| 1. |
- Al-Shishtawy, Ahmad, et al.
(författare)
-
A design methodology for self-management in distributed environments
- 2009
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Ingår i: IEEE International conference on Computational Science and Engineering. - 9780769538235 ; , s. 430-436
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Konferensbidrag (refereegranskat)abstract
- Autonomic computing is a paradigm that aims at reducing administrative overhead by providing autonomic managers to make applications selfmanaging. In order to better deal with dynamic environments, for improved performance and scalability, we advocate for distribution of management functions among several cooperative managers that coordinate their activities in order to achieve management objectives. We present a methodology for designing the management part of a distributed self-managing application in a distributed manner. We define design steps, that includes partitioning of management functions and orchestration of multiple autonomic managers. We illustrate the proposed design methodology by applying it to design and development of a distributed storage service as a case study. The storage service prototype has been developed using the distributing component management system Niche. Distribution of autonomic managers allows distributing the management overhead and increased management performance due to concurrency and better locality.
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| 2. |
- Al-Shishtawy, Ahmad, 1978-, et al.
(författare)
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Distributed Control Loop Patterns for Managing Distributed Applications
- 2008
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Ingår i: SASOW 2008. - LOS ALAMITOS : IEEE Computer Society. - 9781424434688 ; , s. 260-265
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Konferensbidrag (refereegranskat)abstract
- In this paper we discuss various control loop patterns for managing distributed applications with multiple control loops. We introduce a high-level framework, called DCMS, for developing, deploying and managing component-based distributed applications in dynamic environments. The control loops, and interactions among them, are illustrated in the context of a distributed self-managing storage service implemented using DCMS to achieve various self-* properties. Different control loops are used for different self-* behaviours, which illustrates one way to divide application management, which makes for both ease of development and for better scalability and robustness when managers are distributed. As the multiple control loops are not completely independent, we demonstrate different patterns to deal with the interaction and potential conflict between multiple managers.
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| 3. |
- Al-Shishtawy, Ahmad, et al.
(författare)
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Enabling Self-Management Of Component Based Distributed Applications
- 2008
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Ingår i: FROM GRIDS TO SERVICE AND PERVASIVE COMPUTING. - Boston, MA : Springer-Verlag New York. - 9780387094557 ; , s. 163-174
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Konferensbidrag (refereegranskat)abstract
- Deploying and managing distributed applications in dynamic Grid environments requires a high degree of autonomous management. Programming autonomous management in turn requires programming environment support and higher level abstractions to become feasible. We present a framework for programming self-managing component-based distributed applications. The framework enables the separation of application’s functional and non-functional (self-*) parts. The framework extends the Fractal component model by the component group abstraction and one-to-any and one-to-all bindings between components and groups. The framework supports a network-transparent view of system architecture simplifying designing application self-* code. The framework provides a concise and expressive API for self-* code. The implementation of the framework relies on scalability and robustness of the Niche structured p2p overlay network. We have also developed a distributed file storage service to illustrate and evaluate our framework.
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| 4. |
- Al-Shishtawy, Ahmad, 1978-
(författare)
-
Self-Management for Large-Scale Distributed Systems
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Autonomic computing aims at making computing systems self-managing by using autonomic managers in order to reduce obstacles caused by management complexity. This thesis presents results of research on self-management for large-scale distributed systems. This research was motivated by the increasing complexity of computing systems and their management.In the first part, we present our platform, called Niche, for programming self-managing component-based distributed applications. In our work on Niche, we have faced and addressed the following four challenges in achieving self-management in a dynamic environment characterized by volatile resources and high churn: resource discovery, robust and efficient sensing and actuation, management bottleneck, and scale. We present results of our research on addressing the above challenges. Niche implements the autonomic computing architecture, proposed by IBM, in a fully decentralized way. Niche supports a network-transparent view of the system architecture simplifying the design of distributed self-management. Niche provides a concise and expressive API for self-management. The implementation of the platform relies on the scalability and robustness of structured overlay networks. We proceed by presenting a methodology for designing the management part of a distributed self-managing application. We define design steps that include partitioning of management functions and orchestration of multiple autonomic managers.In the second part, we discuss robustness of management and data consistency, which are necessary in a distributed system. Dealing with the effect of churn on management increases the complexity of the management logic and thus makes its development time consuming and error prone. We propose the abstraction of Robust Management Elements, which are able to heal themselves under continuous churn. Our approach is based on replicating a management element using finite state machine replication with a reconfigurable replica set. Our algorithm automates the reconfiguration (migration) of the replica set in order to tolerate continuous churn. For data consistency, we propose a majority-based distributed key-value store supporting multiple consistency levels that is based on a peer-to-peer network. The store enables the tradeoff between high availability and data consistency. Using majority allows avoiding potential drawbacks of a master-based consistency control, namely, a single-point of failure and a potential performance bottleneck.In the third part, we investigate self-management for Cloud-based storage systems with the focus on elasticity control using elements of control theory and machine learning. We have conducted research on a number of different designs of an elasticity controller, including a State-Space feedback controller and a controller that combines feedback and feedforward control. We describe our experience in designing an elasticity controller for a Cloud-based key-value store using state-space model that enables to trade-off performance for cost. We describe the steps in designing an elasticity controller. We continue by presenting the design and evaluation of ElastMan, an elasticity controller for Cloud-based elastic key-value stores that combines feedforward and feedback control.
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| 5. |
- Barucca, G., et al.
(författare)
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Study of excited Ξ baryons with the P¯ ANDA detector
- 2021
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Ingår i: European Physical Journal A. - : Springer Nature. - 1434-6001 .- 1434-601X. ; 57:4
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Tidskriftsartikel (refereegranskat)abstract
- The study of baryon excitation spectra provides insight into the inner structure of baryons. So far, most of the world-wide efforts have been directed towards N∗ and Δ spectroscopy. Nevertheless, the study of the double and triple strange baryon spectrum provides independent information to the N∗ and Δ spectra. The future antiproton experiment P¯ANDA will provide direct access to final states containing a Ξ¯ Ξ pair, for which production cross sections up to μb are expected in p¯p reactions. With a luminosity of L= 10 31 cm- 2 s- 1 in the first phase of the experiment, the expected cross sections correspond to a production rate of ∼106events/day. With a nearly 4 π detector acceptance, P¯ANDA will thus be a hyperon factory. In this study, reactions of the type p¯p → Ξ¯ +Ξ∗ - as well as p¯p → Ξ¯ ∗ +Ξ- with various decay modes are investigated. For the exclusive reconstruction of the signal events a full decay tree fit is used, resulting in reconstruction efficiencies between 3 and 5%. This allows high statistics data to be collected within a few weeks of data taking.
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| 6. |
- Barucca, G., et al.
