| 1. |
- Cito, J., et al.
(author)
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Interactive Production Performance Feedback in the IDE
- 2019
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In: 2019 IEEE/ACM 41st International Conference on Software Engineering (ICSE). - : IEEE. - 9781728108698 ; , s. 971-981
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Book chapter (other academic/artistic)abstract
- Because of differences between development and production environments, many software performance problems are detected only after software enters production. We present PerformanceHat, a new system that uses profiling information from production executions to develop a global performance model suitable for integration into interactive development environments. PerformanceHat's ability to incrementally update this global model as the software is changed in the development environment enables it to deliver near real-time predictions of performance consequences reflecting the impact on the production environment. We build PerformanceHat as an Eclipse plugin and evaluate it in a controlled experiment with 20 professional software developers implementing several software maintenance tasks using our approach and a representative baseline (Kibana). Our results indicate that developers using PerformanceHat were significantly faster in (1) detecting the performance problem, and (2) finding the root-cause of the problem. These results provide encouraging evidence that our approach helps developers detect, prevent, and debug production performance problems during development before the problem manifests in production.
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| 2. |
- Cronhjort, Mikael, et al.
(author)
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Leadership and Pedagogical Skills in Computer Science Engineering by Combining a Degree in Engineering with a Degree in Education
- 2020
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In: 2020 IEEE Frontiers in Education Conference (FIE). - : IEEE. - 0190-5848. - 9781728189611 ; , s. 1-9
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Conference paper (peer-reviewed)abstract
- In this full paper on innovative practice, we describe and discuss findings from dual degree study programmes that combine a master's degree in engineering with a master's degree in education. This innovative study programme design has emerged in Sweden due to an alarming demand for more Upper Secondary School teachers in STEM subjects. Studies on alumni from these programmes indicate that the graduates are highly appreciated not only as teachers in schools, but also in business and industry, e.g. in roles as IT consultants and computer science engineers. Data indicate that the breadth of the combined education, and especially leadership and pedagogical skills, are important factors for these graduates' success as engineers.
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| 3. |
- Da Silva, L., et al.
(author)
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Detecting Semantic Conflicts via Automated Behavior Change Detection
- 2020
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In: 2020 IEEE International Conference on Software Maintenance and Evolution (ICSME). - : IEEE. - 9781728156194 ; , s. 174-184
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Book chapter (other academic/artistic)abstract
- Branching and merging are common practices in collaborative software development. They increase developer productivity by fostering teamwork, allowing developers to independently contribute to a software project. Despite such benefits, branching and merging comes at a cost-the need to merge software and to resolve merge conflicts, which often occur in practice. While modern merge techniques, such as 3-way or structured merge, can resolve many such conflicts automatically, they fail when the conflict arises not at the syntactic, but the semantic level. Detecting such conflicts requires understanding the behavior of the software, which is beyond the capabilities of most existing merge tools. As such, semantic conflicts can only be identified and fixed with significant effort and knowledge of the changes to be merged. While semantic merge tools have been proposed, they are usually heavyweight, based on static analysis, and need explicit specifications of program behavior. In this work, we take a different route and explore the automated creation of unit tests as partial specifications to detect unwanted behavior changes (conflicts) when merging software. We systematically explore the detection of semantic conflicts through unit-test generation. Relying on a ground-truth dataset of 38 software merge scenarios, which we extracted from GitHub, we manually analyzed them and investigated whether semantic conflicts exist. Next, we apply test-generation tools to study their detection rates. We propose improvements (code transformations) and study their effectiveness, as well as we qualitatively analyze the detection results and propose future improvements. For example, we analyze the generated test suites for false-negative cases to understand why the conflict was not detected. Our results evidence the feasibility of using test-case generation to detect semantic conflicts as a method that is versatile and requires only limited deployment effort in practice, as well as it does not require explicit behavior specifications.
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| 4. |
- Gren, Lucas, 1984, et al.
(author)
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Is it Possible to Disregard Obsolete Requirements? - An Initial Experiment on a Potentially New Bias in Software Effort Estimation
- 2017
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In: 2017 Ieee/Acm 10th International Workshop on Cooperative and Human Aspects of Software Engineering (Chase 2017). - : IEEE.
