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  • 1.
    Abad, Shayan
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Computer Science.
    Gholamy, Hassan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Computer Science.
    Evaluation of machine learning models for classifying malicious URLs2023Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Millions of new websites are created daily, making it challenging to determine which ones are safe. Cybersecurity involves protecting companies and users from cyberattacks. Cybercriminals exploit various methods, including phishing attacks, to trick users into revealing sensitive information. In Australia alone, there were over 74,000 reported phishing attacks in 2022, resulting in a financial loss of over $24 million. Artificial intelligence (AI) and machine learning are effective tools in various domains, such as cancer detection, financial fraud detection, and chatbot development. Machine learning models, such as Random Forest and Support Vector Machines, are commonly used for classification tasks. With the rise of cybercrime, it is crucial to use machine learning to identify both known and new malicious URLs. The purpose of the study is to compare different instance selection methods and machine learning models for classifying malicious URLs.

    In this study, a dataset containing approximately 650,000 URLs from Kaggle was used. The dataset consisted of four categories: phishing, defacement, malware, and benign URLs. Three datasets, each consisting of around 170,000 URLs, were generated using instance selection methods (DRLSH, BPLSH, and random selection) implemented in MATLAB. Machine learning models, including SVM, DT, KNNs, and RF, were employed. The study applied these instance selection methods to a dataset of malicious URLs, trained the machine learning models on the resulting datasets, and evaluated their performance using 16 features and one output feature.

    In the process of hyperparameter tuning, the training dataset was used to train four models with different hyperparameter settings. Bayesian optimization was employed to find the best hyperparameters for each model. The classification process was then conducted, and the results were compared. The study found that the random instance selection method outperformed the other two methods, BPLSH and DRLSH, in terms of both accuracy and elapsed time for data selection. The lower accuracies achieved by the DRLSH and BPLSH methods may be attributed to the imbalanced dataset, which led to poor sample selection.

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    Evaluation of machine learning models for classifying malicious URLs
  • 2.
    Abad, Shayan
    et al.
    Department of Computer and Geo-Spatial Sciences, University of Gävle, 801 76 Gävle, Sweden.
    Gholamy, Hassan
    Department of Computer and Geo-Spatial Sciences, University of Gävle, 801 76 Gävle, Sweden.
    Aslani, Mohammad
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Computer and Geospatial Sciences, Computer Science.
    Classification of Malicious URLs Using Machine Learning2023In: Sensors, E-ISSN 1424-8220, Vol. 23, no 18, article id 7760Article in journal (Refereed)
    Abstract [en]

    Amid the rapid proliferation of thousands of new websites daily, distinguishing safe ones from potentially harmful ones has become an increasingly complex task. These websites often collect user data, and, without adequate cybersecurity measures such as the efficient detection and classification of malicious URLs, users’ sensitive information could be compromised. This study aims to develop models based on machine learning algorithms for the efficient identification and classification of malicious URLs, contributing to enhanced cybersecurity. Within this context, this study leverages support vector machines (SVMs), random forests (RFs), decision trees (DTs), and k-nearest neighbors (KNNs) in combination with Bayesian optimization to accurately classify URLs. To improve computational efficiency, instance selection methods are employed, including data reduction based on locality-sensitive hashing (DRLSH), border point extraction based on locality-sensitive hashing (BPLSH), and random selection. The results show the effectiveness of RFs in delivering high precision, recall, and F1 scores, with SVMs also providing competitive performance at the expense of increased training time. The results also emphasize the substantial impact of the instance selection method on the performance of these models, indicating its significance in the machine learning pipeline for malicious URL classification

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    fulltext
  • 3.
    Abbas, Dalia
    et al.
    Halmstad University, School of Information Technology.
    Nanaa, Nashwa
    Halmstad University, School of Information Technology.
    Sustainability Data Extraction System2024Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Sustainability reporting is essential for organizations to report their environmental, social, and governance (ESG) performance. However, extracting, and structuring data from sustainability reports can be challenging, leading to inefficiencies and inconsistencies. This project aims to develop an integrated system for sustainability reporting by leveraging artificial intelligence (AI) techniques, particularly natural language processing (NLP), to extract and structure data from sustainability reports. Utilizing the GPT-3 model by OpenAI, the system processes unstructured text from PDF reports into a structured format compliant with European Sustainability Reporting Standards (ESRS). The system efficiently and accurately extracted crucial sustainability information through a meticulously designed pipeline, including PDF parsing, text sanitizing, batching, parallel API requests, and postprocessing. The system’s effectiveness is evaluated using cosine similarity metrics, comparing model outputs with manually extracted data. The results demonstrate high alignment between the model outputs and manual extractions, validating the system’s performance. This project contributes to advancing sustainability reporting practices, providing organizations with a robust tool for transparent and standardized disclosure of ESG impacts.

    Download full text (pdf)
    fulltext
  • 4. Abbas, Haider
    et al.
    Orlandi, Eugenio
    Aslam Khan, Farrukh
    Popov, Oliver
    Stockholm University, Faculty of Social Sciences, Department of Computer and Systems Sciences.
    Masood, Asif
    Security, Safety and Trust Management2017In: 2017 IEEE 26th International Conference on Enabling Technologies: Infrastructure for Collaborative Enterprises: Proceedings / [ed] Sumitra Reddy, Wojciech Cellary, Mariagrazia Fugini, IEEE Computer Society, 2017, p. 242-243Conference paper (Refereed)
    Abstract [en]

    The continuously evolving nature of today's internet outdates the existing security and safety mechanisms and therefore there is an emerging need to propose robust, powerful and reliable solutions. These advancements have a great impact on the software and system architectures, resulting in a highly dynamic smart networked environment. The systems used within these complex environments have at least two things in common, namely, the need to restrict or grant access for the required resources based on security policy to face security threats, and the need to sustain resilience of the environment in face of safety hazards. Both aspects should consider trust.

