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  • 1.
    Aalberg, Asbjørn Lein
    et al.
    SINTEF Digital, Norway.
    Holen, Siri Mariane
    SINTEF Digital, Norway.
    Aamodt, Edvard
    RISE Research Institutes of Sweden, Säkerhet och transport, Brand och Säkerhet.
    Steen-Hansen, Anne Elise
    RISE Research Institutes of Sweden, Säkerhet och transport, Brand och Säkerhet. NTNU Norwegian University of Science and Technology, Norway.
    Preconditions for Learning from Fires in Norway: Structural, Cultural, Technological, Interactional and Relational Aspects2021Ingår i: Proceedings of the 31st European Safety and Reliability Conference, 2021, s. 1747-1754Konferensbidrag (Refereegranskat)
    Abstract [en]

    Learning from incidents is widely accepted as a core part of safety management. This is also true for fires – however few fires in Norway are investigated. Fires are interesting incidents conceptually due to their potential of devastating outcomes on material and human lives and because they happen across all sectors and industries, businesses, and homes. In Norway, several different actors play a role in investigating and learning from fires, from the fire rescue services to directorates and Non-Governmental Organisations. The present study seeks to understand the preconditions for learning from fires in Norway, with emphasis on the formal actors that play a role in preventing and mitigating fires. Methodologically, the study is based on qualitative interviews conducted with relevant actors from first responders, authorities, and other sectors. We found that there are structural, cultural, technological, and relational aspects that seem to influence learning from fires in Norway. The results were analyzed using thematic analysis and the Pentagon model framework. The findings are discussed in relation to theories from organisational learning and learning from incidents.

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  • 2.
    Abbas, Muhammad
    RISE Research Institutes of Sweden, Digitala system, Industriella system.
    Requirements-Level Reuse Recommendation and Prioritization of Product Line Assets2021Övrigt (Övrigt vetenskapligt)
    Abstract [en]

    Software systems often target a variety of different market segments. Targeting varying customer requirements requires a product-focused development process. Software Product Line (SPL) engineering is one possible approach based on reuse rationale to aid quick delivery of quality product variants at scale. SPLs reuse common features across derived products while still providing varying configuration options. The common features, in most cases, are realized by reusable assets. In practice, the assets are reused in a clone-and-own manner to reduce the upfront cost of systematic reuse. Besides, the assets are implemented in increments, and requirements prioritization also has to be done. In this context, the manual reuse analysis and prioritization process become impractical when the number of derived products grows. Besides, the manual reuse analysis process is time-consuming and heavily dependent on the experience of engineers. In this licentiate thesis, we study requirements-level reuse recommendation and prioritization for SPL assets in industrial settings. We first identify challenges and opportunities in SPLs where reuse is done in a clone-and-own manner. We then focus on one of the identified challenges: requirements-based SPL assets reuse and provide automated support for identifying reuse opportunities for SPL assets based on requirements. Finally, we provide automated support for requirements prioritization in the presence of dependencies resulting from reuse.

  • 3.
    Abbas, Muhammad
    et al.
    RISE Research Institutes of Sweden, Digitala system, Industriella system. Mälardalens University, Sweden.
    Ferrari, Alessio
    CNR-ISTI, Italy.
    Shatnawi, Anas
    Berget-Levrault, France.
    Enoiu, Eduard
    Mälardalens University, Sweden.
    Saadatmand, Mehrdad
    RISE Research Institutes of Sweden, Digitala system, Industriella system.
    Is Requirements Similarity a Good Proxy for Software Similarity?: An Empirical Investigation in Industry2021Ingår i: Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) 27th International Working Conference on Requirements Engineering: Foundation for Software Quality, REFSQ 2021, 12 April 2021 - 15 April 2021, Springer Science and Business Media Deutschland GmbH , 2021, Vol. 12685, s. 3-18Konferensbidrag (Refereegranskat)
    Abstract [en]

    [Context and Motivation] Content-based recommender systems for requirements are typically built on the assumption that similar requirements can be used as proxies to retrieve similar software. When a new requirement is proposed by a stakeholder, natural language processing (NLP)-based similarity metrics can be exploited to retrieve existing requirements, and in turn identify previously developed code. [Question/problem] Several NLP approaches for similarity computation are available, and there is little empirical evidence on the adoption of an effective technique in recommender systems specifically oriented to requirements-based code reuse. [Principal ideas/results] This study compares different state-of-the-art NLP approaches and correlates the similarity among requirements with the similarity of their source code. The evaluation is conducted on real-world requirements from two industrial projects in the railway domain. Results show that requirements similarity computed with the traditional tf-idf approach has the highest correlation with the actual software similarity in the considered context. Furthermore, results indicate a moderate positive correlation with Spearman’s rank correlation coefficient of more than 0.5. [Contribution] Our work is among the first ones to explore the relationship between requirements similarity and software similarity. In addition, we also identify a suitable approach for computing requirements similarity that reflects software similarity well in an industrial context. This can be useful not only in recommender systems but also in other requirements engineering tasks in which similarity computation is relevant, such as tracing and categorization.

  • 4.
    Abbas, Muhammad
    et al.
    RISE Research Institutes of Sweden, Digitala system, Industriella system.
    Ferrari, Alessio
    CNR-ISTI, Italy.
    Shatnawi, Anas
    Berger-Levrault, France.
    Enoiu, Eduard
    Mälardalen University, Sweden.
    Saadatmand, Mehrdad
    RISE Research Institutes of Sweden, Digitala system, Industriella system.
    Sundmark, Daniel
    Mälardalen University, Sweden.
    On the relationship between similar requirements and similar software: A case study in the railway domain2023Ingår i: Requirements Engineering, ISSN 0947-3602, E-ISSN 1432-010X, Vol. 28, s. 23-47Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Recommender systems for requirements are typically built on the assumption that similar requirements can be used as proxies to retrieve similar software. When a stakeholder proposes a new requirement, natural language processing (NLP)-based similarity metrics can be exploited to retrieve existing requirements, and in turn, identify previously developed code. Several NLP approaches for similarity computation between requirements are available. However, there is little empirical evidence on their effectiveness for code retrieval. This study compares different NLP approaches, from lexical ones to semantic, deep-learning techniques, and correlates the similarity among requirements with the similarity of their associated software. The evaluation is conducted on real-world requirements from two industrial projects from a railway company. Specifically, the most similar pairs of requirements across two industrial projects are automatically identified using six language models. Then, the trace links between requirements and software are used to identify the software pairs associated with each requirements pair. The software similarity between pairs is then automatically computed with JPLag. Finally, the correlation between requirements similarity and software similarity is evaluated to see which language model shows the highest correlation and is thus more appropriate for code retrieval. In addition, we perform a focus group with members of the company to collect qualitative data. Results show a moderately positive correlation between requirements similarity and software similarity, with the pre-trained deep learning-based BERT language model with preprocessing outperforming the other models. Practitioners confirm that requirements similarity is generally regarded as a proxy for software similarity. However, they also highlight that additional aspect comes into play when deciding software reuse, e.g., domain/project knowledge, information coming from test cases, and trace links. Our work is among the first ones to explore the relationship between requirements and software similarity from a quantitative and qualitative standpoint. This can be useful not only in recommender systems but also in other requirements engineering tasks in which similarity computation is relevant, such as tracing and change impact analysis.