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Conference paper (peer-reviewed)abstract
- Effort estimation is a complex area in decision-making, and is influenced by a diversity of factors that could increase the estimation error. The effects on effort estimation accuracy of having obsolete requirements in specifications have not yet been studied. This study aims at filling that gap. A total of 150 students were asked to provide effort estimates for different amounts of requirements, and one group was explicitly told to disregard some of the given requirements. The results show that even the extra text instructing participants to exclude requirements in the estimation task, had the subjects give higher estimates. The effect of having obsolete requirements in requirements specifications and backlogs in software effort estimation is not taken into account enough today, and this study provides empirical evidence that it possibly should. We also suggest different psychological explanations to the found effect.
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| 5. |
- Lillack, M., et al.
(author)
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Intention-Based Integration of Software Variants
- 2019
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In: 2019 IEEE/ACM 41st International Conference on Software Engineering (ICSE). - : IEEE. - 9781728108698 ; , s. 831-842
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Book chapter (other academic/artistic)abstract
- Cloning is a simple way to create new variants of a system. While cheap at first, it increases maintenance cost in the long term. Eventually, the cloned variants need to be integrated into a configurable platform. Such an integration is challenging: it involves merging the usual code improvements between the variants, and also integrating the variable code (features) into the platform. Thus, variant integration differs from traditional software merging, which does not produce or organize configurable code, but creates a single system that cannot be configured into variants. In practice, variant integration requires fine-grained code edits, performed in an exploratory manner, in multiple iterations. Unfortunately, little tool support exists for integrating cloned variants. In this work, we show that fine-grained code edits needed for integration can be alleviated by a small set of integration intentions domain-specific actions declared over code snippets controlling the integration. Developers can interactively explore the integration space by declaring (or revoking) intentions on code elements. We contribute the intentions (e.g., 'keep functionality' or 'keep as a configurable feature') and the IDE tool INCLINE, which implements the intentions and live editable views that visualize the integration process and allow declaring intentions producing a configurable integrated platform. In a series of experiments, we evaluated the completeness of the proposed intentions, the correctness and performance of INCLINE, and the benefits of using intentions for variant integration. The experiments show that INCLINE can handle complex integration tasks, that views help to navigate the code, and that it consistently reduces mistakes made by developers during variant integration.
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| 6. |
- Pientka, B., et al.
(author)
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A Type Theory for Defining Logics and Proofs
- 2019
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In: 2019 34TH ANNUAL ACM/IEEE SYMPOSIUM ON LOGIC IN COMPUTER SCIENCE (LICS). - : IEEE. - 9781728136080
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Book chapter (other academic/artistic)abstract
- We describe a Martin-Lof-style dependent type theory, called COCON, that allows us to mix the intensional function space that is used to represent higher-order abstract syntax (HOAS) trees with the extensional function space that describes (recursive) computations. We mediate between HOAS representations and computations using contextual modal types. Our type theory also supports an infinite hierarchy of universes and hence supports type-level computation thereby providing metaprogramming and (small-scale) reflection. Our main contribution is the development of a Kripke-style model for COCON that allows us to prove normalization. From the normalization proof, we derive subject reduction and consistency. Our work lays the foundation to incorporate the methodology of logical frameworks into systems such as Agda and bridges the longstanding gap between these two worlds.
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| 7. |
- Rodrigues, A., et al.
(author)
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A Learning Approach to Enhance Assurances for Real-Time Self-Adaptive Systems
- 2018
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In: SEAMS '18 Proceedings of the 13th International Conference on Software Engineering for Adaptive and Self-Managing Systems. - New York, NY, USA : ACM. - 9781450357159
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Conference paper (peer-reviewed)abstract
- The assurance of real-time properties is prone to context variability. Providing such assurance at design time would require to check all the possible context and system variations or to predict which one will be actually used. Both cases are not viable in practice since there are too many possibilities to foresee. Moreover, the knowledge required to fully provide the assurance for self-adaptive systems is only available at runtime and therefore difficult to predict at early development stages. Despite all the efforts on assurances for self-adaptive systems at design or runtime, there is still a gap on verifying and validating real-time constraints accounting for context variability. To fill this gap, we propose a method to provide assurance of self-adaptive systems, at design-and runtime, with special focus on real-time constraints. We combine off-line requirements elicitation and model checking with on-line data collection and data mining to guarantee the system's goals, both functional and non-functional, with fine tuning of the adaptation policies towards the optimization of quality attributes. We experimentally evaluate our method on a simulated prototype of a Body Sensor Network system (BSN) implemented in OpenDaVINCI. The results of the validation are promising and show that our method is effective in providing evidence that support the provision of assurance.
