| 1. |
- Tischer, Thomas, et al.
(författare)
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Management of anterior cruciate ligament revision in adults: the 2022 ESSKA consensus part III-indications for different clinical scenarios using the RAND/UCLA appropriateness method
- 2023
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Ingår i: KNEE SURGERY SPORTS TRAUMATOLOGY ARTHROSCOPY. - 0942-2056 .- 1433-7347. ; 31:11, s. 4662-4672
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Tidskriftsartikel (refereegranskat)abstract
- PurposeThe aim of the ESSKA 2022 consensus Part III was to develop patient-focused, contemporary, evidence-based, guidelines on the indications for revision anterior cruciate ligament surgery (ACLRev).MethodsThe RAND/UCLA Appropriateness Method (RAM) was used to provide recommendations on the appropriateness of surgical treatment versus conservative treatment in different clinical scenarios based on current scientific evidence in conjunction with expert opinion. A core panel defined the clinical scenarios with a moderator and then guided a panel of 17 voting experts through the RAM tasks. Through a two-step voting process, the panel established a consensus as to the appropriateness of ACLRev for each scenario based on a nine-point Likert scale (in which a score in the range 1-3 was considered 'inappropriate', 4-6 'uncertain', and 7-9 'appropriate').ResultsThe criteria used to define the scenarios were: age (18-35 years vs 36-50 years vs 51-60 years), sports activity and expectation (Tegner 0-3 vs 4-6 vs 7-10), instability symptoms (yes vs no), meniscus status (functional vs repairable vs non-functional meniscus), and osteoarthritis (OA) (Kellgren-Lawrence [KL] grade 0-I-II vs grade III). Based on these variables, a set of 108 clinical scenarios was developed. ACLRev was considered appropriate in 58%, inappropriate in 12% (meaning conservative treatment is indicated), and uncertain in 30%. Experts considered ACLRev appropriate for patients with instability symptoms, aged <= 50 years, regardless of sports activity level, meniscus status, and OA grade. Results were much more controversial in patients without instability symptoms, while higher inappropriateness was related to scenarios with older age (51-60 years), low sporting expectation, non-functional meniscus, and knee OA (KL III).ConclusionThis expert consensus establishes guidelines as to the appropriateness of ACLRev based on defined criteria and provides a useful reference for clinical practice in determining treatment indications.
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| 2. |
- Andersson, Jesper, 1970-, et al.
(författare)
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A conceptual framework for resilience : fundamental definitions, strategies and metrics
- 2021
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Ingår i: Computing. - : Springer. - 0010-485X .- 1436-5057. ; 103, s. 559-588
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Tidskriftsartikel (refereegranskat)abstract
- The resilience system property has become more and more relevant, mainly because of the increasing dependance on a rapidly growing number of software-intensive, complex, socio-technical systems, which are facing uncertainty about changes they are expected to experience during their life-cycle and ways to deal with them. Methodologies for the systematic design and validation of resilience for such systems are thus highly necessary, and require contributions from several different fields. This paper contributes to current resilience research by providing a conceptual framework intended to serve as a common ground for the development of such methodologies. Its main points are: the identification of the main categories of changes a system should face; a clear definition of the different facets of resilience one could want to achieve, expressed in terms of the system dynamics; a mapping of each of these facets to design strategies that are better suited to achieve it; and the corresponding identification of possible metrics that can be used to assess its achievement.
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| 3. |
- Andersson, Jesper, 1970-, et al.
(författare)
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A Distilled Characterization of Resilience and Its Embraced Properties Based on State-Spaces
- 2019
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Ingår i: Software Engineering for Resilient Systems. - Cham : Springer. - 9783030308551 - 9783030308568 ; , s. 11-25
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Konferensbidrag (refereegranskat)abstract
- In recent years, we have observed the increasing interest in the system property resilience. We ascribe this increasing interest to the rapidly growing number of deployed, complex, socio-technical systems, which are facing uncertainty about changes they are expected to experience during their life-cycle and ways to deal with them. This paper contributes to current resilience research by focusing on the different definitions given for this system property, highlighting the risk that, using different terms in different communities, this contributes to create a “tower of Babel” problem, with the consequent difficulty in exchanging ideas and working together towards a common goal. We adopt an extended definition of dependability to define resilience. Based on that, we identify features of resilient systems, capture properties falling under the resilience umbrella, and define a conceptual framework for resilience characterization including how changes affect the system, strategies to design resilience, and discuss metrics for quantifying resilience at design and runtime.
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| 4. |
- Caporuscio, Mauro, 1975-, et al.