  • 5.
    Abbas, Muhammad
    et al.
    RISE Research Institutes of Sweden, Digitala system, Industriella system. Mälardalens University, Sweden.
    Hamayouni, Ali
    Mälardalens University, Sweden.
    Helali Moghadam, Mahshid
    RISE Research Institutes of Sweden.
    Saadatmand, Mehrdad
    RISE Research Institutes of Sweden.
    Strandberg, Per Erik
    Westermo Network Technologies AB, Sweden.
    Making Sense of Failure Logs in an Industrial DevOps Environment2023Ingår i: Advances in Intelligent Systems and Computing book series (AISC,volume 1445): 20th International Conference on Information Technology New Generations, Springer International Publishing , 2023, Vol. 1445, s. 217-226Konferensbidrag (Refereegranskat)
    Abstract [en]

    Processing and reviewing nightly test execution failure logs for large industrial systems is a tedious activity. Furthermore, multiple failures might share one root/common cause during test execution sessions, and the review might therefore require redundant efforts. This paper presents the LogGrouper approach for automated grouping of failure logs to aid root/common cause analysis and for enabling the processing of each log group as a batch. LogGrouper uses state-of-art natural language processing and clustering approaches to achieve meaningful log grouping. The approach is evaluated in an industrial setting in both a qualitative and quantitative manner. Results show that LogGrouper produces good quality groupings in terms of our two evaluation metrics (Silhouette Coefficient and Calinski-Harabasz Index) for clustering quality. The qualitative evaluation shows that experts perceive the groups as useful, and the groups are seen as an initial pointer for root cause analysis and failure assignment.

  • 6.
    Abbas, Muhammad
    et al.
    RISE Research Institutes of Sweden, Digitala system, Industriella system.
    Inayat, Irum
    National University of Computer& Emerging Sciences, Pakistan.
    Jan, Naila
    National University of Computer& Emerging Sciences, Pakistan.
    Saadatmand, Mehrdad
    RISE Research Institutes of Sweden.
    Enoiu, Eduard Paul
    Mälardalen University, Sweden.
    Sundmark, Daniel
    Mälardalen University, Sweden.
    MBRP: Model-based Requirements Prioritization Using PageRank Algorithm2019Ingår i: The 26th Asia-Pacific Software Engineering Conference, IEEE conference proceedings, 2019Konferensbidrag (Refereegranskat)
    Abstract [en]

    Requirements prioritization plays an important role in driving project success during software development. Literature reveals that existing requirements prioritization approaches ignore vital factors such as interdependency between requirements. Existing requirements prioritization approaches are also generally time-consuming and involve substantial manual effort. Besides, these approaches show substantial limitations in terms of the number of requirements under consideration. There is some evidence suggesting that models could have a useful role in the analysis of requirements interdependency and their visualization, contributing towards the improvement of the overall requirements prioritization process. However, to date, just a handful of studies are focused on model-based strategies for requirements prioritization, considering only conflict-free functional requirements. This paper uses a meta-model-based approach to help the requirements analyst to model the requirements, stakeholders, and inter-dependencies between requirements. The model instance is then processed by our modified PageRank algorithm to prioritize the given requirements. An experiment was conducted, comparing our modified PageRank algorithm’s efficiency and accuracy with five existing requirements prioritization methods. Besides, we also compared our results with a baseline prioritized list of 104 requirements prepared by 28 graduate students. Our results show that our modified PageRank algorithm was able to prioritize the requirements more effectively and efficiently than the other prioritization methods.

  • 7.
    Abbas, Muhammad
    et al.
    RISE Research Institutes of Sweden, Digitala system, Industriella system.
    Inayat, Irum
    National University of Computer & Emerging Sciences, Pakistan.
    Saadatmand, Mehrdad
    RISE Research Institutes of Sweden.
    Jan, Naila
    National University of Computer & Emerging Sciences, Pakistan.
    Requirements dependencies-based test case prioritization for extra-functional properties2019Ingår i: IEEE International Conference on Software Testing, Verification and Validation Workshops, IEEE , 2019Konferensbidrag (Refereegranskat)
    Abstract [en]

    The use of requirements’ information in testing is a well-recognized practice in the software development life cycle. Literature reveals that existing tests prioritization and selection approaches neglected vital factors affecting tests priorities, like interdependencies between requirement specifications. We believe that models may play a positive role in specifying these inter-dependencies and prioritizing tests based on these inter-dependencies. However, till date, few studies can be found that make use of requirements inter-dependencies for test case prioritization. This paper uses a meta-model to aid modeling requirements, their related tests, and inter-dependencies between them. The instance of this meta-model is then processed by our modified PageRank algorithm to prioritize the requirements. The requirement priorities are then propagated to related test cases in the test model and test cases are selected based on coverage of extra-functional properties. We have demonstrated the applicability of our proposed approach on a small example case.

  • 8.
    Abbas, Muhammad
    et al.
    RISE Research Institutes of Sweden, Digitala system, Industriella system.
    Saadatmand, Mehrdad
    RISE Research Institutes of Sweden.
    Enoiu, Eduard Paul
    Mälardalens University, Sweden.
    Requirements-driven Reuse Recommendation2021Ingår i: 25th ACM International Systems and Software Product Line Conference, ACM , 2021, Vol. AKonferensbidrag (Refereegranskat)
    Abstract [en]

    This tutorial explores requirements-based reuse recommendation for product line assets in the context of clone-and-own product lines.

  • 9.
    Abbas, Muhammad
    et al.
    RISE Research Institutes of Sweden, Digitala system, Industriella system. Mälardalens University, Sweden.
    Saadatmand, Mehrdad
    RISE Research Institutes of Sweden.
    Enoiu, Eduard Paul
    Mälardalens University, Sweden.
    Sundmark, Daniel
    Mälardalens University, Sweden.
    Lindskog, Claes
    Bombardier Transportation AB, Sweden.
    Automated Reuse Recommendation of Product Line Assets based on Natural Language Requirements2020Ingår i: Reuse in Emerging Software Engineering Practices, Springer International Publishing , 2020, Vol. 12541, s. 173-189Konferensbidrag (Refereegranskat)
    Abstract [en]

    Software product lines (SPLs) are based on reuse rationale to aid quick and quality delivery of complex products at scale. Deriving a new product from a product line requires reuse analysis to avoid redundancy and support a high degree of assets reuse. In this paper, we propose and evaluate automated support for recommending SPL assets that can be reused to realize new customer requirements. Using the existing customer requirements as input, the approach applies natural language processing and clustering to generate reuse recommendations for unseen customer requirements in new projects. The approach is evaluated both quantitatively and qualitatively in the railway industry. Results show that our approach can recommend reuse with 74% accuracy and 57.4% exact match. The evaluation further indicates that the recommendations are relevant to engineers and can support the product derivation and feasibility analysis phase of the projects. The results encourage further study on automated reuse analysis on other levels of abstractions.