  • 5.
    Abbas, Haider
    et al.
    National University of Sciences and Technology (NUST), Islamabad, Pakistan.
    Shahzad, Muhammad
    National University of Sciences and Technology (NUST), Islamabad, Pakistan.
    Safdar, Maliha
    National University of Sciences and Technology (NUST), Islamabad, Pakistan.
    Hemani, Ahmed
    KTH, School of Electrical Engineering and Computer Science (EECS), Electrical Engineering, Electronics and Embedded systems.
    DUDE: Decryption, Unpacking, Deobfuscation, and Endian Conversion Framework for Embedded Devices Firmware2023In: IEEE Transactions on Dependable and Secure Computing, ISSN 1545-5971, E-ISSN 1941-0018Article in journal (Refereed)
    Abstract [en]

    Commercial-Off-The-Shelf (COTS) embedded devices rely on vendor-specific firmware to perform essential tasks. These firmware have been under active analysis by researchers to check security features and identify possible vendor backdoors. However, consistently unpacking newly created filesystem formats has been exceptionally challenging. To thwart attempts at unpacking, vendors frequently use encryption and obfuscation methods. On the other hand, when handling encrypted, obfuscated, big endian cramfs, or custom filesystem formats found in firmware under test, the available literature and tools are insufficient. This study introduces DUDE, an automated framework that provides novel functionalities, outperforming cutting-edge tools in the decryption, unpacking, deobfuscation, and endian conversion of firmware. For big endian compressed romfs filesystem formats, DUDE supports endian conversion. It also supports deobfuscating obfuscated signatures for successful unpacking. Moreover, decryption support for encrypted binaries from the D-Link and MOXA series has also been added, allowing for easier analysis and access to the contents of these firmware files. Additionally, the framework offers unpacking assistance by supporting the extraction of special filesystem formats commonly found in firmware samples from various vendors. A remarkable 78% (1424 out of 1814) firmware binaries from different vendors were successfully unpacked using the suggested framework. This performance surpasses the capabilities of commercially available tools combined on a single platform.

  • 6.
    Abbas, Mhd Yazan
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013). Karlstad University, Faculty of Economic Sciences, Communication and IT, Department of Computer Science.
    Ferzali, Ali
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013). Karlstad University, Faculty of Economic Sciences, Communication and IT, Department of Computer Science.
    A mobile Application development in the Android Studio platform for leave applications2022Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Nowadays, there is a mobile application for almost every need, for instance, training, games, and news applications. Almost all the companies have also their own mobile applications that facilitate the daily communication between their employees and supervisors. In this thesis, the development process of an Android application for the company Askås is created, where the employees can for example send a Flex application or sick leave application, see their registered personal information and edit them. The final result of the project is almost what Askås asked for, An Android application that facilitates their employees’ daily needs. The development process, the results, and the encountered problems are also represented in a more detailed manner in the thesis. 

  • 7.
    Abbas, Syed Muhammad
    et al.
    Jönköping University, School of Engineering, JTH, Computer and Electrical Engineering. Jönköping University, School of Engineering. Jönköping University.
    Henricsson, Christopher
    Jönköping University, School of Engineering, JTH, Computer and Electrical Engineering. Jönköping University, School of Engineering. Jönköping University.
    A Simulation Framework for Efficient Search in P2P Networks with 8-Point HyperCircles2008Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This report concerns the implementation of a simulation framework to evaluate an emerging peer-to-peer network topology scheme using 8-point hypercircles, entitled HyperCircle. This topology was proposed in order to alleviate some of the drawbacks of current P2P systems evolving in an uncontrolled manner, such as scalability issues, network overload and long search times. The framework is supposed to be used to evaluate the advantages of this new topology. The framework has been built on top of an existing simulator software solution, the selection of which was an important part of the development. Weighing different variables such as scalability and API usability, the selection fell on OverSim, an open-source discreet-event simulator based on OMNET++.

    After formalizing the protocol for easier implementation, as well as extending it for better performance, implementation followed using C++ with OverSim’s API and simulation library. Implemented as a module (alongside other stock modules providing their own protocols such as Chord and Kademlia), it can be used in OverSim to simulate a user-defined network using one of the simulation routine applications provided (or using a custom application written by the user). For the purposes of this thesis, the standard application KBRTestApp was used; an application sending test messages between randomly selected nodes, while adding and removing nodes at specific time intervals. The adding and removing of nodes can be configured with probability parameters.

    Tentative testing shows that this implementation of the HyperCircle protocol has a certain performance gain over the OverSim implementations of the Chord and Kademlia protocols, measurable in the time it takes a message to get from sender to recipient. Further testing is outside the scope of this thesis.

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    FULLTEXT01
  • 8.
    Abd Alwaheb, Sofia
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems, Health Informatics and Logistics.
    Implementering DevSecOps metodik vid systemutveckling för hälso och sjukvård2023Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In healthcare, IT security is crucial for protecting both personal information and patient safety. Currently, the implementation of security measures and testing is done after software development, which can reduce efficiency, and pose a potential risk to patient privacy. This study examined the implementation of the DevSecOps methodology in healthcare, focusing on the development phase. By interviewing employees and using security tools such as SAST, code review, penetration testing, and DAST, benefits and challenges were identified. The challenges included a lack of security knowledge and difficulty integrating tools for free. Despite this, the results demonstrated the potential to enhance security, streamline operations, and save money by utilizing free tools and implementing security during the development phase. Training and hiring security-competent personnel were also emphasized as important for maintaining high security standards.

    Download full text (pdf)
    fulltext
  • 9.
    Abdi Dahir, Najiib
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems, Health Informatics and Logistics.
    Dahir Ali, Ikran
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems, Health Informatics and Logistics.
    Privacy preserving data access mechanism for health data2023Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Due to the rise of digitalization and the growing amount of data, ensuring the integrity and security of patient data has become increasingly vital within the healthcare industry, which has traditionally managed substantial quantities of sensitive patient and personal information. This bachelor's thesis focused on designing and implementing a secure data sharing infrastructure to protect the integrity and confidentiality of patient data. Synthetic data was used to enable access for researchers and students in regulated environments without compromising patient privacy. The project successfully achieved its goals by evaluating different privacy-preserving mechanisms and developing a machine learning-based application to demonstrate the functionality of the secure data sharing infrastructure. Despite some challenges, the chosen algorithms showed promising results in terms of privacy preservation and statistical similarity. Ultimately, the use of synthetic data can promote fair decision-making processes and contribute to secure data sharing practices in the healthcare industry.

