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  • 1. Aarts, Fides
    et al.
    Jonsson, Bengt
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik.
    Uijen, Johan
    Vaandrager, Frits
    Generating models of infinite-state communication protocols using regular inference with abstraction2015Inngår i: Formal methods in system design, ISSN 0925-9856, E-ISSN 1572-8102, Vol. 46, nr 1, 1-41 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In order to facilitate model-based verification and validation, effort is underway to develop techniques for generating models of communication system components from observations of their external behavior. Most previous such work has employed regular inference techniques which generate modest-size finite-state models. They typically suppress parameters of messages, although these have a significant impact on control flow in many communication protocols. We present a framework, which adapts regular inference to include data parameters in messages and states for generating components with large or infinite message alphabets. A main idea is to adapt the framework of predicate abstraction, successfully used in formal verification. Since we are in a black-box setting, the abstraction must be supplied externally, using information about how the component manages data parameters. We have implemented our techniques by connecting the LearnLib tool for regular inference with an implementation of session initiation protocol (SIP) in ns-2 and an implementation of transmission control protocol (TCP) in Windows 8, and generated models of SIP and TCP components.

  • 2.
    Abbaspour Asadollah, Sara
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Bugs and Debugging of Concurrent and Multicore Software2016Licentiatavhandling, med artikler (Annet vitenskapelig)
  • 3.
    Abbaspour Asadollah, Sara
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Hansson, Hans
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Sundmark, Daniel
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Eldh, Sigrid
    Ericsson AB, Kista, Sweden.
    Towards Classification of Concurrency Bugs Based on Observable Properties2015Inngår i: Proceedings - 1st International Workshop on Complex Faults and Failures in Large Software Systems, COUFLESS 2015, 2015, 41-47 s.Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In software engineering, classification is a way to find an organized structure of knowledge about objects. Classification serves to investigate the relationship between the items to be classified, and can be used to identify the current gaps in the field. In many cases users are able to order and relate objects by fitting them in a category. This paper presents initial work on a taxonomy for classification of errors (bugs) related to concurrent execution of application level software threads. By classifying concurrency bugs based on their corresponding observable properties, this research aims to examine and structure the state of the art in this field, as well as to provide practitioner support for testing and debugging of concurrent software. We also show how the proposed classification, and the different classes of bugs, relates to the state of the art in the field by providing a mapping of the classification to a number of recently published papers in the software engineering field.

  • 4.
    Abbaspour Asadollah, Sara
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Saadatmand, Mehrdad
    SICS Swedish ICT, Västerås, Sweden.
    Eldh, Sigrid
    Ericsson AB, Kista, Sweden.
    Sundmark, Daniel
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Hansson, Hans
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    A Model for Systematic Monitoring and Debugging of Starvation Bugs in Multicore Software2016Inngår i: 2016 ASE Workshop on Specification, Comprehension, Testing and Debugging of Concurrent Programs SCTDCP2016, 2016Konferansepaper (Fagfellevurdert)
    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.

  • 5.
    Abbaspour Asadollah, Sara
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Sundmark, Daniel
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Eldh, Sigrid
    Ericsson AB, Kista, Sweden .
    Hansson, Hans
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Afza, Wasif
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    10 Years of research on debugging concurrent and multicore software: a systematic mapping studyInngår i: Software quality journal, ISSN 0963-9314, E-ISSN 1573-1367Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Debugging – the process of identifying, localizing and fixing bugs – is a key activity in software development. Due to issues such as non-determinism and difficulties of reproducing failures, debugging concurrent software is significantly more challenging than debugging sequential software. A number of methods, models and tools for debugging concurrent and multicore software have been proposed, but the body of work partially lacks a common terminology and a more recent view of the problems to solve. This suggests the need for a classification, and an up-to-date comprehensive overview of the area. 

    This paper presents the results of a systematic mapping study in the field of debugging of concurrent and multicore software in the last decade (2005– 2014). The study is guided by two objectives: (1) to summarize the recent publication trends and (2) to clarify current research gaps in the field.

    Through a multi-stage selection process, we identified 145 relevant papers. Based on these, we summarize the publication trend in the field by showing distribution of publications with respect to year , publication venues , representation of academia and industry , and active research institutes . We also identify research gaps in the field based on attributes such as types of concurrency bugs, types of debugging processes , types of research  and research contributions.

    The main observations from the study are that during the years 2005–2014: (1) there is no focal conference or venue to publish papers in this area, hence a large variety of conferences and journal venues (90) are used to publish relevant papers in this area; (2) in terms of publication contribution, academia was more active in this area than industry; (3) most publications in the field address the data race bug; (4) bug identification is the most common stage of debugging addressed by articles in the period; (5) there are six types of research approaches found, with solution proposals being the most common one; and (6) the published papers essentially focus on four different types of contributions, with ”methods” being the type most common one.

    We can further conclude that there is still quite a number of aspects that are not sufficiently covered in the field, most notably including (1) exploring correction  and fixing bugs  in terms of debugging process; (2) order violation, suspension  and starvation  in terms of concurrency bugs; (3) validation and evaluation research  in the matter of research type; (4) metric  in terms of research contribution. It is clear that the concurrent, parallel and multicore software community needs broader studies in debugging.This systematic mapping study can help direct such efforts.

  • 6.
    Abbaspour Asadollah, Sara
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Sundmark, Daniel
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Eldh, Sigrid
    Ericsson AB, Kista, Sweden.
    Hansson, Hans
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Paul Enoiu, Eduard
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    A Study on Concurrency Bugs in an Open Source Software2016Inngår i: IFIP Advances in Information and Communication Technology, vol. 472, 2016, Vol. 472, 16-31 s.Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Concurrent programming puts demands on software debugging and testing, as concurrent software may exhibit problems not present in sequential software, e.g., deadlocks and race conditions. In aiming to increase efficiency and effectiveness of debugging and bug-fixing for concurrent software, a deep understanding of concurrency bugs, their frequency and fixingtimes would be helpful. Similarly, to design effective tools and techniques for testing and debugging concurrent software understanding the differences between non-concurrency and concurrency bugs in real-word software would be useful.

  • 7.
    Abbaspour, Sara
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Daniel, Sundmark
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Hansson, Hans
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Runtime Verification for Detecting Suspension Bugs in Multicore and Parallel Software2017Inngår i: Proceedings - 10th IEEE International Conference on Software Testing, Verification and Validation Workshops, ICSTW 2017, 2017, 77-80 s.Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Multicore hardware development increases the popularity of parallel and multicore software, while testing and debugging the software become more difficult, frustrating and costly. Among all types of software bugs, concurrency bugs are both important and troublesome. This type of bugs is increasingly becoming an issue, particularly due to the growing prevalence of multicore hardware. Suspension-based-locking bug is one type of concurrency bugs. This position paper proposes a model based on runtime verification and reflection technique in the context of multicore and parallel software to monitor and detect suspension-based-locking bugs. The model is not only able to detect faults, but also diagnose and even repair them. The model is composed of four layers: Logging, Monitoring, Suspension Bug Diagnosis and Mitigation. The logging layer will observe the events and save them into a file system. The monitoring layer will detect the presents of bugs in the software. The suspension bug diagnosis will identify Suspension bugs by comparing the captured data with the suspension bug properties. Finally, the mitigation layer will reconfigure the software to mitigate the suspension bugs. A functional architecture of a runtime verification tool is also proposed in this paper. This architecture is based on the proposed model and is comprised of different modules. 