(författare)
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The potential of Λ and Ξ- studies with PANDA at FAIR
- 2021
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Ingår i: European Physical Journal A. - : Springer Nature. - 1434-6001 .- 1434-601X. ; 57:4
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Tidskriftsartikel (refereegranskat)abstract
- The antiproton experiment PANDA at FAIR is designed to bring hadron physics to a new level in terms of scope, precision and accuracy. In this work, its unique capability for studies of hyperons is outlined. We discuss ground-state hyperons as diagnostic tools to study non-perturbative aspects of the strong interaction, and fundamental symmetries. New simulation studies have been carried out for two benchmark hyperon-antihyperon production channels: p¯ p→ Λ¯ Λ and p¯ p→ Ξ¯ +Ξ-. The results, presented in detail in this paper, show that hyperon-antihyperon pairs from these reactions can be exclusively reconstructed with high efficiency and very low background contamination. In addition, the polarisation and spin correlations have been studied, exploiting the weak, self-analysing decay of hyperons and antihyperons. Two independent approaches to the finite efficiency have been applied and evaluated: one standard multidimensional efficiency correction approach, and one efficiency independent approach. The applicability of the latter was thoroughly evaluated for all channels, beam momenta and observables. The standard method yields good results in all cases, and shows that spin observables can be studied with high precision and accuracy already in the first phase of data taking with PANDA.
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| 7. |
- Borgquist, Signe, et al.
(författare)
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Long-term exposure to insulin and volumetric mammographic density : Observational and genetic associations in the Karma study
- 2018
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Ingår i: Breast Cancer Research. - : Springer Science and Business Media LLC. - 1465-5411 .- 1465-542X. ; 20:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Long-term insulin exposure has been implicated in breast cancer etiology, but epidemiological evidence remains inconclusive. The aims of this study were to investigate the association of insulin therapy with mammographic density (MD) as an intermediate phenotype for breast cancer and to assess associations with long-term elevated circulating insulin levels using a genetic score comprising 18 insulin-associated variants. Methods: We used data from the KARolinska MAmmography (Karma) project, a Swedish mammography screening cohort. Insulin-treated patients with type 1 (T1D, n = 122) and type 2 (T2D, n = 237) diabetes were identified through linkage with the Prescribed Drug Register and age-matched to 1771 women without diabetes. We assessed associations with treatment duration and insulin glargine use, and we further examined MD differences using non-insulin-treated T2D patients as an active comparator. MD was measured using a fully automated volumetric method, and analyses were adjusted for multiple potential confounders. Associations with the insulin genetic score were assessed in 9437 study participants without diabetes. Results: Compared with age-matched women without diabetes, insulin-treated T1D patients had greater percent dense (8.7% vs. 11.4%) and absolute dense volumes (59.7 vs. 64.7 cm3), and a smaller absolute nondense volume (615 vs. 491 cm3). Similar associations were observed for insulin-treated T2D, and estimates were not materially different in analyses comparing insulin-treated T2D patients with T2D patients receiving noninsulin glucose-lowering medication. In both T1D and T2D, the magnitude of the association with the absolute dense volume was highest for long-term insulin therapy (≥ 5 years) and the long-acting insulin analog glargine. No consistent evidence of differential associations by insulin treatment duration or type was found for percent dense and absolute nondense volumes. Genetically predicted insulin levels were positively associated with percent dense and absolute dense volumes, but not with the absolute nondense volume (percentage difference [95% CI] per 1-SD increase in insulin genetic score = 0.8 [0.0; 1.6], 0.9 [0.1; 1.8], and 0.1 [- 0.8; 0.9], respectively). Conclusions: The consistency in direction of association for insulin treatment and the insulin genetic score with the absolute dense volume suggest a causal influence of long-term increased insulin exposure on mammographic dense breast tissue.
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| 8. |
- Brand, Judith S, et al.
(författare)
-
Chemotherapy, genetic susceptibility, and risk of venous thromboembolism in breast cancer patients
- 2016
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Ingår i: Clinical Cancer Research. - Stockholm : Karolinska Institutet, Dept of Medical Epidemiology and Biostatistics. - 1078-0432. ; 22:21, s. 5249-5255
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Venous thromboembolism (VTE) is highly heritable and a serious complication of cancer and its treatment. We examined the individual and joint effects of chemotherapy and genetic susceptibility on VTE risk in patients with breast cancer. Experimental design: A Swedish population-based study including 4,261 women diagnosed with primary invasive breast cancer between 2001 and 2008 in Stockholm, followed until 2012. Risk stratification by chemotherapy and genetic susceptibility [a polygenic risk score (PRS), including nine established VTE loci] was assessed using Kaplan-Meier and flexible parametric survival analyses, adjusting for patient, tumor, and treatment characteristics. Results: In total, 276 patients experienced a VTE event during a median follow-up of 7.6 years. Patients receiving chemotherapy [HR (95% CI) = 1.98; 1.40-2.80] and patients in the highest 5% of the PRS [HR (95% CI) = 1.90; 1.24-2.91] were at increased risk of developing VTE. Chemotherapy and PRS acted independently on VTE risk and the 1-year cumulative incidence in patients carrying both risk factors was 9.5% compared with 1.3% in patients not having these risk factors (P < 0.001). Stratified analyses by age showed that the risk-increasing effect of PRS was stronger in older patients (P interaction = 0.04), resulting in an excess risk among genetically susceptible patients receiving chemotherapy aged ≥ 60 years (1-year cumulative incidence = 25.0%). Conclusions: Risk stratification by chemotherapy and genetic susceptibility identifies patients with breast cancer at high VTE risk, who could potentially benefit from thromboprophylaxis. Our results further suggest that genetic testing is more informative in older patients with breast cancer.
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| 9. |
- Brand, Judith S, et al.
(författare)
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Infection-related hospitalizations in breast cancer patients : risk and impact on prognosis
- 2016
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Ingår i: Journal of Infection. - Stockholm : Karolinska Institutet, Dept of Medical Epidemiology and Biostatistics. - 0163-4453 .- 1532-2742.
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: Infections are a common cause of hospitalization in breast cancer patients. We studied the risk, clinical characteristics and outcomes of infection-related hospitalizations in this patient population. METHODS: A Swedish registry-based study including 8338 breast cancer patients diagnosed between 2001 and 2008, followed prospectively for infection-related hospitalizations until 2010. Standardized incidence ratios (SIRs) were calculated using background rates from the general female population. Associations with clinical characteristics and mortality were analyzed using flexible parametric survival models. RESULTS: In total, 720 patients experienced an infection-related hospitalization during a median follow-up of 4.9 years. Infection rates were highest within the first year of diagnosis (SIR = 5.61, 95% CI; 4.98-6.32), and site-specific risks were most pronounced for sepsis (SIR = 3.14, 95% CI; 2.66-3.71) and skin infections (SIR = 2.80, 95% CI; 2.24-3.50). Older age at diagnosis, comorbidities, markers of tumor aggressiveness, chemotherapy and axillary node dissection were independent predictors of infectious disease risk. Infection-related hospitalizations were also independently associated with overall and breast cancer-specific death. CONCLUSIONS: A significant number of breast cancer patients are hospitalized with an infection following diagnosis, which in turn predicts poor prognosis. The risk profile of infection-related hospitalizations is multifactorial, including patient, tumor and treatment-related factors.
