Platform for reliable computing on clusters using group communications

Shared clusters represent an excellent platform for the execution of parallel applications given their low price/performance ratio and the presence of cluster infrastructure in many organisations. The focus of recent research efforts are on parallelism management, transport and efficient access to resources, and making clusters easy to use. In this thesis, we examine reliable parallel computing on clusters. The aim of this research is to demonstrate the feasibility of developing an operating system facility providing transport fault tolerance using existing, enhanced and newly built operating system services for supporting parallel applications. In particular, we use existing process duplication and process migration services, and synthesise a group communications facility for use in a transparent checkpointing facility. This research is carried out using the methods of experimental computer science. To provide a foundation for the synthesis of the group communications and checkpointing facilities, we survey and review related work in both fields. For group communications, we examine the V Distributed System, the x-kernel and Psync, the ISIS Toolkit, and Horus. We identify a need for services that consider the placement of processes on computers in the cluster. For Checkpointing, we examine Manetho, KeyKOS, libckpt, and Diskless Checkpointing. We observe the use of remote computer memories for storing checkpoints, and the use of copy-on-write mechanisms to reduce the time to create a checkpoint of a process. We propose a group communications facility providing two sets of services: user-oriented services and system-oriented services. User-oriented services provide transparency and target application. System-oriented services supplement the user-oriented services for supporting other operating systems services and do not provide transparency. Additional flexibility is achieved by providing delivery and ordering semantics independently. An operating system facility providing transparent checkpointing is synthesised using coordinated checkpointing. To ensure a consistent set of checkpoints are generated by the facility, instead of blindly blocking the processes of a parallel application, only non-deterministic events are blocked. This allows the processes of the parallel application to continue execution during the checkpoint operation. Checkpoints are created by adapting process duplication mechanisms, and checkpoint data is transferred to remote computer memories and disk for storage using the mechanisms of process migration. The services of the group communications facility are used to coordinate the checkpoint operation, and to transport checkpoint data to remote computer memories and disk. Both the group communications facility and the checkpointing facility have been implemented in the GENESIS cluster operating system and provide proof-of-concept. GENESIS uses a microkernel and client-server based operating system architecture, and is demonstrated to provide an appropriate environment for the development of these facilities. We design a number of experiments to test the performance of both the group communications facility and checkpointing facility, and to provide proof-of-performance. We present our approach to testing, the challenges raised in testing the facilities, and how we overcome them. For group communications, we examine the performance of a number of delivery semantics. Good speed-ups are observed and system-oriented group communication services are shown to provide significant performance advantages over user-oriented semantics in the presence of packet loss. For checkpointing, we examine the scalability of the facility given different levels of resource usage and a variable number of computers. Low overheads are observed for checkpointing a parallel application. It is made clear by this research that the microkernel and client-server based cluster operating system provide an ideal environment for the development of a high performance group communications facility and a transparent checkpointing facility for generating a platform for reliable parallel computing on clusters

Energy-Efficient Architecture and Sustainable Urban Tourism: Context, Challenges and Solution

Urban tourism, as well as tourism in general, offers great economic opportunities, while at the same time, it increases the destination’s vulnerability to overcrowding and uncontrolled growth. Tourism can and should support sustainable urban development. Sustainable urban tourism and energy efficient architecture are interdependent. Increased stakeholder participation, regional cooperation, sustainable urban mobility, supporting environmental and social innovation, preventing negative social issues, resource efficiency and environmentally acceptable waste management, followed by sustainable hospitality industry architecture, are key drivers for sustainable urban tourism success. Energy-efficient architecture in sustainable urban tourism requires application of energy-efficient concepts, elements and systems. Although considerable effort has been put into raising awareness about the necessity of sustainable urban tourism development, numerous examples of “greenwashing” effect have been detected

