpernahen Umwelt an den menschlichen Körper in seiner gesamten Variabilität erfordert anthropometrische Grundlagen. Die vorliegende Arbeit beschreibt und analysiert die Körpermasse, 17 Längenmaße, 5 Skelettrobustizitätsmaße, 6 Korpulenzmaße, 3 Kopfmaße, 5 Handmaße, 3 Fußmaße, sowie 10 Beweglichkeitsmaße der Wirbelsäule, 8 Beweglichkeitsmaße der Hand, 2 Beweglichkeitsmaße des Beines und 7 Handkräfte von 295 Probanden der drei Altersgruppen 20 bis 29 Jahre, 50 bis 59 Jahre und 60 bis 69 Jahre. Die Untersuchungen wurden im Zeitraum von September 2006 bis April 2007 durchgeführt. Ziel der Arbeit ist es, für den überwiegenden Teil der untersuchten körperlichen Merkmale erstmals für die deutsche Bevölkerung geschlechts- und altersspezifische Mittelwerte und Variabilitätsbereiche bis zum vollendeten 70. Lebensjahr zur Verfügung zu stellen. Das gilt insbesondere für die untersuchten Beweglichkeitsmaße und Handkräfte. Erstmals werden Korrelationen zwischen der Körperform, wie sie sich im Maßzusammenhang der unterschiedlichen Körperbautypen darstellt, der Gelenkbeweglichkeit und den Handkräften vorgestellt. Darüber hinaus wird durch den Vergleich der Ergebnisse der jungen und der beiden älteren Erwachsenengruppen untersucht, welche Unterschiede zwischen den verschiedenen Altersgruppen bestehen. Im Hinblick auf die zeitliche Gültigkeit der aktuellen Untersuchungsergebnisse werden der Einfluss des säkularen Trends und der Einfluss der ontogenetischen Alternsprozesse auf Längenmaße und Korpulenzmaße diskutiert. Die Arbeit zeigt auf, dass innerhalb der untersuchten Probanden eine große Variationsbreite in den Körpermaßen auftritt. Es lassen sich typische Altersunterschiede erkennen. Die Älteren sind im Mittel kleiner, weisen jedoch größere Skelettrobustizitäts- und Korpulenzmaße auf. Die dynamischen Maße weisen auf eine geringere Beweglichkeit der Wirbelsäule, teilweise auch der Hand hin. Die Handkräfte der Frauen werden mit zunehmendem Alter geringer, bei den Männern sind die Älteren kräftiger als die jungen Erwachsenen. Die Ergebnisse deuten auf einen gegenüber früheren Generationen verzögerten Beginn von körperlichen Alterserscheinungen hin, der im Hinblick auf die steigende Lebenserwartung der Bevölkerung eingehender untersucht werden sollte. / The ergonomic adaptation of products of the body close environment to the human body in its whole variability requires an anthropometric basis. The present work describes and analyses the body weight, 17 longitudinal, 5 skeletal and 6 corpulence dimensions of the human body, 3 head dimensions, 5 hand measurements, 3 foot measurements, as well as 10 measurements of the mobility of the spine, 8 mobility measurements of the hand, 2 mobility measurements of the leg and 7 hand forces of 295 test persons of the three age groups 20 to 29 years, 50 to 59 years and 60 to 69 years. The investigations were carried out in the period from September 2006 to April 2007 in Wolfsburg and Potsdam, Germany. The aim of the work is to make available averages and variability areas specific for age and specific for men and women up to the 70th birthday for the German population. This is valid in particular for the examined mobility measurements and hand forces. For the first time correlations are introduced between different body types and joint mobility and hand forces. In addition, it is examined by the comparison of the results of the young ones and both older adult's groups which differences exist between the examined age groups. With regard to the temporal validity of the investigation results the influence of the secular trend and the influence of the ontogenetic ageing processes on longitudinal and corpulence dimensions of the human body are discussed. The work indicates that within the examined test persons a big variation width appears in body measurements. Typical age differences exist. The older people are smaller on average, nevertheless, they show bigger skeletal and corpulence dimensions. The dynamic measurements point to a lower mobility of the spine, partially also of the hand. The hand forces of the women become lower with increasing age. In men the older test persons are stronger than the young adults. The results point to a delayed beginning of physical signs of ageing compared to former generations.
444