  • 8.
    Abdelraheem, Mohammed Ahmed
    et al.
    RISE., Swedish ICT, SICS, Security Lab.
    Gehrmann, Christian
    RISE., Swedish ICT, SICS, Security Lab.
    Lindström, Malin
    Nordahl, Christian
    Executing Boolean Queries on an EncryptedBitmap Index2016Konferansepaper (Fagfellevurdert)
    Abstract [en]

    We propose a simple and efficient searchable symmetric

    encryption scheme based on a Bitmap index that evaluates

    Boolean queries. Our scheme provides a practical

    solution in settings where communications and computations

    are very constrained as it offers a suitable tradeoff

    between privacy and performance.

  • 9.
    Abdelrahman, Ahmed
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för Industriell utveckling, IT och Samhällsbyggnad.
    Detection and Extraction of Sky Regions in Digital Images based on Color Classification2013Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    In many applications of image processing there is a need to extract the solid background which it is usually sky for outdoor images. In our application we present this solution. We developed an automatic algorithm for detection and extraction of sky regions in the color image based on color classification. In which the input image should be in the RGB color space and the blue color is detected and classified. Then the color image is transformed to the binary form and the connected regions are extracted separately. The connected regions are then sorted in a descending order according to the biggest area and the biggest region is identified. Then we merged all objects that have similar sky properties. Experimental results showed that our proposed algorithm can produce good results compared to other existing algorithms.

  • 10. Abdul-Ahad, Amir Stefan
    et al.
    Lindén, Maria
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Larsson, Thomas
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Mahmoud, Waleed A.
    Robust Distance-Based Watermarking for Digital Video2008Inngår i: Proceedings of The Annual SIGRAD Conference, Stockholm, 2008Konferansepaper (Fagfellevurdert)
  • 11.
    Abdulla, Parosh
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik.
    Aronis, Stavros
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datalogi.
    Jonsson, Bengt
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik.
    Sagonas, Konstantinos
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datalogi.
    Optimal dynamic partial order reduction2014Inngår i: Proc. 41st ACM SIGPLAN-SIGACT Symposium on Principles of Programming Languages, New York: ACM Press, 2014, 373-384 s.Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Stateless model checking is a powerful technique for program verification, which however suffers from an exponential growth in the number of explored executions. A successful technique for reducing this number, while still maintaining complete coverage, is Dynamic Partial Order Reduction (DPOR). We present a new DPOR algorithm, which is the first to be provably optimal in that it always explores the minimal number of executions. It is based on a novel class of sets, called source sets, which replace the role of persistent sets in previous algorithms. First, we show how to modify an existing DPOR algorithm to work with source sets, resulting in an efficient and simple to implement algorithm. Second, we extend this algorithm with a novel mechanism, called wakeup trees, that allows to achieve optimality. We have implemented both algorithms in a stateless model checking tool for Erlang programs. Experiments show that source sets significantly increase the performance and that wakeup trees incur only a small overhead in both time and space.

  • 12.
    Abdulla, Parosh Aziz
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik.
    Atig, Mohamed Faouzi
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik.
    Bouajjani, Ahmed
    Ngo, Tuan Phong
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik.
    Context-bounded analysis for POWER2017Inngår i: Tools and Algorithms for the Construction and Analysis of Systems: Part II, Springer, 2017, 56-74 s.Konferansepaper (Fagfellevurdert)
  • 13.
    Abdulla, Parosh Aziz
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik.
    Atig, Mohamed Faouzi
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik.
    Bui, Phi Diep
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik.
    Counter-Example Guided Program Verification2016Inngår i: FM 2016: Formal Methods, Springer, 2016, 25-42 s.Konferansepaper (Fagfellevurdert)
  • 14.
    Abdulla, Parosh Aziz
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik.
    Atig, Mohamed Faouzi
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik.
    Chen, Yu-Fang
    Institute of Information Science, Academia Sinica .
    Holik, Lukas
    Brno University.
    Rezine, Ahmed
    Linköping University.
    Rümmer, Philipp
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik.
    String Constraints for Verification2014Inngår i: Computer Aided Verification - 26th International Conference, {CAV} 2014, Held as Part of the Vienna Summer of Logic, {VSL} 2014, Vienna, Austria, July 18-22, 2014. Proceedings, Springer, 2014, 150-166 s.Konferansepaper (Fagfellevurdert)
    Abstract [en]

    We present a decision procedure for a logic that combines (i) word equations over string variables denoting words of arbitrary lengths, together with (ii) constraints on the length of words, and on (iii) the regular languages to which words belong. Decidability of this general logic is still open. Our procedure is sound for the general logic, and a decision procedure for a particularly rich fragment that restricts the form in which word equations are written. In contrast to many existing procedures, our method does not make assumptions about the maximum length of words. We have developed a prototypical implementation of our decision procedure, and integrated it into a CEGAR-based model checker for the analysis of programs encoded as Horn clauses. Our tool is able to automatically establish the correctness of several programs that are beyond the reach of existing methods.

  • 15.
    Abdulla, Parosh Aziz
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik.
    Atig, Mohamed Faouzi
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik.
    Hofman, Piotr
    Mayr, Richard
    Kumar, K. Narayan
    Chennai Mathematical Institute, Chennai, India.
    Totzke, Patrick
    Infinite-state energy games2014Inngår i: Joint Meeting of the Twenty-Third EACSL Annual Conference on Computer Science Logic (CSL) and the Twenty-Ninth Annual ACM/IEEE Symposium on Logic in Computer Science (LICS), CSL-LICS '14, Vienna, Austria, July 14 - 18, 2014, New York: ACM Press, 2014Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Energy games are a well-studied class of 2-player turn-based games on a finite graph where transitions are labeled with integer vectors which represent changes in a multidimensional resource (the energy). One player tries to keep the cumulative changes non-negative in every component while the other tries to frustrate this.

    We consider generalized energy games played on infinite game graphs induced by pushdown automata (modelling recursion) or their subclass of one-counter automata.

    Our main result is that energy games are decidable in the case where the game graph is induced by a one-counter automaton and the energy is one-dimensional. On the other hand, every further generalization is undecidable: Energy games on one-counter automata with a 2-dimensional energy are undecidable, and energy games on pushdown automata are undecidable even if the energy is one-dimensional. Furthermore, we show that energy games and simulation games are inter-reducible, and thus we additionally obtain several new (un)decidability results for the problem of checking simulation preorder between pushdown automata and vector addition systems.

