The Partition into Hypercontexts Problem for Hyperreconfigurable Architectures

Hyperreconfigurable architectures adapt their reconfiguration abilities during run time in order to achieve fast dynamic reconfiguration. Models for such architectures have been proposed that change their ability for reconfiguration during hyperreconfiguration steps and in ordinary reconfiguration steps reconfigure the actual contexts for a computation within the limits that have been set by the last hyperreconfiguration step. In this paper we study algorithmic aspects of how to optimally decide what hyperreconfiguration steps should be done during a computation in order to minimize the total time necessary for hyperreconfiguration and ordinary reconfiguration. It is shown that the general problem is NP-hard but fast polynomial time algorithms are given to solve this problem on different types of hyperreconfigurable architectures. These include newly introduced architectures that use a cache to store hypercontexts. We define an example hyperreconfigurable architecture and illustrate the introduced concepts for three application problems

Identification of Technology Integration Challenges at Two Global Automotive OEMs

Platform design has been firmly established in the automotive industry as a strategy to provide wider product variety while maintaining cost effective production. But this strategy can struggle to keep up with the pace and nature of emerging technologies. This paper reviews the existing approaches to modelling product platforms, and showcases the challenges at OEMs introducing new technological innovations in their platforms. A gap is identified in the methods to assess the ability of existing platforms to integrate new technologies whenever they become available

On the Design of a Novel Solid Oxide Fuel Cell Combined Cooling, Heating and Power System for UK Residential Needs

Combined cooling, heating and power (CCHP) systems have become a topic of increasing research interest especially now that they may offer substantial improvements for conservation of fuel and electrical power in the domestic residential sector. However, only a few of the fuel cell (FC)-based CCHP systems have considered the inclusion of other power sources as part of their design with respect to diverse criteria for system optimisation. Most of the research undertaken thus far has focused on the performance improvement of CCHP systems when operated as a single energy source and has not considered the operation when connected to the electrical power distribution grid or under dynamic load conditions. The aim of this research project is to design a solid oxide fuel cell (SOFC)-based CCHP hybrid system that maximises system efficiency and minimises emissions and system costs in an objective manner with minimal operator and customer intervention. A new system structure has been designed to improve the flexibility of the system such that its functioning is closer to practical applications in both island and grid-connected modes, and still returns optimised performance with no need for system redesign or reconfiguration. A novel combination of grey relationship analysis (GRA) linked to an entropy weighting approach has been developed to evaluate the sizing values of fuel cells, heat exchangers and absorption chillers to improve the technical, economic and environmental system performance and reduce subjectivity and inaccuracy that could be imported through reliance on subjective human judgement. A new algorithm, denoted as the multi-objective particle swarm optimisation (MOPSO)-GRA has been designed to reduce local optimisation problem caused by standard MOPSO algorithms. The proposed system has been verified with published experimental results and comparative analysis has been carried out to verify the advance and the new algorithms. The main conclusion is that the optimum design of the SOFC-based CCHP hybrid system delivers optimised performance in terms of efficiency, operation and through life economy as well as environmental impact that gives a high degree of flexible compatibility within the energy supply environment in the UK

Models and reconfiguration problems for multi task hyperreconfigurable architectures

Hyperreconfigurable architectures can adapt their reconfiguration abilities during run time and have been proposed to increase the speed of dynamic reconfiguration. They use two types of dynamic reconfiguration steps. In hyperreconfiguration steps they change their ability for reconfiguration and in ordinary reconfiguration steps they reconfigure the actual contexts for a computation within the limits that have been set by the last hyperreconfiguration step. We study the concept of partial hyperreconfiguration for multi tasks environments. We propose several models for partially hyperreconfigurable architectures and study corresponding reconfiguration problems to find optimal (hyper)reconfigurations. While under a general cost model the problem to find optimal (hyper)reconfigurations is known to be NP-complete even for a single task. We identify an interesting special case that can be solved by a polynomial time algorithm even for multiple tasks. We illustrate the introduced concepts with a partially hyperreconfigurable example architecture and describe the results of simulated runs with a small test application

Describing, assessing and embedding flexibility in system architectures with application to wireless terrestrial networks and handset processors