(författare)
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Decentralized Architecture for Energy-Aware Service Assembly
- 2020
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Ingår i: Software Architecture. - Cham : Springer. - 9783030589226 - 9783030589233 ; , s. 57-72
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Konferensbidrag (refereegranskat)abstract
- Contemporary application domains make more and more appealing the vision of applications built as a dynamic and opportunistic assembly of autonomous and independent resources. However, the adoption of such paradigm is challenged by: (i) the openness and scalability needs of the operating environment, which rule out approaches based on centralized architectures and, (ii) the increasing concern for sustainability issues, which makes particularly relevant, in addition to QoS constraints, the goal of reducing the application energy footprint. In this context, we contribute by proposing a decentralized architecture to build a fully functional assembly of distributed services, able to optimize its energy consumption, paying also attention to issues concerning the delivered quality of service. We suggest suitable indexes to measure from different perspectives the energy efficiency of the resulting assembly, and present the results of extensive simulation experiments to assess the effectiveness of our approach.
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| 5. |
- Cardellini, Valeria, et al.
(författare)
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A Decentralized Approach to Network-Aware Service Composition
- 2015
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Ingår i: Service Oriented and Cloud Computing - 4th European Conference, ESOCC 2015, Taormina, Italy, September 15-17, 2015. Proceedings. - Cham : Springer. - 9783319240725 - 9783319240718 ; , s. 34-48
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Konferensbidrag (refereegranskat)abstract
- Dynamic service composition represents a key feature for service-based applications operating in dynamic and large scale network environments, as it allows leveraging the variety of offered services, and to cope with their volatility. However, the high number of services and the lack of central control pose a significant challenge for the scalability and effectiveness of the composition process. We address this problem by proposing a fully decentralized approach to servicecomposition, based on the use of a gossip protocol to support information dissemination and decision making. The proposed system builds and maintains acomposition of services that fulfills both functional and non functional requirements. For the latter, we focus in particular on requirements concerning the composite service completion time, taking into account both the response time and the impact of network latency. Simulation experiments show that our solution converges quickly to a feasible composition and can self-adapt to dynamic changes concerning both service availability and network latency.
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| 6. |
- Cardellini, Valeria, et al.
(författare)
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MOSES : A platform for experimenting with qos-driven self-adaptation policies for service oriented systems
- 2017
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Ingår i: Lecture Notes in Computer Science. - Cham : Springer Verlag. - 9783319741826 ; , s. 409-433
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Konferensbidrag (refereegranskat)abstract
- Architecting software systems according to the service-oriented paradigm, and designing runtime self-adaptable systems are two relevant research areas in today’s software engineering. In this chapter we present MOSES, a software platform supporting QoS-driven adaptation of service-oriented systems. It has been conceived for service-oriented systems architected as composite services that receive requests generated by different classes of users. MOSES integrates within a unified framework different adaptation mechanisms. In this way it achieves a greater flexibility in facing various operating environments and the possibly conflicting QoS requirements of several concurrent users. Besides providing its own self-adaptation functionalities, MOSES lends itself to the experimentation of alternative approaches to QoS-driven adaptation of service-oriented systems thanks to its modular architecture. © Springer International Publishing AG 2017.
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| 7. |
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| 8. |
- D'Angelo, Mirko, et al.
(författare)
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Decentralized learning for self-adaptive QoS-aware service assembly
- 2020
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Ingår i: Future Generation Computer Systems. - : Elsevier. - 0167-739X .- 1872-7115. ; 108, s. 210-227
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Tidskriftsartikel (refereegranskat)abstract
- The highly dynamic nature of future computing systems, where applications dynamically emerge as opportunistic aggregation of autonomous and independent resources available at any given time, requires a radical shift in the adopted computing paradigms. Indeed, they should fully reflect the decentralized perspective of the execution environment and consider QoS, scalability and resilience as key objectives. In this context, the everything-as-a-service (XaaS) paradigm, which envisions the creation of new services as an assembly of independent services available within the environment, can greatly help in tackling the challenges of developing future applications. However, in order to be effective, XaaS paradigm requires self-adaptive service assembly solutions able to cope with the unpredictable variability and scalability of the execution environment, the lack of global knowledge, and the QoS requirements of services to be built. We contribute in this direction by designing a fully decentralized and collective self-adaptive service assembly framework whose main features are: (i) self-assembly, i.e., the ability to operate autonomously, (ii) online-learning, i.e., the ability to dynamically learn from experience, (iii) QoS-awareness, i.e., the inclusion of QoS requirements as driving forces for self-assembly, (iv) scalability, i.e., the ability to cope with a large number of services, and (v) resilience, i.e., the ability to maintain the persistence of service delivery when facing unexpected changes (e.g., in the number and/or QoS of services). Simulation experiments show that our solution makes the system able to quickly converge to viable assemblies that improve and maintain over time the social welfare of the system, despite the local perspective of each participating service.