  • 16.
    Abdulla, Parosh Aziz
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik.
    Atig, Mohamed Faouzi
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik.
    Rezine, Othmane
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik.
    Verification of Directed Acyclic Ad Hoc Networks2013Inngår i: Formal Techniques for Distributed Systems: FORTE 2013, Springer Berlin/Heidelberg, 2013, 193-208 s.Konferansepaper (Fagfellevurdert)
  • 17.
    Abdulla, Parosh Aziz
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik.
    Atig, Mohamed Faouzi
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik.
    Stenman, Jari
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik.
    Computing optimal reachability costs in priced dense-timed pushdown automata2014Inngår i: Language and Automata Theory and Applications: LATA 2014, Springer Berlin/Heidelberg, 2014, 62-75 s.Konferansepaper (Fagfellevurdert)
  • 18.
    Abdulla, Parosh Aziz
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik.
    Atig, Mohamed Faouzi
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik.
    Stenman, Jari
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik.
    Zenoness for Timed Pushdown Automata2014Inngår i: Proceedings 15th International Workshop on Verification of Infinite-State Systems, {INFINITY} 2013, Hanoi, Vietnam, 14th October 2013., 2014, -47 s.Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Timed pushdown automata are pushdown automata extended with a finite set of real-valued clocks. Additionaly, each symbol in the stack is equipped with a value representing its age. The enabledness of a transition may depend on the values of the clocks and the age of the topmost symbol. Therefore, dense-timed pushdown automata subsume both pushdown automata and timed automata. We have previously shown that the reachability problem for this model is decidable. In this paper, we study the zenoness problem and show that it is EXPTIME-complete.

  • 19.
    Abdulla, Parosh Aziz
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik.
    Clemente, Lorenzo
    Mayr, Richard
    Sandberg, Sven
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik.
    Stochastic Parity Games on Lossy Channel Systems2014Inngår i: Logical Methods in Computer Science, ISSN 1860-5974, Vol. 10, nr 4, 21Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We give an algorithm for solving stochastic parity games with almost-sure winning conditions on lossy channel systems, under the constraint that both players are restricted to finitememory strategies. First, we describe a general framework, where we consider the class of 21/2-player games with almost-sure parity winning conditions on possibly infinite game graphs, assuming that the game contains a finite attractor. An attractor is a set of states (not necessarily absorbing) that is almost surely re-visited regardless of the players' decisions. We present a scheme that characterizes the set of winning states for each player. Then, we instantiate this scheme to obtain an algorithm for stochastic game lossy channel systems.

  • 20.
    Abdulla, Parosh Aziz
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik.
    Dwarkadas, Sandhya
    University of Rochester, U.S.A..
    Rezine, Ahmed
    Linköping University.
    Shriraman, Arrvindh
    Simon Fraser University, Canada .
    Yunyun, Zhu
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik.
    Verifying safety and liveness for the FlexTM hybrid transactional memory2013Konferansepaper (Fagfellevurdert)
    Abstract [en]

    We consider the verification of safety (strict serializability and abort consistency) and liveness obstruction and livelock freedom) for the hybrid transactional memory framework FlexTM. This framework allows for flexible implementations of transactional memories based on an adaptation of the MESI coherence protocol. FlexTM allows for both eager and lazy conflict resolution strategies. Like in the case of Software Transactional Memories, the verification problem is not trivial as the number of concurrent transactions, their size, and the number of accessed shared variables cannot be a priori bounded. This complexity is exacerbated by aspects that are specific to hardware and hybrid transactional memories. Our work takes into account intricate behaviours such as cache line based conflict detection, false sharing, invisible reads or non-transactional instructions. We carry out the first automatic verification of a hybrid transactional memory and establish, by adopting a small model approach, challenging properties such as strict serializability, abort consistency, and obstruction freedom for both an eager and a lazy conflict resolution strategies. We also detect an example that refutes livelock freedom. To achieve this, our prototype tool makes use of the latest antichain based techniques to handle systems with tens of thousands of states.

  • 21.
    Abdulla, Parosh Aziz
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik.
    Haziza, Frédéric
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik.
    Holík, Lukás
    Block me if you can!: Context-sensitive parameterized verification2014Inngår i: Static Analysis: SAS 2014, Springer, 2014, 1-17 s.Konferansepaper (Fagfellevurdert)
    Abstract [en]

    We present a method for automatic verification of systems with a parameterized number of communicating processes, such as mutual exclusion protocols or agreement protocols. To that end, we present a powerful abstraction framework that uses an efficient and precise symbolic encoding of (infinite) sets of configurations. In particular, it generalizes downward-closed sets that have successfully been used in earlier approaches to parameterized verification. We show experimentally the efficiency of the method, on various examples, including a fine-grained model of Szymanski’s mutual exclusion protocol, whose correctness, to the best of our knowledge, has not been proven automatically by any other existing methods.

  • 22.
    Abdulla, Parosh Aziz
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik.
    Haziza, Frédéric
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik.
    Holík, Lukás
    Brno Univ Technol, Brno, Czech Republic.
    Parameterized verification through view abstraction2016Inngår i: International Journal on Software Tools for Technology Transfer (STTT), ISSN 1433-2779, E-ISSN 1433-2787, Vol. 18, nr 5, 495-516 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We present a simple and efficient framework for automatic verification of systems with a parametric number of communicating processes. The processes may be organized in various topologies such as words, multisets, rings, or trees. Our method needs to inspect only a small number of processes in order to show correctness of the whole system. It relies on an abstraction function that views the system from the perspective of a fixed number of processes. The abstraction is used during the verification procedure in order to dynamically detect cut-off points beyond which the search of the state space need not continue. We show that the method is complete for a large class of well quasi-ordered systems including Petri nets. Our experimentation on a variety of benchmarks demonstrate that the method is highly efficient and that it works well even for classes of systems with undecidable verification problems. In particular, the method handles the fine-grained and full version of Szymanski's mutual exclusion protocol, whose correctness, to the best of our knowledge, has not been proven automatically by any other existing methods.

