| 1. |
- Bott, Lukas Thomas, et al.
(författare)
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Coulomb dissociation of O-16 into He-4 and C-12
- 2023
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Ingår i: NUCLEAR PHYSICS IN ASTROPHYSICS - X, NPA-X 2022. - : EDP Sciences. - 2100-014X. ; 279
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Konferensbidrag (refereegranskat)abstract
- We measured the Coulomb dissociation of O-16 into He-4 and C-12 within the FAIR Phase-0 program at GSI Helmholtzzentrum fur Schwerionenforschung Darmstadt, Germany. From this we will extract the photon dissociation cross section O-16(alpha,gamma)C-12, which is the time reversed reaction to C-12(alpha,gamma)O-16. With this indirect method, we aim to improve on the accuracy of the experimental data at lower energies than measured so far. The expected low cross section for the Coulomb dissociation reaction and close magnetic rigidity of beam and fragments demand a high precision measurement. Hence, new detector systems were built and radical changes to the (RB)-B-3 setup were necessary to cope with the high-intensity O-16 beam. All tracking detectors were designed to let the unreacted O-16 ions pass, while detecting the C-12 and He-4.
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| 2. |
- de Jong, Roelof S., et al.
(författare)
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4MOST-4-metre Multi-Object Spectroscopic Telescope
- 2014
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Ingår i: Ground-based and Airborne Instrumentation for Astronomy V. - : SPIE. - 0277-786X .- 1996-756X. ; 9147
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Konferensbidrag (refereegranskat)abstract
- 4MOST is a wide-field, high-multiplex spectroscopic survey facility under development for the VISTA telescope of the European Southern Observatory (ESO). Its main science drivers are in the fields of galactic archeology, high-energy physics, galaxy evolution and cosmology. 4MOST will in particular provide the spectroscopic complements to the large area surveys coming from space missions like Gaia, eROSITA, Euclid, and PLATO and from ground-based facilities like VISTA, VST, DES, LSST and SKA. The 4MOST baseline concept features a 2.5 degree diameter field-of-view with similar to 2400 fibres in the focal surface that are configured by a fibre positioner based on the tilting spine principle. The fibres feed two types of spectrographs; similar to 1600 fibres go to two spectrographs with resolution R> 5000 (lambda similar to 390-930 nm) and similar to 800 fibres to a spectrograph with R> 18,000 (lambda similar to 392-437 nm & 515-572 nm & 605-675 nm). Both types of spectrographs are fixed-configuration, three-channel spectrographs. 4MOST will have an unique operations concept in which 5 year public surveys from both the consortium and the ESO community will be combined and observed in parallel during each exposure, resulting in more than 25 million spectra of targets spread over a large fraction of the southern sky. The 4MOST Facility Simulator (4FS) was developed to demonstrate the feasibility of this observing concept. 4MOST has been accepted for implementation by ESO with operations expected to start by the end of 2020. This paper provides a top-level overview of the 4MOST facility, while other papers in these proceedings provide more detailed descriptions of the instrument concept[1], the instrument requirements development[2], the systems engineering implementation[3], the instrument model[4], the fibre positioner concepts[5], the fibre feed[6], and the spectrographs[7].
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| 3. |
- Fassl, Matthias, et al.
(författare)
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Comparing user perceptions of anti-stalkerware apps with the technical reality
- 2022
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Ingår i: Proceedings of the 18th Symposium on Usable Privacy and Security (SOUPS 2022). - : USENIX - The Advanced Computing Systems Association. - 9781939133304 ; , s. 135-154
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Konferensbidrag (refereegranskat)abstract
- Every year an increasing number of users face stalkerware on their phones [84]. Many of them are victims of intimate partner surveillance (IPS) who are unsure how to identify or remove stalkerware from their phones [49]. An intuitive approach would be to choose anti-stalkerware from the app store. However, a mismatch between user expectations and the technical capabilities can produce an illusion of security and risk compensation behavior (i.e., the Peltzmann effect). We compare users' perceptions of anti-stalkerware with the technical reality. First, we applied thematic analysis to app reviews to analyze user perceptions. Then, we performed a cognitive walkthrough of two prominent anti-stalkerware apps available on the Google Play Store and reverse-engineered them to understand their detection features. Our results suggest that users base their trust on the look and feel of the app, the number and type of alerts, and the apps' affordances. We also found that app capabilities do not correspond to the users' perceptions and expectations, impacting their practical effectiveness. We discuss different stakeholders' options to remedy these challenges and better align user perceptions with the technical reality.
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| 4. |
- Ferme, Vincenzo, et al.