Thesis (S.M.)--Massachusetts Institute of Technology, System Design & Management Program, June 2004."January 2004."Includes bibliographical references (p. 165-168).This thesis presents a framework that can be used to identify the flexibility attributes and determine the value of embedding flexibility in system architectures, from the context of network based wireless applications and wireless handset processors Flexibility is first defined and the three dimensions of flexibility - performance, capacity and functionality are explored. This analysis is used to formulate a general model of the dimensions of flexibility. The analysis to determine the value of embedding flexibility is then done using the example of a flexible handset processor. The Black-Scholes model and the Binomial model are presented as methods for computing the economics of financial options. These methods are then applied to computing the value of flexibility options. In order to determine the value of the underlying asset, which is one of the terms needed for the valuation of flexibility, two approaches are presented: conjoint analysis and concept engineering. The bounds of time to expiation are explored. The cost of embedding flexibility is then assessed. Finally, a few methods are proposed for determining the optimal flexibility design vector and implementing a portfolio of real option based flexibility strategy.by Prithviraj Banerjee.S.M

Hierarchical Transactions for Hardware/Software Cosynthesis

Modern heterogeneous devices provide of a variety of computationally diverse components holding tremendous performance and power capability. Hardware-software cosynthesis offers system-level synthesis and optimization opportunities to realize the potential of these evolving architectures. Efficiently coordinating high-throughput data to make use of available computational resources requires a myriad of distributed local memories, caching structures, and data motion resources. In fact, storage, caching, and data transfer components comprise the majority of silicon real estate. Conventional automated approaches, unfortunately, do not effectively represent applications in a way that captures data motion and state management which dictate dominant system costs. Consequently, existing cosynthesis methods suffer from poor utility of computational resources. Automated cosynthesis tailored towards memory-centric optimizations can address the challenge, adapting partitioning, scheduling, mapping, and binding techniques to maximize overall system utility.This research presents a novel hierarchical transaction model that formalizes state and control management through an abstract data/control encapsulation semantic. It is designed from the ground-up to enable efficient synthesis across heterogeneous system components, with an emphasis on memory capacity constraints. It intrinsically encourages a high degree of concurrency and latency tolerance, and provides verification tools to ensure correctness. A unique data/execution hierarchical encapsulation framework guarantees scalable analysis, supporting a novel concept of state and control mobility. A front-end language allows concise expression of designer intent, and is structured with synthesis in mind. Designers express families of valid executions in a minimal format through high-level dependencies, type systems, and computational relationships, allowing synthesis tools to manage lower-level details. This dissertation introduces and exercises the model, discussing language construction, demonstrating control and data-dominated applications, and presenting a synthesis path that exhibits near-linear scalability with problem size

Risk-based design for multidisciplinary complex systems

The ultimate goal of large-scale design organizations are mainly to reduce costs and improve reliability and performance of systems while assessing how much risk (cost, schedule, scope) they can take and still remain competitive. To achieve this goal they need to develop tools to reach the most preferred design product while reducing the time of decision making during the design process, time to market and total costs, as well as increasing reliability, safety, satisfactory, performance. In addition, they should understand attitudes toward risk; know where more information is needed and identify critical factors and assumptions underlying decisions to aid in the design and development cycle of complex systems. To address these needs, this research introduces design organizations can capture, assess, and efficiently and effectively communicate uncertainty through their design processes, and as a result, improve their capacity for delivering complex systems that meet cost, schedule, and performance objectives

