| 1. |
- Sarno, Giovanna, et al.
(författare)
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Intravascular ultrasound radiofrequency analysis after optimal coronary stenting with initial quantitative coronary angiography guidance : an ATHEROREMO sub-study
- 2011
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Ingår i: EuroIntervention. - 1774-024X .- 1969-6213. ; 6:8, s. 977-984
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Tidskriftsartikel (refereegranskat)abstract
- AIMS:To investigate whether the use of intravascular ultrasound virtual histology (IVUS-VH) leads to any improvements in stent deployment, when performed in patients considered to have had an optimal percutaneous coronary intervention (PCI) by quantitative coronary angiography (QCA).METHODS AND RESULTS:After optimal PCI result (residual stenosis by QCA<30%), IVUS-VH was performed in 100 patients by protocol, with the option to use the information left to the discretion of the operators. Patients were categorised as: Group1 (n=54), where the IVUS-VH findings were used to evaluate the need for further optimisation of the stent deployment; and Group2 (n=46), where the IVUS-VH was documentary such that the stenting results were considered optimal according to QCA. Optimal stent deployment on IVUS-VH was defined as: normal stent expansion, absence of stent malapposition, complete lesion coverage as indicated by a plaque burden (PB%) between 30-40% and necrotic core confluent to the lumen<10% or PB%<30% at the 5 mm proximal and distal to the stent. The first IVUS-VH in all patients demonstrated the achievement of optimal stent deployment, incomplete lesion coverage, stent under-expansion and stent-edge dissection in 60%, 31%, 20% and 8% of patients, respectively. There was no stent malapposition. In Group 1, 25 patients had optimal stent deployment and did not require further intervention, whilst in 29 patients further intervention was needed (additional stent, n=18; post-dilatation, n=29). Overall optimal stent deployment was finally achieved in 52/54 patients (96%) in Group 1 and 35/46 (76%) of Group 2, p<0.05.CONCLUSIONS:IVUS-VH may have a role in facilitating optimal stent implantation and complete lesion coverage.
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| 2. |
- Zhang, Yurui, et al.
(författare)
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Early Eocene Ocean Meridional Overturning Circulation : The Roles of Atmospheric Forcing and Strait Geometry
- 2022
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Ingår i: Paleoceanography and Paleoclimatology. - 2572-4517 .- 2572-4525. ; 37:3
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Tidskriftsartikel (refereegranskat)abstract
- Here, we compare the ocean overturning circulation of the early Eocene (47–56 Ma) in eight coupled climate model simulations from the Deep-Time Model Intercomparison Project (DeepMIP) and investigate the causes of the observed inter-model spread. The most common global meridional overturning circulation (MOC) feature of these simulations is the anticlockwise bottom cell, fed by sinking in the Southern Ocean. In the North Pacific, one model (GFDL) displays strong deepwater formation and one model (CESM) shows weak deepwater formation, while in the Atlantic two models show signs of weak intermediate water formation (MIROC and NorESM). The location of the Southern Ocean deepwater formation sites varies among models and relates to small differences in model geometry of the Southern Ocean gateways. Globally, convection occurs in the basins with smallest local freshwater gain from the atmosphere. The global MOC is insensitive to atmospheric CO2 concentrations from 1× (i.e., 280 ppm) to 3× (840 ppm) pre-industrial levels. Only two models have simulations with higher CO2 (i.e., CESM and GFDL) and these show divergent responses, with a collapsed and active MOC, respectively, possibly due to differences in spin-up conditions. Combining the multiple model results with available proxy data on abyssal ocean circulation highlights that strong Southern Hemisphere-driven overturning is the most likely feature of the early Eocene. In the North Atlantic, unlike the present day, neither model results nor proxy data suggest deepwater formation in the open ocean during the early Eocene, while the evidence for deepwater formation in the North Pacific remains inconclusive.
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| 3. |
- Anthony, Richard, et al.
(författare)
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A Future Dynamically Reconfigurable Automotive Software System
- 2008
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Ingår i: Proceedings of the Elektronik im Kraftfahrzeug.