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| 9. |
- de Lemos, Rogerio, et al.
(författare)
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Software Engineering for Self-Adaptive Systems : A Second Research Roadmap
- 2013
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Ingår i: Software Engineering for Self-Adaptive Systems II. - Berlin, Heidelberg : Springer. - 9783642358128 ; , s. 1-32
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The goal of this roadmap paper is to summarize the state-of-the-art and identify research challenges when developing, deploying and managing self-adaptive software systems. Instead of dealing with a wide range of topics associated with the field, we focus on four essential topics of self-adaptation: design space for self-adaptive solutions, software engineering processes for self-adaptive systems, from centralized to decentralized control, and practical run-time verification & validation for self-adaptive systems. For each topic, we present an overview, suggest future directions, and focus on selected challenges. This paper complements and extends a previous roadmap on software engineering for self-adaptive systems published in 2009 covering a different set of topics, and reflecting in part on the previous paper. This roadmap is one of the many results of the Dagstuhl Seminar 10431 on Software Engineering for Self-Adaptive Systems, which took place in October 2010.
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| 10. |
- Grassi, Vincenzo, et al.
(författare)
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A conceptual and architectural characterization of antifragile systems
- 2024
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Ingår i: Journal of Systems and Software. - : Elsevier. - 0164-1212 .- 1873-1228. ; 213
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Tidskriftsartikel (refereegranskat)abstract
- Antifragility is one of the terms that have recently emerged with the aim of indicating a direction that should be pursued toward the objective of designing Information and Communications Technology systems that remain trustworthy despite their dynamic and evolving operating context. We present a characterization of antifragility, aiming to clarify from a conceptual viewpoint the implications of its adoption as a design guideline and its relationships with other approaches sharing a similar objective. To this end, we discuss the inclusion of antifragility (and related concepts) within the well-known dependability taxonomy, which was proposed a few decades ago with the goal of providing a reference framework to reason about the different facets of the general concern of designing dependable systems. From our conceptual characterization, we then derive a possible path toward the engineering of antifragile systems.
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| 11. |
- Grassi, Vincenzo, et al.
(författare)
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Towards a Conceptual Characterization of Antifragile Systems
- 2023
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Ingår i: Proceedings - IEEE 20th International Conference on Software Architecture Companion, ICSA-C 2023. - : IEEE. - 9781665464598 ; , s. 121-125
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Konferensbidrag (refereegranskat)abstract
- Antifragility has recently emerged as a design principle changes during their operations. In this "New Ideas"paper we intend to support the vision that an effective application of this principle requires a clear understanding of the implications of its adoption and of its relationships with other approaches sharing a similar objective. To this end, we argue that a proper conceptual characterization of antifragility can be achieved through its inclusion within the consolidated dependability taxonomy. From this conceptual characterization we identify open architectural challenges towards the definition of a reference model for antifragile systems. © 2023 IEEE.
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| 12. |
- Perez-Palacin, Diego, et al.
(författare)
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QoS-based model driven assessment of adaptive reactive systems
- 2010
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Ingår i: Proceedings : Third International Conference on Software Testing, Verification, and Validation—Workshops. - : IEEE. ; , s. 299-308
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Konferensbidrag (refereegranskat)abstract
- Adaptable reactive software systems continuously interact with their environment responding to external stimuli and triggering events that may be perceived by their users. Designing and maintaining such systems is a challenging task. A key issue to be faced concerns the assessment of their effectiveness, in terms of the ability to meet their required Quality of Service. This paper introduces a model driven approach to support this assessment, with a focus on performance and dependability attributes. Our approach takes advantage from an existing intermediate modeling language and introduces the necessary extensions to cope with reactive systems. The presented model driven framework exploits the idea of defining a model transformation chain that maps a design oriented model of the system to an analysis oriented model that lends itself to the application of a suitable analysis methodology. We identify some key concepts that should be present in the design model of an adaptable reactive system, and show how to devise a transformation from such a model to a target analysis models.
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| 13. |
- Weyns, Danny, et al.