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| 10. |
- Brand, Judith S, et al.
(författare)
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Time-dependent risk and predictors of venous thromboembolism in breast cancer patients: a population-based cohort study
- 2016
-
Ingår i: Cancer. - Stockholm : Karolinska Institutet, Dept of Medical Epidemiology and Biostatistics. - 0008-543X .- 1097-0142.
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Venous thromboembolism (VTE) is a serious complication of cancer and its treatment. The current study assessed the risk and clinical predictors of VTE in breast cancer patients by time since diagnosis. METHODS: This Swedish population-based study included 8338 breast cancer patients diagnosed from 2001 to 2008 in the Stockholm-Gotland region with complete follow-up until 2012. Their incidence of VTE was compared with the incidence among 39,013 age-matched reference individuals from the general population. Cox and flexible parametric models were used to examine associations with patient, tumor, and treatment characteristics, accounting for time-dependent effects. RESULTS: Over a median follow-up of 7.2 years, 426 breast cancer patients experienced a VTE event (cumulative incidence, 5.1%). The VTE incidence was 3-fold increased (hazard ratio [HR], 3.28; 95% confidence interval [CI], 2.87-3.74) in comparison with the incidence in the general population and was highest 6 months after diagnosis (HR, 8.62; 95% CI, 6.56-11.33) with a sustained increase in risk thereafter (HR at 5 years, 2.19; 95% CI, 1.80-2.67). Independent predictors of VTE included the following: older age, being overweight, preexisting VTE, comorbid disease, tumor size > 40 mm, progesterone receptor (PR)-negative status, more than 4 affected lymph nodes, and receipt of chemo- and endocrine therapy. The impact of chemotherapy was limited to early-onset VTE, whereas comorbid disease and PR-negative status were more strongly associated with late-onset events. CONCLUSIONS: This study confirms the long-term risk of VTE in breast cancer patients and identifies a comprehensive set of clinical risk predictors. Temporal associations with patient, tumor, and treatment characteristics provide insight into the time-dependent etiology of VTE.
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| 11. |
- Brand, Per, et al.
(författare)
-
A fault-tolerant mobile-state protocol and its language interface
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Mobile-state protocols are important for distributed object systems. We define a lightweight mobile-state protocol that has a well-defined behavior for site and network failures. The protocol is implemented as part of the Mozart platform for distributed application development based on the Oz 2 language. The protocol provides enough information to the language layer so that we can use the platform to program common fault-tolerant algorithms completely in Oz 2. We formally define the semantics of the network layer and the language interface, and we prove that the protocol correctly implements the language interface.
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| 12. |
- Brand, Per, et al.
(författare)
-
A platform for constructing virtual spaces
- 1998. - 1
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Konferensbidrag (refereegranskat)abstract
- Virtual spaces (worlds) applications are among the most complex of distributed applications. They are both distributed and open. Minimizing network latency, fault-tolerance, persistence, resource control, and security are also important aspects. Designing and implementing virtual spaces is currently difficult in that the already not insignificant complexities of program functionality, distribution, openness, and efficiency are interwound and cannot be tackled separately. We present a distributed programming language, distributed-Oz, that greatly reduces the complexity of distributed programming by clearly separating the different aspects of distributed programming. The design and implementation of distributed-Oz is ongoing work, but considerable progress has been made. The current prototype demonstrates network transparency, that computations behave the same way regardless of how the computation is partitioned between different sites. This is the basis for realizing clean separation of the functionality aspect from other aspects. Network awareness allows the programmer to predict and control network communication patterns. The current system gives the programmer the means to tackle separately the aspects of openness, efficiency (minimizing latency), distribution, and functionality. We have extended distributed-Oz with a tool for graphics in a distributed setting. This extends the idea of network transparency and network awareness to graphics. From the programmers point of view graphics programming for a multi-user application is virtually the same as programming for a single-user application. The differences are necessary extensions for achieving network and site awareness, such as visualization control (deciding which users should see what). Finally we consider virtual space applications, and propose a number of abstractions for use by developers of virtual spaces, relating them to the properties of distributed-Oz upon which they are based.
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| 13. |
- Brand, Per
(författare)
-
The design philosophy of distributed programming systems: the Mozart experience
- 2005. - 2
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Distributed programming is usually considered both difficult and inherently different from concurrent centralized programming. It is thought that the distributed programming systems that we ultimately deploy, in the future, when we've worked out all the details, will require a very different programming model and will even need to be evaluated by new criteria. The Mozart Programming System, described in this thesis, demonstrates that this need not be the case. It is shown that, with a good system design, distributed programming can be seen as an extended form of concurrent programming. This is from the programmer's point-of-view; under the hood the design and implementation will necessarily be more complex. We relate the Mozart system with the classical transparencies of distributed systems. We show that some of these are inherently on the application level, while as Mozart demonstrates, others can and should be dealt with on the language/system level. The extensions to the programming model, given the right concurrent programming base, are mainly concerned with non-functional properties of programs. The models and tuning facilities for failure and performance need to take latency, bandwidth, and partial failure into account. Other than that there need not be any difference between concurrent programming and distributed programming. The Mozart Programming System is based on the concurrent programming language Oz, which integrates, in a coherent way, all three known concurrency or thread-interaction models. These are message-passing (like Erlang), shared objects (like Java with threads) and shared data-flow variables. The Mozart design philosophy is thus applicable over the entire range of concurrent programming languages/systems. We have extracted from the experience with Mozart a number of principles and properties that are applicable to the design and implementation of all (general-purpose) distributed programming systems. The full range of the design and implementation issues behind Mozart are presented. This includes a description of the consistency protocols that make transparency possible for the full language, including distributed objects and distributed data-flow variables. Mozart is extensively compared with other approaches to distributed programming, in general, and to other language-based distributed programming systems, in particular.