(författare)
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Workflow Management Systems Benchmarking : Unfulfilled Expectations and Lessons Learned
- 2017
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Ingår i: PROCEEDINGS OF THE 2017 IEEE/ACM 39TH INTERNATIONAL CONFERENCE ON SOFTWARE ENGINEERING COMPANION (ICSE-C 2017). - : IEEE. - 9781538615898 ; , s. 379-381
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Konferensbidrag (refereegranskat)abstract
- Workflow Management Systems (WfMSs) are a type of middleware that enables the execution of automated business processes. Users rely on WfMSs to construct flexible and easily maintainable software systems. Significant effort has been invested into standardising languages for business processes execution, with standards such as the Web Services Business Process Execution Language 2.0 or the Business Process Model and Notation 2.0. Standardisation aims at avoiding vendor lockin and enabling WfMS users to compare different systems. The reality is that, despite standardisation efforts, different independent research initiatives show that objectively comparing WfMSs is still challenging. As a result, WfMS users are likely to discover unfulfilled expectations while evaluating and using these systems. In this work, we discuss the findings of two research initiatives dealing with WfMSs benchmarking, presenting unfulfilled expectations and lessons learned concerning WfMSs' usability, reliability, and portability. Our goal is to provide advice for practitioners implementing or planning to use WfMSs.
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| 5. |
- Geiger, Matthias, et al.
(författare)
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BPMN Conformance in Open Source Engines
- 2015
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Ingår i: 2015 IEEE Symposium on Service-Oriented System Engineering. - : IEEE. - 9781479983568 ; , s. 21-30
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Konferensbidrag (refereegranskat)
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| 6. |
- Geiger, Matthias, et al.
(författare)
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On the Evolution of BPMN 2.0 Support and Implementation
- 2016
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Ingår i: Service-Oriented System Engineering (SOSE), 2016 IEEE Symposium on Service-Oriented System Engineering (SOSE). - : IEEE. - 9781509022533 ; , s. 119-128
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Konferensbidrag (refereegranskat)
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| 7. |
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| 8. |
- Graña-González, A., et al.
(författare)
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Quasi-free (p,2p) reactions in inverse kinematics for studying the fission yield dependence on temperature
- 2023
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Ingår i: FAIR next generation scientists - 7th Edition Workshop : FAIRness2022 - FAIRness2022. - 1824-8039. ; 419
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Konferensbidrag (refereegranskat)abstract
- Despite the recent experimental and theoretical progress in the investigation of the nuclear fission process, a complete description still represents a challenge in nuclear physics because it is a very complex dynamical process, whose description involves the coupling between intrinsic and collective degrees of freedom, as well as different quantum-mechanical phenomena. To improve on the existing data on nuclear fission, we produce fission reactions of heavy nuclei in inverse kinematics by using quasi-free (p,2p) scattering, which induce fission through particle-hole excitations that can range from few to ten's of MeV. The measurement of the four-momenta of the two outgoing protons allows to reconstruct the excitation energy of the fissioning compound nucleus and therefore to study the evolution of the fission yields with temperature. The realization of this kind of experiment requires a complex experimental setup, providing full isotopic identification of both fission fragments and an accurate measurement of the momenta of the two outgoing protons. This was realized recently at the GSI/FAIR facility and here some preliminary results are presented.
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| 9. |
- Kovatsch, Matthias, et al.
(författare)
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A Low-Power CoAP for Contiki
- 2011. - 11
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Konferensbidrag (refereegranskat)abstract
- Internet of Things devices will by and large be battery-operated, but existing application protocols have typically not been designed with power-efficiency in mind. In low-power wireless systems, power-efficiency is determined by the ability to maintain a low radio duty cycle: keeping the radio off as much as possible. We present an implementation of the IETF Constrained Application Protocol (CoAP) for the Contiki operating system that leverages the ContikiMAC low-power duty cycling mechanism to provide power efficiency. We experimentally evaluate our low-power CoAP, demonstrating that an existing application layer protocol can be made power-efficient through a generic radio duty cycling mechanism. To the best of our knowledge, our CoAP implementation is the first to provide power-efficient operation through radio duty cycling. Our results question the need for specialized low-power mechanisms at the application layer, instead providing low-power operation only at the radio duty cycling layer.
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| 10. |
- Kovatsch, Matthias, et al.
(författare)
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Actinium: A RESTful Runtime Container for Scriptable Internet of Things Applications
- 2012. - 9
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Konferensbidrag (refereegranskat)abstract
- Programming Internet of Things (IoT) applications is challenging because developers have to be knowledgeable in various technical domains, from low-power networking, over embedded operating systems, to distributed algorithms. Hence, it will be challenging to find enough experts to provide software for the vast number of expected devices, which must also be scalable and particularly safe due to the connection to the physical world. To remedy this situation, we propose an architecture that provides Web-like scripting for low-end devices through Cloud-based application servers and a consistent, RESTful programming model. Our novel runtime container Actinium (Ac) exposes scripts, their configuration, and their lifecycle management through a fully RESTful programming interface using the Constrained Application Protocol (CoAP). We endow the JavaScript language with an API for direct interaction with mote-class IoT devices, the CoapRequest object, and means to export script data as Web resources. With Actinium, applications can be created by simply mashing up resources provided by CoAP servers on devices, other scripts, and classic Web services. We also discuss security considerations and show the suitability of this architecture in terms of performance with our publicly available implementation.
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