Gefährlich und nutzlos? Kritik an Philosophie und Rhetorik im klassischen Athen

The arrival of philosophy and the art of rhetoric in 5th and 4th century Athens has left its mark on the city’s cultural life as well as on classical culture in general. The process was, however, accompanied by a sometimes heated discussion about the dangers the new education was expected or supposed to have for the community. This critical discussion cannot be dismissed as mere comical mockery, or be reduced to underlying political conflicts alone. In Athens, the new education’s implications for the communal life of the polis were for the first time discussed in front of a larger public. The first in- depth reconstruction and analysis of this discourse has been the aim of my PhD thesis, made possible by a grant from the Excellence Cluster Topoi. This paper recapitulates its mayor results

DLR Workload Assessment Tool (DLR-WAT)-Official English Version

This article presents an official English translation of the "DLR - Workload Assessment Tool" (DLRWAT), an originally German language questionnaire for subjective self-assessment of workload originally published in 2018. The DLR- WAT assesses deviations from a subjective optimum of workload more explicitly than existing measurement tools such as the NASA-TLX. The rationale behind the development of this tool is found in the increasing coexistence of humans and automation technology in sociotechnical systems across application domains such as transportation. Automation technology assists and takes over tasks formerly executed by humans as actors, resulting in changing human roles ranging for example from more passive monitoring tasks to short term interventions in cases of malfunction. In general, automation can relieve humans and increase their comfort. Yet, the issue of unbalanced workload and especially more prevalent underload needs to be targeted given the changing task environments faced by staff in the transportation domain. However, instruments for the subjective assessment of workload have so far lacked clear differentiation between underload and overload anchored in relation to a subjectively optimal level of workload. The DLR-WAT was developed to fill that gap, while greatly relying on the general format of the widely established NASATLX. The tool comprises a total of eight subscales. On six of the eight subscales (information acquisition, knowledge retrieval, decision-making, motor and physical demand, temporal demand, effort), the respondent can indicate his or her state of workload in relation to the personal optimum, which is located in the middle of each subscale. The two other subscales of the DLR-WAT (frustration, performance) are designed one-dimensionally, since an optimal level of frustration is characterised by the absence of frustration and the highest possible performance equals the theoretical optimum. The consideration of the personal optimum of workload in the first six subscales is thought to enable more detailed workload analyses distinctively imaging underload and overload in the areas represented by the subscales. In designing future transportation systems, this tool enables identification of the targeted balance between overload and underload across subscales and allows informed subsequent allocation of tasks between humans and automation accordingly

Potential of auxiliary strobe lights on train locomotives to improve level crossing safety

Inattentiveness of road users on approach to passive railway crossings represents a major threat to level crossing safety. An auxiliary strobe light system installed on trains in addition to existing headlights may help address this issue by providing an ergonomic way of attracting human attention to the level crossing and to the train. The objective of this paper was to investigate the ergonomics and safety potential of auxiliary strobe light systems. A system was implemented on a real railway vehicle and in the virtual environment of a driving simulator. Acceptance of the system, including its usefulness and perceived benefits and drawbacks, as well as its objective effectiveness, were evaluated using questionnaires, behavioural measures, and eye tracking. The safety potential of the system was evaluated with respect to fatal level crossing accidents. The auxiliary strobe lights were preferred over normal lights and were rated as useful, reducing driving speeds, increasing visual scanning at level crossings, and thus aiding detection of a train. The system has the potential to prevent 6–30% of level crossing accidents in Europe. The results suggest that it might be worthwhile to test auxiliary strobe lights in a larger scale real-world experiment. Especially on railway lines with a high number of passive level crossings, this system can be expected to increase safety by supporting timely detection by road users and preventing accidents caused by inattentiveness

Testing a digital level crossing warning system for road traffic users with a naturalistic driving study

