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OpenPGP is one of the two major standards for end-to-end email security. Several studies showed that serious usability issues exist with tools implementing this standard. However, a widespread assumption is that expert users can handle these tools and detect signature spoofing attacks. We present a user study investigating expert users' strategies to detect signature spoofing attacks in Thunderbird. We observed 25 expert users while they classified eight emails as either having a legitimate signature or not. Studying expert users explicitly gives us an upper bound of attack detection rates of all users dealing with PGP signatures. 52% of participants fell for at least one out of four signature spoofing attacks. Overall, participants did not have an established strategy for evaluating email signature legitimacy. We observed our participants apply 23 different types of checks when inspecting signed emails, but only 8 of these checks tended to be useful in identifying the spoofed or invalid signatures. In performing their checks, participants were frequently startled, confused, or annoyed with the user interface, which they found supported them little. All these results paint a clear picture: Even expert users struggle to verify email signatures, usability issues in email security are not limited to novice users, and developers may need proper guidance on implementing email signature GUIs correctly.
Mittlerweile eine feste Institution und im Terminkalender vieler FM und CREM Verantwortlichen fixiert: Der Münsteraner Facility Management Tag. Seit nunmehr 10 Jahren kommen Interessierte und Freunde der FM-Branche nach Münster, um gemeinsam über Entwicklungen und Trends der Branche zu diskutieren. Der Münsteraner Facility Management Tag verfolgt dabei folgende Schwerpunkte: Darstellung praxisnaher Lösungsansätze Praxisorientierte Wissensvermittlung Stärkung des Transfers zwischen Theorie und Praxis unter dem Motto "Wissenschaft.Praktisch.Machen" Erfahrungsaustausch und best-practice
Mittlerweile eine feste Institution und im Terminkalender vieler FM und CREM Verantwortlichen fixiert: Der Münsteraner Facility Management Tag. Seit nunmehr 10 Jahren kommen Interessierte und Freunde der FM-Branche nach Münster, um gemeinsam über Entwicklungen und Trends der Branche zu diskutieren. Der Münsteraner Facility Management Tag verfolgt dabei folgende Schwerpunkte: Darstellung praxisnaher Lösungsansätze Praxisorientierte Wissensvermittlung Stärkung des Transfers zwischen Theorie und Praxis unter dem Motto "Wissenschaft.Praktisch.Machen" Erfahrungsaustausch und best-practice
A COMPREHENSIVE ACTIVE-BASED LEARNING ENVIRONMENT FOR MANAGEMENT EDUCATION: AN EVALUATIVE STUDY
(2017)
There seems to be a strong distinction between what most business schools prepare their students for and what practicing managers actually do in their professional life [1]. Business education, in general, sees management as analytical and scientific, when empirical evidences indicate that the practicing manager repertoire is comprised not only of analysis but mainly of the development of solutions to illdefined problems [2].
Moreover, the globalization of the economy and the shift from a manufacturing to an informationbased society have led to significant changes in the conditions of work; with post-industrial economies
living an era of continuous market change and creative destruction [3], [4]. This scenario increases the array of responsibilities of higher education institutions which, in addition to providing disciplinary knowledge, should develop in students non-disciplinary competences such as decision-making, problem-solving, interpersonal communication, etc. As argued by Zlatkin-Troitschanskaia, et al. [5],
the development of such competences - sometimes referred as transversal or generic - are increasingly relevant in a society facing constant changes, since they are adaptable to various contexts enhancing the relevancy and the employability of students.
Under this perspective, a change in management education is needed. It should be oriented less on the training of business analysts and more on preparing future managers for solving the ill-designed
problems of real business practice. It is suggested that the focus of business education should move from ‘simply’ providing a body of domain-specific knowledge to give students the opportunity to apply
that knowledge under realistic contexts which better resembling management practice and foster the development of generic competences. In that respect, literature suggested that active-based learning
methods are best fitted for the ‘task’ [6]. More specifically, it points out to a series of ‘desirable’ elements that should be present if one wants to accurately replicate a management learning
environment. This author condensed those elements to form a theoretical proposition: that to build powerful management learning environments one needs to offer students the opportunity to
collectively engage in a series of continuous real-world experiences in a process permeated by careful reflection in and on the action.