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Konferensbidrag (refereegranskat)abstract
- Embedded software systems in vehicles are of rapidly increasing commercial importance for the automotive industry. Current systems employ a static run-time environment; due to the difficulty and cost involved in the development of dynamic systems in a high-integrity embedded control context. A dynamic system, referring to the system configuration, would greatly increase the flexibility of the offered functionality and enable customised software configuration for individual vehicles, adding customer value through plug-and-play capability, and increased quality due to its inherent ability to adjust to changes in hardware and software. We envisage an automotive system containing a variety of components, from a multitude of organizations, not necessarily known at development time. The system dynamically adapts its configuration to suit the run-time system constraints.This paper presents our vision for future automotive control systems that will be regarded in an EU research project, referred to as DySCAS (Dynamically Self-Configuring Automotive Systems). We propose a self-configuring vehicular control system architecture, with capabilities that include automatic discovery and inclusion of new devices, self-optimisation to best-use the processing, storage and communication resources available, self-diagnostics and ultimately self-healing. Such an architecture has benefits extending to reduced development and maintenance costs, improved passenger safety and comfort, and flexible owner customisation.Specifically, this paper addresses the following issues: The state of the art of embedded software systems in vehicles, emphasising the current limitations arising from fixed run-time configurations; and the benefits and challenges of dynamic configuration, giving rise to opportunities for self-healing, self-optimisation, and the automatic inclusion of users’ Consumer Electronic (CE) devices. Our proposal for a dynamically reconfigurable automotive software system platform is outlined and a typical use-case is presented as an example to exemplify the benefits of the envisioned dynamic capabilities.
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| 4. |
- Anthony, Richard, et al.
(författare)
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Towards a Dynamically Reconfigurable Automotive Control System Architecture
- 2007
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Ingår i: Embedded System Design: Topics, Techniques and Trends. - Boston, MA : Springer US. - 9780387722573 ; , s. 71-84
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Konferensbidrag (refereegranskat)abstract
- This paper proposes a vehicular control system architecture that supports self-configuration. The architecture is based on dynamic mapping of processes and services to resources to meet the challenges of future demanding use-scenarios in which systems must be flexible to exhibit context-aware behaviour and to permit customization. The architecture comprises a number of low-level services that will provide the required system functionalities, which include automatic discovery and incorporation of new devices, self-optimisation to best-use the processing, storage and communication resources available, and self-diagnostics. The benefits and challenges of dynamic configuration and the automatic inclusion of users' Consumer Electronic (CE) devices are briefly discussed and the self-management and control-theoretic technologies that will be used are described in outline. A number of generic use-cases have been identified, each with several specific use-case scenarios. To demonstrate the extent of the flexible reconfiguration facilitated by the architecture, some of these use-cases are described, each exemplifying a different aspect of dynamic reconfiguration.
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| 5. |
- Chen, DeJiu, et al.
(författare)
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An Architectural Approach to Autonomics and Self-management of Automotive Embedded Electronic Systems
- 2008
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Ingår i: 4th European Congress ERTS: Embedded Real Time Software 2008. - : SIA (Société des Ingénieurs de l'Automobile - French Automotive Engineers Society).
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Konferensbidrag (refereegranskat)abstract
- Embedded electronic systems in vehiclesare of rapidly increasing commercial importance forthe automotive industry. While current vehicularembedded systems are extremely limited and static,a more dynamic configurable system would greatlysimplify the integration work and increase quality ofvehicular systems. This brings in features likeseparation of concerns, customised softwareconfiguration for individual vehicles, seamlessconnectivity, and plug-and-play capability.Furthermore, such a system can also contribute toincreased dependability and resource optimizationdue to its inherent ability to adjust itself dynamicallyto changes in software, hardware resources, andenvironment condition. This paper describes thearchitectural approach to achieving the goals ofdynamically self-configuring automotive embeddedelectronic systems by the EU research projectDySCAS. The architecture solution outlined in thispaper captures the application and operationalcontexts, expected features, middleware services,functions and behaviours, as well as the basicmechanisms and technologies. The paper alsocovers the architecture conceptualization bypresenting the rationale, concerning the architecturestructuring, control principles, and deploymentconcept. In this paper, we also present the adoptedarchitecture V&V strategy and discuss some openissues in regards to the industrial acceptance.