The points where roads intersect with railroads, called level-crossings, have traditionally been considered dangerous due to the excessive severity of accidents that have occurred involving all kinds of road vehicles and trains. They are most frequently protected with regular safety systems like barriers of light signals, however numerous level-crossings still remain unprotected. In addition, the maintenance status of level crossings differs strongly across Europe. As a consequence, some level crossings pose serious safety threats to road- and rail users, if the level crossing safety infrastructure does not exist or is not properly maintained and operated. Especially at level crossings in urban areas of municipalities in developing countries in Europe, it is often overly costly or even impossible to protect a high number of level crossings and maintain them on a regular basis. Digitalization, the huge coverage of mobile telecommunications networks and the penetration of smart phones and mobile devices in society offer a starting point for alternative, hi tech safety measures, that promise to be cheap as well as effective. Such a system has been developed and tested in Thessaloniki, where a mobile device elicits an auditory as well as a visual warning whenever the user drives in close proximity and heading to any of the 30 level crossings located in the suburbs of the city. Some trains have also been equipped with Global Navigation Satellite System (GNSS) sensors which record and transmit highly accurate spatiotemporal data, so when they approach the level crossings the mobile users also receive the estimated time of arrival on their smart phones and tablets. Three taxis were equipped with a naturalistic driving platform, consisting of cameras and a GPS sensor, to track the behavior of the drivers whenever they approached level crossings. The equipment was installed taking into consideration both the safety of all passengers and the privacy of customers. Only the drivers and surroundings of the vehicles were recorded, for a prolonged period that lasted more than two months and resulted in more than 1TB of relevant video data for further analysis. During the first month the alert system was not activated, in order to collect baseline data. The safety relevant behavior of the drivers in the context of level crossings before the implementation of the assistance system was compared to their behavior when using the system

Side effects of nonlinear profit taxes in an evolutionary market entry model: Abrupt changes, coexisting attractors and hysteresis problems

In order to demonstrate that nonlinear tax systems may have surprising and potentially undesirable side effects, we develop an evolutionary market entry model in which firms decide on the basis of past profit opportunities whether or not to enter a competitive market. Our main focus is on the case of a proportional tax on positive profits. Such a piecewise-linear tax scheme induces a kink in the firms’ profit functions, and may lead to abrupt changes in a market's dynamics, coexisting attractors and hysteresis problems. Since these phenomena can also be observed in more general models, a proper understanding of their basic mechanism may be helpful to explain the intricate behavior of many economic systems

SAFER-LC: Innovative Lösungen für mehr Sicherheit am Bahnübergang

Im hochsicheren System "Bahn" stellen Kreuzungen mit dem Straßenverkehr nach wie vor Punkte mit erhöhtem Risiko dar. Das europäische Projekt SAFER-LC zielt auf die Identifikation von Unfallursachen und die Ableitung von Maßnahmen zur Erhöhung der Sicherheit an Bahnübergängen ab. Dabei werden das physische Erscheinungsbild von Übergängen, existierende Systeme von Signalen und Barrieren und die technischen Möglichkeiten der Digitalisierung und Vernetzung ebenso unter die Lupe genommen wie die Strukturen und Prozesse, in welche die Abwicklung des Schienen- und Straßenverkehrs eingebettet ist

SAFER-LC: Level Crossing Design Meets Traffic Psychology

Human inattentiveness or risk-taking can easily compromise the safety offered by warning signs and approved safety systems in rail and road traffic. For this reason, level crossings remain one of the major vulnerable spots within the railway system. The degree of safety at level crossings does not solely depend on the level of reliability of technical safety systems. Since the safety standard of technical systems at level crossings is extremely high, the most variable factor and most critical point in the context of the level crossing is road user behavior. Within the joint European research project SAFER-LC, human factors were therefore identified as an important starting point to find and develop effective measures that can enhance safety at level crossings. A huge variety of safety measures has been proposed in the past. Some measures focus on improving the visibility of trains and infrastructural elements, some appeal to road users’ understanding of the situation through informative signs or warnings, others use structural changes in the road surface to induce speed reduction. This article provides an overview of road-user-centered measures proposed in the literature to enhance the safety of traverse at level crossings. A descriptive model of three fundamental steps in human information processing – perception of the level crossing, activation of relevant knowledge and formation of behavioral intention – serves as a framework to systemize and categorize road-user-centered safety measures from the literature. The overview offers a psychological perspective on measures that could be implemented by rail and road infrastructure managers to enhance safety at level crossings

Nonsmooth contact dynamics for the large-scale simulation of granular material

For the large-scale simulation of granular material, the Nonsmooth Contact Dynamics Method (NSCD) is examined. First, the equations of motion of nonsmooth mechanical systems are introduced and classified as a Differential Variational Inequality (DVI) that has a structure similar to Differential Algebraic Equations (DAEs). Using a Galerkin projection in time, we derive nonsmooth extensions of the SHAKE and RATTLE schemes. A matrix-free Interior Point Method (IPM) is used for the complementarity problems that need to be solved in each time step. We demonstrate that in this way, the NSCD approach yields highly accurate results and is competitive compared to the Discrete Element Method (DEM)