  • 10.
    Abbas, Nadeem
    et al.
    Linnaeus University, Sweden.
    Andersson, Jesper
    Linnaeus University, Sweden.
    Architectural Reasoning Support for Product-Lines of Self-adaptive Software Systems - A Case Study2015Ingår i: Software Architecture: 9th European Conference, ECSA 2015, Dubrovnik/Cavtat, Croatia, September 7-11, 2015. Proceedings, Springer International Publishing , 2015, 17, s. 20-36Kapitel i bok, del av antologi (Refereegranskat)
    Abstract [en]

    Software architecture serves as a foundation for the design and development of software systems. Designing an architecture requires extensive analysis and reasoning. The study presented herein focuses on the architectural analysis and reasoning in support of engineering self-adaptive software systems with systematic reuse. Designing self-adaptive software systems with systematic reuse introduces variability along three dimensions; adding more complexity to the architectural analysis and reasoning process. To this end, the study presents an extended Architectural Reasoning Framework with dedicated reasoning support for self-adaptive systems and reuse. To evaluate the proposed framework, we conducted an initial feasibility case study, which concludes that the proposed framework assists the domain architects to increase reusability, reduce fault density, and eliminate differences in skills and experiences among architects, which were our research goals and are decisive factors for a system’s overall quality.

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  • 11.
    Abbas, Nadeem
    et al.
    Linnaeus University, Sweden.
    Andersson, Jesper
    Linnaeus University, Sweden.
    Harnessing Variability in Product-lines of Self-adaptive Software Systems2015Ingår i: Proceedings of the 19th International Conference on Software Product Line (SPLC '15), New York, NY, USA: Association for Computing Machinery (ACM), 2015, 12, s. 191-200Konferensbidrag (Refereegranskat)
    Abstract [en]

    This work studies systematic reuse in the context of self-adaptive software systems. In our work, we realized that managing variability for such platforms is different compared to traditional platforms, primarily due to the run-time variability and system uncertainties. Motivated by the fact that recent trends show that self-adaptation will be used more often in future system generation and that software reuse state-of-practice or research do not provide sufficient support, we have investigated the problems and possibly resolutions in this context. We have analyzed variability for these systems, using a systematic reuse prism, and identified a research gap in variability management. The analysis divides variability handling into four activities: (1) identify variability, (2) constrain variability, (3) implement variability, and (4) manage variability. Based on the findings we envision a reuse framework for the specific domain and present an example framework that addresses some of the identified challenges. We argue that it provides basic support for engineering self-adaptive software systems with systematic reuse. We discuss some important avenues of research for achieving the vision.

  • 12.
    Abbasi, Shirin
    et al.
    Islamic Azad University, Iran.
    Rahmani, Amir
    National Yunlin University of Science and Technology, Douliou, Taiwan.
    Balador, Ali
    RISE Research Institutes of Sweden, Digitala system, Industriella system. Mälardalen University, Sweden.
    Sahafi, Amir
    Islamic Azad University, Iran.
    Internet of Vehicles: Architecture, services, and applications2021Ingår i: International Journal of Communication Systems, ISSN 1074-5351, E-ISSN 1099-1131, Vol. 34, nr 10, artikel-id e4793Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The connection between objects and information exchange has been possible in recent years, with the advent of the Internet of Things (IoT) in different industries. We can meet different requirements in each industry utilizing this feature. Intelligent transportation uses the Internet of Vehicles (IoV) as a solution for communication among vehicles. It improves traffic management applications and services to guarantee safety on roads. We categorize services, applications, and architectures and propose a taxonomy for IoV. Then, we study open issues and challenges for future works. We highlighted applications and services due to drivers' requirements and nonfunctional requirements, considering the qualitative characteristic. This paper summarizes the current state of the IoV in architectures, services, and applications. It can be a start view to provide the solutions for challenges in traffic management in cities. The present study is beneficial for smart city developments and management. According to this paper's result, the services and applications evaluate performance with 34% frequency, safety and data accuracy, and security with a 13% frequency in selected papers. These measurements are essential due to the IoV characteristics such as real-time operation, accident avoidance in applications, and complicated user data management. 

  • 13.
    Abbaspour Assadollah, Sara
    et al.
    Mälardalen University, Sweden.
    Saadatmand, Mehrdad
    RISE., Swedish ICT, SICS.
    Eldh, Sigrid
    Ericsson AB, Sweden.
    Sundmark, Daniel
    Mälardalen University, Sweden.
    Hansson, Hans
    Mälardalen University, Sweden.
    A Model for Systematic Monitoring and Debugging of Starvation Bugs in Multicore Software2016Ingår i: Proceedings of the 1st International Workshop on Specification, Comprehension, Testing, and Debugging of Concurrent Programs (SCTDCP 2016), 2016, s. 7-11Konferensbidrag (Refereegranskat)
    Abstract [en]

    With the development of multicore hardware, concurrent, parallel and multicore software are becoming increasingly popular. Software companies are spending a huge amount of time and resources to nd and debug the bugs. Among all types of software bugs, concurrency bugs are also important and troublesome. This type of bugs is increasingly becoming an issue particularly due to the growing prevalence of multicore hardware. In this position paper, we propose a model for monitoring and debugging Starvation bugs as a type of concurrency bugs in multicore software. The model is composed into three phases: monitoring, detecting and debugging. The monitoring phase can support detecting phase by storing collected data from the system execution. The detecting phase can support debugging phase by comparing the stored data with starvation bug's properties, and the debugging phase can help in reproducing and removing the Starvation bug from multicore software. Our intention is that our model is the basis for developing tool(s) to enable solving Starvation bugs in software for multicore platforms.

  • 14.
    Abdelraheem, Mohamed Ahmed
    et al.
    RISE., Swedish ICT, SICS.
    Alizadeh, Javad
    Sharif University of Technology, Iran.
    Alkhzaimi, Hoda A.
    DTU Technical University of Denmark, Denmark.
    Aref, Mohammad Reza
    Sharif University of Technology, Iran.
    Bagheri, Nasour
    Shahid Rajaee Teachers Training University, Iran; IPM Institute for Research in Fundamental Sciences, Iran.
    Gauravaram, Praveen
    Queensland University of Technology, Australia.
    Improved Linear Cryptanalysis of reduced-round SIMON-32 and SIMON-482015Ingår i: Progress in Cryptology - INDOCRYPT 2015, 2015, Vol. 9462, s. 153-179Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this paper we analyse two variants of SIMON family of light-weight block ciphers against linear cryptanalysis and present the best linear cryptanalytic results on these variants of reduced-round SIMON to date. We propose a time-memory trade-off method that finds differential/linear trails for any permutation allowing low Hamming weight differential/linear trails. Our method combines low Hamming weight trails found by the correlation matrix representing the target permutation with heavy Hamming weight trails found using a Mixed Integer Programming model representing the target differential/linear trail. Our method enables us to find a 17-round linear approximation for SIMON-48 which is the best current linear approximation for SIMON-48. Using only the correlation matrix method, we are able to find a 14-round linear approximation for SIMON-32 which is also the current best linear approximation for SIMON-32. The presented linear approximations allow us to mount a 23-round key recovery attack on SIMON-32 and a 24-round Key recovery attack on SIMON-48/96 which are the current best results on SIMON-32 and SIMON-48. In addition we have an attack on 24 rounds of SIMON-32 with marginal complexity.