  • 23.
    Abdulla, Parosh Aziz
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik.
    Haziza, Frédéric
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik.
    Holík, Lukáš
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik.
    All for the price of few: (Parameterized verification through view abstraction)2013Inngår i: Verification, Model Checking, and Abstract Interpretation, Springer Berlin/Heidelberg, 2013, 476-495 s.Konferansepaper (Fagfellevurdert)
  • 24.
    Abdulla, Parosh
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik.
    Jonsson, Bengt
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik.
    Trinh, Cong Quy
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Datorteknik.
    Automated Verification of Linearization Policies2016Inngår i: Automated Verification of Linearization Policies: 23rd International Symposium, SAS 2016, Edinburgh, UK, September 8-10, 2016, Proceedings, 2016Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    We present a novel framework for automated verification of linearizability for concurrent data structures that implement sets, stacks, and queues. The framework requires the user to provide a linearization policy, which describes how linearization point placement in different concurrent threads affect each other; such linearization policies are often provided informally together with descriptions of new algorithms. We present a specification formalism for linearization policies which allows the user to specify, in a simple and concise manner, complex patterns including non-fixed linearization points. To automate verification, we extend thread-modular reasoning to bound the number of considered threads, and use a novel symbolic representation for unbounded heap structures that store data from an unbounded domain. We have implemented our framework in a tool and successfully used it to prove linearizability for a wide range of algorithms, including all implementations of concurrent sets, stacks, and queues based on singly-linked lists that are known to us from the literature.

  • 25.
    Abdullah, Nazri
    et al.
    Universiti Tun Hussien Onn Malaysia, Malaysia .
    Kounelis, Ioannis
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Muftic, Sead
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Security Extensions for Mobile Commerce Objects2014Inngår i: SECURWARE 2014, The Eighth International Conference on Emerging Security Information, Systems and Technologies, 2014Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Electronic commerce and its variance mobile commerce have tremendously increased their popularity in the last several years. As mobile devices have become the most popular mean to access and use the Internet, mobile commerce and its security are timely and very hot topics. Yet, today there is still no consistent model of various m–commerce applications and transactions, even less clear specification of their security. In order to address and solve those issues, in this paper, we first establish the concept of mobile commerce objects, an equivalent of virtual currencies, used for m–commerce transactions. We describe functionalities and unique characteristics of these objects; we follow with security requirements, and then offer some solutions – security extensions of these objects. All solutions are treated within the complete lifecycle of creation and use of the m–commerce objects.

  • 26.
    Abghari, Shahrooz
    et al.
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datalogi och datorsystemteknik.
    García Martín, Eva
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datalogi och datorsystemteknik.
    Johansson, Christian
    NODA Intelligent Systems AB, SWE.
    Lavesson, Niklas
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datalogi och datorsystemteknik.
    Grahn, Håkan
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datalogi och datorsystemteknik.
    Trend analysis to automatically identify heat program changes2017Inngår i: Energy Procedia, Elsevier, 2017, Vol. 116, 407-415 s.Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The aim of this study is to improve the monitoring and controlling of heating systems located at customer buildings through the use of a decision support system. To achieve this, the proposed system applies a two-step classifier to detect manual changes of the temperature of the heating system. We apply data from the Swedish company NODA, active in energy optimization and services for energy efficiency, to train and test the suggested system. The decision support system is evaluated through an experiment and the results are validated by experts at NODA. The results show that the decision support system can detect changes within three days after their occurrence and only by considering daily average measurements.

  • 27. Abouelhoda, Mohamed
    et al.
    Issa, Shady
    Center for Informatics Sciences, Nile University, Giza, Egypt.
    Ghanem, Moustafa
    Tavaxy: integrating Taverna and Galaxy workflows with cloud computing support.2012Inngår i: BMC Bioinformatics, ISSN 1471-2105, E-ISSN 1471-2105, Vol. 13Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    BACKGROUND: Over the past decade the workflow system paradigm has evolved as an efficient and user-friendly approach for developing complex bioinformatics applications. Two popular workflow systems that have gained acceptance by the bioinformatics community are Taverna and Galaxy. Each system has a large user-base and supports an ever-growing repository of application workflows. However, workflows developed for one system cannot be imported and executed easily on the other. The lack of interoperability is due to differences in the models of computation, workflow languages, and architectures of both systems. This lack of interoperability limits sharing of workflows between the user communities and leads to duplication of development efforts.

    RESULTS: In this paper, we present Tavaxy, a stand-alone system for creating and executing workflows based on using an extensible set of re-usable workflow patterns. Tavaxy offers a set of new features that simplify and enhance the development of sequence analysis applications: It allows the integration of existing Taverna and Galaxy workflows in a single environment, and supports the use of cloud computing capabilities. The integration of existing Taverna and Galaxy workflows is supported seamlessly at both run-time and design-time levels, based on the concepts of hierarchical workflows and workflow patterns. The use of cloud computing in Tavaxy is flexible, where the users can either instantiate the whole system on the cloud, or delegate the execution of certain sub-workflows to the cloud infrastructure.

    CONCLUSIONS: Tavaxy reduces the workflow development cycle by introducing the use of workflow patterns to simplify workflow creation. It enables the re-use and integration of existing (sub-) workflows from Taverna and Galaxy, and allows the creation of hybrid workflows. Its additional features exploit recent advances in high performance cloud computing to cope with the increasing data size and complexity of analysis.The system can be accessed either through a cloud-enabled web-interface or downloaded and installed to run within the user's local environment. All resources related to Tavaxy are available at http://www.tavaxy.org.

  • 28.
    Abraham, Erika
    et al.
    RWTH Aachen University, Germany.
    Bekas, Costas
    IBM Research, Switzerland.
    Brandic, Ivona
    Vienna University of Technology, Austria.
    Genaim, Samir
    Complutense University of Madrid, Spain.
    Johnsen, Einar
    University of Oslo, Norway.
    Kondov, Ivan
    Karlsruhe Institute of Technology, Germany.
    Pllana, Sabri
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för datavetenskap (DV).
    Streit, Achim
    Karlsruhe Institute of Technology, Germany.
    Preparing HPC Applications for Exascale: Challenges and Recommendations2015Inngår i: Proceedings: 2015 18th International Conference on Network-Based Information Systems, NBiS 2015 / [ed] Barolli, L; Takizawa, M; Hsu, HH; Enokido, T; Xhafa, F, IEEE conference proceedings, 2015, 401-406 s.Konferansepaper (Fagfellevurdert)
    Abstract [en]

    While the HPC community is working towards the development of the first Exaflop computer (expected around 2020), after reaching the Petaflop milestone in 2008 still only few HPC applications are able to fully exploit the capabilities of Petaflop systems. In this paper we argue that efforts for preparing HPC applications for Exascale should start before such systems become available. We identify challenges that need to be addressed and recommend solutions in key areas of interest, including formal modeling, static analysis and optimization, runtime analysis and optimization, and autonomic computing. Furthermore, we outline a conceptual framework for porting HPC applications to future Exascale computing systems and propose steps for its implementation.

  • 29.
    Abrahamsson, Henrik
    et al.
    Swedish Inst of Computer Science, Kista, Sweden .
    Ahlgren, Bengt
    Swedish Inst of Computer Science, Kista, Sweden .
    Using Empirical Distributions to Characterize Web Client Traffic and to Generate Synthetic Traffic2000Inngår i: Conference Record / IEEE Global Telecommunications ConferenceVolume 1, 2000, 2000, 428-433 s.Konferansepaper (Fagfellevurdert)
    Abstract [en]

    We model a web client using empirical probability distributions for user clicks and transferred data sizes. By using a heuristic threshold value to distinguish user clicks in a packet trace we get a simple method for analyzing large packet traces in order to get information about user OFF times and amount of data transferred due to a user click. We derive the empirical probability distributions from the analysis of the packet trace. The heuristic is not perfect, but we believe it is good enough to produce a useful web client model. We use the empirical model to implement a web client traffic generator. The characteristics of the generated traffic is very close to the original packet trace, including self-similar properties.

