Monitoring of liquid flow through microtubes using a micropressure sensor

The pressure-driven liquid flow through microtubes was studied in a range of very low Reynolds numbers (<0.15) by monitoring the pressure change in situ. Cylindrical microtubes with diameters ranging from 50 ?m to 500 ?m were examined and two types of tube material, namely PEEK polymer and fused silica were compared. A good linear relation for the pressure drop versus flow rate was obtained. Apparent deviations between the measured slopes with those calculated using conventional theory were attributed to uncertainties in the calculated values which are dominated by the uncertainties in the microtube diameters. It was found that a period of stabilisation time was required for reaching a steady flow after the syringe pump was switched on/off or to a different flow rate. The stabilisation time was likely due to the compressibility of the fluid. Insignificant difference between PEEK polymer and fused silica microtubes in terms of flow resistance was observed. The in-situ measurement of pressure drops provides a convenient approach for monitoring fluid flow through microtubes and detecting dimensional changes within microchannels in Lab-on-a-Chip and microreactor systems

Sense of agency, associative learning, and schizotypy

Despite the fact that the role of learning is recognised in empirical and theoretical work on sense of agency (SoA), the nature of this learning has, rather surprisingly, received little attention. In the present study we consider the contribution of associative mechanisms to SoA. SoA can be measured quantitatively as a temporal linkage between voluntary actions and their external effects. Using an outcome blocking procedure, it was shown that training action-outcome associations under conditions of increased surprise augmented this temporal linkage. Moreover, these effects of surprise were correlated with schizotypy scores, suggesting that individual differences in higher level experiences are related to associative learning and to its impact on SoA. These results are discussed in terms of models of SoA, and our understanding of disrupted SoA in certain disorders

Lie algebras: infinite generalizations and deformations

There are many applications of Lie algebras to theoretical physics. This thesis is a study of some new mathematical structures which also are applicable to current physical ideas. The structures studied are Lie algebras of infinite dimension and the deformations of Lie algebras known as quantum algebras. The approach is algebraic, although physical applications are indicated. Chapter 1 The mathematics of finite and infinite dimensional Lie algebras is reviewed, together with an indication of well established uses in physics. The terms and notation used in the rest of the thesis are introduced. Chapter 2 Explicit examples of new infinite dimensional algebras of a type related to the algebras of conformal transformations on arbitrary genus Riemann surfaces are given. The relationship of these algebras to the Virasoro algebra is discussed. Chapter 3 The sine algebra is introduced and its relationship to the Moyal bracket discussed. The finite Lie algebras are given in a trigonometric basis. The many applications of the Moyal algebra are reviewed. Chapter 4 An original proof of the uniqueness of the Moyal algebra is presented. It is shown that the Moyal bracket is the most general Lie bracket of functions of two variables, and thus that the underlying associative star product is unique. It follows that all 2-index Lie algebras correspond to the Moyal algebra in some basis. Chapter 5 Quantum deformations of Lie algebras, or quantum algebras, are introduced. The many deformations of su(2) are described and the associativity conditions are discussed. Some new higher dimensional and infinite dimensional quantum algebras are given. Chapter 6 Quantum groups are discussed as groups of transformations of the quantum plane. Higher dimensional quantum groups and quantum supergroups are also described

Characterizing and Predicting Human Visual Perception of Unmanned Aerial Vehicle Gestures

Unmanned Aerial Vehicles (UAVs) are being used in public domains and hazardous environments where effective communication strategies are critical. UAV gesture techniques have been shown to communicate meaning to human observers and may be ideal in contexts that require lightweight systems such as unmanned aerial flight, however, this work may be limited to an idealized range of viewer perspectives. As gesture is a visual communication technique it is necessary to consider how the perception of a robot gesture may suffer from obfuscation or self-occlusion from some viewpoints. This thesis presents the results of three online user-studies that examine participants’ ability to accurately perceive the intended shape of two-dimensional UAV gestures from varying viewer perspectives. We used a logistic regression model to characterize participant gesture classification accuracy, demonstrating that viewer perspective does impact how participants perceive the shape of UAV gestures. Our results yielded a viewpoint angle threshold from beyond which participants were able to assess the intended shape of a gesture’s motion with 90% accuracy. We also present methods for prediction of intraset gesture differentiability and viewpoint perceptibility. We demonstrate that differentiability is correlated to trajectory difference measures and viewpoint perceptibilty can be predicted within one standard error of mean participant responses. These findings will enable UAV gesture systems that, with a high degree of confidence, ensure gesture motions can be accurately perceived by human observers. Advisors: Brittany Duncan and Carrick Detweile