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| 8. |
- Bucaioni, A., et al.
(author)
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Aligning Architecture with Business Goals in the Automotive Domain
- 2021
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In: 2021 IEEE 18th International Conference on Software Architecture (ICSA) 22-26 March 2021, Stuttgart, Germany. - : IEEE. - 9781728162607
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Conference paper (peer-reviewed)abstract
- When designing complex automotive systems in practice, employed technologies and architectural decisions need to reflect business goals. While the software architecture community has acknowledged the need to align business goals with architectural decisions, there is a lack of practical approaches to achieve this alignment. In this paper, we intend to close this gap by providing a systematic approach for architecture-business alignment. The approach describes how to align architecture with business concerns by eliciting goals, identifying quality attributes, and deriving architectural tactics. We iteratively developed and evaluated the approach together with an international automotive manufacturer. We show the application of the proposed approach within our participating company leveraging a use case related to software-over-the-air technologies. The proposed approach is perceived as beneficial by our participants, since it provides a structured mechanism to align architecture and business goals by determining key architectural concerns as quality attributes and tactics.
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| 9. |
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| 10. |
- Falkman, Petter, 1972, et al.
(author)
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Verification of Operation Sequences in Process Simulate by Connecting a Formal Verification Tool
- 2009
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In: 2009 IEEE INTERNATIONAL CONFERENCE ON CONTROL AND AUTOMATION, Christchurch, NEW ZEALAND, DEC 09-11, 2009. - 9781424447060 ; 1-3, s. 1207-1212
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Conference paper (peer-reviewed)abstract
- It is very advantages to use virtual techniques for testing and developing new hardware and software systems. It is cost effective since no real machine or manufactory system is needed. It is safe since there are no real components that can be damaged. Simulation is a fast design method since the time can go faster then real time and the machine can be set to desired machine states without time consumption. Novel concepts can be tested prior to manufacturing. However, it is of greatest importance that the virtual model can be trusted so that the results of the development and tests can be directly transferred to a real system without any manual last minute changes. Testing all possible scenarios within a system by simulation is an ambiguous task and is impossible to do with todays complex systems. The present paper introduces a method for combining virtual development and simulation techniques with tools for formal verification methods. The aim is to enable the use of formal verification techniques and by doing that guaranteeing a correct system behavior.
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| 11. |
- Frennert, Susanne, PhD, et al.
(author)
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Using attention cards to facilitate active participation in eliciting old adults' requirements for assistive robots
- 2013
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In: IEEE International Workshop on Robot and Human Interactive Communication. - : IEEE conference proceedings. - 9781479905072 ; , s. 774-779, s. 774-779
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Conference paper (peer-reviewed)abstract
- Engaging old users in the exploration of future product concepts can be challenging. It is of great value to find ways to actively involve them in the design of novel technologies intended for them, particularly when they have no prior experience of the technology in question. One obstacle in this process is that many old people do not identify themselves as being old or they think that it (the technology) would be good for others but not themselves. This paper presents a card method to overcome this obstacle. A full-day workshop with three internal focus groups was run with 14 participants. Based on our experience, we propose a way in which active participation in the process of eliciting user requirements for assistive robots from old users with no prior experience of assistive robots can be carried out.