  • 30.
    Abrahamsson, Henrik
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Björkman, Mats
    Mälardalens högskola, Akademin för innovation, design och teknik.
    Robust Traffic Engineering using L-balanced Weight-Settings in OSPF/IS-IS2008Annet (Annet vitenskapelig)
  • 31.
    Abrahamsson, Henrik
    et al.
    SICS AB, Kista, Sweden .
    Hagsand, Olof
    Dynarc AB, Kista, Sweden .
    Marsh, Ian
    SICS AB, Kista, Sweden .
    TCP over High Speed Variable Capacity Links: A Simulation Study for Bandwidth Allocation2002Inngår i: Protocols for High Speed Networks Workshop, 2002, 117-129 s.Konferansepaper (Fagfellevurdert)
  • 32.
    Abtahi, Farhad
    et al.
    KTH, Skolan för teknik och hälsa (STH), Medicinsk teknik, Medicinska sensorer, signaler och system.
    Berndtsson, Andreas
    Abtahi, Shirin
    Seoane, Fernando
    KTH, Skolan för teknik och hälsa (STH), Medicinsk teknik, Medicinska sensorer, signaler och system.
    Lindecrantz, Kaj
    KTH, Skolan för teknik och hälsa (STH), Medicinsk teknik, Medicinska sensorer, signaler och system.
    Development and preliminary evaluation of an Android based heart rate variability biofeedback system2014Inngår i: Engineering in Medicine and Biology Society (EMBC), 2014 36th Annual International Conference of the IEEE, IEEE conference proceedings, 2014, 3382-3385 s.Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The reduced Heart Rate Variability (HRV) is believed to be associated with several diseases such as congestive heart failure, diabetes and chronic kidney diseases (CKD). In these cases, HRV biofeedback may be a potential intervention method to increase HRV which in turn is beneficial to these patients. In this work, a real-time Android biofeedback application based on a Bluetooth enabled ECG and thoracic electrical bioimpedance (respiration) measurement device has been developed. The system performance and usability have been evaluated in a brief study with eight healthy volunteers. The result demonstrates real-time performance of system and positive effects of biofeedback training session by increased HRV and reduced heart rate. Further development of the application and training protocol is ongoing to investigate duration of training session to find an optimum length and interval of biofeedback sessions to use in potential interventions.

  • 33.
    Adamov, Alexander
    et al.
    Harkivskij Nacionalnij Universitet Radioelectroniki, UKR.
    Carlsson, Anders
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datalogi och datorsystemteknik.
    Cloud incident response model2016Inngår i: Proceedings of 2016 IEEE East-West Design and Test Symposium, EWDTS 2016, Institute of Electrical and Electronics Engineers (IEEE), 2016Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper addresses the problem of incident response in clouds. A conventional incident response model is formulated to be used as a basement for the cloud incident response model. Minimization of incident handling time is considered as a key criterion of the proposed cloud incident response model that can be done at the expense of embedding infrastructure redundancy into the cloud infrastructure represented by Network and Security Controllers and introducing Security Domain for threat analysis and cloud forensics. These architectural changes are discussed and applied within the cloud incident response model. © 2016 IEEE.

  • 34.
    Addazi, Lorenzo
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Ciccozzi, Federico
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Langer, Philip
    EclipsSource, Austria.
    Posse, Ernesto
    Zeligsoft, Canada.
    Towards Seamless Hybrid Graphical-Textual Modelling for UML and Profiles2017Inngår i: Lecture Notes in Computer Science, vol. 10376, Springer, 2017, 20-33 s.Kapittel i bok, del av antologi (Fagfellevurdert)
    Abstract [en]

    Domain-specific modelling languages, in particular those described in terms of UML profiles, use graphical notations to maximise human understanding and facilitate communication among stakeholders. Nevertheless, textual notations are preferred for specific purposes, due to the nature of a specific domain, or for personal preference. The mutually exclusive use of graphical or textual modelling is not sufficient for the development of complex systems developed by large heterogeneous teams. We envision a modern modelling framework supporting seamless hybrid graphical and textual modelling. Such a framework would provide several benefits, among which: flexible separation of concerns, multi-view modelling based on multiple notations, convenient text-based editing operations, and text-based model editing outside the modelling environment, and faster modelling activities. In this paper we describe our work towards such a framework for UML and profiles. The uniqueness is that both graphical and textual modelling are done on a common persistent model resource, thus dramatically reducing the need for synchronisation among the two notations.

  • 35.
    Adekolu, Adekunle Matthew
    et al.
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE).
    Khan, Hasan
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE).
    Neelam, Neelam
    Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE).
    Network Monitoring2014Independent thesis Basic level (university diploma), 5 poäng / 7,5 hpOppgave
    Abstract [en]

    Managing a network is a very big functional area along with performance, devicemaintenance, security, performance, monitoring, troubleshooting, plan of changeand etc. Among all of these monitoring plays a vital role. It can cover a wide area ofnetwork management. Monitoring is the only way to find out whether the networkis functioning according to plan. In order to know what is happening in a network,how its functioning at any given time, a network should have a logging system. Nowa day this logging activity is done by Network monitoring tool. It lets user know thestatus of the network at any given time. This logging can give the user a wide viewwhat can't be seen in general. For example the statistics of a week or month, even ayear. Monitoring is a very important issue in an organization network which aroseover the time.In this project we are going to implement some well known network monitoringtools in a real world scenario and we will investigate how this monitoring tool canhelp network administrators to monitor a network . Moreover, what kind ofinformation we can extract from a network by these tools.The purpose of this project is to get an overall idea about the importance of networkmonitoring and what are the facts need to be considered while monitoring anetwork. There are lots of pros and cons in monitoring a network. So choosing theappropriate tool for monitoring is very important. Monitoring a network with theleast effects on network performance is the best solution in case of monitoring.The outcome from these monitoring tools is a wide range of useful data andintegration of these data produces the status of the network at any give time.Moreover these data will be logged to create a statistical report. Different users suchas a network admin and organization can use this information from differentperspectives to make a network more efficient for users.

  • 36.
    Aflaki, Kamyar
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för datavetenskap (DV).
    Penetration And Security Testing As A Mean To Securing Universal Web Applications2014Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    The domain of Information Technology has been discussed focusing the security of in-formation based on web application. The main purpose of the paper is to pinpoint andexplain the main attacks on web applications. In the study the I have used real world webapplication to demonstrate different types of attacks and the ways of prevention againstthem. Cyber criminals are using certain tactics to gather sensitive information throughweb applications, thus it is important to study this domain of IT. Experiment has beenconducted to demonstrate the concept and achieved outcomes have been explained. It hasbeen concluded that the most of the web application vulnerabilities come from a bad de-sign, according to Microsoft Developer Network (MSDN) Design Guidelines for SecureWeb Applications, and most of the threats can be prevented by considering basics of webapplication security while designing the application.