Using a common accessibility profile to improve accessibility

Fourney, David W. 03 December 2007
People have difficulties using computers. Some have more difficulties than others. There is a need for guidance in how to evaluate and improve the accessibility of systems for users. Since different users have considerably different accessibility needs, accessibility is a very complex issue.<p>ISO 9241-171 defines accessibility as the "usability of a product, service, environment or facility by people with the widest range of capabilities." While this definition can help manufacturers make their products more accessible to more people, it does not ensure that a given product is accessible to a particular individual.<p>A reference model is presented to act as a theoretical foundation. This Universal Access Reference Model (UARM) focuses on the accessibility of the interaction between users and systems, and provides a mechanism to share knowledge and abilities between users and systems. The UARM also suggests the role assistive technologies (ATs) can play in this interaction. The Common Accessibility Profile (CAP), which is based on the UARM, can be used to describe accessibility.<p>The CAP is a framework for identifying the accessibility issues of individual users with particular systems configurations. It profiles the capabilities of systems and users to communicate. The CAP can also profile environmental interference to this communication and the use of ATs to transform communication abilities. The CAP model can be extended as further general or domain specific requirements are standardized.<p>The CAP provides a model that can be used to structure various specifications in a manner that, in the future, will allow computational combination and comparison of profiles.<p>Recognizing its potential impact, the CAP is now being standardized by the User Interface subcommittee the International Organization for Standardization and the International Electrotechnical Commission.
445

Hrushovski and Ramsey Properties of Classes of Finite Inner Product Structures, Finite Euclidean Metric Spaces, and Boron Trees

Jasinski, Jakub 31 August 2011 (has links)
We investigate two combinatorial properties of classes of finite structures, as well as related applications to topological dynamics. Using the Hrushovski property of classes of finite structures -- a finite extension property of homomorphisms -- we can show the existence of ample generics. For example, Solecki proved the existence of ample generics in the context of finite metric spaces that do indeed possess this extension property. Furthermore, Kechris, Pestov and Todorcevic have shown that the Ramsey property of Fraisse classes of finite structures implies that the automorphism group of the corresponding Fraisse limit is extremely amenable, i.e., it possesses a very strong fixed point property. Gromov and Milman had shown that the unitary group of the infinite-dimensional separable Hilbert space is extremely amenable using non-combinatorial methods. This result encourages a deeper look into structural Euclidean Ramsey theory, i.e., Euclidean Ramsey theory in which we colour more than just points. In particular, we look at complete finite labeled graphs whose vertex sets are subsets of the Hilbert space and whose labels correspond to the inner products. We prove "Ramsey-type" and "Hrushovski-type" theorems for linearly ordered metric subspaces of "sufficiently" orthogonal sets. In particular, the latter is used to show a "Hrushovski version" of the Ramsey-type Matousek-Rodl theorem for simplices. It is known that the square root of the metric induced by the distance between vertices in graphs produces a metric space embeddable in a Euclidean space if and only if the graph is a metric subgraph of the Cartesian product of three types of graphs. These three are the half-cube graphs, the so-called cocktail party graphs, and the Gosset graph. We show that the class of metric spaces related to half-cube graphs -- metric spaces on sets with the symmetric difference metric -- satisfies the Hrushovski property up to 3 points, but not more. Moreover, the amalgamation in this class can be too restrictive to permit the Ramsey Property. Finally, following the work of Fouche, we compute the Ramsey degrees of structures induced by the leaf sets of boron trees. Also, we briefly show that this class does not satisfy the full Hrushovski property. Fouche's trees are in fact related to ultrametric spaces, as was observed by Lionel Nguyen van The. We augment Fouche's concept of orientation so that it applies to these boron tree structures. The upper bound computation of the Ramsey degree in this case, turns out to be an "asymmetric" version of the Graham-Rothschild theorem. Finally, we extend these structures to "oriented" ones, yielding a Ramsey class and a corresponding Fraisse limit whose automorphism group is extremely amenable.
446

Hrushovski and Ramsey Properties of Classes of Finite Inner Product Structures, Finite Euclidean Metric Spaces, and Boron Trees

