Introduction to topological defects: from liquid crystals to particle physics

Liquid crystals are assemblies of rod-like molecules which self-organize to form mesophases, in-between ordinary liquids and anisotropic crystals. At each point, the molecules collectively orient themselves along a privileged direction, which locally defines an orientational order. Sometimes, this order is broken and singularities appear in the form of topological defects. This tutorial article is dedicated to the geometry, topology and physics of these defects. We introduce the main models used to describe the nematic phase and discuss the isotropic-nematic phase transition. Then, we present the different families of defects in nematics and examine some of their physical outcomes. Finally, we show that topological defects are universal patterns of nature, appearing not only in soft matter, but also in biology, cosmology, geology and even particle physics.Comment: 40 pages, 9 figures, review pape

Adoption of AI-empowered industrial robots in auto component manufacturing companies

The usage of AI-empowered Industrial Robots (InRos) is booming in the Auto Component Manufacturing Companies (ACMCs) across the globe. Based on a model leveraging the Technology, Organisation, and Environment (TOE) framework, this work examines the adoption of InRos in ACMCs in the context of an emerging economy. This research scrutinises the adoption intention and potential use of InRos in ACMCs through a survey of 460 senior managers and owners of ACMCs in India. The findings indicate that perceived compatibility, external pressure, perceived benefits and support from vendors are critical predictors of InRos adoption intention. Interestingly, the study also reveals that IT infrastructure and government support do not influence InRos adoption intention. Furthermore, the analysis suggests that perceived cost issues negatively moderate the relationship between the adoption intention and potential use of InRos in ACMCs. This study offers a theoretical contribution as it deploys the traditional TOE framework and discovers counter-intuitively that IT resources are not a major driver of technology adoption: as such, it suggests that a more comprehensive framework than the traditional RBV should be adopted. The work provides managerial recommendations for managers, shedding light on the antecedents of adoption intention and potential use of InRos at ACMCs in a country where the adoption of InRos is in a nascent stage

A software testing estimation and process control model

The control of the testing process and estimation of the resource required to perform testing is key to delivering a software product of target quality on budget. This thesis explores the use of testing to remove errors, the part that metrics and models play in this process, and considers an original method for improving the quality of a software product. The thesis investigates the possibility of using software metrics to estimate the testing resource required to deliver a product of target quality into deployment and also determine during the testing phases the correct point in time to proceed to the next testing phase in the life-cycle. Along with the metrics Clear ratio. Chum, Error rate halving. Severity shift, and faults per week, a new metric 'Earliest Visibility' is defined and used to control the testing process. EV is constructed upon the link between the point at which an error is made within development and subsequently found during testing. To increase the effectiveness of testing and reduce costs, whilst maintaining quality the model operates by each test phase being targeted at the errors linked to that test phase and the ability for each test phase to build upon the previous phase. EV also provides a measure of testing effectiveness and fault introduction rate by development phase. The resource estimation model is based on a gradual refinement of an estimate, which is updated following each development phase as more reliable data is available. Used in conjunction with the process control model, which will ensure the correct testing phase is in operation, the estimation model will have accurate data for each testing phase as input. The proposed model and metrics have been developed and tested on a large-scale (4 million LOC) industrial telecommunications product written in C and C++ running within a Unix environment. It should be possible to extend this work to suit other environments and other development life-cycles

Exploring Software Testing Strategies Used on Software Applications in the Government

Developing a defect-free software application is a challenging task. Despite many years of experience, the intense development of reliable software remains a challenge. For this reason, software defects identified at the end of the testing phase are more expensive than those detected sooner. The purpose of this multiple case study is to explore the testing strategies software developers use to ensure the reliability of software applications in the government contracting industry. The target population consisted of software developers from 3 government contracting organizations located along the East Coast region of the United States. Lehman’s laws of software evolution was the conceptual framework. The data collection process included semistructured interviews with software developers (n = 10), including a review of organizational documents (n = 77). Thematic analysis was used to identify patterns and codes from the interviews. Member checking activities were triangulated with organizational documents to produce 4 major themes: (a) communication and collaboration with all stakeholders, (b) development of well-defined requirements, (c) focus on thorough documentation, and (d) focus on automation testing. The results of this study may contribute to information about testing strategies that may help organizations improve or enhance their testing practices. The results of this study may serve as a foundation for positive social change by potentially improving citizens’ experience with government software applications as a result of potential improvement in software testing practice