  • 37.
    Afshar, Sara
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Khalilzad, Nima
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Behnam, Moris
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Bril, Reinder J.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system. Universiteit Eindhoven, Eindhoven, Netherlands.
    Nolte, Thomas
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Intra-component Resource Sharing on a Virtual Multiprocessor Platform2016Inngår i: ACM SIGBED Review: Special Issue on 8th International Workshop on Compositional Theory and Technology for Real-Time Embedded Systems, 2016, 31-32 s.Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Component-based software development facilitates the development process of large and complex software systems. By the advent of multiprocessors, the independently developed components can be integrated on a multi-core platform to achieve an efficient use of system hardware and a decrease in system power consumption and costs. In this paper, we consider a virtual multiprocessor platform where each component can be dynamically allocated to any set of processors of the platform with a maximum concurrency level. Global-EDF is used for intra-component scheduling. The existing analysis for such systems have assumed that tasks are independent. In this paper, we enable intra-component resource sharing for this platform. We investigate using a spin-based resource sharing protocol with the accompanying analysis that extends the existing analysis for independent tasks. We briefly illustrate and evaluate our initial results with an example.

  • 38.
    Afshar, Sara
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Moghaddami Khalilzad, Nima
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Nemati, Farhang
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system.
    Nolte, Thomas
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system. 0000-0001-6132-7945.
    Resource Sharing among Prioritized Real-Time Applications on Multiprocessors2015Inngår i: ACM SIGBED Review - Special Issue on the 6th International Workshop on Compositional Theory and Technology for Real-Time Embedded Systems Homepage archiveVolume 12 Issue 1, 2015, 46-55 s.Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this paper, we propose a new protocol for handling resource sharing among prioritized real-time applications composed on a multiprocessor platform. We propose an optimal priority assignment algorithm which assigns unique priorities to the applications based on information in their interfaces. We have performed experimental evaluations to compare the proposed protocol (called MSOS-Priority) to the current state of the art locking protocols under multiprocessor partitioned scheduling, i.e., MPCP, MSRP, FMLP, MSOS, and OMLP. The valuations show that MSOS-Priority mostly performs significantly better than alternative approaches.

  • 39.
    Afzal, Wasif
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system. Bahria University, Islamabad, Pakistan.
    Alone, Snehal
    Chalmers University of Technology, Sweden.
    Glocksien, Kerstin
    Chalmers University of Technology, Sweden.
    Torkar, Richard
    Chalmers University of Technology, Sweden.
    Software Test Process Improvement Approaches: A Systematic Literature Review and an Industrial Case Study2016Inngår i: Journal of Systems and Software JSS, ISSN 0164-1212, Vol. 111, 1-33 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Software test process improvement (STPI) approaches are frameworks that guide software development organizations to improve their software testing process. We have identified existing STPI approaches and their characteristics (such as completeness of development, availability of information and assessment instruments, and domain limitations of the approaches) using a systematic literature review (SLR). Furthermore, two selected approaches (TPI NEXT and TMMi) are evaluated with respect to their content and assessment results in industry. As a result of this study, we have identified 18 STPI approaches and their characteristics. A detailed comparison of the content of TPI NEXT and TMMi is done. We found that many of the STPI approaches do not provide sufficient information or the approaches do not include assessment instruments. This makes it difficult to apply many approaches in industry. Greater similarities were found between TPI NEXT and TMMi and fewer differences. We conclude that numerous STPI approaches are available but not all are generally applicable for industry. One major difference between available approaches is their model representation. Even though the applied approaches generally show strong similarities, differences in the assessment results arise due to their different model representations.

  • 40.
    Afzal, Wasif
    et al.
    Mälardalens högskola, Akademin för innovation, design och teknik, Inbyggda system. Bahria University, Islamabad, Pakistan .
    Torkar, Richard
    Blekinge Institute of Technology, Karlskrona, Sweden; Chalmers University of Technology, Sweden.
    Towards benchmarking feature subset selection methods for software fault prediction2016Inngår i: Computational Intelligence and Quantitative Software Engineering / [ed] Witold Pedrycz, Giancarlo Succi and Alberto Sillitti, Springer-Verlag , 2016, 33-58 s.Kapittel i bok, del av antologi (Annet vitenskapelig)
    Abstract [en]

    Despite the general acceptance that software engineering datasets often contain noisy, irrele- vant or redundant variables, very few benchmark studies of feature subset selection (FSS) methods on real-life data from software projects have been conducted. This paper provides an empirical comparison of state-of-the-art FSS methods: information gain attribute ranking (IG); Relief (RLF); principal com- ponent analysis (PCA); correlation-based feature selection (CFS); consistency-based subset evaluation (CNS); wrapper subset evaluation (WRP); and an evolutionary computation method, genetic program- ming (GP), on five fault prediction datasets from the PROMISE data repository. For all the datasets, the area under the receiver operating characteristic curve—the AUC value averaged over 10-fold cross- validation runs—was calculated for each FSS method-dataset combination before and after FSS. Two diverse learning algorithms, C4.5 and na ??ve Bayes (NB) are used to test the attribute sets given by each FSS method. The results show that although there are no statistically significant differences between the AUC values for the different FSS methods for both C4.5 and NB, a smaller set of FSS methods (IG, RLF, GP) consistently select fewer attributes without degrading classification accuracy. We conclude that in general, FSS is beneficial as it helps improve classification accuracy of NB and C4.5. There is no single best FSS method for all datasets but IG, RLF and GP consistently select fewer attributes without degrading classification accuracy within statistically significant boundaries.

  • 41.
    Agelfors, Eva
    et al.
    KTH, Tidigare Institutioner, Talöverföring och musikakustik.
    Beskow, Jonas
    Dahlquist, M
    Granström, Björn
    Lundeberg, M
    Salvi, Giampiero
    Spens, K-E
    Öhman, Tobias
    Two methods for Visual Parameter Extraction in the Teleface Project1999Inngår i: Proceedings of Fonetik, Gothenburg, Sweden, 1999Konferansepaper (Annet vitenskapelig)
  • 42.
    Aghanavesi, Somayeh
    Högskolan Dalarna, Akademin Industri och samhälle, Datateknik.
    Smartphone-based Parkinson’s disease symptom assessment2017Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    This thesis consists of four research papers presenting a microdata analysis approach to assess and evaluate the Parkinson’s disease (PD) motor symptoms using smartphone-based systems. PD is a progressive neurological disorder that is characterized by motor symptoms. It is a complex disease that requires continuous monitoring and multidimensional symptom analysis. Both patients’ perception regarding common symptom and their motor function need to be related to the repeated and time-stamped assessment; with this, the full extent of patient’s condition could be revealed. The smartphone enables and facilitates the remote, long-term and repeated assessment of PD symptoms. Two types of collected data from smartphone were used, one during a three year, and another during one-day clinical study. The data were collected from series of tests consisting of tapping and spiral motor tests. During the second time scale data collection, along smartphone-based measurements patients were video recorded while performing standardized motor tasks according to Unified Parkinson’s disease rating scales (UPDRS).