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| 12. |
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| 13. |
- Tong, Renbin
(author)
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Efficient Solid-State Power Amplifiers for RF Power Source Applications
- 2022
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Doctoral thesis (other academic/artistic)abstract
- Radio Frequency (RF) power sources are extensively applied in various fields. Radioisotope production, i.e., the production of short-lived radioactive isotopes, for positron emission tomography (PET) is one of the most important applications in the medical and healthcare domains. Full-time operation and substantial maintenance of such systems lead to high operating expenses. Hence, the development of more efficient and reliable RF power amplifiers, which are the main contributors to the energy consumption and maintenance costs of the RF power sources, is a high priority. Solid-state technology has emerged as a viable alternative to conventional vacuum tube based high-power RF/microwave systems, offering advanced control, reliability, and ease of use. Power amplifiers based on solid-state technology enable dynamic adjustment of power to optimize the transmitted energy. Furthermore, solid-state power amplifiers (SSPA) technology shows a longer lifetime leading to increased uptime and lower maintenance costs. Concisely, with the introduction of solid-state technology in high-power RF sources, RF energy can be generated more efficiently and more controllable in a smaller form factor, allowing for more compact systems with less downtime and less maintenance. This thesis is one step further toward demonstrating the feasibility of such systems.The thesis first introduces the RF measurement setup. It implements automation for quick measurements and supports the evaluation of the high-power RF performance of the developed SSPA modules. Moreover, a novel thru-only de-embedding approach is developed to address the calibration difficulties under multi-port excitation conditions. The second part of the thesis deals with the development and analysis of efficient kilowatt SSPA modules. A multimode SSPA with quasi-static supply control for power regulation is implemented. It achieves more than 90% efficiency over a 5 dB output power back-off range. Another compact and efficient SSPA, implemented in push-pull architecture, adopts harmonic load-pull integrated with the same quasi-static supply modulation which also achieves 90% efficiency over a 5 dB output power back-off range. The implemented SSPAs improve the state-of-the-art in these frequency bands and power ranges.This thesis broadens RF SSPA theoretical research to the kilowatt power range and provides a new understanding of high-power SSPAs from circuits, design methodologies, and analytical approaches. And it leads to new methods and tools to improve the energy efficiency of high-power RF sources. The knowledge gained and technology developed is not limited to RF power sources in radioisotope production applications, it can also be applied in the communication industry, such as radar systems, and other RF energy systems in industrial, scientific, and medical (ISM) fields, such as particle accelerators, welding, drying, heating, and many more.
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| 14. |
- Xie, Minshu, 1988, et al.
(author)
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Improved coupling of nanowire-based high-T-c SQUID magnetometers-simulations and experiments
- 2017
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In: Superconductor Science & Technology. - : IOP Publishing. - 0953-2048 .- 1361-6668. ; 30:11
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Journal article (peer-reviewed)abstract
- Superconducting quantum interference devices (SQUIDs) based on high critical-temperature superconducting nanowire junctions were designed, fabricated, and characterized in terms of their potential as magnetometers for magnetoencephalography (MEG). In these devices, the high kinetic inductance of junctions and the thin film thickness (50 nm) pose special challenges in optimizing the field coupling. The high kinetic inductance also brings difficulties in reaching a low SQUID noise. To explore the technique for achieving a high field sensitivity, single-layer devices with a directly connected pickup loop and flip-chip devices with an inductively coupled flux transformer using a two-level coupling approach were fabricated and tested. Two-level coupling is an approach designed for flip-chip nanowire-based SQUIDs, in which a washer type SQUID pickup loop is introduced as an intermediate coupling level between the SQUID loop and the flux transformer input coil. The inductances and effective areas of all these devices were simulated. We found that at T = 77 K, flip-chip devices with the two-level coupling approach (coupling coefficient of 0.37) provided the best effective area of 0.46 mm(2) among all the tested devices. With a flux noise level of 55 mu Phi(0) Hz-1/2, the field sensitivity level was 240 fTHz-1/2. This sensitivity is not yet adequate for MEG applications but it is the best level ever reached for nanowire-based high-Tc SQUID magnetometers.
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| 15. |
- Zirath, Herbert, 1955, et al.
(author)
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On the status of Low Noise Millimeterwave MMIC Receivers
- 2009
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In: APMC: 2009 ASIA PACIFIC MICROWAVE CONFERENCE. - 9781424428014 ; 1-5, s. 1303-1306
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Conference paper (other academic/artistic)abstract
- The status of integrated receivers for remote sensing and communication applications from 60 GHz to higher frequencies is reviewed. Recent receiver results for silicon and technologies are compared with Schottky diode receivers.
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