The uses and limitations of telegrams in official correspondence between Ceylon's Governor General and the Secretary of State for the Colonies, circa 1870-1900

'Dieser Artikel stellt einige Beispiele des Gebrauchs von Telegrammen im Austausch offizieller Korrespondenz von Ceylons Gouverneur und dem Secretary of State for the Colonies vor. Er versucht außerdem zu beschreiben, wo dabei die Grenzen der Verwendung von Telegrammen lagen. Die Analyse in diesem Artikel beginnt mit dem Jahr 1870 - nachdem der telegraphische Nachrichtenverkehr zwischen Ceylon und England durch Ceylons Verbindung zum Roten-Meer-Kabel über den Anschluss nach Madras in Indien aufgebaut und stabil war. Der Untersuchungszeitraum endet mit der Wende zum 20. Jahrhundert aus Gründen der zeitlichen Rahmung. Das verwendete Material umfasst Telegramme und Briefe aus den Aufzeichnungen von Ceylons Originalkorrespondenz, die in den Nationalarchiven in Kew, London, aufbewahrt werden.' (Autorenreferat)'This article attempts to provide some examples of Ceylon's Governor's and the Secretary of State for the Colonies' uses of telegrams in communicating official correspondence. It also tries to describe the limitations of using telegrams to this end. The analysis of the article starts from 1870 - after telegraphic communication between Ceylon and England became established and stable by Ceylon's connection to the Red Sea Cable through its telegraphic link with Madras, India. The period of examination of this article ends right around the turn of the twentieth-century, for reasons of frame. The materials consulted herein include telegrams and letters found in Ceylon's original correspondence records kept at the National Archives in Kew, London.' (author's abstract

Optimizing the roles of unit and non-unit protection methods within DC microgrids

The characteristic behavior of physically compact, multiterminal dc networks under electrical fault conditions can produce demanding protection requirements. This represents a significant barrier to more widespread adoption of dc power distribution for microgrid applications. Protection schemes have been proposed within literature for such networks based around the use of non-unit protection methods. This paper shows however that there are severe limitations to the effectiveness of such schemes when employed for more complex microgrid network architectures. Even current differential schemes, which offer a more effective, though costly, protection solution, must be carefully designed to meet the design requirements resulting from the unique fault characteristics of dc microgrids. This paper presents a detailed analysis of dc microgrid behavior under fault conditions, illustrating the challenging protection requirements and demonstrating the shortcomings of non-unit approaches for these applications. Whilst the performance requirements for the effective operation of differential schemes in dc microgrids are shown to be stringent, the authors show how these may be met using COTS technologies. The culmination of this work is the proposal of a flexible protection scheme design framework for dc microgrid applications which enables the required levels of fault discrimination to be achieved whilst minimizing the associated installation costs

The valuation of railroads

Thesis (B.S.)--University of Illinois, 1914.Typescript and ms.Includes bibliographical references

Design and implementation of extensible middleware for non-repudiable interactions

PhD ThesisNon-repudiation is an aspect of security that is concerned with the creation of irrefutable audits of an interaction. Ensuring the audit is irrefutable and verifiable by a third party is not a trivial task. A lot of supporting infrastructure is required which adds large expense to the interaction. This infrastructure comprises, (i) a non-repudiation aware run-time environment, (ii) several purpose built trusted services and (iii) an appropriate non-repudiation protocol. This thesis presents design and implementation of such an infrastructure. The runtime environment makes use of several trusted services to achieve external verification of the audit trail. Non-repudiation is achieved by executing fair non-repudiation protocols. The Fairness property of the non-repudiation protocol allows a participant to protect their own interests by preventing any party from gaining an advantage by misbehaviour. The infrastructure has two novel aspects; extensibility and support for automated implementation of protocols. Extensibility is achieved by implementing the infrastructure in middleware and by presenting a large variety of non-repudiable business interaction patterns to the application (a non-repudiable interaction pattern is a higher level protocol composed from one or more non-repudiation protocols). The middleware is highly configurable allowing new non-repudiation protocols and interaction patterns to be easily added, without disrupting the application. This thesis presents a rigorous mechanism for automated implementation of non-repudiation protocols. This ensures that the protocol being executed is that which was intended and verified by the protocol designer. A family of non-repudiation protocols are taken and inspected. This inspection allows a set of generic finite state machines to be produced. These finite state machines can be used to maintain protocol state and manage the sending and receiving of appropriate protocol messages. A concrete implementation of the run-time environment and the protocol generation techniques is presented. This implementation is based on industry supported Web service standards and services.EPSRC, The Hewlett Packard Arjuna La