(författare)
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On Patterns for Decentralized Control in Self-Adaptive Systems
- 2013
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Ingår i: Software Engineering for Self-Adaptive Systems II. - Berlin, Heidelberg : Springer. - 9783642358128 ; , s. 76-107
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Konferensbidrag (refereegranskat)abstract
- Self-adaptation is typically realized using a control loop. Oneprominent approach for organizing a control loop in self-adaptive systemsis by means of four components that are responsible for the primary functionsof self-adaptation: Monitor, Analyze, Plan, and Execute, togetherforming a MAPE loop. When systems are large, complex, and heterogeneous,a single MAPE loop may not be sufficient for managing alladaptation in a system, so multiple MAPE loops may be introduced. Inself-adaptive systems with multiple MAPE loops, decisions about how todecentralize each of the MAPE functions must be made. These decisionsinvolve how and whether the corresponding functions from multiple loopsare to be coordinated (e.g., planning components coordinating to preparea plan for an adaptation). To foster comprehension of self-adaptive systemswith multiple MAPE loops and support reuse of known solutions,it is crucial that we document common design approaches for engineers.As such systematic knowledge is currently lacking, it is timely to reflecton these systems to: (a) consolidate the knowledge in this area, and (b)to develop a systematic approach for describing different types of controlin self-adaptive systems. We contribute with a simple notation fordescribing interacting MAPE loops, which we believe helps in achieving(b), and we use this notation to describe a number of existing patternsof interacting MAPE loops, to begin to fulfill (a). From our study, weoutline numerous remaining research challenges in this area.
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| 14. |
- Weyns, Danny, et al.
(författare)
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Perpetual assurances for self-adaptive systems
- 2017
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Ingår i: Software Engineeringfor Self-Adaptive Systems III, Assurances. - Cham : Springer. - 9783319741826 - 9783319741833 ; , s. 31-63
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Bokkapitel (refereegranskat)abstract
- Providing assurances for self-adaptive systems is challenging. A primary underlying problem is uncertainty that may stem from a variety of different sources, ranging from incomplete knowledge to sensor noise and uncertain behavior of humans in the loop. Providing assurances that the self-adaptive system complies with its requirements calls for an enduring process spanning the whole lifetime of the system. In this process, humans and the system jointly derive and integrate new evidence and arguments, which we coined perpetual assurances for self-adaptive systems. In this paper, we provide a background framework and the foundation for perpetual assurances for self-adaptive systems. We elaborate on the concrete challenges of offering perpetual assurances, requirements for solutions, realization techniques and mechanisms to make solutions suitable. We also present benchmark criteria to compare solutions. We then present a concrete exemplar that researchers can use to assess and compare approaches for perpetual assurances for self-adaptation. © Springer International Publishing AG 2017.
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| 15. |
- Weyns, Danny, et al.
(författare)
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Towards a Research Agenda for Understanding and Managing Uncertainty in Self-Adaptive Systems
- 2023
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Ingår i: Software Engineering Notes. - : ACM Publications. - 0163-5948 .- 1943-5843. ; 48:4, s. 20-36
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Tidskriftsartikel (refereegranskat)abstract
- Despite considerable research efforts on handling uncertainty in self-adaptive systems, a comprehensive understanding of the precise nature of uncertainty is still lacking. This paper summarises the findings of the 2023 Bertinoro Seminar on Uncertainty in Self- Adaptive Systems, which aimed at thoroughly investigating the notion of uncertainty, and outlining open challenges associated with its handling in self-adaptive systems. The seminar discussions were centered around five core topics: (1) agile end-toend handling of uncertainties in goal-oriented self-adaptive systems, (2) managing uncertainty risks for self-adaptive systems, (3) uncertainty propagation and interaction, (4) uncertainty in self-adaptive machine learning systems, and (5) human empowerment under uncertainty. Building on the insights from these discussions, we propose a research agenda listing key open challenges, and a possible way forward for addressing them in the coming years.
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| 16. |
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| 17. |
- Zanchetti, Alberto, et al.
(författare)
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Blood pressure and low-density lipoprotein-cholesterol lowering for prevention of strokes and cognitive decline: a review of available trial evidence.
- 2014
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Ingår i: Journal of Hypertension. - 1473-5598. ; 32:9, s. 1741-1750
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Forskningsöversikt (refereegranskat)abstract
- It is well established by a large number of randomized controlled trials that lowering blood pressure (BP) and low-density lipoprotein cholesterol (LDL-C) by drugs are powerful means to reduce stroke incidence, but the optimal BP and LDL-C levels to be achieved are largely uncertain. Concerning BP targets, two hypotheses are being confronted: first, the lower the BP, the better the treatment outcome, and second, the hypothesis that too low BP values are accompanied by a lower benefit and even higher risk. It is also unknown whether BP lowering and LDL-C lowering have additive beneficial effects for the primary and secondary prevention of stroke, and whether these treatments can prevent cognitive decline after stroke.
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| 18. |
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