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  • 15.
    Abdelraheem, Mohamed Ahmed
    et al.
    RISE - Research Institutes of Sweden, ICT, SICS.
    Andersson, Tobias
    RISE - Research Institutes of Sweden, ICT, SICS.
    Gehrmann, Christian
    Lund university, Sweden.
    Searchable Encrypted Relational Databases:Risks and Countermeasures2017Ingår i: Data Privacy Management, Cryptocurrencies and Blockchain Technology: ESORICS 2017 International Workshops, DPM 2017 and CBT 2017, Oslo, Norway, September 14-15, 2017, Proceedings / [ed] Joaquin Garcia-Alfaro et al., Gewerbestrasse 11, 6330 Cham, Switzerland: Springer Nature , 2017, Vol. 10436, s. 70-85Konferensbidrag (Refereegranskat)
    Abstract [en]

    We point out the risks of protecting relational databases viaSearchable Symmetric Encryption (SSE) schemes by proposing an infer-ence attack exploiting the structural properties of relational databases.We show that record-injection attacks mounted on relational databaseshave worse consequences than their file-injection counterparts on un-structured databases. Moreover, we discuss some techniques to reducethe effectiveness of inference attacks exploiting the access pattern leak-age existing in SSE schemes. To the best of our knowledge, this is thefirst work that investigates the security of relational databases protectedby SSE schemes.

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  • 16.
    Abella, J.
    et al.
    Barcelona Supercomputing Center, Spain.
    Perez, J.
    BRTA Basque Research and Technology Alliance, Spain.
    Englund, Cristofer
    RISE Research Institutes of Sweden, Digitala system, Mobilitet och system.
    Zonooz, B.
    Navinfo Europe, Netherlands.
    Giordana, G.
    AIKO Srl, Italy.
    Donzella, C.
    Exida Development Srl, Italy.
    Cazorla, F. J.
    Barcelona Supercomputing Center, Spain.
    Mezzetti, E.
    Barcelona Supercomputing Center, Spain.
    Serra, I.
    Barcelona Supercomputing Center, Spain.
    Brando, A.
    Barcelona Supercomputing Center, Spain.
    Agirre, I.
    BRTA Basque Research and Technology Alliance, Spain.
    Eizaguirre, F.
    BRTA Basque Research and Technology Alliance, Spain.
    Bui, Thanh
    RISE Research Institutes of Sweden, Digitala system, Mobilitet och system.
    Arani, E.
    Navinfo Europe, Netherlands.
    Sarfraz, F.
    Navinfo Europe, Netherlands.
    Balasubramaniam, A.
    Navinfo Europe, Netherlands.
    Badar, A.
    Navinfo Europe, Netherlands.
    Bloise, I.
    AIKO Srl, Italy.
    Feruglio, L.
    AIKO Srl, Italy.
    Cinelli, I.
    AIKO Srl, Italy.
    Brighenti, D.
    Exida Engineering Srl, Italy.
    Cunial, D.
    Exida Engineering Srl, Italy.
    SAFEXPLAIN: Safe and Explainable Critical Embedded Systems Based on AI2023Ingår i: Proceedings -Design, Automation and Test in Europe, DATE, Institute of Electrical and Electronics Engineers Inc. , 2023Konferensbidrag (Refereegranskat)
    Abstract [en]

    Deep Learning (DL) techniques are at the heart of most future advanced software functions in Critical Autonomous AI-based Systems (CAIS), where they also represent a major competitive factor. Hence, the economic success of CAIS industries (e.g., automotive, space, railway) depends on their ability to design, implement, qualify, and certify DL-based software products under bounded effort/cost. However, there is a fundamental gap between Functional Safety (FUSA) requirements on CAIS and the nature of DL solutions. This gap stems from the development process of DL libraries and affects high-level safety concepts such as (1) explainability and traceability, (2) suitability for varying safety requirements, (3) FUSA-compliant implementations, and (4) real-time constraints. As a matter of fact, the data-dependent and stochastic nature of DL algorithms clashes with current FUSA practice, which instead builds on deterministic, verifiable, and pass/fail test-based software. The SAFEXPLAIN project tackles these challenges and targets by providing a flexible approach to allow the certification - hence adoption - of DL-based solutions in CAIS building on: (1) DL solutions that provide end-to-end traceability, with specific approaches to explain whether predictions can be trusted and strategies to reach (and prove) correct operation, in accordance to certification standards; (2) alternative and increasingly sophisticated design safety patterns for DL with varying criticality and fault tolerance requirements; (3) DL library implementations that adhere to safety requirements; and (4) computing platform configurations, to regain determinism, and probabilistic timing analyses, to handle the remaining non-determinism.

  • 17. Aberer, Karl
    et al.
    Onana Alima, Luc
    RISE., Swedish ICT, SICS.
    Ghodsi, Ali
    RISE., Swedish ICT, SICS.
    Girdzijauskas, Sarunas
    RISE., Swedish ICT, SICS, Computer Systems Laboratory.
    Hauswirth, Manfred
    Haridi, Seif
    RISE., Swedish ICT, SICS, Computer Systems Laboratory.
    The essence of P2P: A reference architecture for overlay networks2005Konferensbidrag (Refereegranskat)
    Abstract [en]

    The success of the P2P idea has created a huge diversity of approaches, among which overlay networks, for example, Gnutella, Kazaa, Chord, Pastry, Tapestry, P-Grid, or DKS, have received specific attention from both developers and researchers. A wide variety of algorithms, data structures, and architectures have been proposed. The terminologies and abstractions used, however, have become quite inconsistent since the P2P paradigm has attracted people from many different communities, e.g., networking, databases, distributed systems, graph theory, complexity theory, biology, etc. In this paper we propose a reference model for overlay networks which is capable of modeling different approaches in this domain in a generic manner. It is intended to allow researchers and users to assess the properties of concrete systems, to establish a common vocabulary for scientific discussion, to facilitate the qualitative comparison of the systems, and to serve as the basis for defining a standardized API to make overlay networks interoperable.

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  • 18.
    Abrahamsson, Henrik
    RISE., Swedish ICT, SICS. School of Innovation, Design and Engineering.
    Network overload avoidance by traffic engineering and content caching2012Doktorsavhandling, monografi (Övrigt vetenskapligt)
    Abstract [en]

    The Internet traffic volume continues to grow at a great rate, now driven by video and TV distribution. For network operators it is important to avoid congestion in the network, and to meet service level agreements with their customers. This thesis presents work on two methods operators can use to reduce links loads in their networks: traffic engineering and content caching. This thesis studies access patterns for TV and video and the potential for caching. The investigation is done both using simulation and by analysis of logs from a large TV-on-Demand system over four months. The results show that there is a small set of programs that account for a large fraction of the requests and that a comparatively small local cache can be used to significantly reduce the peak link loads during prime time. The investigation also demonstrates how the popularity of programs changes over time and shows that the access pattern in a TV-on-Demand system very much depends on the content type. For traffic engineering the objective is to avoid congestion in the network and to make better use of available resources by adapting the routing to the current traffic situation. The main challenge for traffic engineering in IP networks is to cope with the dynamics of Internet traffic demands. This thesis proposes L-balanced routings that route the traffic on the shortest paths possible but make sure that no link is utilised to more than a given level L. L-balanced routing gives efficient routing of traffic and controlled spare capacity to handle unpredictable changes in traffic. We present an L-balanced routing algorithm and a heuristic search method for finding L-balanced weight settings for the legacy routing protocols OSPF and IS-IS. We show that the search and the resulting weight settings work well in real network scenarios.