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| 6. |
- Chen, DeJiu, et al.
(författare)
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Developing a Context-aware Architecture in DySCAS
- 2007
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Konferensbidrag (refereegranskat)abstract
- Software systems in vehicles are of rapidly increasing commercial importance for the automotive industry. Current vehicular embedded systems exhibit a fixed software structure and the possibilities for software upgrades are limited. Due to increasing expectations of context-awareness, dependability, flexibility, cost efficiency and time-to-market; we argue that it is now necessary to enable advanced features that are based on dynamic configuration.To reach the goals of dynamically self-configuring automotive systems, we propose an architecture which is currently being developed in the EC funded DySCAS project. We describe the proposed architecture, with a focus on its support for adaptive behavior. To illustrate the type and extent of adaptability achievable, a set of generic use case classes are briefly described and the requirements they place on the architecture and in particular the adaptive aspects, are discussed.The architecture is based on a distributed hierarchical control and decision strategy, which through the policy-based middleware functions and underlying technologies allows separation-of-concerns, on-line reconfiguration, seamless connectivity, plug-and-play capability, and also increased dependability and resource optimization. Decision points are concerned with both application and resource aspects and are dispersed throughout a distributed platform, allowing the embedding of numerous policies to make context-aware decisions whilst avoiding excessive complexity. The approach is scalable and provides additional freedom for engineers to define the dynamic configuration characteristics.The developed architecture is so far on a functional level and has been validated against system requirements. Current work concentrates on defining the corresponding software architecture, considering automotive platforms and constraints.
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| 7. |
- Chen, DeJiu, et al.
(författare)
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DySCAS System Architecture
- 2007
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Rapport (refereegranskat)abstract
- This deliverable provides an architectural strategy and overall system design forthe DySCAS middleware system as a first step towards a complete systemspecification. The DySCAS Basic Architecture captures both the systemconceptualization and an initial function-level outline without consideringimplementation and technology details. It defines the middleware system in termsof its application and operational contexts, expected features, middleware servicesthat group functions, behaviours, as well as the structuring and implementationdecisions that are most crucial to satisfy the given set of requirements. In thisdocument, we also outline some fundamental strategies for binding themiddleware components to the target platforms and infrastructures and forhandling potential errors at both initialization-time and rum-time, while taking thetechnology support and domain needs into consideration.This deliverable also covers the rationale behind the architecture solutions andprovides a generic framework that relates architecture principles and styles, wellknownmechanisms, and reference models to the expected functionalities andqualities of DySCAS. The aim is to consolidate the proposed solutions and also tofacilitate the communications between DySCAS partners and to third-parties.
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| 8. |
- Chen, DeJiu, et al.
(författare)
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DySCAS System Specification - Part II : Specification of DySCAS MiddlewareReference Architecture
- 2008
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Rapport (refereegranskat)abstract
- The purpose of this document is to provide a comprehensive definition of theDySCAS Middleware Reference Architecture, including the DySCASArchitecture Model together with the underlying DySCAS Component Model andDySCAS Information Model. The component model provides a standardizedapproach to the interfaces, internal structure and behaviours of middlewareservices. The information model constitutes an ontology and effective means forcapturing and formulating the meta-information of system configuration. Suchinformation is typically concerned with the system architecture specification andoperation status that is necessary for run-time configuration management.This document serves as a guide for understanding the functionalities andsemantics of this reference architecture in detail.
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| 9. |
- Lunt, Daniel J., et al.