Astronomy is driven by the quest for higher sensitivity and improved angular resolution in order to detect fainter or smaller objects. The far-infrared to submillimeter domain is a unique probe of the cold and obscured Universe, harboring for instance the precious signatures of key elements such as water. Space observations are mandatory given the blocking effect of our atmosphere. However the methods we have relied on so far to develop increasingly larger telescopes are now reaching a hard limit, with the JWST illustrating this in more than one way (e.g. it will be launched by one of the most powerful rocket, it requires the largest existing facility on Earth to be qualified). With the Thinned Aperture Light Collector (TALC) project, a concept of a deployable 20 m annular telescope, we propose to break out of this deadlock by developing novel technologies for space telescopes, which are disruptive in three aspects: • An innovative deployable mirror whose topology, based on stacking rather than folding, leads to an optimum ratio of collecting area over volume, and creates a telescope with an eight times larger collecting area and three times higher angular resolution compared to JWST from the same pre-deployed volume; • An ultra-light weight segmented primary mirror, based on electrodeposited Nickel, Composite and Honeycomb stacks, built with a replica process to control costs and mitigate the industrial risks; • An active optics control layer based on piezo-electric layers incorporated into the mirror rear shell allowing control of the shape by internal stress rather than by reaction on a structure. We present in this paper the roadmap we have built to bring these three disruptive technologies to technology readiness level 3. We will achieve this goal through design and realization of representative elements: segments of mirrors for optical quality verification, active optics implemented on representative mirror stacks to characterize the shape correction capabilities, and mechanical models for validation of the deployment concept. Accompanying these developments, a strong system activity will ensure that the ultimate goal of having an integrated system can be met, especially in terms of (a) scalability toward a larger structure, and (b) verification philosophy.
This paper uses the findings from a literature review and series of expert interviews to develop a richer and Purchasing and Supply Management (PSM) context-specific perspective of the different key techniques, tools and principles that can be used to develop gamified learning to enhance the skills required by PSM professionals in dealing with current and future challenges, such as the transformation to Industry 4.0. It also provides further details of the different stages of implementing gamified learning, which can enhance the success of any such provision.
Introduction: Many disease processes are accompanied and promoted
by increased inflammation in the body. Increased concentrations of high-sensitivity C-reactive protein (hs-CRP) in the blood are an indicator of subclinical inflammation, increased disease risk, and an increased risk of early death. A healthy plant-based diet and increased physical activity have been shown to reduce hs-CRP concentrations.
Objectives: Our objective was to test if a healthy lifestyle intervention program can improve hs-CRP levels and other risk factors.
Methodology: We are conducting a non-randomized, controlled intervention study with 6 times of measurement (baseline, after 2.5, 6, 12, 18 and 24 months). Participants in the intervention group (n = 104) took part in a 2.5-month intensive lifestyle program focusing on a plant-based diet (PBD), physical activity, stress management and group support. Currently they are in the less intensive phase (monthly seminars) which will be completed after 24 months. The control group (n = 62) did not take part in any program. In both groups hs-CRP was assessed, and participants with an infection/common cold at any of the times of measurement were excluded from the analyses.
Results: In the intervention group (n = 97) we observed a reduction in hsCRP from baseline to 2.5 months (p < 0.001). In the control group (n = 46) hs-CRP levels increased non-significantly. The changes from baseline to 2.5 months were significantly different between intervention and control (p < 0.01).
Conclusion: Our program led to a clinically relevant reduction in hs-CRP.
Continued follow-up will show if this improvement can be maintained in the intervention group. Our study confirms that a PBD and healthier lifestyle choices can lower hs-CRP.
Teaching People to program is a crucial requirement for our society to deal with the complexity of 21st-century challenges. In many teaching systems, the student is required to use a particular programming language or development environment. This paper presents an intelligent tutoring system to support blended learning scenarios, where the students can choose their programming language and development environment. For that, the system provides an interface where the students request test data and submit results to unit test their algorithms. The submitted results are analyzed by a machine learning system that detects common errors and provides adaptive feedback to the student. With this system, we are focusing on teaching algorithms rather than specific programming language semantics. The technical evaluation tested with the implementation of Mean and Median algorithm shows that the system can distinguish between error cases with an error rate under 20%. A first survey, with a small group of students, shows that the system helps them detect common errors and arrive at a correct/valid solution. We are in the process of testing the system with a larger group of students for gathering statistically reliable data.