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  • 19.
    Abrahamsson, Henrik
    RISE., Swedish ICT, SICS, Decisions, Networks and Analytics lab.
    Traffic measurement and analysis1999Rapport (Övrigt vetenskapligt)
    Abstract [en]

    Measurement and analysis of real traffic is important to gain knowledge about the characteristics of the traffic. Without measurement, it is impossible to build realistic traffic models. It is recent that data traffic was found to have self-similar properties. In this thesis work traffic captured on the network at SICS and on the Supernet, is shown to have this fractal-like behaviour. The traffic is also examined with respect to which protocols and packet sizes are present and in what proportions. In the SICS trace most packets are small, TCP is shown to be the predominant transport protocol and NNTP the most common application. In contrast to this, large UDP packets sent between not well-known ports dominates the Supernet traffic. Finally, characteristics of the client side of the WWW traffic are examined more closely. In order to extract useful information from the packet trace, web browsers use of TCP and HTTP is investigated including new features in HTTP/1.1 such as persistent connections and pipelining. Empirical probability distributions are derived describing session lengths, time between user clicks and the amount of data transferred due to a single user click. These probability distributions make up a simple model of WWW-sessions.

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  • 20.
    Abrahamsson, Henrik
    et al.
    RISE., Swedish ICT, SICS, Decisions, Networks and Analytics lab.
    Ahlgren, Bengt
    RISE., Swedish ICT, SICS, Decisions, Networks and Analytics lab.
    Temporal Characteristics of Large IP Traffic Flows2003Rapport (Övrigt vetenskapligt)
    Abstract [en]

    Several studies of Internet traffic have shown that it is a small percentage of the flows that dominate the traffic. This is often referred to as the mice and elephants phenomenon. It has been proposed that this might be one of very few invariants of Internet traffic and that this property could somehow be used for traffic engineering purposes. The idea being that one in a scalable way could control a major part of the traffic by only keeping track of a small number of flows. But for this the large flows must also be stable in the meaning that they should be among the largest flows during long periods of time. In this work we analyse packet traces of Internet traffic and study the temporal characteristics of large aggregated traffic flows defined by destination address prefixes.

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    FULLTEXT01
  • 21.
    Abrahamsson, Henrik
    et al.
    RISE., Swedish ICT, SICS, Decisions, Networks and Analytics lab.
    Ahlgren, Bengt
    RISE., Swedish ICT, SICS, Decisions, Networks and Analytics lab.
    Using empirical distributions to characterize web client traffic and to generate synthetic traffic2000Konferensbidrag (Refereegranskat)
    Ladda ner fulltext (ps)
    fulltext
  • 22.
    Abrahamsson, Henrik
    et al.
    RISE., Swedish ICT, SICS, Decisions, Networks and Analytics lab.
    Ahlgren, Bengt
    RISE., Swedish ICT, SICS, Decisions, Networks and Analytics lab.
    Alonso, Juan
    RISE - Research Institutes of Sweden (2017-2019), ICT, SICS.
    Andersson, Anders
    RISE - Research Institutes of Sweden (2017-2019), ICT, SICS.
    Kreuger, Per
    RISE., Swedish ICT, SICS, Decisions, Networks and Analytics lab.
    A Multi Path Routing Algorithm for IP Networks Based on Flow Optimisation.2002Konferensbidrag (Refereegranskat)
    Ladda ner fulltext (pdf)
    fulltext
  • 23.
    Abrahamsson, Henrik
    et al.
    RISE., Swedish ICT, SICS, Decisions, Networks and Analytics lab.
    Ahlgren, Bengt
    RISE., Swedish ICT, SICS, Decisions, Networks and Analytics lab.
    Alonso, Juan
    RISE - Research Institutes of Sweden (2017-2019), ICT, SICS.
    Andersson, Anders
    RISE - Research Institutes of Sweden (2017-2019), ICT, SICS.
    Kreuger, Per
    RISE., Swedish ICT, SICS, Decisions, Networks and Analytics lab.
    From QoS provisioning to QoS charging2002Ingår i: Proceedings of the Second International Workshop on Internet Charging and QoS Technologies, ICQT 2002, 2002, 1, Vol. Lectures Notes in Computer Science (LNCS) no. 2511, s. 135-144Konferensbidrag (Refereegranskat)
  • 24.
    Abrahamsson, Henrik
    et al.
    RISE - Research Institutes of Sweden, ICT, SICS.
    Ahlgren, Bengt
    RISE - Research Institutes of Sweden, ICT, SICS.
    Lindvall, Patrik
    TeliaSonera, Sweden.
    Nieminen, Johanna
    TeliaSonera, Sweden.
    Tholin, Per
    TeliaSonera, Sweden.
    Traffic Characteristics on 1Gbit/s Access Aggregation Links2017Konferensbidrag (Refereegranskat)
    Abstract [en]

    Large network operators have thousands or tens of thousands of access aggregation links that they need to manage and dimension properly. Measuring and understanding the traffic characteristics on these type of links are therefore essential. What do the traffic intensity characteristics look like on different timescales from days down to milliseconds? How do the characteristics differ if we compare links with the same capacity but with different type of clients and access technologies? How do the traffic characteristics differ from that on core network links? These are the type of questions we set out to investigate in this paper. We present the results of packet level measurements on three different 1Gbit/s aggregation links in an operational IP network. We see large differences in traffic characteristics between the three links. We observe highly skewed link load probability densities on timescales relevant for buffering (i.e. 10-milliseconds). We demonstrate the existence of large traffic spikes on short timescales (10-100ms) and show their impact on link delay. We also found that these traffic bursts often are caused by only one or a few IP flows.

  • 25.
    Abrahamsson, Henrik
    et al.
    RISE., Swedish ICT, SICS, Decisions, Networks and Analytics lab.
    Ahlgren, Bengt
    RISE., Swedish ICT, SICS, Decisions, Networks and Analytics lab.
    Tholin, Per
    TeliaSonera, Sweden.
    Delay and Traffic Intensity Monitoring in an Operational IP Network2015Ingår i: 11th Swedish National Computer Networking Workshop (SNCNW 2015), Karlstad, Sweden, 2015, 6Konferensbidrag (Refereegranskat)
  • 26.
    Abrahamsson, Henrik
    et al.
    RISE., Swedish ICT, SICS, Decisions, Networks and Analytics lab.
    Björkman, Mats
    Mälardalen University, Sweden.
    Caching for IPTV distribution with time-shift2013Konferensbidrag (Refereegranskat)
    Abstract [en]

    Today video and TV distribution dominate Internet traffic and the increasing demand for high-bandwidth multimedia services puts pressure on Internet service providers. In this paper we simulate TV distribution with time-shift and investigate the effect of introducing a local cache close to the viewers. We study what impact TV program popularity, program set size, cache replacement policy and other factors have on the caching efficiency. The simulation results show that introducing a local cache close to the viewers significantly reduces the network load from TV-on-Demand services. By caching 4% of the program volume we can decrease the peak load during prime time by almost 50%. We also show that the TV program type and how program popularity changes over time can have a big influence on cache hit ratios and the resulting link loads.