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| 14. |
- Brand, Per, 1952-
(författare)
-
The design philosophy of distributed programming systems : the Mozart experience
- 2005
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Distributed programming is usually considered both difficult and inherently different from concurrent centralized programming. It is thought that the distributed programming systems that we ultimately deploy, in the future, when we've worked out all the details, will require a very different programming model and will even need to be evaluated by new criteria. The Mozart Programming System, described in this thesis, demonstrates that this need not be the case. It is shown that, with a good system design, distributed programming can be seen as an extended form of concurrent programming. This is from the programmer's point-of-view; under the hood the design and implementation will necessarily be more complex. We relate the Mozart system with the classical transparencies of distributed systems. We show that some of these are inherently on the application level, while as Mozart demonstrates, others can and should be dealt with on the language/system level. The extensions to the programming model, given the right concurrent programming base, are mainly concerned with non-functional properties of programs. The models and tuning facilities for failure and performance need to take latency, bandwidth, and partial failure into account. Other than that there need not be any difference between concurrent programming and distributed programming. The Mozart Programming System is based on the concurrent programming language Oz, which integrates, in a coherent way, all three known concurrency or thread-interaction models. These are message-passing (like Erlang), shared objects (like Java with threads) and shared data-flow variables. The Mozart design philosophy is thus applicable over the entire range of concurrent programming languages/systems. We have extracted from the experience with Mozart a number of principles and properties that are applicable to the design and implementation of all (general-purpose) distributed programming systems. The full range of the design and implementation issues behind Mozart are presented. This includes a description of the consistency protocols that make transparency possible for the full language, including distributed objects and distributed data-flow variables. Mozart is extensively compared with other approaches to distributed programming, in general, and to other language-based distributed programming systems, in particular
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| 15. |
- Brand, Per, et al.
(författare)
-
The Role of Overlay Services In a Self-Managing Framework for Dynamic Virtual Organizations
- 2008
-
Ingår i: Making Grids Work. - Boston, MA : Springer-Verlag New York. - 9780387784489 ; , s. 153-164
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Konferensbidrag (refereegranskat)abstract
- We combine and extend recent results in autonomic computing and structuredpeer-to-peer to build an infrastructure for constructing and managing dynamic vir-tual organizations. The paper focuses on the middle layer of the proposed infras-tructure, in-between the Niche overlay system on the bottom, and an architecture-based management system based on Jade on the top. The middle layer, theoverlay services, are responsible for all sensing and actuation carried out by theVO management. We describe in detail the API of the resource and componentoverlay services both on the management node and the nodes hosting resources.We present a simple use case demonstrating resource discovery, initial deploy-ment, self-configuration as a result of resource availability change, self-healing,self-tuning and self-protection. The advantages of the design are 1) the overlayservices are in themselves self-managing, and sensor/actuation services they pro-vide are robust, 2) management can be dealt with declaratively and at a high-level,and 3) the overlay services provide good scalability in dynamic VOs.
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| 16. |
- Colzani, Edoardo, et al.
(författare)
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Risk of hospitalization and death due to bone fractures after breast cancer: a registry-based cohort study
- 2016
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Ingår i: British Journal of Cancer. - Stockholm : Karolinska Institutet, Dept of Medical Epidemiology and Biostatistics. - 0007-0920 .- 1532-1827.
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Bone fractures may have an impact on prognosis of breast cancer. The long-term risks of bone fracture in breast cancer patients have not been thoroughly studied. METHODS: Poisson regression was used to investigate the incidence of hospitalisation due to bone fracture comparing women with and without breast cancer based on Swedish National registers. Cox regression was used to investigate the risk of being hospitalised with bone fracture, and subsequent risk of death, in a regional cohort of breast cancer patients. RESULTS: For breast cancer patients, the 5-year risk of bone fracture hospitalisation was 4.8% and the 30-day risk of death following a bone fracture hospitalisation was 2.0%. Compared with the general population, breast cancer patients had incidence rate ratios of 1.25 (95% CI: 1.23-1.28) and 1.18 (95% CI: 1.14-1.22) for hospitalisation due to any bone fracture and hip fracture, respectively. These ratios remained significantly increased for 10 years. Comorbidities (Charlson Comorbidity Index 1) were associated with the risk of being hospitalised with bone fracture. Women taking aromatase inhibitors were at an increased risk as compared with women taking tamoxifen (HR=1.48; 95% CI: 0.98-2.22). Breast cancer patients hospitalised for a bone fracture showed a higher risk of death (HR=1.83; 95% CI: 1.50-2.22) compared with those without bone fracture. CONCLUSIONS: Women with a previous breast cancer diagnosis are at an increased risk of hospitalisation due to a bone fracture, particularly if they have other comorbidities.
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| 17. |
- de Palma, Noel, et al.
(författare)
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Tools for Architecture Based Autonomic Systems
- 2009
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Ingår i: ICAS. - : IEEE Communications Society. - 9781424436842 ; , s. 313-320
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Konferensbidrag (refereegranskat)abstract
- Recent years have seen a growing interest in autonomic computing, an approach to providing systems with self managing properties. Autonomic computing aims to address the increasing complexity of the administration of large systems. The contribution of this paper is to provide a generic tool to ease the development of autonomic managers. Using this tool, an administrator provides a set of alternative architectures and specifies conditions that are used by autonomic managers to update architectures at runtime. Software changes are computed as architectural differences in terms of component model artifacts (components, attributes, bindings, etc.). These differences are then used to migrate into the next architecture by reconfiguring only the required part of the running system.
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| 18. |
- De Palma, Noel, et al.
(författare)
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Tools for Autonomic Computing
- 2009. - 10
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Ingår i: 5th International Conference on Autonomic and Autonomous Systems (ICAS 2009). - : IEEE Computer Society. ; , s. 313-320
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Konferensbidrag (refereegranskat)
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| 19. |
- Drejhammar, Frej, et al.
(författare)
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Flow Java : Declarative Concurrency for Java
- 2003
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Ingår i: Proceedings of the Nineteenth International Conference on Logic Programming. ; , s. 346-360
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Konferensbidrag (refereegranskat)
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| 20. |
- Drejhammar, Frej, et al.
(författare)
-
Flow Java: declarative concurrency for Java.
- 2003. - 1
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Ingår i: Proceedings of the Nineteenth International Conference on Logic Programming.
-
Konferensbidrag (refereegranskat)abstract
- Logic variables pioneered by (concurrent) logic and concurrent constraint programming are powerful mechanisms for automatically synchronizing concurrent computations. They support a declarative model of concurrency that avoids explicitly suspending and resuming computations. This paper presents Flow Java which conservatively extends Java with single assignment variables and futures as variants of logic variables. The extension is conservative with respect to object-orientation, types, parameter passing, and concurrency in Java. Futures support secure concurrent abstractions and are essential for seamless integration of single assignment variables into Java. We show how Flow Java supports the construction of simple and concise concurrent programming abstractions. We present how to moderately extend compilation and the runtime architecture of an existing Java implementation for Flow Java. Evaluation using standard Java benchmarks shows that in most cases the overhead is between 10% and 40%. For some pathological cases the runtime increases by up to 75%.
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| 21. |
- El-Ansary, Sameh, et al.