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    Examensarbete
  • 10.
    Abdollahi, Meisam
    et al.
    Iran Univ Sci & Technol, Tehran, Iran..
    Baharloo, Mohammad
    Inst Res Fundamental Sci IPM, Tehran, Iran..
    Shokouhinia, Fateme
    Amirkabir Univ Technol, Tehran, Iran..
    Ebrahimi, Masoumeh
    KTH, School of Electrical Engineering and Computer Science (EECS), Electrical Engineering, Electronics and Embedded systems, Electronic and embedded systems.
    RAP-NoC: Reliability Assessment of Photonic Network-on-Chips, A simulator2021In: Proceedings of the 8th ACM international conference on nanoscale computing and communication (ACM NANOCOM 2021), Association for Computing Machinery (ACM) , 2021Conference paper (Refereed)
    Abstract [en]

    Nowadays, optical network-on-chip is accepted as a promising alternative solution for traditional electrical interconnects due to lower transmission delay and power consumption as well as considerable high data bandwidth. However, silicon photonics struggles with some particular challenges that threaten the reliability of the data transmission process.The most important challenges can be considered as temperature fluctuation, process variation, aging, crosstalk noise, and insertion loss. Although several attempts have been made to investigate the effect of these issues on the reliability of optical network-on-chip, none of them modeled the reliability of photonic network-on-chip in a system-level approach based on basic element failure rate. In this paper, an analytical model-based simulator, called Reliability Assessment of Photonic Network-on-Chips (RAP-NoC), is proposed to evaluate the reliability of different 2D optical network-on-chip architectures and data traffic. The experimental results show that, in general, Mesh topology is more reliable than Torus considering the same size. Increasing the reliability of Microring Resonator (MR) has a more significant impact on the reliability of an optical router rather than a network.

  • 11.
    Abdollahporan, Farzad
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Vandermaesen, Elvira
    Mälardalen University, School of Innovation, Design and Engineering.
    Evaluation of the Impacts of Meraki API on Network Delivery Automation2024Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In today's ever-automating world, businesses are increasingly focused on optimizing network operations, including configuration, management, and troubleshooting. This study scrutinizes the comparison between manual and automated methodologies within the framework of the cloud-based Cisco Meraki platform. Our objective is to establish decisive criteria for identifying the most advantageous circumstances for automation, particularly in network configuration. To achieve this, we constructed a network consisting of three Meraki devices. Automation of network configuration was facilitated through the development of Python scripts leveraging the Meraki API library in conjunction with configuration files. The configuration files were constructed in various file formats–Excel, CSV, JSON, and YAML– in order to assess their impact on automation effectiveness. Moreover, manual configuration tasks were undertaken by three network technicians with varying levels of Meraki proficiency. A comprehensive series of tests, encompassing both automated and manual methods, was subsequently conducted, focusing on metrics such as execution time and keystroke count. Through meticulous analysis, we provided valuable insights into the effectiveness of automation in network configuration processes. Results demonstrated that the use of JSON files in the automation process yielded the shortest completion time and required the fewest keystrokes compared to other automation methods. Moreover, manual configuration via the Meraki dashboard GUI exhibited comparable efficiency to automation methods in networks with a small number of devices. Nonetheless, owing to the capacity to reuse configuration files with minor adjustments for similar setups, the true advantage of automation over manual configuration becomes apparent as the device count increases.

    Download full text (pdf)
    DVA333_FarzadAbdollahporan_ElviraVandermaesen
  • 12.
    Abdul Sater, Malek
    et al.
    Malmö University, Faculty of Technology and Society (TS), Department of Computer Science and Media Technology (DVMT).
    Mohamed, Reem
    Malmö University, Faculty of Technology and Society (TS), Department of Computer Science and Media Technology (DVMT).
    Parkinson’s disease tremor assessment: Leveragingsmartphones for symptom measurement2023Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Parkinson's disease (PD) is a progressive, chronic neurodegenerative disorder that impacts patients' quality of life. Hand tremor is a hallmark motor symptom of PD. However, current clinical tremor assessment methods are time-consuming and expensive and may not capture the full extent of tremor fluctuations. The built-in sensors in smartphones offer an accessible and cost-effective alternative for objective tremor assessment.

    This study presents a systematic approach to developing a quantitative algorithm for Parkinson's disease tremor assessment using Inertial Measurement Unit (IMU) data. This study begins with a comprehensive data visualisation and understanding phase, leading to the design decision to implement a multiple linear regression model for tremor severity prediction. The IMU data, collected from 10 patients, is pre-processed and normalised to ensure consistency and account for varying degrees of tremor severity.

    Feature extraction is conducted based on insights from literature, resulting in 16 unique features. These unique features are extracted for each of the acceleration and rotation rate data, resulting in 582 total features over both hands and all three tremor types. Recursive Feature Elimination with Cross-Validation (RFECV) is employed for feature selection, identifying the most relevant features contributing to tremor severity prediction. A multiple linear regression model is implemented and trained using the Leave-One-Out with Cross-Validation (LOOCV) method.

    The model's performance is evaluated resulting in a mean MSE of 0.88, a mean MAE of 0.69, and an R² of 0.88. The results indicate a strong correlation between predicted and actual tremor severity, suggesting the model's high validity. The selected features show a high correlation with the patient's MDS-UPDRS scores, further validating their relevance in predicting tremor severity. Greater results could be achieved, but sample size was the greatest limitation during this study.

    This study demonstrates the potential of using IMU data and multiple linear regression modelling for accurate PD tremor assessment within Mobistudy, contributing to the field of quantitative PD analysis.

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    fulltext
  • 13.
    Abdulla, PA
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Mathematics and Computer Science, Department of Information Technology. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Mathematics and Computer Science, Department of Information Technology, Computer Systems. DEPARTMENT OF COMPUTER SYSTEMS.
    Boasson, L
    Bouajjani, A
    Effective Lossy Queue Languages.2001In: ICALP'2001, 28th Int. Colloquium on Automata, Languages and Programmming., 2001Conference paper (Refereed)
  • 14.
    Abdulla, PA
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Mathematics and Computer Science, Department of Information Technology. DEPARTMENT OF COMPUTER SYSTEMS.
    Jonsson, B
    Channel Abstractions in Protocol Verification2001In: CONCUR'2001, 12th Int. Conf. on Concurrency Theory, 2001Conference paper (Refereed)
  • 15.
    Abdulla, Parosh A.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computer Systems.
    Delzanno, Giorgio
    Univ Genoa, DIBRIS, Genoa, Italy..
    Parameterized verification2016In: International Journal on Software Tools for Technology Transfer, ISSN 1433-2779, E-ISSN 1433-2787, Vol. 18, no 5, p. 469-473Article in journal (Other academic)
    Abstract [en]

    The goal of parameterized verification is to prove the correctness of a system specification regardless of the number of its components. The problem is of interest in several different areas: verification of hardware design, multithreaded programs, distributed systems, and communication protocols. The problem is undecidable in general. Solutions for restricted classes of systems and properties have been studied in areas like theorem proving, model checking, automata and logic, process algebra, and constraint solving. In this introduction to the special issue, dedicated to a selection of works from the Parameterized Verification workshop PV '14 and PV '15, we survey some of the works developed in this research area.