    At first, the objective of this thesis was to elaborate the state of the art, sensor systems, and measures that were used to detect, assess and quantify the four cardinal and dyskinetic motor symptoms. This was done through a review study. The review showed that smartphones as the new generation of sensing devices are preferred since they are considered as part of patients’ daily accessories, they are available and they include high-resolution activity data. Smartphones can capture important measures such as forces, acceleration and radial displacements that are useful for assessing PD motor symptoms.

    Through the obtained insights from the review study, the second objective of this thesis was to investigate whether a combination of tapping and spiral drawing tests could be useful to quantify dexterity in PD. More specifically, the aim was to develop data-driven methods to quantify and characterize dexterity in PD. The results from this study showed that tapping and spiral drawing tests that were collected by smartphone can detect movements reasonably well related to under- and over-medication.

    The thesis continued by developing an Approximate Entropy (ApEn)-based method, which aimed to measure the amount of temporal irregularity during spiral drawing tests. One of the disabilities associated with PD is the impaired ability to accurately time movements. The increase in timing variability among patients when compared to healthy subjects, suggests that the Basal Ganglia (BG) has a role in interval timing. ApEn method was used to measure temporal irregularity score (TIS) which could significantly differentiate the healthy subjects and patients at different stages of the disease. This method was compared to two other methods which were used to measure the overall drawing impairment and shakiness. TIS had better reliability and responsiveness compared to the other methods. However, in contrast to other methods, the mean scores of the ApEn-based method improved significantly during a 3-year clinical study, indicating a possible impact of pathological BG oscillations in temporal control during spiral drawing tasks. In addition, due to the data collection scheme, the study was limited to have no gold standard for validating the TIS. However, the study continued to further investigate the findings using another screen resolution, new dataset, new patient groups, and for shorter term measurements. The new dataset included the clinical assessments of patients while they performed tests according to UPDRS. The results of this study confirmed the findings in the previous study. Further investigation when assessing the correlation of TIS to clinical ratings showed the amount of temporal irregularity present in the spiral drawing cannot be detected during clinical assessment since TIS is an upper limb high frequency-based measure. 

  • 43.
    Aghanavesi, Somayeh
    et al.
    Högskolan Dalarna, Akademin Industri och samhälle, Datateknik.
    Westin, Jerker
    Högskolan Dalarna, Akademin Industri och samhälle, Datateknik.
    A review of Parkinson’s disease cardinal and dyskinetic motor symptoms assessment methods using sensor systems2016Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper is reviewing objective assessments of Parkinson’s disease(PD) motor symptoms, cardinal, and dyskinesia, using sensor systems. It surveys the manifestation of PD symptoms, sensors that were used for their detection, types of signals (measures) as well as their signal processing (data analysis) methods. A summary of this review’s finding is represented in a table including devices (sensors), measures and methods that were used in each reviewed motor symptom assessment study. In the gathered studies among sensors, accelerometers and touch screen devices are the most widely used to detect PD symptoms and among symptoms, bradykinesia and tremor were found to be mostly evaluated. In general, machine learning methods are potentially promising for this. PD is a complex disease that requires continuous monitoring and multidimensional symptom analysis. Combining existing technologies to develop new sensor platforms may assist in assessing the overall symptom profile more accurately to develop useful tools towards supporting better treatment process.

  • 44.
    Aghighi, Meysam
    Linköpings universitet, Institutionen för datavetenskap, Programvara och system. Linköpings universitet, Tekniska fakulteten.
    Computational Complexity of some Optimization Problems in Planning2017Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Automated planning is known to be computationally hard in the general case. Propositional planning is PSPACE-complete and first-order planning is undecidable. One method for analyzing the computational complexity of planning is to study restricted subsets of planning instances, with the aim of differentiating instances with varying complexity. We use this methodology for studying the computational complexity of planning. Finding new tractable (i.e. polynomial-time solvable) problems has been a particularly important goal for researchers in the area. The reason behind this is not only to differentiate between easy and hard planning instances, but also to use polynomial-time solvable instances in order to construct better heuristic functions and improve planners. We identify a new class of tractable cost-optimal planning instances by restricting the causal graph. We study the computational complexity of oversubscription planning (such as the net-benefit problem) under various restrictions and reveal strong connections with classical planning. Inspired by this, we present a method for compiling oversubscription planning problems into the ordinary plan existence problem. We further study the parameterized complexity of cost-optimal and net-benefit planning under the same restrictions and show that the choice of numeric domain for the action costs has a great impact on the parameterized complexity. We finally consider the parameterized complexity of certain problems related to partial-order planning. In some applications, less restricted plans than total-order plans are needed. Therefore, a partial-order plan is being used instead. When dealing with partial-order plans, one important question is how to achieve optimal partial order plans, i.e. having the highest degree of freedom according to some notion of flexibility. We study several optimization problems for partial-order plans, such as finding a minimum deordering or reordering, and finding the minimum parallel execution length.

  • 45.
    Aghighi, Meysam
    et al.
    Linköpings universitet, Institutionen för datavetenskap, Programvara och system. Linköpings universitet, Tekniska fakulteten.
    Bäckström, Christer
    Linköpings universitet, Institutionen för datavetenskap, Programvara och system. Linköpings universitet, Tekniska fakulteten.
    A Multi-parameter Complexity Analysis of Cost-optimal and Net-benefit Planning2016Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Aghighi and Bäckström have previously studied cost-optimal planning (COP) and net-benefit planning (NBP) for three action cost domains: the positive integers (Z_+), the non-negative integers (Z_0) and the positive rationals (Q_+). These were indistinguishable under standard complexity analysis for both problems, but separated for COP using parameterised complexity analysis. With the plan cost, k, as parameter, COP was W[2]-complete for Z_+, but para-NP-hard for both Z_0 and Q_+, i.e. presumably much harder. NBP was para-NP-hard for all three domains, thus remaining unseparable. We continue by considering combinations with several additional parameters and also the non-negative rationals (Q_0). Examples of new parameters are the plan length, l, and the largest denominator of the action costs, d. Our findings include: (1) COP remains W[2]-hard for all domains, even if combining all parameters; (2) COP for Z_0 is in W[2] for the combined parameter {k,l}; (3) COP for Q_+ is in W[2] for {k,d} and (4) COP for Q_0 is in W[2] for {k,d,l}. For NBP we consider further additional parameters, where the most crucial one for reducing complexity is the sum of variable utilities. Our results help to understand the previous results, eg. the separation between Z_+ and Q_+ for COP, and to refine the previous connections with empirical findings.