(författare)
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DeepMIP : model intercomparison of early Eocene climatic optimum (EECO) large-scale climate features and comparison with proxy data
- 2021
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Ingår i: Climate of the Past. - : Copernicus GmbH. - 1814-9324 .- 1814-9332. ; 17:1, s. 203-227
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Tidskriftsartikel (refereegranskat)abstract
- We present results from an ensemble of eight climate models, each of which has carried out simulations of the early Eocene climate optimum (EECO, similar to 50 million years ago). These simulations have been carried out in the framework of the Deep-Time Model Intercomparison Project (DeepMIP; http://www.deepmip.org , last access: 10 January 2021); thus, all models have been configured with the same paleogeographic and vegetation boundary conditions. The results indicate that these non-CO2 boundary conditions contribute between 3 and 5 degrees C to Eocene warmth. Compared with results from previous studies, the DeepMIP simulations generally show a reduced spread of the global mean surface temperature response across the ensemble for a given atmospheric CO2 concentration as well as an increased climate sensitivity on average. An energy balance analysis of the model ensemble indicates that global mean warming in the Eocene compared with the preindustrial period mostly arises from decreases in emissivity due to the elevated CO2 concentration (and associated water vapour and long-wave cloud feedbacks), whereas the reduction in the Eocene in terms of the meridional temperature gradient is primarily due to emissivity and albedo changes owing to the non-CO2 boundary conditions (i.e. the removal of the Antarctic ice sheet and changes in vegetation). Three of the models (the Community Earth System Model, CESM; the Geophysical Fluid Dynamics Laboratory, GFDL, model; and the Norwegian Earth System Model, NorESM) show results that are consistent with the proxies in terms of the global mean temperature, meridional SST gradient, and CO2, without prescribing changes to model parameters. In addition, many of the models agree well with the first-order spatial patterns in the SST proxies. However, at a more regional scale, the models lack skill. In particular, the modelled anomalies are substantially lower than those indicated by the proxies in the southwest Pacific; here, modelled continental surface air temperature anomalies are more consistent with surface air temperature proxies, implying a possible inconsistency between marine and terrestrial temperatures in either the proxies or models in this region. Our aim is that the documentation of the large-scale features and model-data comparison presented herein will pave the way to further studies that explore aspects of the model simulations in more detail, for example the ocean circulation, hydrological cycle, and modes of variability, and encourage sensitivity studies to aspects such as paleogeography, orbital configuration, and aerosols.
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| 10. |
- Niezgodzki, Igor, et al.
(författare)
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Simulation of Arctic sea ice within the DeepMIP Eocene ensemble : Thresholds, seasonality and factors controlling sea ice development
- 2022
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Ingår i: Global and Planetary Change. - : Elsevier BV. - 0921-8181 .- 1872-6364. ; 214
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Tidskriftsartikel (refereegranskat)abstract
- The early Eocene greenhouse climate maintained by high atmospheric CO2 concentrations serves as a testbed for future climate changes dominated by increasing CO2 forcing. In particular, the early Eocene Arctic region is important in the context of future CO2 driven climate warming in the northern polar region and associated shrinking Arctic sea ice. Here, we present early Eocene Arctic sea ice simulations carried out by six coupled climate models within the framework of the Deep-Time Model Intercomparison Project (DeepMIP). We find differences in sea ice responses to CO2 changes across the ensemble and compare the results with available proxy-based sea ice reconstructions from the Arctic Ocean. Most of the models simulate seasonal sea ice presence at high CO2 levels (≥ 840 ppmv = 3× pre-industrial (PI) level of 280 ppmv). However, the threshold when sea ice permanently disappears from the ocean varies considerably between the models (from <840 ppmv to >1680 ppmv). Based on a one-dimensional energy balance model analysis we find that the greenhouse effect likely caused by increased atmospheric water vapor concentration plays an important role in the inter-model spread in Arctic winter surface temperature changes in response to a CO2 rise from 1× to 3× the PI level. Furthermore, differences in simulated surface salinity in the Arctic Ocean play an important role in the control of local sea ice formation. These differences result from different implementations of river run-off between the models, but also from differences in the exchange of waters between a brackish Arctic and a more saline North Atlantic Ocean that are controlled by the width of the gateway between both basins. As there is no geological evidence for Arctic sea ice in the early Eocene, its presence in most of the simulations with 3× PI CO2 level indicates either a higher CO2 level and/or an overly weak polar sensitivity in these models.
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