Path Relinking, Cycle-Based Neighbourhoods and Capacitated Multicommodity Network Design

In this paper, we propose a path relinking procedure for the fixed-charge capacitated multicommodity network design problem. Cycle-based neighbourhoods are used both to move along paths between elite solutions and to generate the elite candidate set by a tabu-like local search procedure. Several variants of the method are implemented and compared. Extensive computational experiments indicate that the path relinking procedure offers excellent results. It systematically outperforms the cycle-based tabu search method in both solution quality and computational effort and offers the best current meta-heuristic for this difficult class of problems.     

Traffic with an fBm Limit: Convergence of the Stationary Workload Process

Highly-aggregated traffic in communication networks is often modeled as fractional Brownian motion (fBm). This is justified by the theoretical result that the sum of a large number of on–off inputs, with either on-times or off-times having a heavy-tailed distribution with infinite variance, converges to fBm, after rescaling time appropriately. For performance analysis purposes, the key question is whether this convergence carries over to the stationary buffer content process. In this paper it is shown that, in a heavy-traffic queueing environment, this property indeed holds.     

Schwefelbestimmung in Stahl und Eisen

Ohne Zusammenfassung     

High-performance liquid chromatographic-radioimmunoassay method for the measurement of angiotensin II peptides in human plasma

A highly selective high-performance liquid chromatographic-radioimmunoassay method for the measurement of individual endogenous angiotensin peptides in human plasma is described. This method allows the complete resolution of the immunoreactive angiotensin II peptides. We have also measured the angiotensin peptide levels and compared them in both pooled and individual human plasma. The effects of inhibition of angiotensin-converting enzyme on the angiotensin peptide levels have also been observed in a patient with renovascular hypertension with the plasma angiotensin II level being reduced greater than seven-fold. This new methodology was validated by recovery experiments in plasma over a range of physiological levels using two methods of detection, radioimmunoassay and liquid scintillation counting. Consistent recoveries near 80% have been achieved for each peptide in plasma at concentrations over a physiological range. The described method enables the direct measurement of the circulating angiotensin peptides and the elucidation of their specific roles in physiological and disease states.     

Study of segmental orientation in poly (vinyl chloride)/poly (α-methyl-α-n-propyl-β-propiolactone) blends by fourier-transform infrared spectroscopy

Fourier-transform infrared (FTIR) spectroscopy has been used to investigate the segmental orientation of poly(vinyl chloride) (PVC)/poly (α-methyl-α-n-propyl-β-propiolactone) (PMPPL) blends in uniaxially stretched samples over a wide range of compositions and draw ratios. The results indicate that for pure PVC, syndiotactic segments reach a higher degree of orientation than isotactic segments and gauche conformations. Similarly, for pure PMPPL, crystalline segments orient more than amorphous segments at any given elongation. Thus, for both polymers, the higher orientation is obtained for the more rigid segments or those located in a more rigid (crystalline) phase. The addition of the macromolecular plasticizer PMPPL has no effect on the orientation of PVC syndiotactic segments, but it lowers the orientation of PVC gauche conformations, suggesting that the polyester is located in the amorphous regions of PVC. Finally, the PMPPL orientation function initially decreases with the addition of PVC and thereafter remains constant. The results are discussed in terms of interpenetrating networks and relaxation processes.     

The subconvexity problem for Rankin–Selberg L-functions and equidistribution of Heegner points. II

We prove a general subconvex bound in the level aspect for Rankin–Selberg L-functions associated with two primitive holomorphic or Maass cusp forms over Q. We use this bound to establish the equidistribution of incomplete Galois orbits of Heegner points on Shimura curves associated with indefinite quaternion algebras over Q. Mathematics Subject Classification (2000) 11F66, 11F67, 11M41     

Régulateurs syntomiques et valeurs de fonctionsL p-adiques II

Sans résuméOblatum 15-III-1991 & 2-X-1992 & 14-I-1992 & 3-III-1993 & 17-V-1993