  • 46.
    Aghighi, Meysam
    et al.
    Linköpings universitet, Institutionen för datavetenskap, Programvara och system. Linköpings universitet, Tekniska fakulteten.
    Bäckström, Christer
    Linköpings universitet, Institutionen för datavetenskap, Programvara och system. Linköpings universitet, Tekniska fakulteten.
    Plan Reordering and Parallel Execution -- A Parameterized Complexity View2017Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Bäckström has previously studied a number of optimization problems for partial-order plans, like finding a minimum deordering (MCD) or reordering (MCR), and finding the minimum parallel execution length (PPL), which are all NP-complete. We revisit these problems, but applying parameterized complexity analysis rather than standard complexity analysis. We consider various parameters, including both the original and desired size of the plan order, as well as its width and height. Our findings include that MCD and MCR are W[2]-hard and in W[P] when parameterized with the desired order size, and MCD is fixed-parameter tractable (fpt) when parameterized with the original order size. Problem PPL is fpt if parameterized with the size of the non-concurrency relation, but para-NP-hard in most other cases. We also consider this problem when the number (k) of agents, or processors, is restricted, finding that this number is a crucial parameter; this problem is fixed-parameter tractable with the order size, the parallel execution length and k as parameter, but para-NP-hard without k as parameter.

  • 47.
    Aghighi, Meysam
    et al.
    Linköpings universitet, Institutionen för datavetenskap, Programvara och system. Linköpings universitet, Tekniska högskolan.
    Jonsson, Peter
    Linköpings universitet, Institutionen för datavetenskap, Programvara och system. Linköpings universitet, Tekniska högskolan.
    Ståhlberg, Simon
    Linköpings universitet, Institutionen för datavetenskap, Programvara och system. Linköpings universitet, Tekniska högskolan.
    Tractable Cost-Optimal Planning over Restricted Polytree Causal Graphs2015Inngår i: Proceedings of the Twenty-Ninth AAAI Conference on Artificial Intelligence, AAAI Press, 2015Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Causal graphs are widely used to analyze the complexity of planning problems. Many tractable classes have been identified with their aid and state-of-the-art heuristics have been derived by exploiting such classes. In particular, Katz and Keyder have studied causal graphs that are hourglasses (which is a generalization of forks and inverted-forks) and shown that the corresponding cost-optimal planning problem is tractable under certain restrictions. We continue this work by studying polytrees (which is a generalization of hourglasses) under similar restrictions. We prove tractability of cost-optimal planning by providing an algorithm based on a novel notion of variable isomorphism. Our algorithm also sheds light on the k-consistency procedure for identifying unsolvable planning instances. We speculate that this may, at least partially, explain why merge-and-shrink heuristics have been successful for recognizing unsolvable instances.

  • 48.
    Aguilar, Xavier
    KTH, Skolan för datavetenskap och kommunikation (CSC), High Performance Computing and Visualization (HPCViz).
    Towards Scalable Performance Analysis of MPI Parallel Applications2015Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

      A considerably fraction of science discovery is nowadays relying on computer simulations. High Performance Computing  (HPC) provides scientists with the means to simulate processes ranging from climate modeling to protein folding. However, achieving good application performance and making an optimal use of HPC resources is a heroic task due to the complexity of parallel software. Therefore, performance tools  and runtime systems that help users to execute  applications in the most optimal way are of utmost importance in the landscape of HPC.  In this thesis, we explore different techniques to tackle the challenges of collecting, storing, and using  fine-grained performance data. First, we investigate the automatic use of real-time performance data in order to run applications in an optimal way. To that end, we present a prototype of an adaptive task-based runtime system that uses real-time performance data for task scheduling. This runtime system has a performance monitoring component that provides real-time access to the performance behavior of anapplication while it runs. The implementation of this monitoring component is presented and evaluated within this thesis. Secondly, we explore lossless compression approaches  for MPI monitoring. One of the main problems that  performance tools face is the huge amount of fine-grained data that can be generated from an instrumented application. Collecting fine-grained data from a program is the best method to uncover the root causes of performance bottlenecks, however, it is unfeasible with extremely parallel applications  or applications with long execution times. On the other hand, collecting coarse-grained data is scalable but  sometimes not enough to discern the root cause of a performance problem. Thus, we propose a new method for performance monitoring of MPI programs using event flow graphs. Event flow graphs  provide very low overhead in terms of execution time and  storage size, and can be used to reconstruct fine-grained trace files of application events ordered in time.

  • 49.
    Aguilar, Xavier
    et al.
    KTH, Skolan för datavetenskap och kommunikation (CSC), High Performance Computing and Visualization (HPCViz).
    Fürlinger, Karl
    Ludwig-Maximilians-Universitat (LMU).
    Laure, Erwin
    KTH, Skolan för datavetenskap och kommunikation (CSC), High Performance Computing and Visualization (HPCViz).
    MPI Trace Compression Using Event Flow Graphs2014Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Understanding how parallel applications behave is crucial for using high-performance computing (HPC) resources efficiently. However, the task of performance analysis is becoming increasingly difficult due to the growing complexity of scientific codes and the size of machines. Even though many tools have been developed over the past years to help in this task, current approaches either only offer an overview of the application discarding temporal information, or they generate huge trace files that are often difficult to handle.

    In this paper we propose the use of event flow graphs for monitoring MPI applications, a new and different approach that balances the low overhead of profiling tools with the abundance of information available from tracers. Event flow graphs are captured with very low overhead, require orders of magnitude less storage than standard trace files, and can still recover the full sequence of events in the application. We test this new approach with the NERSC-8/Trinity Benchmark suite and achieve compression ratios up to 119x.

  • 50.
    Aguilar, Xavier
    et al.
    KTH, Skolan för datavetenskap och kommunikation (CSC), High Performance Computing and Visualization (HPCViz).
    Fürlinger, Karl
    Laure, Erwin
    KTH, Skolan för datavetenskap och kommunikation (CSC), High Performance Computing and Visualization (HPCViz).
    Visual MPI Performance Analysis using Event Flow Graphs2015Inngår i: Procedia Computer Science, ISSN 1877-0509, Vol. 51, 1353-1362 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Event flow graphs used in the context of performance monitoring combine the scalability and low overhead of profiling methods with lossless information recording of tracing tools. In other words, they capture statistics on the performance behavior of parallel applications while pre- serving the temporal ordering of events. Event flow graphs require significantly less storage than regular event traces and can still be used to recover the full ordered sequence of events performed by the application.  In this paper we explore the usage of event flow graphs in the context of visual performance analysis. We show that graphs can be used to quickly spot performance problems, helping to better understand the behavior of an application. We demonstrate our performance analysis approach with MiniFE, a mini-application that mimics the key performance aspects of finite- element applications in High Performance Computing (HPC).

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