  • 16.
    Abdulla, Parosh A.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computer Systems.
    Delzanno, Giorgio
    Univ Genoa, Genoa, Italy..
    Montali, Marco
    Free Univ Bolzano, Bolzano, Italy..
    Well Structured Transition Systems with History2015In: Electronic Proceedings in Theoretical Computer Science, E-ISSN 2075-2180, no 193, p. 115-128Article in journal (Refereed)
    Abstract [en]

    We propose a formal model of concurrent systems in which the history of a computation is explicitly represented as a collection of events that provide a view of a sequence of configurations. In our model events generated by transitions become part of the system configurations leading to operational semantics with historical data. This model allows us to formalize what is usually done in symbolic verification algorithms. Indeed, search algorithms often use meta-information, e.g., names of fired transitions, selected processes, etc., to reconstruct (error) traces from symbolic state exploration. The other interesting point of the proposed model is related to a possible new application of the theory of well-structured transition systems (wsts). In our setting wsts theory can be applied to formally extend the class of properties that can be verified using coverability to take into consideration (ordered and unordered) historical data. This can be done by using different types of representation of collections of events and by combining them with wsts by using closure properties of well-quasi orderings.

  • 17. Abdulla, Parosh Aziz
    Carrying Probabilities to the Infinite World2011In: CONCUR'2011, 22nd International Conference on Concurrency Theory., 2011Conference paper (Refereed)
  • 18.
    Abdulla, Parosh Aziz
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Mathematics and Computer Science, Department of Information Technology. DEPARTMENT OF COMPUTER SYSTEMS.
    Using (Timed) Petri Nets for Verification of Parametrized (Timed) Systems2001In: VEPAS'2001, Verification of Parameterized Systems, 2001Conference paper (Refereed)
  • 19.
    Abdulla, Parosh Aziz
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computer Systems.
    Atig, Mohamed Faouzi
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computer Systems.
    Kaxiras, Stefanos
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computer Architecture and Computer Communication.
    Leonardsson, Carl
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computer Systems.
    Ros, Alberto
    Zhu, Yunyun
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computer Systems.
    Fencing programs with self-invalidation and self-downgrade2016In: Formal Techniques for Distributed Objects, Components, and Systems, Springer, 2016, p. 19-35Conference paper (Refereed)
  • 20.
    Abdulla, Parosh Aziz
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computer Systems.
    Chen, Yu-Fang
    Clemente, Lorenzo
    Holík, Lukás
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computer Systems.
    Hong, Chih-Duo
    Mayr, Richard
    Vojnar, Tomás
    Advanced Ramsey-based Büchi automata inclusion testing2011In: CONCUR 2011 — Concurrency Theory, Springer Berlin/Heidelberg, 2011, p. 187-202Conference paper (Refereed)
  • 21.
    Abdulla, Parosh Aziz
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computer Systems.
    Delzanno, Giorgio
    Univ Genoa, I-16126 Genoa, Italy..
    Rezine, Othmane
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computer Systems. Uppsala Univ, Uppsala, Sweden..
    Sangnier, Arnaud
    Univ Paris Diderot, CNRS, LIAFA, Paris, France..
    Traverso, Riccardo
    FBK, Trento, Italy..
    Parameterized verification of time-sensitive models of ad hoc network protocols2016In: Theoretical Computer Science, ISSN 0304-3975, E-ISSN 1879-2294, Vol. 612, p. 1-22Article in journal (Refereed)
    Abstract [en]

    We study decidability and undecidability results for parameterized verification of a formal model of timed Ad Hoc network protocols. The communication topology is defined by an undirected graph and the behaviour of each node is defined by a timed automaton communicating with its neighbours via broadcast messages. We consider parameterized verification problems formulated in terms of reachability. In particular we are interested in searching for an initial configuration from which an individual node can reach an error state. We study the problem for dense and discrete time and compare the results with those obtained for (fully connected) networks of timed automata.

  • 22.
    Abdulla, Parosh Aziz
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology.
    Delzanno, Giorgio
    Van Begin, Laurent
    A classification of the expressive power of well-structured transition systems2011In: Information and Computation, ISSN 0890-5401, E-ISSN 1090-2651, Vol. 209, no 3, p. 248-279Article in journal (Refereed)
    Abstract [en]

    We compare the expressive power of a class of well-structured transition systems that includes relational automata (extensions of), Petri nets, lossy channel systems, constrained multiset rewriting systems, and data nets. For each one of these models we study the class of languages generated by labeled transition systems describing their semantics. We consider here two types of accepting conditions: coverability and reachability of a fixed a priori configuration. In both cases we obtain a strict hierarchy in which constrained multiset rewriting systems is the most expressive model.

  • 23.
    Abdulla, Parosh Aziz
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Mathematics and Computer Science, Department of Information Technology. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Mathematics and Computer Science, Department of Information Technology, Computer Systems. Datorteknik.
    Jonsson, Bengt
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Mathematics and Computer Science, Department of Information Technology. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Mathematics and Computer Science, Department of Information Technology, Computer Systems. Datorteknik.
    Model checking of systems with many identical timed processes2003In: Theoretical Computer Science, ISSN 0304-3975, Vol. 290, no 1, p. 241-264Article in journal (Refereed)
  • 24. Abdulla, Parosh Aziz
    et al.
    Leino, Rustan
    TACAS'2011, 17th International ConferenceTools and Algorithms for the Construction and Analysis of Systems.2011Conference proceedings (editor) (Refereed)
  • 25.
    Abdulla, Parosh Aziz
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computer Systems.
    Richard, Mayr
    Computing Optimal Coverability Costs in Priced Timed Petri Nets2011In: LICS'2011, Proceedings of the 26th Annual IEEE Symposium on Logic in Computer Science, 2011, p. 399-408Conference paper (Refereed)
    Abstract [en]

    We consider timed Petri nets, i.e., unbounded Petri nets where each token carries a real-valued clock. Transition arcs are labeled with time intervals, which specify constraints on the ages of tokens. Our cost model assigns token storage costs per time unit to places, and firing costs to transitions. We study the cost to reach a given control-state. In general, a cost-optimal run may not exist. However, we show that the infimum of the costs is computable.

