6,237 research outputs found
A grid computing framework for commercial simulation packages
No full textThis thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.An increased need for collaborative research among different organizations, together with continuing advances in communication technology and computer hardware, has facilitated the development of distributed systems that can provide users non-trivial access to geographically dispersed computing resources (processors, storage, applications, data, instruments, etc.) that are administered in multiple computer domains. The term grid computing or grids is popularly used to refer to such distributed systems. A broader definition of grid computing includes the use of computing resources within an organization for running organization-specific applications. This research is in the context of using grid computing within an enterprise to maximize the use of available hardware and software resources for processing enterprise applications. Large scale scientific simulations have traditionally been the primary benefactor of grid computing. The application of this technology to simulation in industry has, however, been negligible. This research investigates how grid technology can be effectively exploited by simulation practitioners using Windows-based commercially available simulation packages to model simulations in industry. These packages are commonly referred to as Commercial Off-The-Shelf (COTS) Simulation Packages (CSPs). The study identifies several higher level grid services that could be potentially used to support the practise of simulation in industry. It proposes a grid computing framework to investigate these services in the context of CSP-based simulations. This framework is called the CSP-Grid Computing (CSP-GC) Framework. Each identified higher level grid service in this framework is referred to as a CSP-specific service. A total of six case studies are presented to experimentally evaluate how grid computing technologies can be used together with unmodified simulation packages to support some of the CSP-specific services. The contribution of this thesis is the CSP-GC framework that identifies how simulation practise in industry may benefit from the use of grid technology. A further contribution is the recognition of specific grid computing software (grid middleware) that can possibly be used together with existing CSPs to provide grid support. With its focus on end-users and end-user tools, it is intended that this research will encourage wider adoption of grid computing in the workplace and that simulation users will derive benefit from using this technology
Provenance-based trust for grid computing: Position Paper
No full textCurrent evolutions of Internet technology such as Web Services, ebXML, peer-to-peer and Grid computing all point to the development of large-scale open networks of diverse computing systems interacting with one another to perform tasks. Grid systems (and Web Services) are exemplary in this respect and are perhaps some of the first large-scale open computing systems to see widespread use - making them an important testing ground for problems in trust management which are likely to arise. From this perspective, today's grid architectures suffer from limitations, such as lack of a mechanism to trace results and lack of infrastructure to build up trust networks. These are important concerns in open grids, in which "community resources" are owned and managed by multiple stakeholders, and are dynamically organised in virtual organisations. Provenance enables users to trace how a particular result has been arrived at by identifying the individual services and the aggregation of services that produced such a particular output. Against this background, we present a research agenda to design, conceive and implement an industrial-strength open provenance architecture for grid systems. We motivate its use with three complex grid applications, namely aerospace engineering, organ transplant management and bioinformatics. Industrial-strength provenance support includes a scalable and secure architecture, an open proposal for standardising the protocols and data structures, a set of tools for configuring and using the provenance architecture, an open source reference implementation, and a deployment and validation in industrial context. The provision of such facilities will enrich grid capabilities by including new functionalities required for solving complex problems such as provenance data to provide complete audit trails of process execution and third-party analysis and auditing. As a result, we anticipate that a larger uptake of grid technology is likely to occur, since unprecedented possibilities will be offered to users and will give them a competitive edge
Towards more effective testing of communications-critical large scale systems
No full textThis thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.A publication based on the research from this thesis has been published and can be cited as Nabulsi, MA and Hierons, RM (2014), A new test framework for communications-critical large scale systems, IEEE Software, In press. The published version can be accessed via the link below.None of today’s large scale systems could function without the reliable availability of a varied range of network communications capabilities. Whilst software, hardware and communications technologies have been advancing throughout the past two decades, the methods commonly used by industry for testing large scale systems which incorporate critical communications interfaces have not kept pace. This thesis argues for the need for a specifically tailored framework to achieve effective testing of communications-critical large scale systems (CCLSS). The thesis initially discusses how generic test approaches are leading to inefficient and costly test activities in industry. The thesis then presents the form and features of an alternative CCLSS domain-specific test framework, develops its ideas further into a detailed and structured test approach for one of its layers, and then provides a detailed example of how this framework can be applied using a real-life case study. The thesis concludes with a qualitative as well a simulation-based evaluation of the framework’s benefits observed during the case study and an evaluation by expert external participants considering whether similar benefits can be realised if the framework is adopted for the testing of other comparable systems. Requirements data from a second CCLSS is included in the evaluation by external participants as a second smaller case study