  • 27.
    Abrahamsson, Henrik
    et al.
    RISE., Swedish ICT, SICS, Decisions, Networks and Analytics lab.
    Björkman, Mats
    Robust Traffic Engineering using L-balanced Weight-Settings in OSPF/IS-IS2009Konferensbidrag (Refereegranskat)
  • 28.
    Abrahamsson, Henrik
    et al.
    RISE., Swedish ICT, SICS, Decisions, Networks and Analytics lab.
    Björkman, Mats
    Simulation of IPTV caching strategies2010Konferensbidrag (Refereegranskat)
    Abstract [en]

    IPTV, where television is distributed over the Internet Protocol in a single operator network, has become popular and widespread. Many telecom and broadband companies have become TV providers and distribute TV channels using multicast over their backbone networks. IPTV also means an evolution to time-shifted television where viewers now often can choose to watch the programs at any time. However, distributing individual TV streams to each viewer requires a lot of bandwidth and is a big challenge for TV operators. In this paper we present an empirical IPTV workload model, simulate IPTV distribution with time-shift, and show that local caching can limit the bandwidth requirements significantly.

  • 29.
    Abrahamsson, Henrik
    et al.
    RISE., Swedish ICT, SICS, Decisions, Networks and Analytics lab.
    Gunnar, Anders
    RISE., Swedish ICT, SICS.
    Traffic engineering in ambient networks: challenges and approaches2004Ingår i: Swedish National Computer Networking Workshop, 2004, 1Konferensbidrag (Refereegranskat)
    Abstract [en]

    The focus of this paper is on traffic engineering in ambient networks. We describe and categorize different alternatives for making the routing more adaptive to the current traffic situation and discuss the challenges that ambient networks pose on traffic engineering methods. One of the main objectives of traffic engineering is to avoid congestion by controlling and optimising the routing function, or in short, to put the traffic where the capacity is. The main challenge for traffic engineering in ambient networks is to cope with the dynamics of both topology and traffic demands. Mechanisms are needed that can handle traffic load dynamics in scenarios with sudden changes in traffic demand and dynamically distribute traffic to benefit from available resources. Trade-offs between optimality, stability and signaling overhead that are important for traffic engineering methods in the fixed Internet becomes even more critical in a dynamic ambient environment.

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  • 30.
    Abrahamsson, Henrik
    et al.
    RISE., Swedish ICT, SICS, Decisions, Networks and Analytics lab.
    Hagsand, Olof
    Marsh, Ian
    RISE - Research Institutes of Sweden (2017-2019), ICT, SICS.
    TCP over High Speed Variable Capacity Links: A Simulation Study for Bandwidth Allocation2002Konferensbidrag (Refereegranskat)
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  • 31.
    Abrahamsson, Henrik
    et al.
    RISE Research Institutes of Sweden, Digitala system, Industriella system.
    Henriksson, Daniel
    Lunet, Sweden.
    Makonyi, Karoly
    Savantic, Sweden.
    Menéndez Hurtado (, David
    Savantic, Sweden.
    Sandell, Johan
    Waystream, Sweden.
    Towards automated and proactive anomaly detection in a fiber access network2023Ingår i: Proceedings of 18th Swedish National Computer Networking and Cloud Computing Workshop (SNCNW 2023), Kristianstad, June 14-15, 2023., 2023Konferensbidrag (Refereegranskat)
    Abstract [en]

    Communication networks are vital for society and network availability is therefore crucial. There is a huge potential in using network telemetry data and machine learning algorithms to proactively detect anomalies and remedy problems before they affect the customers. In practice, however, there are many steps on the way to get there. In this paper we present ongoing development work on efficient data collection pipelines, anomaly detection algorithms and analysis of traffic patterns and predictability.

  • 32.
    Abrahamsson, Henrik
    et al.
    RISE., Swedish ICT, SICS, Decisions, Networks and Analytics lab.
    Kreuger, Per
    RISE., Swedish ICT, SICS, Decisions, Networks and Analytics lab.
    A case for resource management in IPTV distribution2008Konferensbidrag (Refereegranskat)
  • 33.
    Abrahamsson, Henrik
    et al.
    RISE., Swedish ICT, SICS, Decisions, Networks and Analytics lab.
    Kreuger, Per
    RISE., Swedish ICT, SICS, Decisions, Networks and Analytics lab.
    Resource Management for IPTV distribution2009Ingår i: ERCIM News, Vol. 77Artikel i tidskrift (Övrigt vetenskapligt)
  • 34.
    Abrahamsson, Henrik
    et al.
    RISE., Swedish ICT, SICS, Decisions, Networks and Analytics lab.
    Marsh, Ian
    RISE - Research Institutes of Sweden (2017-2019), ICT, SICS.
    DTMsim - DTM channel simulation in ns2001Rapport (Övrigt vetenskapligt)
    Abstract [en]

    Dynamic Transfer Mode (DTM) is a ring based MAN technology that provides a channel abstraction with a dynamically adjustable capacity. TCP is a reliable end to end transport protocol capable of adjusting its rate. The primary goal of this work is investigate the coupling of dynamically allocating bandwidth to TCP flows with the affect this has on the congestion control mechanism of TCP. In particular we wanted to find scenerios where this scheme does not work, where either all the link capacity is allocated to TCP or congestion collapse occurs and no capacity is allocated to TCP. We have created a simulation environment using ns-2 to investigate TCP over networks which have a variable capacity link. We begin with a single TCP Tahoe flow over a fixed bandwidth link and progressively add more complexity to understand the behaviour of dynamically adjusting link capacity to TCP and vice versa.

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    FULLTEXT01
  • 35.
    Abrahamsson, Henrik
    et al.
    RISE., Swedish ICT, SICS, Decisions, Networks and Analytics lab.
    Nordmark, Mattias
    TeliaSonera AB, Sweden.
    Program Popularity and Viewer Behaviour in a Large TV-on-Demand System2012Konferensbidrag (Refereegranskat)
    Abstract [en]

    Today increasingly large volumes of TV and video are distributed over IP-networks and over the Internet. It is therefore essential for traffic and cache management to understand TV program popularity and access patterns in real networks. In this paper we study access patterns in a large TV-on-Demand system over four months. We study user behaviour and program popularity and its impact on caching. The demand varies a lot in daily and weekly cycles. There are large peaks in demand, especially on Friday and Saturday evenings, that need to be handled. We see that the cacheability, the share of requests that are not first-time requests, is very high. Furthermore, there is a small set of programs that account for a large fraction of the requests. We also find that the share of requests for the top most popular programs grows during prime time, and the change rate among them decreases. This is important for caching. The cache hit ratio increases during prime time when the demand is the highest, and aching makes the biggest difference when it matters most. We also study the popularity (in terms of number of requests and rank) of individual programs and how that changes over time. Also, we see that the type of programs offered determines what the access pattern will look like.

  • 36.
    Adawi, Tom
    et al.
    Chalmers University of Technology, Sweden.
    Burden, Håkan
    RISE., Swedish ICT, Viktoria.
    Olsson, Dennis
    University of Gothenburg, Sweden.
    Mattiasson, Rickard
    University of Gothenburg, Sweden.
    Characterizing Software Engineering Students' Discussions during Peer Instruction: Opportunities for Learning and Implications for Teaching2016Ingår i: International Journal of Engineering Education, ISSN 0949-149X, Vol. 32, nr 2, s. 927-936Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Peer instruction is a method for activating students during lectures, which has gained a considerable amount of attention in higher education due to claims of dramatic improvement in learning gains. The purpose of this qualitative research study is to investigate what types of discussions engineering students engage in during a peer instruction session and what learning possibilities that are enabled by these different types of discussions. We observed twelve students during six separate and simulated peer instruction sessions and the students were interviewed individually after the sessions.Ananalysis of the data revealed that the students engaged in three qualitatively different types of discussions: affirmative discussions, motivating discussions, and argumentative discussions. We characterize these different types of discussions in terms of the number of alternative answers the students discuss, the extent to which they draw on prior knowledge and experiences, as well as the fundamental difference between an explanation and an argument. A good opportunity for learning is opened up when students are aspiring to find the truth, not simply being satisfied with what they believe to be true. We conclude that students do not always engage in discussions that support their learning in the best way, and we discuss implications for using peer instruction as a teaching method.