  • 26.
    Abdulla, Parosh
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Mathematics and Computer Science, Department of Information Technology. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Mathematics and Computer Science, Department of Information Technology, Computer Systems. DoCS.
    Ben Henda, Noomene
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Mathematics and Computer Science, Department of Information Technology. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Mathematics and Computer Science, Department of Information Technology, Computer Systems. DoCS.
    Mayr, Richard
    Sandberg, Sven
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Mathematics and Computer Science, Department of Information Technology. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Mathematics and Computer Science, Department of Information Technology, Computer Systems. Datalogi.
    Limiting Behavior of Markov Chains with Eager Attractors2006In: Third International Conference on the Quantitative Evaluation of Systems (QEST), 2006, p. 253-262Conference paper (Refereed)
  • 27.
    Abdulnoor, John
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems, Health Informatics and Logistics.
    Gawriyeh, Ramy
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems, Health Informatics and Logistics.
    A study of methods to synchronize different sensors between two smartphones2021Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Obtaining data simultaneously from different sensors located on different mobile devices can be useful for applications such as sports and medicine. In order for the data from the different sensors to be combined for analysis, the mobile devices need to be time synchronized first. This paper presents an application that can be used to calculate the difference between the internal clocks of two android devices using a combination of the Cristian and Marzullo algorithms. Different methods to connect the devices over Wi-Fi as well as the internet are tested to determine the optimal method for clock synchronization. The paper also validates the synchronization by testing different sensors on two identical android smartphones. The results show that clock synchronization between two mobile devices can be achieved with a round-trip time of 2 milliseconds or less using Wi-Fi Direct. Validation of the synchronization shows that a delay of 7 milliseconds or less can be achieved between two sensors of the same type on two identical android smartphones. It also shows that the least achievable delay between sensors of different types is 16 milliseconds. The conclusion is that once two android smartphones’ clocks are synchronized, only data from sensors of the same type can be combined, with the exception of the camera sensor. Further testing with more robust equipment is needed in order to eliminate human error which could possibly yield more desirable results.

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  • 28.
    Abebe, Henok Girma
    KTH, School of Architecture and the Built Environment (ABE), Philosophy and History, Philosophy.
    Road Safety Policy in Addis Ababa: A Vision Zero Perspective2022In: Sustainability, E-ISSN 2071-1050, Vol. 14, no 9, p. 1-22Article in journal (Refereed)
    Abstract [en]

    In this article, the Addis Ababa city road safety policies are examined and analysed based on the Vision Zero approach to road safety work. Three major policy documents are explored and assessed in terms of how they compare with Vision Zero policy in Sweden, concerning how road safety problems are conceptualised, the responsibility ascriptions promoted, the nature of goal setting concerning road safety objectives, and the specific road safety interventions promoted. It is concluded that there is a big difference between the Swedish Vision Zero approach to road safety work and the Addis Ababa road safety approach in terms of how road safety problems are framed and how responsibility ascriptions are made. In Addis Ababa, policy documents primarily frame road safety problems as individual road user problems and, hence, the responsibility for traffic safety is mainly left to the individual road users. The responsibility extended to other system components such as the vehicles, road design, and the operation of the traffic is growing but still very limited. It is argued that in order to find and secure long-term solutions for traffic safety in the city, a paradigm shift is needed, both regarding what are perceived to be the main causes of road safety problems in the city and who should be responsible for ensuring that road fatalities and injuries are prevented.

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  • 29.
    Abo Khalaf, Mulham
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Computer and Electrical Engineering (2023-).
    Edge on Wheels: Design and Challenges in Real-time Object Detection2024Conference paper (Refereed)
    Abstract [en]

    Teleoperation is increasingly valued for its costeffectiveness and safety benefits in managing workflows acrossindustries like harbor automation, construction, transportationand logistics, mining, and forestry. Ensuring the safe operation ofheavy machinery involves effectively transferring and visualizingthe vehicle’s state and surroundings to remote operators for realtime tasks. Multi-camera video-based environment perceptionand state knowledge are crucial but bandwidth-intensive. Toaddress this, integrating computing functions at the edge isvital. This paper presents ”edge on wheels,” a system designusing the YOLO model for object detection/depth perceptiontasks. We divide the design into edge and cloud components,where offloading decisions on edge and cloud are based onworkload, task priority, and network quality. Finally, we discusschallenges and future enhancements for real-time object detectionin teleoperated driving scenarios.

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  • 30.
    Aboelwafa, Mariam
    et al.
    American University of Cairo, Egypt.
    Seddik, Karim G.
    American University of Cairo, Egypt.
    Eldefrawy, Mohammed
    Halmstad University, Sweden.
    Gadallah, Yasser
    American University of Cairo, Egypt.
    Gidlund, Mikael
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Information Systems and Technology.
    A Machine Learning-Based Technique for False Data Injection Attacks Detection in Industrial IoT2020In: IEEE Internet of Things Journal, ISSN 2327-4662, Vol. 7, no 9, p. 8462-8471Article in journal (Refereed)
    Abstract [en]

    The accelerated move towards the adoption of the industrial Internet of Things (IIoT) paradigm has resulted in numerous shortcomings as far as security is concerned. One of the IIoT affecting critical security threats is what is termed as the ” False Data Injection” (FDI) attack. The FDI attacks aim to mislead the industrial platforms by falsifying their sensor measurements. FDI attacks have successfully overcome the classical threat detection approaches. In this study, we present a novel method of FDI attack detection using Autoencoders (AEs). We exploit the sensor data correlation in time and space, which in turn can help identify the falsified data. Moreover, the falsified data are cleaned using the denoising AEs. Performance evaluation proves the success of our technique in detecting FDI attacks. It also significantly outperforms a support vector machine (SVM) based approach used for the same purpose. The denoising AE data cleaning algorithm is also shown to be very effective in recovering clean data from corrupted (attacked) data.