Compositional Scheduling Analysis Using Standard Event Models

Embedded real-time systems must meet a variety of timing requirements, such as deadlines and limited load or bandwidth. These properties depend heavily on interactions between tasks and on the scheduling of tasks and communications. Unfortunately, the current practice of specialization and re-use results in increasingly heterogeneous systems, which specifically complicates the scheduling analysis problem. Todays best practice of timed simulation is increasingly unreliable, mainly because the corner cases are extremely difficult to find and debug. As an alternative, a variety of systematic and formal approaches to scheduling analysis have been proposed. Most of them, however, are either limited to sub-problems, or use unwieldy and complex models that distract designers in practice. This thesis presents a novel, structured analysis procedure that a) can cope with the increasing complexity and heterogeneity of embedded systems, b) provides the modularity and flexibility that the established, re-use driven system integration style requires, and c) facilitates system integration using a comprehensible analytical model. The approach uses intuitive and standardized event models to represent the interfaces between different components and their scheduling. The clear interface structure allows -for the first time- the modular composition of heterogeneous sub-system analysis techniques. This provides designers with the flexibility to use their preferred scheduling and analysis techniques locally without compromising global scheduling analysis. This new analysis procedure has been implemented in the SymTA/S tool. As it can be efficiently applied in practice, it provides a serious and promising complement to simulation.Eingebettete Echtzeitsysteme müssen eine Vielzahl von Zeit- und Performanzanforderungen erfüllen, z.B. maximale Reaktionszeiten oder vorgegebene Kommunikationsbandbreiten. Die Echtzeiteigenschaften hängen stark vom Zusammenspiel der Einzelkomponenten sowie deren Scheduling ab. Unglücklicherweise führt gerade die in der Praxis etablierte Wiederverwendung von spezialisierten Komponenten zu einer Heterogenität, die die Schedulinganalyse zusätzlich erschwert. Die heute eingesetzten Simulationsverfahren sind zusehends unzuverlässig, da die kritischen Randfälle in der Praxis kaum mehr vollständig bestimmt werden können. Als Alternative wurde eine Vielzahl systematischer und formaler Ansätze vorgeschlagen. Meist sind diese jedoch entweder auf spezielle Teilprobleme beschränkt oder für den Allgemeinfall zu unhandlich und finden daher nur eine geringe Akzeptanz in der industriellen Praxis. In dieser Arbeit wird ein neues Verfahren zur Schedulinganalyse vorgestellt, das a) die steigende Komplexität und Heterogenität angemessen erfasst, b) über die Modularität und Flexibilität verfügt, die mit Wiederverwendung und Integration erforderlich ist, und c) die Integration durch ein nachvollziehbares Analysemodell unterstützt. Das Analysemodell erfasst die komplexen Abhängigkeiten zwischen Komponenten mit Hilfe von intuitiven, standardisierten Ereignismodellen. Die klare Strukturierung dieser Schnittstellen erlaubt erstmals die modulare Komposition von Analysen heterogener Systemteile. Dies gibt Entwicklern die nötige Flexibilität, ihre bevorzugten lokalen Entwurfsmethoden zu benutzen, ohne auf die globale Schedulinganalyse verzichten zu müssen. Das Verfahren bildet die Grundlage für das SymTA/S Analysewerkzeug und ist in der Praxis sehr effizient einsetzbar, womit sich eine ernstzunehmende und viel versprechende Ergänzung zur heute etablierten Performanz-Simulation eröffnet

Supporting integrated care pathways with workflow technology

Modern healthcare has moved to a focus on providing patient centric care rather than disease centred care. This new approach is provided by a unique care team which is formed to treat a patient. At the start of the treatment, the care team decide on the treatment pathway for the patient. This is a series of treatment stages where at the end of each stage, the care team use the patient’s current condition to decide whether the treatment moves to the next stage, continues in the treatment stage, or moves to an unanticipated stage. The initial treatment pathway for each patient is based on the clinical guidelines in an Integrated Care Pathway (ICP) [1] modified to suit the patient state. This research mapped a patient ICP decided by the healthcare providers into a Workflow Management System (WFMS) [2]. The clinical guidelines reflect the patient-centric flow to create an IT system supporting the care team. In the initial stage of the research the IT development team at Velindre Hospital identified that team communication and care coordination were obstacles hindering the implementation of a patient-centric delivery model. This was investigated to determine the causes, which were identified as difficulty in accessing the medical information held in dispersed legacy systems. Moreover, a major constraint in the domain is the need to keep legacy systems in operation and so there is a need to investigate approaches to enhance their functionalities. These information systems cannot be changed across all healthcare organisations and their complete autonomy needs to be retained as they are in constant use at the sites. Using workflow technology, an independent application representing an ICP was implemented. This was used to construct an independent layer in the software architecture to interact with legacy Clinical Information Systems (CISs) and so evolve their offered functionalities to support the teams. This was used to build a Virtual Organisation (VO) [3, 4] around a patient which facilitates patient-centric care. Moreover, the VO virtually integrates the data from legacy systems and ensures its availability (as needed) at the different treatment stages along the care pathway. Implications of the proposal include: formalising the treatment process, filtering and gathering the patient’s information, ensuring care continuity, and pro-acting to change. Evaluation of the proposal involved three stages; First, usefulness evaluation by the healthcare providers representing the users; Second, setup evaluation by developers of CISs; and Finally, technical evaluation by the community of the technology. The evaluation proved; the healthcare providers’ need for an adaptive and a proactive system, the possibility of adopting the proposed system, and the novelty and innovation of the proposed approach. The research proposes a patient-centric system achieved by creating a version of an ICP in the system for each patient. It also provides focussed support for team communication and care coordination, by identifying the treatment stages and providing the care team requirements at each stage. It utilises the data within the legacy system to be proactive. Moreover, it makes these required data for the actions available from the running legacy system which is required for patient-centred care. In the future the worth could be extended by mapping other ICPs into the system. This work has been published in four full papers. It found acceptance in the health informatics community [5, 6, 7] as well as the BPM community [8, 9]. It is also the winner of the 2011 “Global Award of Excellence in Adaptive Case Management (ACM)” in “Medical and Healthcare” [10] of the Workflow Management Coalition (WFMC) [11].EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Supporting integrated care pathways with workflow technology

