TY  - CHAP
A1  - Tran, Thanh Ngoc
A1  - Staat, Manfred
A1  - Kreißig, R.
T1  - Calculation of load carrying capacity of shell structures with elasto-plastic material by direct methods
N2  - Proceedings of the International Conference on Material Theory and Nonlinear Dynamics. MatDyn. Hanoi, Vietnam, Sept. 24-26, 2007, 8 p. In this paper, a method is introduced to determine the limit load of general shells using the finite element method. The method is based on an upper bound limit and shakedown analysis with elastic-perfectly plastic material model. A non-linear constrained optimisation problem is solved by using Newton’s method in conjunction with a penalty method and the Lagrangean dual method. Numerical investigation of a pipe bend subjected to bending moments proves the effectiveness of the algorithm.
KW  - Finite-Elemente-Methode
Y1  - 2007
ER  - 
TY  - CHAP
A1  - Fredebeul-Krein, Markus
T1  - 10 years of liberalised telecom markets in Germany: Assessing the degree of competition on the markets for voice telephony
N2  - Market data for the German telecom market shows that Deutsche Telekom as the former incumbent is constantly loosing shares on all arkets for voice telephony: the market for local calls, the market for long-distance calls and the market for international calls. At the same time prices decline steadily with the latest trend being that operators offer voice services free of charge, the costs of which are covered by a monthly subscription charge. Against this background the paper examines the state of policy and regulatory reform in the telecommunications sector in Germany almost 10 years after the liberalisation of the fixed telecommunications market. Thereby the focus is on the analysis of the competitive conditions that have been established on the German market for voice telephony services. If these retail markets are competitive, there might be a need to remove remaining regulatory provisions. In the new environment of converging markets the future challenge of regulating fixed telecom markets might be to ensure that access to the network and/or services of a potentially dominant provider in a relevant market will satisfy requirements for openness and non-discrimination.
KW  - Telekommunikationsmarkt
KW  - Telekommunikationsmarkt
Y1  - 2007
N1  - paper presented at 18th European Regional ITS Conference of the International Telecommunications Society, September 2-4, 2007 Istanbul, Turkey
ER  -