Cloud computing and context-awareness: A study of the adapted user experience
No full textThis thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.Today, mobile technology is part of everyday life and activities and the mobile
ecosystems are blossoming, with smartphones and tablets being the major growth drivers. The mobile phones are no longer just another device, we rely on their capabilities in work and in private. We look to our mobile phones for timely and updated information and we rely on this being provided any time of any day at any place. Nevertheless, no matter how much you trust and love your mobile phone the quality of the information and the user experience is directly associated with the sources and presentation of information. In this perspective, our activities, interactions and preferences help shape the quality of service, content and products we use. Context-aware systems use such information about end-users as input mechanisms for producing applications based on mobile, location, social, cloud and customized content services. This represents new possibilities for extracting aggregated user-centric information and includes novel
sources for context-aware applications. Accordingly, a Design Research based
approach has been taken to further investigate the creation, presentation and tailoring of user-centric information. Through user evaluated experiments findings show how multi-dimensional context-aware information can be used to create adaptive
solutions tailoring the user experience to the users’ needs. Research findings in this
work; highlight possible architectures for integration of cloud computing services in
a heterogeneous mobile environment in future context-aware solutions. When it comes to combining context-aware results from local computations with those of cloud based services, the results provide findings that give users tailored and adapted experiences based on the collective efforts of the two
A conceptual system design and managerial complexity competency model
No full textThis thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.Complex adaptive systems are usually difficult to design and control. There are several particular methods for coping with complexity, but there is no general approach to build complex adaptive systems. The challenges of designing complex adaptive systems in a highly dynamic world drive the need for anticipatory capacity within engineering organizations, with a goal of enabling the design of systems that can cope with an unpredictable environment. This thesis explores this question of enhancing anticipatory capacity through the study of a complex adaptive system design methodology and complexity management competencies. A general introduction to challenges and issues in complex adaptive systems design is given, since a good understanding of the industrial context is considered necessary in order to avoid oversimplification of the problem, neglecting certain important factors and being unaware of important influences and relationships. In addition, a general introduction to complex thinking is given, since designing complex adaptive systems requires a non-classical thought, while practical notions of complexity theory and design are put forward. Building on these, the research proposes a Complex Systems Life-Cycle Understanding and Design (CXLUD) methodology to aid system architects and engineers in the design and control of complex adaptive systems. Starting from a creative anticipation construct - a loosening mechanism to allow for more options to be considered, the methodology proposes a conceptual framework and a series of stages to follow to find proper mechanisms that will promote elements to desired solutions by actively interacting among themselves. To illustrate the methodology, a financial systemic risks infrastructure systems architecture development case study is presented. The final part of this thesis develops a conceptual model to analyse managerial complexity competency model from a qualitative phenomenological study perspective. The model developed in this research is called Understanding-Perception-Action (UPA) managerial complexity competency model. The results of this competency model can be used to help ease project manager’s transition into complex adaptive projects, as well as serve as a foundation to launch qualitative and quantitative research into this area of project complexity management
Arms: a decentralised naming model for object-based distributed computing systems
No full textEntities communicate with one another in distributed computing systems via symbolic names. Implementing such communication requires a naming scheme that dynamically maps these symbolic names to physical nodes and processes. Traditionally, a centralised name server is deployed to perform such translations. However, a collaborative and dynamic environment requires a decentralised naming system due to reasons of efficiency and reliability.
ARMS (Adaptive, Randomised and Migration-enabled Scheme) is a novel decentralised naming scheme for distributed object-oriented computing systems. A notable feature of ARMS is that it provides direct naming supports for the patterns of object communication and object migration processes to achieve greater performance and scalability in executing object-oriented software within a distributed environment. These supports are driven by three key components: 1) an adaptive locating protocol that exploits the patterns of object communication and explores the best routing path in the face of the changing network conditions, 2) a randomised overlay that is a scalable and flexible substrate for routing name queries, and 3) a hybrid relocation scheme that provides a transparent and efficient means of referencing migrated objects.