Accommodating the Individual

How did the Greeks respond to the experiences of uncertainty that they so acutely made in the aftermath of Alexander the Great's world-changing conquest of the Persian Empire? How were old values upheld and reshaped? And how did the societies of Greek cities and royal courts accommodate the overwhelming newfound power of Greek individuals? By developing a custom methodology, this book tries to shed new light on the complex textuality of the period of the Diadochi, the successors of Alexander. In four case studies, new readings are presented of Theophrastus Characters and Xenophon's Cyropaedia, but also of the substantial early Hellenistic anecdotal material, as well as the Colossus of Rhodes. The studies are united by an interest in how these texts cast the relationships between individuals and how they constructed various media of interrelation, such as money, friendship, women and the divine. Reading these texts on these terms reveals how values were renegotiated through paradoxes and inverted stories that subtly reshaped the utopias of the 4th century BCE. Overall, the study's hypothesis is that this particular brand of social storytelling contributed to the stabilisation of the nascent Hellenistic world by providing new visions of society capable of accommodating individual power and offering a new sense of control and place

A multi-agent architecture for internet distributed computing system

This thesis presents the developed taxonomy of the agent-based distributed computing systems. Based on this taxonomy, a design, implementation, analysis and distribution protocol of a multi-agent architecture for internet-based distributed computing system was developed. A prototype of the designed architecture was implemented on Spider III using the IBM Aglets software development kit (ASDK 2.0) and the language Java

The Commune Movement during the 1960s and the 1970s in Britain, Denmark and the United States

The communal revival that began in the mid-1960s developed into a new mode of activism, ‘communal activism’ or the ‘commune movement’, forming its own politics, lifestyle and ideology. Communal activism spread and flourished until the mid-1970s in many parts of the world. To analyse this global phenomenon, this thesis explores the similarities and differences between the commune movements of Denmark, UK and the US. By examining the motivations for the communal revival, links with 1960s radicalism, communes’ praxis and outward-facing activities, and the crisis within the commune movement and responses to it, this thesis places communal activism within the context of wider social movements for social change. Challenging existing interpretations which have understood the communal revival as an alternative living experiment to the nuclear family, or as a smaller part of the counter-culture, this thesis argues that the commune participants created varied and new experiments for a total revolution against the prevailing social order and its dominant values and institutions, including the patriarchal family and capitalism. Communards embraced autonomy and solidarity based on individual communes’ situations and tended to reject charismatic leadership. Functioning as an independent entity, each commune engaged with their local communities designing various political and cultural projects. They interacted with other social movements groups through collective work for the women’s liberation and environmentalist movement. As a genuine grass root social movement communal activism became an essential part of Left politics bridging the 1960s and 1970s

Measuring circularity in food supply chain using life cycle assessment : refining oil from olive kernel

Valorization of food waste is a potential strategy toward a circular food supply chain. In this regard, measuring the circularity of food waste valorization systems is highly important to better understand multiple environmental impacts. Therefore, this study investigated the circularity of a food waste valorization system (refining oil from olive kernel) using a life cycle assessment methodology. An inventory of an industrial-based olive kernel oil production system is also provided in this study. The system boundary was the cradle to the factory gate of the production system. The results indicated that natural gas consumption was the highest contributor to most of the investigated impact categories. The global warming potential of one kg of oil produced from olive kernel was calculated to be 1.37 kg CO(2)eq. Moreover, the calculated damages of 1 kg oil production from olive kernel to human health, ecosystem quality, and resource depletion were 5.29 x 10(-7) DALY, 0.12 PDF center dot m(2)center dot yr., and 24.40 MJ, respectively

Predicting the Future

Due to the increased capabilities of microprocessors and the advent of graphics processing units (GPUs) in recent decades, the use of machine learning methodologies has become popular in many fields of science and technology. This fact, together with the availability of large amounts of information, has meant that machine learning and Big Data have an important presence in the field of Energy. This Special Issue entitled “Predicting the Future—Big Data and Machine Learning” is focused on applications of machine learning methodologies in the field of energy. Topics include but are not limited to the following: big data architectures of power supply systems, energy-saving and efficiency models, environmental effects of energy consumption, prediction of occupational health and safety outcomes in the energy industry, price forecast prediction of raw materials, and energy management of smart buildings

Cells in Space

Discussions and presentations addressed three aspects of cell research in space: the suitability of the cell as a subject in microgravity experiments, the requirements for generic flight hardware to support cell research, and the potential for collaboration between academia, industry, and government to develop these studies in space. Synopses are given for the presentations and follow-on discussions at the conference and papers are presented from which the presentations were based. An Executive Summary outlines the recommendations and conclusions generated at the conference