Modern healthcare has moved to a focus on providing patient centric care rather than disease centred care. This new approach is provided by a unique care team which is formed to treat a patient. At the start of the treatment, the care team decide on the treatment pathway for the patient. This is a series of treatment stages where at the end of each stage, the care team use the patient’s current condition to decide whether the treatment moves to the next stage, continues in the treatment stage, or moves to an unanticipated stage. The initial treatment pathway for each patient is based on the clinical guidelines in an Integrated Care Pathway (ICP) [1] modified to suit the patient state. This research mapped a patient ICP decided by the healthcare providers into a Workflow Management System (WFMS) [2]. The clinical guidelines reflect the patient-centric flow to create an IT system supporting the care team. In the initial stage of the research the IT development team at Velindre Hospital identified that team communication and care coordination were obstacles hindering the implementation of a patient-centric delivery model. This was investigated to determine the causes, which were identified as difficulty in accessing the medical information held in dispersed legacy systems. Moreover, a major constraint in the domain is the need to keep legacy systems in operation and so there is a need to investigate approaches to enhance their functionalities. These information systems cannot be changed across all healthcare organisations and their complete autonomy needs to be retained as they are in constant use at the sites. Using workflow technology, an independent application representing an ICP was implemented. This was used to construct an independent layer in the software architecture to interact with legacy Clinical Information Systems (CISs) and so evolve their offered functionalities to support the teams. This was used to build a Virtual Organisation (VO) [3, 4] around a patient which facilitates patient-centric care. Moreover, the VO virtually integrates the data from legacy systems and ensures its availability (as needed) at the different treatment stages along the care pathway. Implications of the proposal include: formalising the treatment process, filtering and gathering the patient’s information, ensuring care continuity, and pro-acting to change. Evaluation of the proposal involved three stages; First, usefulness evaluation by the healthcare providers representing the users; Second, setup evaluation by developers of CISs; and Finally, technical evaluation by the community of the technology. The evaluation proved; the healthcare providers’ need for an adaptive and a proactive system, the possibility of adopting the proposed system, and the novelty and innovation of the proposed approach. The research proposes a patient-centric system achieved by creating a version of an ICP in the system for each patient. It also provides focussed support for team communication and care coordination, by identifying the treatment stages and providing the care team requirements at each stage. It utilises the data within the legacy system to be proactive. Moreover, it makes these required data for the actions available from the running legacy system which is required for patient-centred care. In the future the worth could be extended by mapping other ICPs into the system. This work has been published in four full papers. It found acceptance in the health informatics community [5, 6, 7] as well as the BPM community [8, 9]. It is also the winner of the 2011 “Global Award of Excellence in Adaptive Case Management (ACM)” in “Medical and Healthcare” [10] of the Workflow Management Coalition (WFMC) [11].EThOS - Electronic Theses Online ServiceGBUnited Kingdo