Jasinski, Jakub 31 August 2011 (has links)
We investigate two combinatorial properties of classes of finite structures, as well as related applications to topological dynamics. Using the Hrushovski property of classes of finite structures -- a finite extension property of homomorphisms -- we can show the existence of ample generics. For example, Solecki proved the existence of ample generics in the context of finite metric spaces that do indeed possess this extension property. Furthermore, Kechris, Pestov and Todorcevic have shown that the Ramsey property of Fraisse classes of finite structures implies that the automorphism group of the corresponding Fraisse limit is extremely amenable, i.e., it possesses a very strong fixed point property. Gromov and Milman had shown that the unitary group of the infinite-dimensional separable Hilbert space is extremely amenable using non-combinatorial methods. This result encourages a deeper look into structural Euclidean Ramsey theory, i.e., Euclidean Ramsey theory in which we colour more than just points. In particular, we look at complete finite labeled graphs whose vertex sets are subsets of the Hilbert space and whose labels correspond to the inner products. We prove "Ramsey-type" and "Hrushovski-type" theorems for linearly ordered metric subspaces of "sufficiently" orthogonal sets. In particular, the latter is used to show a "Hrushovski version" of the Ramsey-type Matousek-Rodl theorem for simplices. It is known that the square root of the metric induced by the distance between vertices in graphs produces a metric space embeddable in a Euclidean space if and only if the graph is a metric subgraph of the Cartesian product of three types of graphs. These three are the half-cube graphs, the so-called cocktail party graphs, and the Gosset graph. We show that the class of metric spaces related to half-cube graphs -- metric spaces on sets with the symmetric difference metric -- satisfies the Hrushovski property up to 3 points, but not more. Moreover, the amalgamation in this class can be too restrictive to permit the Ramsey Property. Finally, following the work of Fouche, we compute the Ramsey degrees of structures induced by the leaf sets of boron trees. Also, we briefly show that this class does not satisfy the full Hrushovski property. Fouche's trees are in fact related to ultrametric spaces, as was observed by Lionel Nguyen van The. We augment Fouche's concept of orientation so that it applies to these boron tree structures. The upper bound computation of the Ramsey degree in this case, turns out to be an "asymmetric" version of the Graham-Rothschild theorem. Finally, we extend these structures to "oriented" ones, yielding a Ramsey class and a corresponding Fraisse limit whose automorphism group is extremely amenable.
447

Security metric based risk assessment.

Khan, Moazzam 30 April 2013 (has links)
Modern day computer networks have become very complex and attackers have benefited due to this complexity and have found vulnerabilities and loopholes in the network architecture. In order to identify the attacks from an attacker all aspects of network architecture needs to be carefully examined such as packet headers, network scans, versions of applications, network scans, network anomalies etc. and after the examination attributes playing a significant impact on the security posture of the organization needs to be highlighted so that resources and efforts are directed towards those attributes. In this work we extensively look at network traffic at dormitory network of a large campus and try to identify the attributes that play a significant role in the infection of a machine. Our scheme is to collect as much attributes from the network traffic applying the heuristic of network infection and then devise a scheme called decision centric rank ordering of security metric that gives the priority to the security metrics so that network administrators can channel their efforts in the right direction. Another aspect of this research is to identify the probability of an attack on a communication infrastructure. A communication infrastructure becomes prone to attack if certain elements exist in it, such as vulnerabilities in the comprising elements of the system, existence of an attacker and motivation for him to attack. Focus of this study is on vulnerability assessment and security metrics such as user behavior, operating systems, user applications, and software updates. To achieve a quantified value of risk, a set of machines is carefully observed for the security metrics. Statistical analysis is applied on the data collected from compromised machines and the quantified value of risk is achieved.
448

Using a common accessibility profile to improve accessibility

Fourney, David W. 03 December 2007 (has links)
People have difficulties using computers. Some have more difficulties than others. There is a need for guidance in how to evaluate and improve the accessibility of systems for users. Since different users have considerably different accessibility needs, accessibility is a very complex issue.<p>ISO 9241-171 defines accessibility as the "usability of a product, service, environment or facility by people with the widest range of capabilities." While this definition can help manufacturers make their products more accessible to more people, it does not ensure that a given product is accessible to a particular individual.<p>A reference model is presented to act as a theoretical foundation. This Universal Access Reference Model (UARM) focuses on the accessibility of the interaction between users and systems, and provides a mechanism to share knowledge and abilities between users and systems. The UARM also suggests the role assistive technologies (ATs) can play in this interaction. The Common Accessibility Profile (CAP), which is based on the UARM, can be used to describe accessibility.<p>The CAP is a framework for identifying the accessibility issues of individual users with particular systems configurations. It profiles the capabilities of systems and users to communicate. The CAP can also profile environmental interference to this communication and the use of ATs to transform communication abilities. The CAP model can be extended as further general or domain specific requirements are standardized.<p>The CAP provides a model that can be used to structure various specifications in a manner that, in the future, will allow computational combination and comparison of profiles.<p>Recognizing its potential impact, the CAP is now being standardized by the User Interface subcommittee the International Organization for Standardization and the International Electrotechnical Commission.
449

