Die bei Zugfahrten in Eisenbahntunneln auftretenden druckwellen‐ und strömungsinduzierten aerodynamischen Belastungen werden dargelegt und in Bezug auf die Beanspruchungswirkungen der in modernen ...Bahntunneln ausgeführten unterschiedlichen Einbauten diskutiert. Es wird gezeigt, dass die in den derzeitigen Richtlinien und Normen angegebenen Belastungsgrößen tw. unvollständig sind und insbesondere die Effekte einer Wirbelablösung am Heck des fahrenden Zugs mit der daraus sich einstellenden hochgradig dynamischen Wirbelschleppe nicht abdecken. Im Zuge von mehreren Messkampagnen und begleitenden numerischen Simulationsberechnungen wurden in Österreich die in der Realität bei Zugfahrten in Eisenbahntunneln tatsächlich auftretenden aerodynamischen Belastungen abgeleitet und darauf aufbauend für unterschiedliche Einbauten die bei der Bemessung anzusetzenden Belastungswerte formuliert. Bei den Simulationsberechnungen wurde insbesondere auch die bei langen Tunneln maßgebende Fahrt von mehreren Zügen dicht hintereinander untersucht. Die Durchführung dieser numerischen Simulationsberechnungen und Messkampagnen unter realen Betriebsbedingungen in schnell befahrenen eingleisigen Eisenbahntunneln sowie die erzielten Ergebnisse werden dargelegt.
Aerodynamic loads to installations in high‐speed railway tunnels
The pressure wave and flow‐induced aerodynamic loads occurring during train runs in railway tunnels are described and discussed with reference to the different installations in modern railway tunnels. It is shown that the load values given in the current guidelines and standards are partly incomplete and in particular do not cover the effects of vortex shedding at the rear of the moving train with the resulting highly dynamic wake vortex. In the course of several measurement campaigns and accompanying numerical simulations, the aerodynamic loads actually occurring in reality during train travel in railway tunnels were recorded in Austria and based on this, the load values to be used in the design were formulated for different installations. In the numerical simulations, the decisive travel of several trains in close succession in long tunnels was also examined. The execution of these numerical simulations and measurement campaigns under real operating conditions in fast single‐track railway tunnels as well as the results obtained are presented.
Tajni nadzor komunikacija koji se rabi za potrebe nacionalne sigurnosti i u svrhu provođenja policijskih istražnih radnji vrijedno je tehničko sredstvo i koristan alat tijela policijskog, pravosudnog ...i sigurnosnog sustava. U tehničkim aspektima, ovo polje bilježi značajne pomake u posljednjem desetljeću gdje su dostupni softver i platforme za provođenje tajnog nadzora proširene mogućnostima nadzora širokog spektra različitih komunikacijskih kanala. Funkcija tajnog nadzora komunikacija u suštini predstavlja ograničenje temeljnih prava pojedinaca na području Europske unije i država članica. Svrha ovog rada kao priloga raspravi o mehanizmima tajnog nadzora jest izložiti osobine modela naprednog softvera razvijenog u svrhu tajnog nadzora, usporedba s najčešćim modelima tajnog nadzora i analiza softverske arhitekture definirane od strane Europskog instituta za telekomunikacijske norme (ETSI) kao dominantne norme u ovom području. Iako se ovaj model arhitekture tajnog nadzora razvio inicijalno za nadzor glasovnih komunikacija, može ga se uspješno primijeniti i za tajni nadzor komunikacija koje koriste internet protokol (IP). Konačno, članak pruža komparativni pregled različitog softvera tajnog nadzora u skladu s regulativom funkcije tajnog nadzora.
•The study applied the image repair discourse to the German business environment.•Mortification and reduce offensiveness appeared within the frame of corrective action.•Denial emerged within the ...frame of transcendence.•Contrary to past research on image repair, the company made little use of mortification.•The image repair strategies met the stakeholders’ expectations with regard to detail- orientation and crisis context.
This analysis expands on the image restoration discourse and adapts it to the German business environment. It takes into account the cultural dimensions of uncertainty ambiguity and long-term orientation (Hofstede, 2011) to analyze Deutsche Telekom’s image repair attempts in the aftermath of a spying scandal. The results reveal that the strategies of mortification and reduce offensiveness emerged within the frame of corrective action while denial was present in the overarching theme of transcendence. The use of corrective action and transcendence as larger frames for crisis communication meets the stakeholders’ expectations in terms of a systematic overview of details and a focus on the crisis's context. The results reveal the need for continued research that ascertains ways of adapting the image repair discourse to international business environments. Finally, the results of this study can be used by companies that operate in Germany in their attempt to reduce the negative impact of a crisis on their reputation.