(författare)
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A Framework for Peer-To-Peer Lookup Services based on k-ary search
- 2002
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Locating entities in peer-to-peer environments is a fundamentaloperation. Recent studies show that the concept of distributed hash table can be used to design scalable lookup schemes with good performance (i.e. small routing table and lookup length). In this paper, we propose a simple framework for deriving decentralized lookup algorithms. The proposed framework is simple in that it is based on the well-known concept of k-ary search. To demonstrate the applicability of our framework, we show how it can be used to instantiate Chord. When deriving a generalized Chord from our framework, we obtain better performance in terms of the routing table size (38% smaller than the generalization suggested by the Chord authors).
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| 22. |
- El-Ansary, Sameh, et al.
(författare)
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Efficient broadcast in structured P2P networks
- 2003
-
Ingår i: Lecture Notes in Computer Science. - 0302-9743 .- 1611-3349. ; 2735, s. 304-314
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Tidskriftsartikel (refereegranskat)abstract
- In this position paper, we present an efficient algorithm for performing a broadcast operation with minimal cost in structured DHT-based P2P networks. In a system of N nodes, a broadcast message originating at an arbitrary node reaches all other nodes after exactly N - 1 messages. We emphasize the perception of a class of DHT systems as a form of distributed k-ary search and we take advantage of that perception in constructing a spanning tree that is utilized for efficient broadcasting. We consider broadcasting as a basic service that adds to existing DHTs the ability to search using arbitrary queries as well as dissiminate/collect global information.
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| 23. |
- El-Ansary, Sameh, et al.
(författare)
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Experience with a physics-style approach for the study of self properties in structured overlay networks
- 2004
-
Ingår i: SELF-STAR.
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- This paper gives a brief summary of our experience in applying a physics-style approach for analyzing the behavior of structured overlay networks that deploy self-organization and self-repair policies. Such systems are not always simple to model analytically and simulation of scales of interest can be prohibitive. Physicists deal with scale by characterizing a system using intensive variables, i.e. variables that are size independent. The approach proved its substantial usefulness when applied to satisfiability theory and it is the hope that it can be as useful in the field of large-scale distributed systems. We report here our finding of one simple self-organization-related intensive variable, and a more complex self-repair-related intensive variable.
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| 24. |
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| 25. |
- Engert, Andreas, et al.
(författare)
-
The European Hematology Association Roadmap for European Hematology Research : a consensus document
- 2016
-
Ingår i: Haematologica. - Pavia, Italy : Ferrata Storti Foundation (Haematologica). - 0390-6078 .- 1592-8721. ; 101:2, s. 115-208
-
Tidskriftsartikel (refereegranskat)abstract
- The European Hematology Association (EHA) Roadmap for European Hematology Research highlights major achievements in diagnosis and treatment of blood disorders and identifies the greatest unmet clinical and scientific needs in those areas to enable better funded, more focused European hematology research. Initiated by the EHA, around 300 experts contributed to the consensus document, which will help European policy makers, research funders, research organizations, researchers, and patient groups make better informed decisions on hematology research. It also aims to raise public awareness of the burden of blood disorders on European society, which purely in economic terms is estimated at (sic)23 billion per year, a level of cost that is not matched in current European hematology research funding. In recent decades, hematology research has improved our fundamental understanding of the biology of blood disorders, and has improved diagnostics and treatments, sometimes in revolutionary ways. This progress highlights the potential of focused basic research programs such as this EHA Roadmap. The EHA Roadmap identifies nine 'sections' in hematology: normal hematopoiesis, malignant lymphoid and myeloid diseases, anemias and related diseases, platelet disorders, blood coagulation and hemostatic disorders, transfusion medicine, infections in hematology, and hematopoietic stem cell transplantation. These sections span 60 smaller groups of diseases or disorders. The EHA Roadmap identifies priorities and needs across the field of hematology, including those to develop targeted therapies based on genomic profiling and chemical biology, to eradicate minimal residual malignant disease, and to develop cellular immunotherapies, combination treatments, gene therapies, hematopoietic stem cell treatments, and treatments that are better tolerated by elderly patients.
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| 26. |
- Fazey, Ioan, et al.
(författare)
-
Transforming knowledge systems for life on Earth : Visions of future systems and how to get there
- 2020
-
Ingår i: Energy Research & Social Science. - : Elsevier. - 2214-6296 .- 2214-6326. ; 70
-
Tidskriftsartikel (refereegranskat)abstract
- Formalised knowledge systems, including universities and research institutes, are important for contemporary societies. They are, however, also arguably failing humanity when their impact is measured against the level of progress being made in stimulating the societal changes needed to address challenges like climate change. In this research we used a novel futures-oriented and participatory approach that asked what future envisioned knowledge systems might need to look like and how we might get there. Findings suggest that envisioned future systems will need to be much more collaborative, open, diverse, egalitarian, and able to work with values and systemic issues. They will also need to go beyond producing knowledge about our world to generating wisdom about how to act within it. To get to envisioned systems we will need to rapidly scale methodological innovations, connect innovators, and creatively accelerate learning about working with intractable challenges. We will also need to create new funding schemes, a global knowledge commons, and challenge deeply held assumptions. To genuinely be a creative force in supporting longevity of human and non-human life on our planet, the shift in knowledge systems will probably need to be at the scale of the enlightenment and speed of the scientific and technological revolution accompanying the second World War. This will require bold and strategic action from governments, scientists, civic society and sustained transformational intent.
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| 27. |
- Ghodsi, Ali, et al.
(författare)
-
Self-Correcting Broadcast in Distributed Hash Tables
- 2003
-
Ingår i: Proceedings of the Fifteenth IASTED International Conference on Parallel and Distributed Computing and Systems. - 088986392X ; , s. 93-98
-
Konferensbidrag (refereegranskat)abstract
- We present two broadcast algorithms that can be used on top of distributed hash tables (DHTs) to perform group communication and arbitrary queries. Unlike other P2P group communication mechanisms, which either embed extra information in the DHTs or use random overlay networks, our algorithms take advantage of the structured DHT overlay networks without maintaining additional information. The proposed algorithms do not send any redundant messages. Furthermore the two algorithms ensure 100% coverage of the nodes in the system even when routing information is outdated as a result of dynamism in the network. The first algorithm performs some correction of outdated routing table entries with a low cost of correction traffic. The second algorithm exploits the nature of the broadcasts to extensively update erroneous routing information at the cost of higher correction traffic. The algorithms are validated and evaluated in our stochastic distributed-algorithms simulator.
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| 28. |
- Haridi, Seif, et al.