  • 37.
    Adewumi, Oluwatosin
    et al.
    Luleå University of Technology, Sweden.
    Brännvall, Rickard
    RISE Research Institutes of Sweden, Digitala system, Datavetenskap. Luleå University of Technology, Sweden.
    Abid, Nosheen
    Luleå University of Technology, Sweden.
    Pahlavan, Maryam
    Luleå University of Technology, Sweden.
    Sabah Sabry, Sana
    Luleå University of Technology, Sweden.
    Liwicki, Foteini
    Luleå University of Technology, Sweden.
    Liwicki, Marcus
    Luleå University of Technology, Sweden.
    Småprat: DialoGPT for Natural Language Generation of Swedish Dialogue by Transfer Learning2022Ingår i: Vol. 3 (2022): Proceedings of the Northern Lights Deep Learning Workshop 2022, Septentrio Academic Publishing , 2022, Vol. 3Konferensbidrag (Refereegranskat)
    Abstract [en]

    Building open-domain conversational systems (or chatbots) that produce convincing responses is a recognized challenge. Recent state-of-the-art (SoTA) transformer-based models for the generation of natural language dialogue have demonstrated impressive performance in simulating human-like, single-turn conversations in English.This work investigates, by an empirical study, the potential for transfer learning of such models to Swedish language. DialoGPT, an English language pre-trained model, is adapted by training on three different Swedish language conversational datasets obtained from publicly available sources: Reddit, Familjeliv and the GDC. Perplexity score (an automated intrinsic metric) and surveys by human evaluation were used to assess the performances of the fine-tuned models. We also compare the DialoGPT experiments with an attention-mechanism-based seq2seq baseline model, trained on the GDC dataset. The results indicate that the capacity for transfer learning can be exploited with considerable success. Human evaluators asked to score the simulated dialogues judged over 57% of the chatbot responses to be human-like for the model trained on the largest (Swedish) dataset. The work agrees with the hypothesis that deep monolingual models learn some abstractions which generalize across languages. We contribute the codes, datasets and model checkpoints and host the demos on the HuggingFace platform.

  • 38.
    Adler, Daniel
    RISE - Research Institutes of Sweden, ICT, SICS.
    Virtual Audio - Three-Dimensional Audio in Virtual Environments1996Rapport (Övrigt vetenskapligt)
    Abstract [en]

    Three-dimensional interactive audio has a variety ofpotential uses in human-machine interfaces. After lagging seriously behind the visual components, the importance of sound is now becoming increas-ingly accepted. This paper mainly discusses background and techniques to implement three-dimensional audio in computer interfaces. A case study of a system for three-dimensional audio, implemented by the author, is described in great detail. The audio system was moreover integrated with a virtual reality system and conclusions on user tests and use of the audio system is presented along with proposals for future work at the end of the paper. The thesis begins with a definition of three-dimensional audio and a survey on the human auditory system to give the reader the needed knowledge of what three-dimensional audio is and how human auditory perception works.

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  • 39.
    Afanasov, Mikhail
    et al.
    Politecnico di Milano, Italy.
    Iavorskii, Aleksandr
    John Wiley & Sons Inc, Russia.
    Mottola, Luca
    RISE - Research Institutes of Sweden, ICT, SICS. Politecnico di Milano, Italy.
    Programming Support for Time-sensitive Adaptation in Cyberphysical Systems2018Ingår i: ACM SIGBED Review, Vol. 14, nr 4, s. 27-32Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Cyberphysical systems (CPS) integrate embedded sensors,actuators, and computing elements for controlling physicalprocesses. Due to the intimate interactions with thesurrounding environment, CPS software must continuouslyadapt to changing conditions. Enacting adaptation decisionsis often subject to strict time requirements to ensure controlstability, while CPS software must operate within the tightresource constraints that characterize CPS platforms. Developersare typically left without dedicated programmingsupport to cope with these aspects. This results in either toneglect functional or timing issues that may potentially ariseor to invest significant efforts to implement hand-crafted solutions.We provide programming constructs that allow developersto simplify the specification of adaptive processingand to rely on well-defined time semantics. Our evaluationshows that using these constructs simplifies implementationswhile reducing developers’ effort, at the price of a modestmemory and processing overhead.

  • 40.
    Afanasov, Mikhail
    et al.
    Politecnico di Milano, Italy.
    Mottola, Luca
    RISE - Research Institutes of Sweden, ICT, SICS. Politecnico di Milano, Italy.
    Ghezzi, Carlo
    Politecnico di Milano, Italy.
    Software Adaptation in Wireless Sensor Networks2018Ingår i: ACM Transactions on Autonomous and Adaptive Systems, Vol. 12, nr 4, s. 1-29Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We present design concepts, programming constructs, and automatic verification techniques to support thedevelopment of adaptive Wireless Sensor Network (WSN) software. WSNs operate at the interface betweenthe physical world and the computing machine, and are hence exposed to unpredictable environment dynamics.WSN software must adapt to these dynamics to maintain dependable and efficient operation. Whilesignificant literature exists on the necessary adaptation logic, developers are left without proper support inmaterializing such a logic in a running system. Our work fills this gap with three key contributions: i) designconcepts help developers organize the necessary adaptive functionality and understand their relations,ii) dedicated programming constructs simplify the implementations, iii) custom verification techniques allowdevelopers to check the correctness of their design before deployment. We implement dedicated toolsupport to tie the three contributions, facilitating their practical application. Our evaluation considers representativeWSN applications to analyze code metrics, synthetic simulations, and cycle-accurate emulationof popular WSN platforms. The results indicate that our work is effective in simplifying the developmentof adaptive WSN software; for example, implementations are provably easier to test and to maintain, therun-time overhead of our dedicated programming construct is negligible, and our verification techniquesreturn results in a matter of seconds.

  • 41.
    Afrasiabi, Roodabeh
    et al.
    KTH Royal Institute of Technology, Sweden.
    Soderberg, Lovisa M.
    KTH Royal Institute of Technology, Sweden.
    Joensson, Haakan N.
    KTH Royal Institute of Technology, Sweden.
    Björk, Per
    RISE., Swedish ICT, Acreo.
    Svahn, Helene A.
    KTH Royal Institute of Technology, Sweden.
    Linnros, Jan
    KTH Royal Institute of Technology, Sweden.
    Integration of a droplet-based microfluidic system and silicon nanoribbon FET sensor2016Ingår i: Micromachines, E-ISSN 2072-666X, Vol. 7, nr 8, artikel-id 134Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We present a novel microfluidic system that integrates droplet microfluidics with a silicon nanoribbon field-effect transistor (SiNR FET), and utilize this integrated system to sense differences in pH. The device allows for selective droplet transfer to a continuous water phase, actuated by dielectrophoresis, and subsequent detection of the pH level in the retrieved droplets by SiNR FETs on an electrical sensor chip. The integrated microfluidic system demonstrates a label-free detection method for droplet microfluidics, presenting an alternative to optical fluorescence detection. In this work, we were able to differentiate between droplet trains of one pH-unit difference. The pH-based detection method in our integrated system has the potential to be utilized in the detection of biochemical reactions that induce a pH-shift in the droplets.

