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Crustal response to inflation imaged by mapping of subsurface faults, slip directions, and stress changes during the 1993–1998 unrest in Hengill, SW-Iceland
(2022-11) Blanck, Hanna; Vogfjörd, Kristín S.; Geirsson, Halldór; Hjörleifsdóttir, Vala; Department of Engineering
Between 1993 and 1998, the Hengill volcanic region in southwest Iceland was subject to a significant volcano-tectonic event which caused a total of 8 cm uplift and induced >90 thousand earthquakes, most of magnitude smaller than 2 ML and a small intrusion has been proposed as its cause. In this paper, we study fault activation around the uplift center to analyze whether the Coulomb stress change induced by such an intrusion would cause the observed crustal response. The locations of a subset of 12,000 micro-earthquakes are significantly improved by a double-difference relocation algorithm and the use of cross-correlation of waveforms to refine phase arrival times. The vast majority of seismic activity is scattered, but twenty-five (25) rectangular prisms, consisting of 11 to 363 earthquakes and 200 to 3000 m long, were identified and are interpreted as faults. Most of these faults are sub-vertical (within 5° from vertical) and only two faults dip at angles of 62° and 65°, respectively. Focal mechanism analysis of individual events was applied to estimate slip direction on these faults. Simulation of the Coulomb stress changes reveals that the stress changes would have been able to induce the observed fault movement on 22 of 25 faults. Discrepancies on the remaining faults are likely caused by uncertainties in the rake directions. Our results emphasize that the seismicity caused by a volume change in the crust is controlled by the interplay between the local stress field and the induced stresses.
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What does current science tell us about the accuracy, reliability, and completeness of intoxicated witnesses? A case example of the murder of a prime minister
(2022-10-28) Hildebrand Karlén, Malin; de Bejczy, Andrea; Anckarsäter, Henrik; Guðjónsson, Gísli
Generally, the testimony of intoxicated witnesses has been considered relatively unreliable, but recent research has nuanced the knowledge base regarding these vulnerable witnesses. Purpose: To demonstrate the application of recent research findings regarding intoxicated witnesses to the statements made by a key witness to the murder of Olof Palme, Sweden's prime minister, in 1986. An additional purpose was to illustrate the use of a nuanced calculation of blood alcohol concentration (BAC) for researchers. Methods: The Palme murder has been debated since the crime was committed and no one has yet been sentenced. One of the witnesses was intoxicated and to estimate a range for his BAC at the time, a comprehensive BAC calculation was conducted in this study to illustrate important factors to consider in these types of cases. Results: Through the demonstration of the use of a nuanced BAC formula and by applying recent research results from studies on intoxicated witnesses, it was estimated that the possible BAC of the witness in the Palme-case at the time of the witnessed crime ranged between BAC = 0 to BAC = 0.13, depending on the type of alcoholic beverage consumed and whether the witness was a social or heavy drinker. This puts the witness either well within the span of maintained completeness as well as maintained accuracy rate (if considering: lowest dose and heavy drinker), or slightly exceeding this span into the BAC-range of reduced completeness but maintained accuracy rate (if considering: highest dose and social drinker). He was questioned immediately, and thereafter repeatedly, and he reported similar information throughout the interviews, which is in line with previous results on information maintenance over repeated interviews among intoxicated witnesses. Conclusion: The current case example shows how recent research on intoxicated witnesses can be applied in praxis, illustrating important factors for legal practitioners to consider when interpreting information from intoxicated witnesses. It also provides legal practitioners and researchers with an example of a structured approach to more nuanced BAC-calculations.
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Open Challenges of Interactive Video Search and Evaluation
(Association for Computing Machinery, Inc, 2022-10-10) Loko, Jakub; Schoeffmann, Klaus; Bailer, Werner; Rossetto, Luca; Jónsson, Björn Þór; Department of Computer Science
During the last 10 years of Video Browser Showdown (VBS), there were many different approaches tested for known-item search and ad-hoc search tasks. Undoubtedly, teams incorporating state-of-the-art models from the machine learning domain had an advantage over teams focusing just on interactive interfaces. On the other hand, VBS results indicate that effective means of interaction with a search system is still necessary to accomplish challenging search tasks. In this tutorial, we summarize successful deep models tested at the Video Browser Showdown as well as interfaces designed on top of corresponding distance/similarity spaces. Our broad experience with competition organization and evaluation will be presented as well, focusing on promising findings and also challenging problems from the most recent iterations of the Video Browser Showdown.
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Teaching project management in a virtual environment : The Virtual Scrum Simulator (ScrumSim)
(Association for Computing Machinery, 2022-10-08) Visescu, Ioana; Blindu, Alin; Radhakrishnan, Unnikrishnan; Kadenic, Maja; Chinello, Francesco; Koumaditis, Konstantinos
The Scrum Simulator (ScrumSim) is an interactive multiplayer VR simulation that places the participant in a virtual collaboration environment, in order to train them in the use of a project management methodology i.e., Scrum. In VR, the participants as a team, with the assistance of two avatars, perform intuitive tasks in sprints, cooperate, discuss, interact with the environment and receive feedback on their performance and tasks. The novelty of this approach lies not only in the unique design elements but also in the use of avatars and the utilisation of in-game data (task efficiency and communication).
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Adopting digital government shared-services centers : A case from Iceland
(Association for Computing Machinery, 2022-10-04) Hjaltalin, Illugi T.; Amaral, Luis; Soares, Delfina; Zheng, Lei; Department of Business and Economics
The overall objective of this study is to understand how shared services adoption by governments can affect public sector reforms and public value. In this ongoing research paper, a case study involving a deployment of a government digital shared-services center is outlined. The adoption process is analyzed through a framework inspired by systems theory and public value theory. Initial results suggest that networked collaborative governance in the form of cross-sector collaborations can play an important role in public value (co)creation. However, the findings also indicate a barrier to public innovation. This involves a zero-error culture in state agencies. In this context, strong leadership skills and diverse use of relevant administrative instruments at various stages in the innovation process are found to be critical factors for the successful adoption of shared services. This study contributes empirically and theoretically to the latest research on ICT and public value by scrutinizing a successful case of a shared-services unit within central government.

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