(författare)
-
Efficient logic variables for distributed computing
- 1999
-
Ingår i: ACM Transactions on Programming Languages and Systems. - : Association for Computing Machinery (ACM). - 0164-0925 .- 1558-4593. ; 21:3, s. 569-626
-
Tidskriftsartikel (refereegranskat)abstract
- We define a practical algorithm for distributed rational tree unification and prove its correctness in both the off-line and on-line cases. We derive the distributed algorithm from a centralized one, showing clearly the trade-offs between local and distributed execution. The algorithm is used to realize logic variables in the Mozart Programming System, which implements the Oz language (see http://www.mozart-oz.org). Oz appears to the programmer as a concurrent object-oriented language with dataflow synchronization Logic variables implement the dataflow behavior. We show that logic variables can easily be added to the more restricted models of Java and ML, thus providing an alternative way to do concurrent programming in these languages. We present common distributed programming idioms in a network-transparent way using logic variables. We show that in common cases the algorithm maintains the same message latency as explicit message passing. In addition, it is able to handle uncommon cases that arise from the properties of latency tolerance and third-party independence. This is evidence that using logic variables in distributed computing is beneficial at both the system and language levels. At the system level, they improve latency tolerance and third-party independence. At the language level, they help make network-transparent distribution practical.
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| 29. |
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| 30. |
- Haridi, Seif, et al.
(författare)
-
Programming languages for distributed applications
- 1998
-
Ingår i: New generation computing. - 0288-3635 .- 1882-7055. ; 16:3, s. 223-261
-
Tidskriftsartikel (refereegranskat)abstract
- Much progress has been made in distributed computing in the areas of distribution structure, open computing, fault tolerance, and security. Yet, writing distributed applications remains difficult because the programmer has to manage models of these areas explicitly. A major challenge is to integrate the four models into a coherent development platform. Such a platform should make it possible to cleanly separate an application's functionality from the other four concerns. Concurrent constraint programming, an evolution of concurrent logic programming, has both the expressiveness and the formal foundation needed to attempt this integration. As a first step, we have designed and built a platform that separates an application's functionality from its distribution structure. We have prototyped several collaborative tools with this platform, including a shared graphic editor whose design is presented in detail. The platform efficiently implements Distributed Oz, which extends the Oz language with constructs to express the distribution structure and with basic primitives for open computing, failure detection and handling, and resource control. Oz appears to the programmer as a concurrent object-oriented language with dataflow synchronization. Oz is based on a higher-order, state-aware, concurrent constraint computation model.
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| 31. |
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| 32. |
- Hollestelle, Antoinette, et al.
(författare)
-
No clinical utility of KRAS variant rs61764370 for ovarian or breast cancer
- 2016
-
Ingår i: Gynecologic Oncology. - : Elsevier BV. - 0090-8258 .- 1095-6859. ; 141:2, s. 386-401
-
Tidskriftsartikel (refereegranskat)abstract
- Objective Clinical genetic testing is commercially available for rs61764370, an inherited variant residing in a KRAS 3′ UTR microRNA binding site, based on suggested associations with increased ovarian and breast cancer risk as well as with survival time. However, prior studies, emphasizing particular subgroups, were relatively small. Therefore, we comprehensively evaluated ovarian and breast cancer risks as well as clinical outcome associated with rs61764370. Methods Centralized genotyping and analysis were performed for 140,012 women enrolled in the Ovarian Cancer Association Consortium (15,357 ovarian cancer patients; 30,816 controls), the Breast Cancer Association Consortium (33,530 breast cancer patients; 37,640 controls), and the Consortium of Modifiers of BRCA1 and BRCA2 (14,765 BRCA1 and 7904 BRCA2 mutation carriers). Results We found no association with risk of ovarian cancer (OR = 0.99, 95% CI 0.94-1.04, p = 0.74) or breast cancer (OR = 0.98, 95% CI 0.94-1.01, p = 0.19) and results were consistent among mutation carriers (BRCA1, ovarian cancer HR = 1.09, 95% CI 0.97-1.23, p = 0.14, breast cancer HR = 1.04, 95% CI 0.97-1.12, p = 0.27; BRCA2, ovarian cancer HR = 0.89, 95% CI 0.71-1.13, p = 0.34, breast cancer HR = 1.06, 95% CI 0.94-1.19, p = 0.35). Null results were also obtained for associations with overall survival following ovarian cancer (HR = 0.94, 95% CI 0.83-1.07, p = 0.38), breast cancer (HR = 0.96, 95% CI 0.87-1.06, p = 0.38), and all other previously-reported associations. Conclusions rs61764370 is not associated with risk of ovarian or breast cancer nor with clinical outcome for patients with these cancers. Therefore, genotyping this variant has no clinical utility related to the prediction or management of these cancers.
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| 33. |
- Jiao, Xiang, et al.
(författare)
-
PHIP - a novel candidate breast cancer susceptibility locus on 6q14.1
- 2017
-
Ingår i: Oncotarget. - : IMPACT JOURNALS LLC. - 1949-2553. ; 8:61, s. 102769-102782
-
Tidskriftsartikel (refereegranskat)abstract
- Most non-BRCA1/2 breast cancer families have no identified genetic cause. We used linkage and haplotype analyses in familial and sporadic breast cancer cases to identify a susceptibility locus on chromosome 6q. Two independent genome-wide linkage analysis studies suggested a 3 Mb locus on chromosome 6q and two unrelated Swedish families with a LOD > 2 together seemed to share a haplotype in 6q14.1. We hypothesized that this region harbored a rare high-risk founder allele contributing to breast cancer in these two families. Sequencing of DNA and RNA from the two families did not detect any pathogenic mutations. Finally, 29 SNPs in the region were analyzed in 44,214 cases and 43,532 controls from BCAC, and the original haplotypes in the two families were suggested as low-risk alleles for European and Swedish women specifically. There was also some support for one additional independent moderate-risk allele in Swedish familial samples. The results were consistent with our previous findings in familial breast cancer and supported a breast cancer susceptibility locus at 6q14.1 around the PHIP gene.
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| 34. |
- Kalavri, Vasiliki, 1986-, et al.
(författare)
-
PonIC : Using stratosphere to speed up pig analytics
- 2013
-
Ingår i: Lecture Notes in Computer Science. - Berlin, Heidelberg : Springer Berlin Heidelberg. - 9783642400469 ; , s. 279-290
-
Konferensbidrag (refereegranskat)abstract
- Pig, a high-level dataflow system built on top of Hadoop MapReduce, has greatly facilitated the implementation of data-intensive applications. Pig successfully manages to conceal Hadoop's one input and two-stage inflexible pipeline limitations, by translating scripts into MapReduce jobs. However, these limitations are still present in the backend, often resulting in inefficient execution. Stratosphere, a data-parallel computing framework consisting of PACT, an extension to the MapReduce programming model and the Nephele execution engine, overcomes several limitations of Hadoop MapReduce. In this paper, we argue that Pig can highly benefit from using Stratosphere as the backend system and gain performance, without any loss of expressiveness. We have ported Pig on top of Stratosphere and we present a process for translating Pig Latin scripts into PACT programs. Our evaluation shows that Pig Latin scripts can execute on our prototype up to 8 times faster for a certain class of applications.