The performance of ARMS has been examined using a number of real world Java-based benchmarking programs. Based on results in this study, ARMS has found to be superior to its structural counterpart – the Chord model because of the adaptive routing protocol and the resilient overlay. Furthermore, ARMS has shown to be superior in a number of other performance metrics
Human intent prediction for adaptive lighting based on a limited data scenario
No full textThis electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Thesis: S.M. in Architecture Studies, Massachusetts Institute of Technology, Department of Architecture, 2019Thesis: S.M., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2019Cataloged from student-submitted PDF of thesis.Includes bibliographical references (pages 75-80).An adaptive environment involves various ubiquitous computing and computer-aided technologies. It provides users with environmental supports such as lighting, air conditioning, motion assistance. Among the different control schemes, lighting is an essential element because it strongly affects people's visual experience and work productivity. The generalized residential lighting system is limited to create a personalized and responsive environment. Additionally, multiple and complex light sources make it difficult for users to obtain optimized lighting configurations. In general, an intelligent control system requires an extensive database of user habits in order to infer different user intents. In this work, we present a new personalized lighting control method that can learn explicit and implicit context though knowledge-based background and interactions. Instead of collecting a large amount of personal data, we explore the possibility to achieve a valid control method based on a limited data scenario. We consider language as one of the most important inputs from users when they are interacting with a smart environment. Although there has been a large amount of work in automatic control based on speech recognition, the situation is different for using language to control lights according to different preferences. In our study, on the one hand, multiple dimensions of representation of lighting status are studied and organized in a way that can be derived from people's language input. We have generated a learning model and a small database based on the hierarchy of different lighting settings. On the other hand, besides the learning part, we explore how users can directly teach the lighting system. That is, through continuous interactions, the control system learns users' profiles through limited interaction data and gradually becomes consistent with specific personal preferences. In addition to lighting control methods, we also introduce the different components of typical lighting systems and networks. This work contributes to fundamental knowledge in the areas of ubiquitous computing and home automation.Jiamin Sun.S.M. in Architecture StudiesS.M.S.M. in Architecture Studies Massachusetts Institute of Technology, Department of ArchitectureS.M. Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Scienc
Construction of a support tool for the design of the activity structures based computer system architectures
No full textThis thesis was submitted for the degree of Doctor of Philosophy and was awarded by Brunel University.This thesis is a reapproachment of diverse design concepts, brought to bear upon the computer system
engineering problem of identification and control of highly constrained multiprocessing (HCM)
computer machines. It contributes to the area of meta/general systems methodology, and brings
a new insight into the design formalisms, and results afforded by bringing together various design
concepts that can be used for the construction of highly constrained computer system architectures.
A unique point of view is taken by assuming the process of identification and control of HCM
computer systems to be the process generated by the Activity Structures Methodology (ASM).
The research in ASM has emerged from the Neuroscience research, aiming at providing the
techniques for combining the diverse knowledge sources that capture the 'deep knowledge' of this
application field in an effective formal and computer representable form. To apply the ASM design
guidelines in the realm of the distributed computer system design, we provide new design definitions
for the identification and control of such machines in terms of realisations. These realisation definitions
characterise the various classes of the identification and control problem. The classes covered
consist of:
1. the identification of the designer activities,
2. the identification and control of the machine's distributed structures of behaviour,
3. the identification and control of the conversational environment activities (i.e. the randomised/
adaptive activities and interactions of both the user and the machine environments),
4. the identification and control of the substrata needed for the realisation of the machine, and
5. the identification of the admissible design data, both user-oriented and machineoriented,
that can force the conversational environment to act in a self-regulating
manner.
All extent results are considered in this context, allowing the development of both necessary
conditions for machine identification in terms of their distributed behaviours as well as the substrata
structures of the unknown machine and sufficient conditions in terms of experiments on the unknown
machine to achieve the self-regulation behaviour.
We provide a detailed description of the design and implementation of the support software tool
which can be used for aiding the process of constructing effective, HCM computer systems, based
on various classes of identification and control. The design data of a highly constrained system, the
NUKE, are used to verify the tool logic as well as the various identification and control procedures.
Possible extensions as well as future work implied by the results are considered.Government of Ira
Tagged repair techniques for defect tolerance in hybrid nano/CMOS architecture
No full textWe propose two new repair techniques for hybrid nano/CMOS computing architecture with lookup table based Boolean logic. Our proposed techniques use tagging mechanism to provide high level of defect tolerance and we present theoretical equations to predict the repair capability including an estimate of the repair cost. The repair techniques are efficient in utilization of spare units and capable of targeting upto 20% defect rates, which is higher than recently reported repair techniques
Knowledge representation within information systems in manufacturing environments
No full textThis thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.Representing knowledge as information content alone is insufficient in providing us with an understanding of the world around us. A combination of context as well as reasoning of the information content is fundamental to representing knowledge in an information system. Knowledge Representation is typically concerned with providing structures and theories that are used as a basis for intelligent reasoning. For this research however, the author defines an alternative meaning, which is related to how knowledge is used in a given context. Thus, this dissertation provides a contribution to the field of knowledge within information systems, in terms of the development of a frame-of-reference that will support the reader in navigating through the different forms of explicit and tacit knowledge use within the manufacturing industry. In doing so, the dissertation also presents the generation of a novel classification of three forms of knowledge (Structural, Interpretive and Evaluative forms); the development of a conceptual framework which highlights the drivers for knowledge transformation; and the development of a conceptual model which seeks to envelop both the content as well as the context of knowledge (Semiotic as well as Symbiotic factors). This is established through the use of an Empirical, Quantitative case study approach, that seeks to explore an interpretivist view of knowledge representation within two information systems contexts, within two UK manufacturing organisations. The first case study presents how a-priori knowledge assumptions are used in a computer aided engineering decision-making task within a high technology manufacturing company. The second case study shows how knowledge is used within the IT/IS investment evaluation decision making process, within a manufacturing SME. In doing so, both case studies attempt to elucidate the inherent, underlying relationship between explicit and tacit knowledge, via a frame-of-reference developed by the author which defines key drivers for knowledge transformation
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