Metrical Problems in Minkowski Geometry

Fankhänel, Andreas 19 October 2012 (has links) (PDF)
In this dissertation we study basic metrical properties of 2-dimensional normed linear spaces, so-called (Minkowski or) normed planes. In the first chapter we introduce a notion of angular measure, and we investigate under what conditions certain angular measures in a Minkowski plane exist. We show that only the Euclidean angular measure has the property that in an isosceles triangle the base angles are of equal size. However, angular measures with the property that the angle between orthogonal vectors has a value of pi/2, i.e, a quarter of the full circle, exist in a wider variety of normed planes, depending on the type of orthogonality. Due to this we have a closer look at isosceles and Birkhoff orthogonality. Finally, we present results concerning angular bisectors. In the second chapter we pay attention to convex quadrilaterals. We give definitions of different types of rectangles and rhombi and analyse under what conditions they coincide. Combinations of defining properties of rectangles and rhombi will yield squares, and we will see that any two types of squares are equal if and only if the plane is Euclidean. Additionally, we define a ``new\'\' type of quadrilaterals, the so-called codises. Since codises and rectangles coincide in Radon planes, we will explain why it makes sense to distinguish these two notions. For this purpose we introduce the concept of associated parallelograms. Finally we will deal with metrically defined conics, i.e., with analogues of conic sections in normed planes. We define metric ellipses (hyperbolas) as loci of points that have constant sum (difference) of distances to two given points, the so-called foci. Also we define metric parabolas as loci of points whose distance to a given point equals the distance to a fixed line. We present connections between the shape of the unit ball B and the shape of conics. More precisely, we will see that straight segments and corner points of B cause, under certain conditions, that conics have straight segments and corner points, too. Afterwards we consider intersecting ellipses and hyperbolas with identical foci. We prove that in special Minkowski planes, namely in the subfamily of polygonal planes, confocal ellipses and hyperbolas intersect in a way called Birkhoff orthogonal, whenever the respective ellipse is large enough.
450

Study of the sonic apparatus of ophidiid fishes from Taiwan

Ou-Yang, Jui 01 September 2010 (has links)
Ophidiidae are major benthopelagic fishes with wide distribution and depth range. Three types of sonic structural patterns have been described in some studied ophidiid fishes, however, the significance of the different types of the sonic apparatus, and the distribution in the subfamilies remain unclear. In addition, although the sonic apparatus and the sonic mechanisms of the high frequency sounds produced by cusk-eels has been explained, the characteristics of extrinsic swimbladder sonic muscle is still unknown. In this study, I investigated three ophidiid subfamilies from Taiwan and reviewed the published data to study the morphological traits of their sonic apparatus. Inaddition, Hoplobrotula armata were related to study the proteomic characterization of the extrinsic swimbladder sonic muscle. Results indicate that the 13 ophidiid species in this study could be grouped into five sonic structural patterns, and three subfamilies could be separated accordingly. Furthermore, because the sister group of the family Ophidiidae-carapidae is soniferous, I suggest that the common ancestor of the three ophidiid subfamilies should also be soniferous. Comparisons made in regarded to environmental factors indicate that diversity of sonic apparatus in three ophidiids subfamiliesis depth dependent. The extrinsic swimbladder sonic muscles could be separated into ventral sonic muscle and intermediate sonic muscle. The histological cross-sections of the ventral sonic muscle fibers show peripheral ring myofibrillar region and central core and they are similar with the sonic muscle. Ventral muscle weights were higher in males than females, but the muscle fibers are smaller in males. Protein values of ventral sonic muscles showed high expression in fast and long duration constructional proteins, and males were higher in protein expression than females. Intermediate sonic muscles, on the other hand, were larger in females than males. The cross-sections of muscle fibers were similar to the white muscle. Expression in the fast constructional related protein in the intermediate sonic muscle was higher than ventral sonic muscles, and the metabolically related protein was lower than ventral sonic muscles. The phylogeny of ophidiiform fishes is not clear at present; the sonic-apparatus diversity in ophidiid fishes observed in this study becomes useful to reveal the relationship phylogenetic of ophidiids fishes. Regard the physiology of sound production, I suggest that the larger ventral sonic muscle in males are be provides a better constructional ability, and their smaller fibers are adaptative for energy metabolism regarded for continuous fast constraction and fatigue resistance. The longer intermediate sonic muscle in females is a better constructional ability than male. In intermediate sonic muscle were be fast constructional related protein, higher in expression than the ventral sonic muscles, the metabolic related protein was lower than the ventral sonic muscles. These results suggest that the intermediate sonic muscle has a hight constructional ability but has a disventage of being easily fatigue.

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