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| 35. |
- Klintskog, Erik, et al.
(författare)
-
A Generic Middleware for Intra-Language Transparent Distribution
- 2003. - 1
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This document presents the philosophy and design of our language independent middleware, the Distribution Subsystem(DSS). A notion of abstract entity types enables the DSS to offer distribution support for virtually any high level programming language. A novel framework for entity consistency protocols is presented. The framework greatly simplifies the development of new protocols, indicated by the numerous protocols provided by the DSS implementation. A roadmap of how to couple a programming system to the DSS is also given
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| 36. |
- Klintskog, Erik, et al.
(författare)
-
A peer-to-peer approach to enhance middleware connectivity
- 2004
-
Ingår i: LECT NOTE COMPUT SCI. - Berlin, Heidelberg : Springer Berlin Heidelberg. ; , s. 71-82
-
Konferensbidrag (refereegranskat)abstract
- One of the problems of middleware for shared state is that they are designed, explicitly or implicitly, for symmetric networks. However, since the Internet is not symmetric, end-to-end process connectivity cannot be guaranteed. Our solution to this is to provide the middleware with a network abstraction layer that masks the asymmetry of the network and provides the illusion of a symmetric network. We describe the communication service of our middleware, the Distribution Subsystem (DSS), which carefully separates connections to remote processes from the protocols that communicate over them. This separation is used to plug-in a peer-to-peer module to provide symmetric and persistent connectivity. The P2P module can provide both up-to-date addresses for mobile processes as well as route discovery to overcome asymmetric links.
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| 37. |
- Klintskog, Erik, et al.
(författare)
-
A peer-to-peer approach to enhance middleware connectivity
- 2003. - 1
-
Konferensbidrag (refereegranskat)abstract
- One of the problems of middleware for shared state is that they are designed, explicitly or implicitly, for symmetric networks. However, since the Internet is not symmetric, end-to-end process connectivity cannot be guaranteed. Our solution to this is to provide the middleware with a network abstraction layer that masks the asymmetry of the network and provides the illusion of a symmetric network. We describe the communication service of our middleware, the Distribution Subsystem~(DSS), which carefully separates connections to remote processes from the protocols that communicate over them. This separation is used to plug-in a peer-to-peer module to provide symmetric and persistent connectivity. The P2P module can provide both up-to-date addresses for mobile processes as well as route discovery to overcome asymmetric links.
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| 38. |
- Klintskog, Erik, et al.
(författare)
-
Fractional Weighted Reference Counting
- 2001
-
Ingår i: Euro-Par 2001. - Berlin : Springer Verlag. ; , s. 486-490
-
Konferensbidrag (refereegranskat)abstract
- We introduce a scheme for distributed garbage collectionthat is an extension of Weighted Reference Counting. This scheme represents weights as fractions. It solves the problem of limited weight, preservesthe property of third-party independence, and does not induce extra messages for reference merging.
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| 39. |
- Klintskog, Erik, et al.
(författare)
-
Home Migration Using a Structured Peer-To-PeerOverlay Network
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- This paper presents the design and implementation of a decentralized home-migration protocol for the Distribution SubSystem(DSS) middleware. The DSS provides generic distribution support for shared data structures in open distributed systems. Previous approaches for migrating homes, such as forward pointers, broadcasts, and centralized directory services are known to have disadvantages. We propose using a structured P2P system to store the location of migrated homes. This enables seamless migration of homes, without the need for lengthy forward pointer chains that degrade performance and robustness. Nor is a dedicated data-base that requires administrative effort needed. The presented design depicts how the self-organizing aspects of peer-to-peer computing can be used to construct a fault-tolerant, scalable, efficient, distributed home-location service to enhance middleware functionality.
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| 40. |
- Klintskog, Erik, et al.
(författare)
-
Making the Distribution Subsystem Secure
- 2004
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This report presents how the Distribution Subsystem is made secure. A set of different security threats to a shared data programming system are identifed. The report presents the extensions nessesary to the DSS in order to cope with the identified security threats by maintaining reference security. A reference to a shared data structure cannot be forged or guessed; only by proper delegation can a thread acquire access to data originating at remote processes. Referential security is a requirement for secure distributed applications. By programmatically restricting access to distributed data to trusted nodes, a distributed application can be made secure. However, for this to be true, referential security must be supported on the level of the implementation.
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| 41. |
- Klintskog, Erik, et al.
(författare)
-
The design and evaluation of a middleware library for distribution of language entities
- 2003
-
Ingår i: ADVANCES IN COMPUTING SCIENCE - ASIAN 2003 - PROGRAMMING LANGUAGES AND DISTRIBUTED COMPUTATION. - Berlin, Heidelberg : Springer Berlin Heidelberg. - 3540206329 ; , s. 243-259
-
Konferensbidrag (refereegranskat)abstract
- The paper presents a modular design of a distribution middleware that supports the wide variety of entities that exist in high level languages. Such entities are classified into mutables, immutables and transients. The design is factorized in order to allow multiple consistency protocols for the same entity type, and multiple coordination strategies for implementing the protocols that differ in their failure behavior. The design is implemented and evaluated. It shows a very competitive performance.
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| 42. |
- Kolodner, Elliot K, et al.
(författare)
-
A cloud environment for data-intensive storage services
- 2011
-
Ingår i: IEEE third international conference on Cloud computing technology and science (CloudCom), 2011. - : IEEE conference proceedings. - 9781467300902 ; , s. 357-366
-
Konferensbidrag (refereegranskat)abstract
- The emergence of cloud environments has made feasible the delivery of Internet-scale services by addressing a number of challenges such as live migration, fault tolerance and quality of service. However, current approaches do not tackle key issues related to cloud storage, which are of increasing importance given the enormous amount of data being produced in today's rich digital environment (e.g. by smart phones, social networks, sensors, user generated content). In this paper we present the architecture of a scalable and flexible cloud environment addressing the challenge of providing data-intensive storage cloud services through raising the abstraction level of storage, enabling data mobility across providers, allowing computational and content-centric access to storage and deploying new data-oriented mechanisms for QoS and security guarantees. We also demonstrate the added value and effectiveness of the proposed architecture through two real-life application scenarios from the healthcare and media domains.
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| 43. |
- Lusk, E., et al.
(författare)
-
The Aurora or-parallel Prolog system
- 1990. - 2
-
Ingår i: New generation computing. - : ICOT, Tokyo, Japan. - 0288-3635 .- 1882-7055. ; 7:2,3, s. 243-271
-
Tidskriftsartikel (refereegranskat)
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| 44. |
- Meyer, H., et al.