  • 31.
    Abrahamsson, Amanda
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Computer and Electrical Engineering (2023-).
    Föreningswebbplats med bokningssystem2024Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The overall goal for the projekt was to create a website with booking-functionality for Kristinehamnsortens biodlareförening, an organisation for beekeepers in and around Kristinehamns municipality. The website was created using PHP, SASS and JavaScript, with a REST-api for booking beekeeping-equipment written in PHP and connected to a MySQL-database. Through the REST-api functionality was created to allow members of the organisation to make reservations for renting equipment as well as the ability for the board members to log in to an admin-page and see the reservations made. The webside was design in a modular fashing where content can easily be added into modules of differens sizes, to make adding, editing and deleting content simple and seamless. The projects work was evaluated on teams with a couple of members from the organisation, where minor changes to the color and size was made for certain elements. The choice to create a REST-api for this purpose proved to be superfluous, and the login-funktionality was instead created using a direct connection to the database. There are also plans to in the future convert the bookingsystem to be a direct connect as well.

  • 32.
    Abrahamsson, Beatrice
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Computer and Electrical Engineering (2023-).
    Manage Packages: Utveckling av Gameplans administration av produktpaket2023Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report reviews the work done during the project carried out at the company Learn2Esport. The company has designed a platform for education in e-sports called Gameplan. The purpose of the project has been to implement a new design for the platform's pages that contain the product packages. The goal is to make these pages clearer and more user-friendly, which is important for administrators and the company's efficiency. The development has been done in React with the scripting language TypeScript. The work has involved a reconstruction of the index page that prints all packages as well as the implementation of sub-pages for each package. For each sub-page, four tabs have been created where different data related to the package is printed under each tab.

  • 33.
    Abrahamsson, Björn
    Linköping University, Department of Electrical Engineering.
    Architectures for Multiplication in Galois Rings2004Independent thesis Basic level (professional degree)Student thesis
    Abstract [en]

    This thesis investigates architectures for multiplying elements in Galois rings of the size 4^m, where m is an integer.

    The main question is whether known architectures for multiplying in Galois fields can be used for Galois rings also, with small modifications, and the answer to that question is that they can.

    Different representations for elements in Galois rings are also explored, and the performance of multipliers for the different representations is investigated.

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  • 34.
    Abrahamsson, Henrik
    Mälardalen University, School of Innovation, Design and Engineering.
    Internet Traffic Management2008Licentiate thesis, comprehensive summary (Other scientific)
  • 35.
    Abrahamsson, Henrik
    Mälardalen University, School of Innovation, Design and Engineering.
    Network overload avoidance by traffic engineering and content caching2012Doctoral thesis, comprehensive summary (Other academic)
    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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  • 36.
    Abrahamsson, Henrik
    et al.
    Swedish Institute of Computer Science, Kista, Sweden.
    Björkman, Mats
    Mälardalen University, School of Innovation, Design and Engineering.
    Caching for IPTV distribution with time-shift2013In: 2013 International Conference on Computing, Networking and Communications, ICNC 2013, IEEE , 2013, p. 916-921Conference paper (Refereed)
    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

  • 37.
    Abrahamsson, Henrik
    et al.
    Swedish Institute of Computer Science.
    Björkman, Mats
    Mälardalen University, School of Innovation, Design and Engineering.
    Simulation of IPTV caching strategies2010In: Proceedings of the 2010 International Symposium on Performance Evaluation of Computer and Telecommunication Systems, 2010, p. 187-193Conference paper (Refereed)
    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.

  • 38.
    Abrahamsson, Henrik
    et al.
    Swedish Institute of Computer Science, Kista, Sweden.
    Nordmark, Mattias
    TeliaSonera AB, Stockholm, Sweden .
    Program popularity and viewer behaviour in a large TV-on-Demand system2012In: IMC '12 Proceedings of the 2012 ACM conference on Internet measurement conference, New York: ACM , 2012, p. 199-210Conference paper (Refereed)
    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.

  • 39.
    Abrahamsson, Lars
    Linköping University, Department of Electrical Engineering.
    A portal based system for indoor environs2006Independent thesis Basic level (professional degree), 20 points / 30 hpStudent thesis
    Abstract [en]

    The purpose of this thesis is to document the development of the graphics part of an extremely pluggable game engine/lab environment for a course in advanced game programming. This thesis is one out of five, and concerns indoor, realtime computer 3D graphics. It covers state-of-the-art techniques such as GLSL - the OpenGL Shading Language - and more well known techniques such as portal based rendering.

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  • 40.
    Abrahamsson, Linn
    et al.
    Linköping University, Department of Computer and Information Science, Software and Systems.
    Melin Wenström, Peter
    Linköping University, Department of Computer and Information Science, Software and Systems.
    Användning av prototyper som verktyg för kravhantering i agil mjukvaruutveckling: - En fallstudie2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Requirements Engineering (RE) in Agile Software Development (ASD) is a challenge thatmany face and several techniques exist when doing so. One such technique is prototyping, when a model of a product is used to gather important information in software develop-ment. To describe how much a prototype resembles the product the notion of fidelity is used. The aim of this study is to contribute to research regarding prototyping in ASD,and to examine the effect of a prototype’s fidelity when using prototypes in discussionsduring RE. A case study is performed at the company Exsitec where staff are interviewedregarding prototyping in software development. Thereafter, two prototypes of low andhigh fidelity are developed and used in interviews as a basis for discussion. Based on thisstudy, the use of prototypes in software projects can help customers trust the process,improve communication with customers, and facilitate when trying to reach consensusamong different stakeholders. Furthermore, depending on how they are used, prototypescan contribute to understanding the big picture of the requirements and can also serve asdocumentation. The study also shows some, albeit subtle, differences in the informationcollected using prototypes with low and high fidelity. The use of a high fidelity prototypeseems to generate more requirements, but makes interviewees less likely to come up withlarger, more comprehensive requirement changes.

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  • 41.
    Abrahamsson, Marcus
    Linköping University, Department of Computer and Information Science, Database and information techniques. Linköping University, The Institute of Technology.
    A platform for third-party applications on the web2013Independent thesis Basic level (degree of Bachelor), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [en]

    A trend seen on the web today is to create a platform where externally developed applications can run inside some kind of main application. This is often done by providing an API to access data and business logic of your service and a sandbox environment in which third-party applications can run. By providing this, it is made possible for external developers to come up with new ideas based on your service. Some good examples on this are Spotify Apps, Apps on Facebook and SalesForce.com.

