Distributed data cache designs for clustered VLIW processors

Wire delays are a major concern for current and forthcoming processors. One approach to deal with this problem is to divide the processor into semi-independent units referred to as clusters. A cluster usually consists of a local register file and a subset of the functional units, while the L1 data cache typically remains centralized in What we call partially distributed architectures. However, as technology evolves, the relative latency of such a centralized cache will increase, leading to an important impact on performance. In this paper, we propose partitioning the L1 data cache among clusters for clustered VLIW processors. We refer to this kind of design as fully distributed processors. In particular; we propose and evaluate three different configurations: a snoop-based cache coherence scheme, a word-interleaved cache, and flexible LO-buffers managed by the compiler. For each alternative, instruction scheduling techniques targeted to cyclic code are developed. Results for the Mediabench suite'show that the performance of such fully distributed architectures is always better than the performance of a partially distributed one with the same amount of resources. In addition, the key aspects of each fully distributed configuration are explored.Peer ReviewedPostprint (published version

Energy efficiency in discrete-manufacturing systems: insights, trends, and control strategies

Since the depletion of fossil energy sources, rising energy prices, and governmental regulation restrictions, the current manufacturing industry is shifting towards more efficient and sustainable systems. This transformation has promoted the identification of energy saving opportunities and the development of new technologies and strategies oriented to improve the energy efficiency of such systems. This paper outlines and discusses most of the research reported during the last decade regarding energy efficiency in manufacturing systems, the current technologies and strategies to improve that efficiency, identifying and remarking those related to the design of management/control strategies. Based on this fact, this paper aims to provide a review of strategies for reducing energy consumption and optimizing the use of resources within a plant into the context of discrete manufacturing. The review performed concerning the current context of manufacturing systems, control systems implemented, and their transformation towards Industry 4.0 might be useful in both the academic and industrial dimension to identify trends and critical points and suggest further research lines.Peer ReviewedPreprin

Scheduling of non-repetitive lean manufacturing systems under uncertainty using intelligent agent simulation

World-class manufacturing paradigms emerge from specific types of manufacturing systems with which they remain associated until they are obsolete. Since its introduction the lean paradigm is almost exclusively implemented in repetitive manufacturing systems employing flow-shop layout configurations. Due to its inherent complexity and combinatorial nature, scheduling is one application domain whereby the implementation of manufacturing philosophies and best practices is particularly challenging. The study of the limited reported attempts to extend leanness into the scheduling of non-repetitive manufacturing systems with functional shop-floor configurations confirms that these works have adopted a similar approach which aims to transform the system mainly through reconfiguration in order to increase the degree of manufacturing repetitiveness and thus facilitate the adoption of leanness. This research proposes the use of leading edge intelligent agent simulation to extend the lean principles and techniques to the scheduling of non-repetitive production environments with functional layouts and no prior reconfiguration of any form. The simulated system is a dynamic job-shop with stochastic order arrivals and processing times operating under a variety of dispatching rules. The modelled job-shop is subject to uncertainty expressed in the form of high priority orders unexpectedly arriving at the system, order cancellations and machine breakdowns. The effect of the various forms of the stochastic disruptions considered in this study on system performance prior and post the introduction of leanness is analysed in terms of a number of time, due date and work-in-progress related performance metrics

Resource provisioning in Science Clouds: Requirements and challenges

Cloud computing has permeated into the information technology industry in the last few years, and it is emerging nowadays in scientific environments. Science user communities are demanding a broad range of computing power to satisfy the needs of high-performance applications, such as local clusters, high-performance computing systems, and computing grids. Different workloads are needed from different computational models, and the cloud is already considered as a promising paradigm. The scheduling and allocation of resources is always a challenging matter in any form of computation and clouds are not an exception. Science applications have unique features that differentiate their workloads, hence, their requirements have to be taken into consideration to be fulfilled when building a Science Cloud. This paper will discuss what are the main scheduling and resource allocation challenges for any Infrastructure as a Service provider supporting scientific applications

Bexley report: a report to MCCH on a suitable transport policy for its Bexley services

This report presents the findings of and recommendations from the study commissioned by MCCH to advise on a comprehensive transport policy for MCCH to use in providing services in both its residential homes and day-care centres in Bexley. It describes the current positions of transport supply for, and of transport demand by the community of people with learning difficulties in the London Borough of Bexley. It also considers the extent to which the transport supply is meeting or not meeting the transport demands and the expressed needs of the people and/or their representatives. The report considers the implications for improvement in transport provision of certain proposed actions by MCCH. Finally, the report presents some recommendations based on a user-centred strategy to help MCCH incorporate their concept of empowering their service users through suitable transport provision. This study has been conducted with the ethos and operational objectives of the MCCH group firmly in mind. MCCH has an objective to enhance quality of life for their service users and is very concerned with ensuring that its service users are enabled to exercise the rights and opportunities of citizenship with particular reference to freedom of choice in time and mode of travel. MCCH holds that real improvement in services to learning disability people must include increased range and choice of people-centred opportunities that address the total needs and aspirations of service users and their carers, underpinned by values and principles of good practice. Thus MCCH desires to put back in the control of users, the lever of decision making as regards services provided to 4 them and intends to do this by actively eliciting user/stakeholders involvement in decision-making. Contrary to the standard social service transport provision style, MCCH desires to create choice for service-users, feeling that people should be able to decide whether, e.g. to go by bus or train and be supported in their decision and not be constrained by the schedule of the provided transport. The specific terms of reference for this study are 1. To examine the current demand for, and provision of, transport within MCCH’s Bexley services. To assess how best these services might be reconfigured and managed, having regard to: · Desire to increase empowerment and choice for service users · Optimizing the integration of the transport management in Bexley within MCCH’s organization, in the light of most efficient use of resources and practice elsewhere in MCCH · Desire to better integrate residential services with day services in Bexley · MCCH’s intention to reconfigure Bexley day services · The move of service users towards ‘supported living’ as opposed to registered care · The objectives and concerns of all parties involved, including Bexley Social Services, Bexley Transport Services, the parents/relatives/carers of the service users and the service users themselves · The way vehicles are currently owned and funded · Efficiency and cost 2. To produce outline proposals, plans and specifications of how a reconfigured transport service would look and operate, including details of resource requirements in enough detail to allow reasonably accurate costing to be derived