Bit Bang 7: Future of Energy

This book is the 7th in the Bit Bang series of books produced as multidisciplinary teamwork exercises by doctoral students participating in the course Bit Bang 7: Future of Energy at Aalto University during the academic year 2014–2015. The course aims at fostering teamwork and multidisciplinary collaboration, as well as providing participants with a global, futurecentric perspective on the energy sector. The growing global demand for energy and diminishing natural resources are driving the development of eco-efficient energy sources, new ways of doing business, and designing our living environment. Bit Bang 7 addresses the topic of energy sources and technologies from the perspective of their economic, environmental and social sustainability. The course elaborates on the interconnectedness of these phenomena, and links them to possible future scenarios, global megatrends and ethical considerations. Will we see disruptive changes in our energy future? Can we impact consumption patterns, ways of doing business, and our way of life? Are we creating a sustainable future for the generations to come? Working in teams, the students set out to answer questions related to the changing energy sector and to brainstorm radical scenarios of what the future could hold. This joint publication contains articles produced as teamwork assignments for the course, in which the students were encouraged to take novel and radical views on the future of energy. The Bit Bang series of courses is supported by the Multidisciplinary Institute of Digitalisation and Energy (MIDE). Previous Bit Bang publications are available from http:/mide.aalto.fi

Civil and Military Airworthiness

Effective safety management has always been a key objective for the broader airworthiness sector. This book is focused on safety themes with implications on airworthiness management. It offers a diverse set of analyses on aircraft maintenance accidents, empirical and systematic investigations on important continuing airworthiness matters and research studies on methodologies for the risk and safety assessment in continuing and initial airworthiness. Overall, this collection of research and review papers is a valuable addition to the published literature, useful for the community of aviation professionals and researchers

Information systems failure: A business-led knowledge requirements framework for modelling business requirements

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.Our work will be mainly concerned with improving the crucial first stage (the requirements stage) of any system development methodology in order to improve requirements. A framework has been developed, called "knowledge requirements framework (KRF)" to help customers and system developers bridge the knowledge and understanding gaps at the initial requirements stage of the Information Technology System (ITS) development process. Unclear business requirements, mismatch of knowledge and understanding are among the major factors that contributes to some ITS failures worldwide. The aim is to capture functional requirements at the initial stage of the system development process and to integrate systems and people use them in the development process. Multi-surveys are conducted, capture and highlight the criteria of initial requirements exactness and executability. Knowledge and understanding gaps, which occur in the development process, are described. These gaps constitute the problem at the invisible architecture in the initial requirements stage, as they expose mismatch of both knowledge and understanding problems (Requirements/Specifications). A notation to describe this framework is elaborated, novel techniques and tools for the construction and application of customer requirements in systems development are developed and used in KRF to facilitate bridging these gaps. The resulting prototype KRF is developed and used against some example problems in retail organisations, and so shown to be sufficient in principle of handling all the negotiation problems at the initial requirements stage, singly and in combination. Also, it is shown how KRF sub-process can be combined and used to elicit information and knowledge mining between both the customer and the system developer using human communication and interaction capture as an example. Systems these days are living systems, changeable, in business and the human factor in developing them cannot be excluded. It is further shown how these techniques and tools can be augmented with established methodologies rather than inventing new ones and to enable management to react as quickly as possible to global changing market conditions. This proposed framework is also evaluated and tested against the original criteria of initial requirements, exactness and executability

Epistemology of Experimental Gravity - Scientific Rationality

The evolution of gravitational tests from an epistemological perspective framed in the concept of rational reconstruction of Imre Lakatos, based on his methodology of research programmes. Unlike other works on the same subject, the evaluated period is very extensive, starting with Newton's natural philosophy and up to the quantum gravity theories of today. In order to explain in a more rational way the complex evolution of the gravity concept of the last century, I propose a natural extension of the methodology of the research programmes of Lakatos that I then use during the paper. I believe that this approach offers a new perspective on how evolved over time the concept of gravity and the methods of testing each theory of gravity, through observations and experiments. I argue, based on the methodology of the research programmes and the studies of scientists and philosophers, that the current theories of quantum gravity are degenerative, due to the lack of experimental evidence over a long period of time and of self-immunization against the possibility of falsification. Moreover, a methodological current is being developed that assigns a secondary, unimportant role to verification through observations and/or experiments. For this reason, it will not be possible to have a complete theory of quantum gravity in its current form, which to include to the limit the general relativity, since physical theories have always been adjusted, during their evolution, based on observational or experimental tests, and verified by the predictions made. Also, contrary to a widespread opinion and current active programs regarding the unification of all the fundamental forces of physics in a single final theory, based on string theory, I argue that this unification is generally unlikely, and it is not possible anyway for a unification to be developed based on current theories of quantum gravity, including string theory. In addition, I support the views of some scientists and philosophers that currently too much resources are being consumed on the idea of developing quantum gravity theories, and in particular string theory, to include general relativity and to unify gravity with other forces, as long as science does not impose such research programs. DOI: 10.13140/RG.2.2.35350.7072