  • 42. Africano, Diana
    et al.
    Clark, Brendon
    RISE., Swedish ICT, Interactive Institute. Design Research Unit.
    Design för kulturell mångfald2006Ingår i: Västerbotten (Umeå. 1920), Västerbotten (Umeå. 1920) , 2006, 10, s. 36-39Kapitel i bok, del av antologi (Övrigt vetenskapligt)
  • 43. Aggoun, Abderrahmane
    et al.
    Beldiceanu, Nicolas
    Carlsson, Mats
    RISE., Swedish ICT, SICS.
    Fages, François
    Integrating rule-based modelling and constraint programming for solving industrial packing problems2010Ingår i: ERCIM News, ISSN 0926-4981, E-ISSN 1564-0094, s. 34-35Artikel i tidskrift (Övrig (populärvetenskap, debatt, mm))
    Abstract [en]

    Packing items in bins is an old but nevertheless challenging combinatorial problem with numerous applications in industry. We report on an original approach based on constraint programming and rule-based modelling, which has been investigated in the framework of the FP6 ‘specific targeted research project’ Net-WMS (Towards integrating virtual reality and optimization techniques in a new generation of Networked businesses in Warehouse Management Systems under constraints). It has applications in the automotive industry.

  • 44.
    Ahlgren, Bengt
    RISE., Swedish ICT, SICS, Decisions, Networks and Analytics lab.
    A host interface to the DTM high speed network1992Konferensbidrag (Refereegranskat)
  • 45.
    Ahlgren, Bengt
    RISE., Swedish ICT, SICS, Decisions, Networks and Analytics lab.
    A performance model for integrated layer processing1997Konferensbidrag (Refereegranskat)
    Abstract [en]

    Integrated Layer Processing is an implementation technique for data manipulation functions in communication protocols. The purpose of this technique is to increase communication performance. It reduces the number of memory accesses and thus relieves the memory bandwidth bottleneck. Integrated Layer Processing can however, in some situations, substantially increase the number of memory accesses, and therefore instead reduce performance. The main reason is contention for processor registers. We present a performance model that captures the memory behavior of data manipulation functions for both integrated and sequential implementations. By comparing the model to measurements of real and synthetic data manipulation functions, we show that the model accurately predicts the performance. The model can be used to assess whether an integrated implementation will perform better or worse than a sequential implementation. The situations where integration would reduce performance can then be avoided without spending a lot of effort on a more complex integrated implementation.

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  • 46.
    Ahlgren, Bengt
    RISE., Swedish ICT, SICS, Decisions, Networks and Analytics lab.
    Improving computer communication performance by reducing memory bandwidth consumption1997Doktorsavhandling, monografi (Övrigt vetenskapligt)
  • 47.
    Ahlgren, Bengt
    RISE., Swedish ICT, SICS, Decisions, Networks and Analytics lab.
    NetInf Routing Using Hints2013Konferensbidrag (Refereegranskat)
    Abstract [en]

    We define a global routing mechanism for the NetInf protocol, part of the NetInf information-centric networking architecture. The mechanism makes use of two levels of aggregation in order to provide the scalability needed for a global network. An anticipated $10^{15}$ number of individual named data objects are aggregated to in the order of 500K routing hints which are very feasible to handle with existing routing technology. The hints are then used to forward requests for named data towards the publisher.

  • 48.
    Ahlgren, Bengt
    et al.
    RISE., Swedish ICT, SICS, Decisions, Networks and Analytics lab.
    Andersson, Anders
    Hagsand, Olof
    RISE - Research Institutes of Sweden (2017-2019), ICT, SICS.
    Marsh, Ian
    RISE - Research Institutes of Sweden (2017-2019), ICT, SICS.
    Dimensioning links for IP telephony2001Ingår i: Proceedings of the 2nd IP-Telephony Workshop (IPtel 2001), 2-3 April 2001, New York City, New York, USA, 2001, 1Konferensbidrag (Refereegranskat)
    Abstract [en]

    Packet loss is an important parameter for dimensioning network links or traffic classes carrying IP telephony traffic. We present a model based on the Markov modulated Poisson process (MMPP) which calculates packet loss probabilities for a set of super positioned voice input sources and the specified link properties. We do not introduce another new model to the community, rather try and verify one of the existing models via extensive simulation and a real world implementation. A plethora of excellent research on queuing theory is still in the domain of ATM researchers and we attempt to highlight its validity to the IP Telephony community. Packet level simulations show very good correspondence with the predictions of the model. Our main contribution is the verification of the MMPP model with measurements in a laboratory environment. The loss rates predicted by the model are in general close to the measured loss rates and the loss rates obtained with simulation. The general conclusion is that the MMPP-based model is a tool well suited for dimensioning links carrying packetized voice in a system with limited buffer space.

  • 49.
    Ahlgren, Bengt
    et al.
    RISE., Swedish ICT, SICS, Decisions, Networks and Analytics lab.
    Andersson, Anders
    RISE - Research Institutes of Sweden (2017-2019), ICT, SICS.
    Hagsand, Olof
    RISE - Research Institutes of Sweden (2017-2019), ICT, SICS.
    Marsh, Ian
    RISE - Research Institutes of Sweden (2017-2019), ICT, SICS.
    Dimensioning Links for IP Telephony2000Rapport (Övrigt vetenskapligt)
    Abstract [en]

    Transmitting telephone calls over the Internet causes problems not present in current telephone technology such as packet loss and delay due to queueing in routers. In this undergraduate thesis we study how a Markov modulated Poisson process is applied as an arrival process to a multiplexer and we study the performance in terms of loss probability. The input consists of the superposition of independent voice sources. The predictions of the model is compared with results obtained with simulations of the multiplexer made with a network simulator. The buffer occupancy distribution is also studied and we see how this distribution changes as the load increases.

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    FULLTEXT01
  • 50.
    Ahlgren, Bengt
    et al.
    RISE., Swedish ICT, SICS, Decisions, Networks and Analytics lab.
    Aranda, Pedro A.
    Chemouil, Prosper
    Correia, Luis M.
    Holger, Karl
    Oueslati, Sara
    Söllner, Michael
    Welin, Annikki
    Content, Connectivity and Cloud: Ingredients for the Network of the Future2011Ingår i: IEEE Communications Magazine, ISSN 0163-6804, E-ISSN 1558-1896, Vol. 49, s. 62-70Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A new network architecture for the Internet needs ingredients from three approaches: information-centric networking, cloud computing integrated with networking, and open connectivity. Information-centric networking considers pieces of information as first-class entities of a networking architecture, rather than only indirectly identifying and manipulating them via a node hosting that information; this way, information becomes independent from the devices they are stored in, enabling efficient and application-independent information caching in the network. Cloud networking offers a combination and integration of cloud computing and virtual networking. It is a solution that distributes the benefits of cloud computing more deeply into the network, and provides a tighter integration of virtualisation features at computing and networking levels. To support these concepts, open connectivity services need to provide advanced transport and networking mechanisms, making use of network and path diversity (even leveraging direct optical paths) and encoding techniques, and dealing with ubiquitous mobility of user, content and information objects in a unified way.

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