    Ipendo Systems AB is a company that develops a web platform for intellectual properties. Currently most things on this platform are developed by developers at Ipendo Systems AB. Some interest has though risen to enable external developers to create applications that will in some way run inside the main platform.

    In this thesis an analysis of already existing solutions has been done. These solutions were Spotify Apps and Apps on Facebook. The two have different approaches on how to enable third-party applications to run inside their own service. Facebook’s solution builds mainly on iframe embedded web pages where data access is provided through a web API. Spotify on the other hand hosts the third-party applications themselves but the applications may only consist of HTML5, CSS3 and JavaScript.

    In addition to the analysis a prototype was developed. The purpose of the prototype was to show possible ways to enable third-party applications to run inside your own service. Two solutions showing this were developed. The first one was based on Facebook’s approach with iframing of external web pages. The second was a slightly modified version of Spotify’s solution with only client-side code hosted by the main application. To safely embed the client side code in the main application a sandboxing tool for JavaScript called Caja was used.

    Of the two versions implemented in the prototype was the Iframe solution considered more ready to be utilized in a production environment than Caja. Caja could be seen as an interesting technique for the future but might not be ready to use today. The reason behind this conclusion was that Caja decreased the performance of the written JavaScript as well as adding complexity while developing the third-party applications.

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  • 42.
    Abrahamsson, Robin
    et al.
    Linköping University, Department of Computer and Information Science, Software and Systems.
    Berntsen, David
    Linköping University, Department of Computer and Information Science, Software and Systems.
    Comparing modifiability of React Native and two native codebases2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Creating native mobile application on multiple platforms generate a lot of duplicate code. This thesis has evaluated if the code quality attribute modifiability improves when migrating to React Native. One Android and one iOS codebase existed for an application and a third codebase was developed with React Native. The measurements of the codebases were based on the SQMMA-model. The metrics for the model were collected with static analyzers created specifically for this project. The results created consists of graphs that show the modifiability for some specific components over time and graphs that show the stability of the platforms. These graphs show that when measuring code metrics on applications over time it is better to do this on a large codebase that has been developed for some time. When calculating a modifiability value the sum of the metrics and the average value of the metrics between files should be used and it is shown that the React Native platform seems to be more stable than native.

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  • 43.
    Abrahamsson, William
    et al.
    Linnaeus University, Faculty of Technology, Department of computer science and media technology (CM).
    Theo, Davnert
    Linnaeus University, Faculty of Technology, Department of computer science and media technology (CM).
    Grid-Based Focus Stacking InMicroscopic Photography: Utilizing Grid Systems For Noise Reduction2024Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Microscope cameras possess high zoom capabilities and are frequently used for quality control in various industries. Visus Technology is a company that manufactures and sells these cameras, along with control software. The problem is that these cameras can only be set to one focus depth at a time. Therefore, we were tasked with implementing a fast focus stacking algorithm that combines multiple input images with different focus depths, resulting in a composite image with consistent focus throughout. This will later be integrated into the control software.

    We initially approached the problem by choosing pixels with the highest Laplacian intensity. This resulted in very noisy output images since the blurry images could sometimes produce high-intensity pixels where they were not supposed to be. To address this, we implemented a grid-based focus stacking algorithm. The algorithm divides the input images into tiles, filtering out the blurriest tiles to exclude them from the stacking process. The result is a composite image with significantly reduced blur.

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  • 44.
    Adewumi, Tosin
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Alkhaled, Lama
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Mokayed, Hamam
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Liwicki, Foteini
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Liwicki, Marcus
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    ML_LTU at SemEval-2022 Task 4: T5 Towards Identifying Patronizingand Condescending Language2022In: Proceedings of the 16th International Workshop on Semantic Evaluation (SemEval-2022) / [ed] Guy Emerson, Natalie Schluter, Gabriel Stanovsky, Ritesh Kumar, Alexis Palmer, Nathan Schneider, Siddharth Singh, Shyam Ratan, Association for Computational Linguistics , 2022, p. 473-478Conference paper (Refereed)
    Abstract [en]

    This paper describes the system used by the Machine Learning Group of LTU in subtask 1 of the SemEval-2022 Task 4: Patronizing and Condescending Language (PCL) Detection. Our system consists of finetuning a pretrained text-to-text transfer transformer (T5) and innovatively reducing its out-of-class predictions. The main contributions of this paper are 1) the description of the implementation details of the T5 model we used, 2) analysis of the successes & struggles of the model in this task, and 3) ablation studies beyond the official submission to ascertain the relative importance of data split. Our model achieves an F1 score of 0.5452 on the official test set.

  • 45.
    Adhi, Boma
    et al.
    RIKEN, Ctr Computat Sci R CCS, Wako, Saitama, Japan..
    Cortes, Carlos
    RIKEN, Ctr Computat Sci R CCS, Wako, Saitama, Japan..
    Tan, Yiyu
    RIKEN, Ctr Computat Sci R CCS, Wako, Saitama, Japan..
    Kojima, Takuya
    RIKEN, Ctr Computat Sci R CCS, Wako, Saitama, Japan.;Univ Tokyo, Grad Sch Informat Sci & Technol, Tokyo, Japan..
    Podobas, Artur
    KTH, School of Electrical Engineering and Computer Science (EECS), Computer Science, Computational Science and Technology (CST).
    Sano, Kentaro
    RIKEN, Ctr Computat Sci R CCS, Wako, Saitama, Japan..
    Exploration Framework for Synthesizable CGRAs Targeting HPC: Initial Design and Evaluation2022In: 2022 IEEE 36Th International Parallel And Distributed Processing Symposium Workshops (IPDPSW 2022), Institute of Electrical and Electronics Engineers (IEEE) , 2022, p. 639-646Conference paper (Refereed)
    Abstract [en]

    Among the more salient accelerator technologies to continue performance scaling in High-Performance Computing (HPC) are Coarse-Grained Reconfigurable Arrays (CGRAs). However, what benefits CGRAs will bring to HPC workloads and how those benefits will be reaped is an open research question today. In this work, we propose a framework to explore the design space of CGRAs for HPC workloads, which includes a tool flow of compilation and simulation, a CGRA HDL library written in SystemVerilog, and a synthesizable CGRA design as a baseline. Using RTL simulation, we evaluate two well-known computation kernels with the baseline CGRA for multiple different architectural parameters. The simulation results demonstrate both correctness and usefulness of our exploration framework.