Die Deutsche Telekom ist die mit Abstand größte Betreiberin von Fest- und Mobilfunknetzen in Deutschland. Deshalb kommt ihrer strategischen Positionierung nationale Bedeutung für die Entwicklung der ...infrastrukturellen Grundlagen der Digitalisierung zu. Nachfolgend wird angenommen, dass diese Positionierung wesentlich durch die Vorstandsvorsitzenden der Deutschen Telekom geprägt wird. Die Kapitalmarktbewertung des Konzerns während der Amtszeiten der vier bisherigen Vorstandsvorsitzenden werden unter Einbezug von drei Börsenindizes und den Big-Five-Tech-Unternehmen verglichen. Daraus werden Schlussfolgerungen zu aus Kapitalmarktsicht sinnvollen Strategieelementen der Deutschen Telekom und zur Berechtigung wirtschaftspolitischer Forderungen nach Netzinvestitionsabgaben von großen Over-The-Top-Unternehmen gezogen.
Assuming that CEOs significantly shape a firm's strategic positioning, the present study looks at two stock-exchange valuation criteria of the largest German telecommunications network operator, Deutsche Telekom, to reflect on the performance of the four CEOs leading the firm since its Initial Public Offering in 1996. The criteria are the average annual change rate of Deutsche Telekom's (1) share price and (2) market capitalisation during a CEO's term of office. The two measures are compared between the CEOs and with eight benchmarks (three stock indices, big-five tech companies). Results suggest that (1) Deutsche Telekom's present CEO outperforms his predecessors mainly due to a clear emphasis on Deutsche Telekom's mobile communication business in the US and (2) the CEO-independent lower value of Deutsche Telekom relative to Google, Apple, Meta, Microsoft, Amazon and other large over-the-top platform providers cannot be remedied through network access fees/cost contributions imposed on OTT companies.
Zusammenfassung
Insbesondere bei längsschnittlichen Evaluationen erscheinen gemischt-methodische Ansätze im Bereich Mixed Methods sinnvoll, da sich die Studien prinzipiell dazu eignen, ...Evaluationsgegenstände von hohem Komplexitätsgrad zu erfassen, wie es beispielsweise dynamische Veränderungsprozesse in Bildungsstrukturen sind. Der Artikel stellt anhand der längsschnittlichen Entwicklung von professionsbezogenen Überzeugungen von Mathematiklehramtsstudierenden dar, wie in einem derartigen Ansatz durch die Integration von durch verschiedene Forschungsmethoden gewonnenen Ergebnissen Makro- und Mikrostrukturen berücksichtigt werden können. Mit Hilfe von latenten Wachstumskurvenmodellen konnte die Entwicklung von Überzeugungen von 235 Lehramtsstudierenden an fünf Hochschulen längsschnittlich modelliert werden. Fallbasiert konnten auf der Grundlage von 19 Interviews anschließend Zusammenhänge zwischen institutionellen Rahmenbedingungen und der individuellen Entwicklung von Überzeugungen herausgestellt werden. Es konnte u. a. eine hohe Zustimmung zu konstruktivistisch orientierten Lehr- und Lernformen festgestellt werden, die sich zum Teil auf die Erfahrungen universitärer Lehre zurückführen lassen.
The article analyses the systemic framework of the operation of the Intelligence and Security Service of the Ministry of Defence (Obvescevalnovarnostna sluzba OVS) and parliamentary control over its ...operations. It takes as its focus a recent case related to the Defence Minister's order to the Service to produce material on the effects of the privatisation of the Telekom Slovenije on the operation of the Service in the light of Slovenia's defence interests. A linguostylistic analysis of the media reporting on the case was carried out. The findings show that while after 25 years as an independent state Slovenia has established the institutional framework for the operation of OVS and arranged parliamentary control over its work, it has not as yet managed to achieve the harmonised operation of all state policies in the field of national security. Rather than contributing to the resolution of certain dilemmas with regard to the legal, political and expert aspects of the operation of the civil intelligence and security service in the context of Slovenian national defence, media reporting used a selection of topicalized linguistic means (actualisms, i.e. stylistically marked linguistic means) in headlines to characterise the event as a scandal, and the OVS as a military intelligence service.
This study investigates the internal and external strategic choices that telecommunications firms, operating in a dynamic network environment, make to adapt to changes and to respond quickly in order ...to create or to sustain their competitive advantage. In particular, in the European telecommunications industry incumbent firms have faced important challenges from new technologies, liberalization and the convergence of markets. The leading European telecommunications companies initially focused on new markets and new businesses, emphasizing their plans to become major players in relevant markets. However, after the telecommunications euphoria companies were more restrained due to their huge burden of debt and their market value. Through refocusing or restructuring, these companies have tried to streamline their businesses in order to restore their value and to improve their competitiveness. Insight into the specific strategic actions of traditional telecommunications companies in Europe to the recent developments in the industry is provided from the analysis of three leading traditional telecommunications companies: BT, Deutsche Telekom and KPN.
PDF