(författare)
-
Overview of progress in European medium sized tokamaks towards an integrated plasma-edge/wall solution
- 2017
-
Ingår i: Nuclear Fusion. - : Institute of Physics Publishing (IOPP). - 0029-5515 .- 1741-4326. ; 57:10
-
Tidskriftsartikel (refereegranskat)abstract
- Integrating the plasma core performance with an edge and scrape-off layer (SOL) that leads to tolerable heat and particle loads on the wall is a major challenge. The new European medium size tokamak task force (EU-MST) coordinates research on ASDEX Upgrade (AUG), MAST and TCV. This multi-machine approach within EU-MST, covering a wide parameter range, is instrumental to progress in the field, as ITER and DEMO core/pedestal and SOL parameters are not achievable simultaneously in present day devices. A two prong approach is adopted. On the one hand, scenarios with tolerable transient heat and particle loads, including active edge localised mode (ELM) control are developed. On the other hand, divertor solutions including advanced magnetic configurations are studied. Considerable progress has been made on both approaches, in particular in the fields of: ELM control with resonant magnetic perturbations (RMP), small ELM regimes, detachment onset and control, as well as filamentary scrape-off-layer transport. For example full ELM suppression has now been achieved on AUG at low collisionality with n = 2 RMP maintaining good confinement H-H(98,H-y2) approximate to 0.95. Advances have been made with respect to detachment onset and control. Studies in advanced divertor configurations (Snowflake, Super-X and X-point target divertor) shed new light on SOL physics. Cross field filamentary transport has been characterised in a wide parameter regime on AUG, MAST and TCV progressing the theoretical and experimental understanding crucial for predicting first wall loads in ITER and DEMO. Conditions in the SOL also play a crucial role for ELM stability and access to small ELM regimes.
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| 45. |
- Meyer, H., et al.
(författare)
-
Overview of progress in European medium sized tokamaks towards an integrated plasma-edge/wall solution
- 2017
-
Ingår i: Nuclear Fusion. - : Institute of Physics Publishing (IOPP). - 0029-5515 .- 1741-4326. ; 57:10
-
Tidskriftsartikel (refereegranskat)abstract
- Integrating the plasma core performance with an edge and scrape-off layer (SOL) that leads to tolerable heat and particle loads on the wall is a major challenge. The new European medium size tokamak task force (EU-MST) coordinates research on ASDEX Upgrade (AUG), MAST and TCV. This multi-machine approach within EU-MST, covering a wide parameter range, is instrumental to progress in the field, as ITER and DEMO core/pedestal and SOL parameters are not achievable simultaneously in present day devices. A two prong approach is adopted. On the one hand, scenarios with tolerable transient heat and particle loads, including active edge localised mode (ELM) control are developed. On the other hand, divertor solutions including advanced magnetic configurations are studied. Considerable progress has been made on both approaches, in particular in the fields of: ELM control with resonant magnetic perturbations (RMP), small ELM regimes, detachment onset and control, as well as filamentary scrape-off-layer transport. For example full ELM suppression has now been achieved on AUG at low collisionality with n = 2 RMP maintaining good confinement H-H(98,H-y2) approximate to 0.95. Advances have been made with respect to detachment onset and control. Studies in advanced divertor configurations (Snowflake, Super-X and X-point target divertor) shed new light on SOL physics. Cross field filamentary transport has been characterised in a wide parameter regime on AUG, MAST and TCV progressing the theoretical and experimental understanding crucial for predicting first wall loads in ITER and DEMO. Conditions in the SOL also play a crucial role for ELM stability and access to small ELM regimes.
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| 46. |
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| 47. |
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| 48. |
- Onana Alima, Luc, et al.
(författare)
-
DKS(N, k, f) : A family of low communication, scalable and fault-tolerant infrastructures for P2P applications
- 2003
-
Ingår i: CCGRID 2003. - LOS ALAMITOS : IEEE COMPUTER SOC. - 0769519199 ; , s. 344-350
-
Konferensbidrag (refereegranskat)abstract
- In this paper, we present EKS(N,k,f), a family of infrastructures for building Peer-To-Peer applications. Each instance of EKS(N,k,f) is a fully decentralized overlay network characterized by three parameters: N the maximum number of nodes that can be in the network; k the search arity within the network and f the degree of fault-tolerance. Once these parameters are instantiated, the resulting network has several desirable properties. The first property, which is the main contribution of this paper, is that there is no separate procedure for maintaining routing tables; instead, any out-of-date or erroneous routing entry is eventually corrected on-the-fly thereby, eliminating unnecessary bandwidth consumption. The second property is that each lookup request is resolved in at Most log(k)(N) overlay hops under normal operations. Third, each node maintains only (k - 1) log(k)(N) + 1 addresses of other nodes for routing purposes. Fourth, new nodes can join and existing nodes can leave at will with a negligible disturbance to the ability to resolve lookups in logk(N) hops in average. Fifth, any pair key/value that is inserted into the system is guaranteed to be located even in the presence of concurrent joins. Sixth, even if f consecutive nodes fail simultaneously, correct lookup is still guaranteed.
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| 49. |
- Popov, Konstantin, et al.
(författare)
-
An efficient incremental marshaling framework for distributed systems
- 2005
-
Ingår i: Future Generation Computer Systems. - : Elsevier BV. - 0167-739X .- 1872-7115. ; 21:5, s. 717-724
-
Tidskriftsartikel (refereegranskat)abstract
- We present an efficient and incremental (un)marshaling framework designed for distributed applications. A marshaler/ unmarshaler pair converts arbitrary structured data between its host and network representations. This technology can also be used for persistent storage. Our framework simplifies the design of efficient and flexible marshalers. The network latency is reduced by concurrent execution of (un)marshaling and network operations. The framework is actually used in Mozart, a distributed programming system that implements Oz, a multi-paradigm concurrent language.
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| 50. |
- Popov, Konstantin, et al.
(författare)
-
An Efficient Marshaling Framework for Distributed Systems
- 2003
-
Ingår i: PARALLEL COMPUTING TECHNOLOGIES, PROCEEDINGS. - Berlin : Springer Berlin/Heidelberg. - 9783540406730 ; , s. 324-331
-
Konferensbidrag (refereegranskat)abstract
- An efficient (un)marshaling framework is presented. It is de-signed for distributed applications implemented in languages such asC++. A marshaler/unmarshaler pair converts arbitrary structured databetween its host and network representations. This technology can alsobe used for persistent storage. Our framework simplifies the design of effi-cient and flexible marshalers. The network latency is reduced by concur-rent execution of (un)marshaling and network operations. The frameworkis actually used in Mozart, a distributed programming system that imple-ments Oz, a multi-paradigm concurrent language. Mozart, including theimplementation of the framework, is available at www.mozart-oz.org .
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