Design and evaluation of a scalable hierarchical application component placement algorithm for cloud resource allocation

In the context of cloud systems, mapping application components to a set of physical servers and assigning resources to those components is challenging. For large-scale clouds, traditional resource allocation systems, which rely on a centralized management paradigm, become ineffective and inefficient. Therefore, there is an essential need of providing new management solutions that scale well with the size of large cloud systems. In this paper a distributed and hierarchical component placement algorithm is presented, evaluated and compared to a centralized algorithm. Each application is represented as a collection of interacting services, and multiple service types with differing placement characteristics are considered. Our evaluations show that the proposed algorithm is at least 84.65 times faster and offers better scalability compared with a central approach, while the percentage of servers used and fully placed applications remains close to that of the centralized algorithm

Context Data Management for Large Scale Context-Aware Ubiquitous Systems

Ph.DDOCTOR OF PHILOSOPH

DEFINING SMALL-SCALE FARMERS IN THE SOUTH AFRICAN CONTEXT

South African agriculture is comprised of mainly two categories of farmers -- the subsistence farmers in the former homeland areas and the large-scale commercial (mainly white) farmers. This is in contrast with the situation in many other countries in the world where one would find a whole range of farm sizes, ranging from the very small or subsistence farmer to the very large farmer/agribusiness. The paper highlights the situation of small-scale farmers in an international context and compares it with the South African situation that is totally different. Within this context, this paper has as basic premise that in South Africa the concept of "small-scale farmer" is usually value-laden, creates wrong impressions and is often viewed in a negative light. "Small-scale" is often equated with a backward, nonproductive, non-commercial, subsistence agriculture that we find in parts of the former homeland areas. This paper endeavours to correct the negative perceptions towards smallscale farms by redefining the small-scale farmer and laying to rest the fallacy that small relates to land size only.Farm Management,

T-Reqs: Tool Support for Managing Requirements in Large-Scale Agile System Development

T-Reqs is a text-based requirements management solution based on the git version control system. It combines useful conventions, templates and helper scripts with powerful existing solutions from the git ecosystem and provides a working solution to address some known requirements engineering challenges in large-scale agile system development. Specifically, it allows agile cross-functional teams to be aware of requirements at system level and enables them to efficiently propose updates to those requirements. Based on our experience with T-Reqs, we i) relate known requirements challenges of large-scale agile system development to tool support; ii) list key requirements for tooling in such a context; and iii) propose concrete solutions for challenges.Comment: Accepted for publication in Proc. of 26th IEEE Int. Requirements Eng. Conf., Demo Track, Banff, Alberta, Canada, 201

SYSTEMS ANALYSIS OF LIVESTOCK WASTE MANAGEMENT: A STUDY OF LARGE-SCALE DAIRYING

The analytical approach to studying waste management is investigated here in the context of large scale dairying. The typical short-run approach that regards waste management as separable from primary production is contrasted with a longer-run systems approach in which waste management is regarded as an interdependent stage of production. Failure to consider interdependencies between waste management and agricultural production could compromise potential efficiencies in the overall system. Furthermore, cooperative waste treatment and disposal among livestock producers may contribute to greater efficiency and afford opportunities for resource conservation and recovery through waste utilization.Environmental Economics and Policy, Livestock Production/Industries,

Understanding and supporting large-scale requirements management

Large market-driven software companies face new challenges in requirements engineering and management that emerged due to their recent extensive growth. At the same time, the pressure generated by competitors’ and users’ expectations demands being more competitive, creative and flexible to more quickly respond to a rapidly changing market situation. In the pursuit of staying competitive in this context, new ideas on how to improve the current software engineering practice are requested to help maintaining the engineering efficiency while coping with growing size and complexity of requirements engineering processes and their products. This thesis focuses on understanding and supporting large-scale requirements management for developing software products to open markets. In particular, this thesis focuses on the following requirements management activities in the mentioned context, namely: scope management, variability management and requirements consolidation. The goals of the research effort in this thesis are to provide effective methods in supporting mentioned requirements management activities in a situation when the size of them and their complexity require large time and skills efforts. Based on empirical research, where both quantitative and qualitative approaches were utilized, this thesis reports on possible improvements for managing variability and presents visualization techniques to assist scope management for large-scale software product development contexts. Both reported ideas are empirically evaluated in case studies in a large-scale context. Additionally, the benefits of using linguistic methods for requirements consolidation are investigated in a replicated experimental study based on a relevant industry scenario

Community water management and agricultural extension services: effects, impacts and perceptions in the coastal zone of Bangladesh

The coastal region of Bangladesh is prone to natural disasters and these events are expected to worsen as a result of climate change. Combined with anthropogenic factors, these events challenge livelihood opportunities, especially crop production. Waterlogging, tidal activity and the lack of proper drainage facilities are major constraints to agricultural production in these areas. The CGIAR Research Program on Water, Land and Ecosystems (WLE) tested, at pilot scale, the combination of innovative agricultural technologies with improved water management to overcome these challenges. This report assesses this intervention by observing the effects, measuring the short-term impacts and understanding the perceptions. The results highlight the need to integrate the interventions into the local context, and acknowledge that institutions and markets need to mature to harness the benefits from innovations. It also underlines the potential of multi-scale interventions combining plot-level and farmer-led innovations, community management and rehabilitation of large schemes

Decentralized fault-tolerant control of inland navigation networks: a challenge

Inland waterways are large-scale networks used principally for navigation. Even if the transport planning is an important issue, the water resource management is a crucial point. Indeed, navigation is not possible when there is too little or too much water inside the waterways. Hence, the water resource management of waterways has to be particularly efficient in a context of climate change and increase of water demand. This management has to be done by considering different time and space scales and still requires the development of new methodologies and tools in the topics of the Control and Informatics communities. This work addresses the problem of waterways management in terms of modeling, control, diagnosis and fault-tolerant control by focusing in the inland waterways of the north of France. A review of proposed tools and the ongoing research topics are provided in this paper.Peer ReviewedPostprint (published version

The Evolving Role of Systems Analysis in Process and Methods in Large-Scale Public Socio-Technical Systems

The ESD definition of Large-Scale Socio-Technical Systems is large-scale and complex systems in which both human and non-human elements interact where the social and/or management dimensions tend to dominate. The word public has been added here to indicate that subset which are quasi public systems, i.e. the problems of public management of resources such as clean air and water or energy in which public policy is needed to drive and set the context for public investment and regulation which in turn influence private individual and corporate decisions. Systems analysis plays an important role in the formation of strategic policy for managing these resources. The paradigm of systems analysis as applied to large-scale open systems has not changed over the years. It is still the mantra of Problem Identification, Systems Modeling, Generation of Alternatives (Optimization), Evaluation and Implementation. However, both the process by which systems analysis is carried out, and the systems methods used in that process have evolved significantly and for the better. This paper deals with a description of these evolving methods and processes in the context of large-scale energy and environmental systems. In particular, pathways to the future in energy and environmental management are discussed as long-term system analysis problems. Systems Analysis process changes and methods changes, which have occurred and will need evolution in the future, are identified