  • 46.
    Adolfsson, Klas
    Linköping University, Department of Electrical Engineering.
    TCP performance in an EGPRS system2003Independent thesis Advanced level (degree of Magister), 20 points / 30 hpStudent thesis
    Abstract [en]

    The most widely used protocol for providing reliable service and congestion control in the Internet is the Transmission Control Protocol (TCP). When the Internet is moving towards more use in mobile applications it is getting more important to know how TCP works for this purpose.

    One of the technologies used for mobile Internet is the Enhanced General Packet Radio Service (EGPRS) extension to the popular GSM system. This thesis presents a low-level analysis of TCP performance in an EGPRS system and an overview of existing TCP, GSM and EGPRS technologies.

    The bottleneck in an EGPRS system is the wireless link – the connection between the mobile phone and the GSM base station. The data transfer over the wireless link is mainly managed by the complex RLC/MAC protocol.

    In this thesis, simulations were made to identify some problems with running TCP and RLC/MAC together. The simulations were made using existing EGPRS testing software together with a new TCP module. The simulation software is also briefly described in the thesis.

    Additionaly, some suggestions are given in order to enhance performance, both by changing the EGPRS system and by modifying the TCP algorithms and parameters.

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  • 47.
    Adolfsén, Emmy
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Information Systems and Technology.
    Webbplats för Vemdalen Catering: Funktionalitet mot användarvänlighet i Wordpress2021Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The objective of this project is a, for client, optimized website built in Wordpress using Beaver Builder and Beaver Themer plugin, together with a basic set of chosen plugins for a modern, secure and cost effective Wordpress site. The projects also includes an evaluation of and analysis about how functionality and design could be prioritized for optimal delivery and client satisfaction. The purpose is to get a satisfied client and to procure enough knowledge to build websites in Beaver Builder with a healthy priority of funcionality and design. A market research have been done with questions about websites within the swedish hospitality industry. The design have been made, with the result in consideration, to be clear, simple and, with the help of pictures, to bring the right sense of purpose.Usability testing on both big screens and small screens have been made with surveys. The result shows that the website is clear, neat and easy to navigate. The website of Vemdalen Catering have been published on the domain vemdalencatering.se. The website is built in Wordpress with chosen plugins. The design is responsive, works well on different screen sizes and is, according to usability testing, also user friendly.Validation has been performed and shows results following the set objectives. Search engine optimization has been performed. Evaluation and analysis from the result of usability testing, market research, SE ranking and Google Analytics shows that a priority for design and experience in many cases can be higher than availability, depending on target group, and that more work is needed to rank higher up in Googles search engines and essentially aquire more visitors on the website.

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  • 48.
    Afshar, Sara
    et al.
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Behnam, Moris
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Bril, Reinder J.
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems. Technische Universiteit Eindhoven, Eindhoven, Netherlands.
    Nolte, Thomas
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Resource Sharing Under Global Scheduling with Partial Processor Bandwidth2015In: 2015 10th IEEE International Symposium on Industrial Embedded Systems, SIES 2015 - Proceedings, 2015, p. 195-206Conference paper (Refereed)
    Abstract [en]

    Resource efficient approaches are of great importance for resource constrained embedded systems. In this paper, we present an approach targeting systems where tasks of a critical application are partitioned on a multi-core platform and by using resource reservation techniques, the remaining bandwidth capacity on each core is utilized for one or a set of non-critical application(s). To provide a resource efficient solution and to exploit the potential parallelism of the extra applications on the multi-core processor, global scheduling is used to schedule the tasks of the non-critical applications. Recently a specific instantiation of such a system has been studied where tasks do not share resources other than the processor. In this paper, we enable semaphore-based resource sharing among tasks within critical and non-critical applications using a suspension-based synchronization protocol. Tasks of non-critical applications have partial access to the processor bandwidth. The paper provides the systems schedulability analysis where blocking due to resource sharing is bounded. Further, we perform experimental evaluations under balanced and unbalanced allocation of tasks of a critical application to cores.

  • 49.
    Aftab, Nadeem
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Information Systems and Technology.
    Disocclusion Inpainting using Generative Adversarial Networks2020Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The old methods used for images inpainting of the Depth Image Based Rendering (DIBR) process are inefficient in producing high-quality virtual views from captured data. From the viewpoint of the original image, the generated data’s structure seems less distorted in the virtual view obtained by translation but when then the virtual view involves rotation, gaps and missing spaces become visible in the DIBR generated data. The typical approaches for filling the disocclusion tend to be slow, inefficient, and inaccurate. In this project, a modern technique Generative Adversarial Network (GAN) is used to fill the disocclusion. GAN consists of two or more neural networks that compete against each other and get trained. This study result shows that GAN can inpaint the disocclusion with a consistency of the structure. Additionally, another method (Filling) is used to enhance the quality of GAN and DIBR images. The statistical evaluation of results shows that GAN and filling method enhance the quality of DIBR images.

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    Afzal, Ayesha
    et al.
    Erlangen National High Performance Computing Center (NHR@FAU), 91058, Erlangen, Germany.
    Hager, Georg
    Erlangen National High Performance Computing Center (NHR@FAU), 91058, Erlangen, Germany.
    Wellein, Gerhard
    Erlangen National High Performance Computing Center (NHR@FAU), 91058, Erlangen, Germany; Department of Computer Science, University of Erlangen-Nürnberg, 91058, Erlangen, Germany.
    Markidis, Stefano
    KTH, School of Electrical Engineering and Computer Science (EECS), Computer Science, Computational Science and Technology (CST).
    Exploring Techniques for the Analysis of Spontaneous Asynchronicity in MPI-Parallel Applications2023In: Parallel Processing and Applied Mathematics - 14th International Conference, PPAM 2022, Revised Selected Papers, Springer Nature , 2023, p. 155-170Conference paper (Refereed)
    Abstract [en]

    This paper studies the utility of using data analytics and machine learning techniques for identifying, classifying, and characterizing the dynamics of large-scale parallel (MPI) programs. To this end, we run microbenchmarks and realistic proxy applications with the regular compute-communicate structure on two different supercomputing platforms and choose the per-process performance and MPI time per time step as relevant observables. Using principal component analysis, clustering techniques, correlation functions, and a new “phase space plot,” we show how desynchronization patterns (or lack thereof) can be readily identified from a data set that is much smaller than a full MPI trace. Our methods also lead the way towards a more general classification of parallel program dynamics.

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