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141.
Two techniques for voltage reduction are presented, both of which can significantly reduce the power consumption of digital CMOS circuits. The fixed reduction of voltage is applicable to small systems with a low initial consumption, however, the optimum voltage is not reached and the correct operation of the circuit is not guaranteed. The self-adjusted reduction of voltage is adapted to bigger digital systems. The correct operation of the digital circuit is guaranteed, and the supply voltage is near the optimum for the speed requirements. This technique is more versatile, accurate, and reliable than the fixed one 相似文献
142.
Quantum computers hold the promise of solving certain computational tasks much more efficiently than classical computers. We review recent experimental advances towards a quantum computer with trapped ions. In particular, various implementations of qubits, quantum gates and some key experiments are discussed. Furthermore, we review some implementations of quantum algorithms such as a deterministic teleportation of quantum information and an error correction scheme. 相似文献
143.
Schmid M. Weber R. Graf T. Roos M. Weber H.P. 《Quantum Electronics, IEEE Journal of》2000,36(5):620-626
The results of numerical simulations based on finite-element methods for thermally induced birefringence in Nd:YAG crystal rods are compared with measurements and analytical solutions. A novel analytical solution for inhomogeneous pumping is presented. It is shown that the behavior of thermally induced birefringence is very sensitive to the pump geometry 相似文献
144.
St. J. Von Przyłęcki 《Colloid and polymer science》1938,85(2-3):251-255
Ohne ZusammenfassungBearbeitet von H. Kauffmann (Leipzig). 相似文献
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146.
C. Roos 《Mathematical Programming》1990,46(1-3):79-84
Recently T. Terlaky has proposed a new pivoting rule for the criss-cross simplex method for linear programming and he proved that his rule is convergent. In this note we show that the required number of iterations may be exponential in the number of variables and constraints of the problem. 相似文献
147.
Gerritsma R Lanyon BP Kirchmair G Zähringer F Hempel C Casanova J García-Ripoll JJ Solano E Blatt R Roos CF 《Physical review letters》2011,106(6):060503
We report on quantum simulations of relativistic scattering dynamics using trapped ions. The simulated state of a scattering particle is encoded in both the electronic and vibrational state of an ion, representing the discrete and continuous components of relativistic wave functions. Multiple laser fields and an auxiliary ion simulate the dynamics generated by the Dirac equation in the presence of a scattering potential. Measurement and reconstruction of the particle wave packet enables a frame-by-frame visualization of the scattering processes. By precisely engineering a range of external potentials we are able to simulate text book relativistic scattering experiments and study Klein tunneling in an analogue quantum simulator. We describe extensions to solve problems that are beyond current classical computing capabilities. 相似文献
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W. Roos 《General Relativity and Gravitation》1976,7(5):431-444
The existence problem of matter sources for given stationary axisymmetric solutions of Einstein's vacuum field equations is investigated. The existence of sources of a differentially or rigidly rotating perfect fluid can be proved at least in the neighborhood of boundary surfaces if these can be chosen suitably (theorem). In particular, there exist such half-local perfect fluid sources for the Kerr metric. Hence the existence of a global regular Kerr-interior solution cannot be excluded by local considerations in an arbitrarily small neighborhood of a possible boundary.Work supported in part by the Deutsche Forschungsgemeinschaft. 相似文献