京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第18947号 / 工博第3989号 / 新制||工||1614(附属図書館) / 31898 / 京都大学大学院工学研究科航空宇宙工学専攻 / (主査)教授 泉田 啓, 教授 琵琶 志朗, 教授 西脇 眞二 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

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Formal studies of models of concurrency are usually focused on two major models: Interleaving abstraction (Bergstra, 2001; Milner, 1990) and partially ordered causality (Diekert and Rozenberg, 1995; Jensen, 1997; Reisig, 1998). Although very mature, these models retain a known limitation: Neither of them can model the “not later than” relationship effectively, which causes problems with specifying priorities, error recovery, time testing, inhibitor nets, etc. See for reference: Best and Koutny (1992); Janicki (2008); Janicki and Koutny (1995); Juhas et al. (2006); Kleijn and Koutny (2004). A solution, proposed independently (in this order) in (Lamport, 1986; Gaifman and Pratt, 1987) and (Janicki and Koutny, 1991), suggests to model concurrent behaviours by an ordered structure, i.e. a triple (X, R1, R2), where X is the set of event occurrences, and R1 and R2 are two binary relations on X. The relation R1 is interpreted as “causality”, i.e. an abstraction of the “earlier than” relationship, and R2 is interpreted as “weak causality”, an abstraction of the “not later than” relationship. For ordered structures’ model, the following two kinds of relational structures are of special importance: stratified order structures (SO-structures) and interval order structures (IO-structures). The SO-structures can fully model concurrent behaviours when system executions (operational semantics) are described in terms of stratified orders, while the IO-structures can fully model concurrent behaviours when system executions are described in terms of interval orders (Janicki, 2008; Janicki and Koutny, 1997). It was argued in (Janicki and Koutny, 1993), and also implicitly in a 1914 Wiener’s paper Wiener (1914), that any execution that can be observed by a single observer must be an interval order. Thus, IO-structures provide a very definitive model of concurrency. However, the theory of IO-structures remains far less developed than its simpler counterpart - the theory of SO-structures. One of the most important concepts lying at the core of partial orders and algebraic structures theory is the concept of transitive closure of relations. The equivalent of transitive closure for SO-structures, called <>-closure, has been proposed in (Janicki and Koutny, 1995) and consequently used in (Janicki and Koutny, 1995; Juhas et al., 2006; Kleijn and Koutny, 2004) and others. However, a similar concept for IO-structures has not been proposed. In this thesis we define that concept. We introduce the transitive closure for IO-structures, called the []-closure. We prove that it has same properties as the standard transitive closure for partial orders and []-closure for SO-structures (published in Janicki and Zubkova (2009); Janicki et al. (2009)), and provide some comparison of different versions of transitive closure used in various relational structures. Some properties of another recently introduced *-closure (Janicki et al., 2013) are also discussed. / Thesis / Master of Science (MSc)

Increasing costs for space shuttle missions translate to smaller, lighter, and more flexible satellites that maintain or improve current dynamic requirements. This is especially true for optical systems and surfaces. Lightweight, inflatable structures, otherwise known as gossamer structures, are smaller, lighter, and more flexible than current satellite technology. Unfortunately, little research has been performed investigating cost effective and feasible methods of dynamic analysis and control of these structures due to their inherent, non-linear dynamic properties. Gossamer spacecraft have the potential of introducing lenses and membrane arrays in orbit on the order of 25 m in diameter. With such huge structures in space, imaging resolution and communication transmissibility will correspondingly increase in orders of magnitude. A daunting problem facing gossamer spacecraft is their highly flexible nature. Previous attempts at ground testing have produced only localized deformation of the structure's skin rather than excitation of the global (entire structure's) modes. Unfortunately, the global modes are necessary for model parameter verification. The motivation of this research is to find an effective and repeatable methodology for obtaining the dynamic response characteristics of a flexible, inflatable structure. By obtaining the dynamic response characteristics, a suitable control technique may be developed to effectively control the structure's vibration. Smart materials can be used for both active dynamic analysis as well as active control. In particular, piezoelectric materials, which demonstrate electro-mechanical coupling, are able to sense vibration and consequently can be integrated into a control scheme to reduce such vibration. Using smart materials to develop a vibration analysis and control algorithm for a gossamer space structure will fulfill the current requirements of space satellite systems. Smart materials will help spawn the next generation of space satellite technology. / Master of Science