Quick UDP Internet Connections (QUIC) is a novel transport protocol introducing known features in a new protocol design. To investigate these features and the design, we developed a QUIC implementation in the INET simulation model suite.
In this paper, we describe that implementation, its validation and a result achieved using the simulation model. The result shows the negative impact on throughput, when raising the acknowledgment ratio. We propose a solution and describe how it solves the issue.
A user-friendly Pitot probe data reduction Excel-Refprop-Routine for non-ideal gas flow applications
(2021)
Sediment bypass tunnels are an effective and sustainable strategy against reservoir sedimentation. Sediments are diverted into the down-stream during floods without deposition in the reservoir, hence mor-phological and ecological variability increases. One major drawback of these tunnels is the severe invert abrasion due to a combination of high flow velocities and bedload sediment transport. The abrasion phenom-ena is briefly described, different abrasion prediction models are pre-sented and their applicability for the estimation of concrete abrasion is discussed.
A major drawback of sediment bypass tunnels is the potential for severe invert abrasion due to intense bedload sediment transport. This paper briefly describes the abrasion phenomena as well as the available models used to predict invert material loss. The application and calibration is demonstrated on the basis of the Mud Mountain sediment bypass tunnel, Washington, USA.
For a long time, a large number of top managers in listed companies have regarded communication with their shareholders as a necessary evil and now, in times of activist investors, are faced not only with the great challenges of opening up to shareholders and revealing their own corporate strategy, but also at the same time have to withstand the massive external pressure from activist investors, who are rarely majority shareholders. To achieve this, it is essential that a complete rethink-ing of the communication strategy of those responsible for the company takes place.
Adaptive laser resonators with deformable MOEMS mirrors under closed-loop control are discussed and experimental results are presented. The requirements for deformable mirrors and for closed-loop control systems of these mirrors are analyzed. Several deformable mirrors have been characterized and the results are presented. Currently available membrane mirrors deform under laser load and need further development before they can be used for aberration correction of solid state lasers above some tens of Watts. Nevertheless, the results are encouraging and the requirements are within reach of currently available technology. Finally, we demonstrate an Nd.YVO4-laser with a closed-loop adaptive resonator and more than 6 W of output power. The closed-loop system was able to compensate artificially introduced aberrations from a phase plate.
GSI Darmstadt currently builds a high-energy petawatt Nd:glass laser system, called PHELIX (Petawatt High-Energy Laser for Heavy-Ion Experiments). PHELIX will offer the world-wide unique combination of a high current, high-energy heavy-ion beam with an intense laser beam. Aberrations due to the beam transport and due to the amplification process limit the focusability and the intensity at the target. We have investigated the aberrations of the different amplification stages. The pre-amplifier stage consists of three rod-amplifiers which cause mainly defocus, but also a small part of coma and astigmatism. The main amplifier consists of five disk amplifiers with a clear aperture of 315 mm. These large disk-amplifiers cause pump-shot aberrations which occur instantly. After a shot, the disk amplifiers need a cooling time of several hours to relax to their initial state. This limits the repetition rate and causes long-term aberrations. We will present first measurements of the pump-shot and long-term aberrations caused by the pre- and the main amplifier in a single-pass configuration. In this context, we will present the adaptive optics system which is implemented in the PHELIX beam line and discuss its capability to compensate for the pump-shot and long-term aberrations.
This paper focusses on effective teaching and learning methods in the context of a larger project that aims to align objectives in higher education with employer requirements in the field of purchasing and supply management (PSM). The reason is that little is known about which specific skills and competencies of PSM professionals are needed outside academia and which learning objective higher education should incorporate to meet the practical PSM requirements of firms and organisations. Practice as well as literature share the understanding that PSM professionals need a well-balanced mixture of knowledge and soft-skills: the merely explicit know-what (codified knowledge), know-why (theory), know-how (method) and inter- & intrapersonal soft skills.
Active optics is an enabling technology for future large space telescopes. Image-based wavefront control uses an image-sharpness metric to evaluate the optical performance. A control algorithm iteratively adapts a corrective element to maximize this metric, without reconstructing the wavefront. We numerically study a sharpness metric in the space of Zernike modes, and reveal that for large aberrations the Zernike modes are not orthogonal with respect to this metric. The findings are experimentally verified by using a unimorph deformable mirror as
corrective element. We discuss the implications for the correction process and the design of control algorithms.