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Yes / Buildings and construction have been identified as having the greatest potential for circular economy value creation. One source of value creation is to recover and reuse building products from end-of-service-life buildings, rather than destructive demolition and downcycling. While there is a trade in non-structural and heritage product recovery and reuse, the largest volume, mass and value of most buildings comprise structural elements – concrete, brick and masonry, and steel – which present many challenges. A comprehensive literature review confirms limited attention to innovation and advanced techniques to address these challenges and therefore the potential reuse of the stocks of accumulated building products globally and associated environmental benefits. Potential techniques being tested in an Engineering and Physical Sciences Research Council circular economy research programme are referenced as a key building block towards circular economy building system redesign. / Engineering and Physical Sciences Research Council - research project Rebuild (EPSRC EP/P008917/1)

Published Article / There have been numerous national- and international-level calls for the reform of engineering education. This includes the need for a shift to a knowledge economy - one that utilises knowledge as the key engine of competitive growth. However, despite several initiatives to address reform, relatively little has changed in the content and conduct of engineering education. It has been argued that engineering education has entered a period where changes are required, but that the management structures that are in place do not provide the needed support to encourage and facilitate these changes in order to promote innovation. The current study employed a multiple case study method to explore challenges faced by the deans of four engineering faculties in four non-adjacent countries and to explain the organisational structures and management processes employed to deal with these challenges in their unique contexts. The analysis identified four areas of challenges and innovative structures and management practices that can be transferred and implemented in other contexts.

This thesis describes a new computer-based method for the generation of finite element meshes. It relies upon the Schwarz-Christoffel transformation, a conformal mapping from conplex variable theory. This mapping is defined and some examples of its use in classical fluid dynamics are given. A practical method for evaluating the parameters defining this transformation is described and emphasis is placed on the efficiency of the solution process in order that coirputer run times may be kept as short as possible. A theorem in Euclidean geometry is stated and proved which links the theory of the Schwarz-Christoffel mapping and the geometrical use to which it is put here. Two such Schwarz-Christoffel transformations are used to construct a mapping between any two polygons. The desirable properties of a finite element mesh are stated and a method is described which atteirpts to generate such a mesh in any sinply-connected two-dimensional region. Numbering of the nodes is an inherent part of the generation scheme, thus ensuring that the optimum bandwidth of the resulting system of linear equations in the analysis phase is obtained. In order to be able to present example meshes, a particular element type, the three-noded triangle, is used and a section describing the enumeration of hexagons, all of whose internal angles are 2n/3, is included. The thesis includes a brief survey of existing methods of two-dimensional mesh generation as well as several example meshes.

International Telemetering Conference Proceedings / October 28-31, 1996 / Town and Country Hotel and Convention Center, San Diego, California / The Interactive Analysis and Display System (IADS) provides the structures flight test engineer with enhanced test-data processing, management, and display capabilities necessary to perform safety critical aircraft analysis in near real time during a flight test mission. Germane to hazardous, fast-paced flight test programs is a need for enhanced situational awareness in the Mission Control Room (MCR). The IADS provides an enhanced situational awareness by providing an analysis and display capability designed to enhance the confidence of the engineer in making clearance decisions within the MCR environment. The IADS will allow the engineer to achieve this confidence level by providing a real-time display capability along with a simultaneous near real-time processing capability consisting of both time domain and frequency domain analyses. The system provides for displaying real-time data while performing interactive and automated near real-time analyses. The system also alerts the engineer when displayed and non-displayed parameters exceed predefined threshold limits. Both real-time data and results created in near real-time may be compared to predicted data on workstations to enhance the user’s confidence in making point-to-point clearance decisions. The IADS also provides a post-flight capability at the engineers project area desktop. Having a user interface that is common with the real-time system, the post-flight IADS provides all of the capabilities of the real-time IADS plus additional data storage and data organization to allow the engineer to perform structural analysis with test data from the complete test program. This paper discusses the system overview and capabilities of the IADS.

International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, Nevada / The Interactive Analysis and Display System (IADS) provides the structures flight test engineer with enhanced test-data processing, management and display capabilities necessary to perform safety critical aircraft analysis in near real-time during a flight test mission. The IADS provides enhanced situational awareness through an analysis and display capability designed to increase the confidence of the engineer in making clearance decisions within the Mission control Room (MCR) environment. The engineer achieves this confidence level through IADS’ real-time display capability and simultaneous near real-time processing capability consisting of both time domain and frequency domain analyses. The system displays real-time data while performing interactive and automated near real-time analyses; alerting the engineer when displayed parameters exceed predefined threshold limits. Real-time data and results created in near real-time may be compared to previous flight test data to enhance the user’s confidence in making point-to-point clearance decisions. The IADS provides a post flight capability at the engineer’s project area desktop, with a user interface common with the real-time system. The post flight IADS provides all of the capabilities of the real-time IADS with additional data access and data organization, allowing the engineer to perform structural analysis with test data from the each flight and compile summary plots and tables over the most of the test program. The IADS promotes teamwork by allowing the engineers to share data and test results during a mission and in the post flight environment. This paper discusses the system overview and capabilities of the IADS.