Improved solutions to dynamic and stochastic maritime pick-up and delivery problems using local search.

Heuristics for stochastic and dynamic vehicle routing problems are often kept relatively simple, in part due to the high computational burden resulting from having to consider stochastic information in some form. In this work, three existing heuristics are extended by three different local search variations: a first improvement descent using stochastic information, a tabu search using stochastic information when updating the incumbent solution, and a tabu search using stochastic information when selecting moves based on a list of moves determined through a proxy evaluation. In particular, the three local search variations are designed to utilize stochastic information in the form of sampled scenarios. The results indicate that adding local search using stochastic information to the existing heuristics can further reduce operating costs for shipping companies by 0.5–2 %. While the existing heuristics could produce structurally different solutions even when using similar stochastic information in the search, the appended local search methods seem able to make the final solutions more similar in structure.

Climbing Combinatorial Fitness Landscapes

International audience

Use of survival analysis as a tool for the genetic improvement of age at first conception in Nellore cattle

Restricted breeding seasons in beef cattle lead to censoring of reproductive data. In this paper, age at first conception (AFC) of Nellore females exposed to the sires for the first time between 11 and 16 months of age, was studied aiming to verify the possibility of genetically advance sexual precocity using a survival model. The final data set contained 6699 records of AFC in days. Records of females that did not calve in the next year following exposure to the sire were considered censored (77.5% of total). The model used was a Weibull mixed survival model including effects of contemporary groups, period (fixed) and animal (random). The effect of the contemporary groups on AFC was important (p < 0.01). Heritabilities were 0.51 and 0.76 in logarithmic and original scales respectively. Results indicate that it is possible to genetically advance sexual precocity, using the outcome of survival analysis of AFC as selection criterion. They also suggest that improvements of the environment could advance sexual precocity too, thus an adequate pregnancy rate for farmers could quickly be achieved.

Improvement of interferon-beta related skin reactions after diluent halving: first experience of five patients

The spectrum of side effects related to interferon beta-1b (INF-1b) treatment may compromise long-term adherence.

First lessons in speech improvement /

Mode of access: Internet.

Gaming Regulatory Improvement Act of 1999 : hearing before the Committee on Indian Affairs, United States Senate, One Hundred Sixth Congress, first session, on S. 309, to amend the Indian Gaming Regulatory Act.

"March 24, 1999, Washington, DC"--Pt. 1.

Social Security Trust Fund Integrity and Benefits Improvement Act of 1991 : hearing before the Subcommittee on Social Security of the Committee on Ways and Means, House of Representatives, One Hundred Second Congress, first session, on H.R. 2838 ... September 17, 1991.

"Serial 102-58."

Snake river, Oreg., Wash., and Idaho : hearings before the Committee on Rivers and Harbors, House of Representatives, Seventy-seventy Congress, first session on the subject of the improvement of the Snake river, Oreg., Wash., and Idaho. September 22, and October 15, 1941.

Mode of access: Internet.

Improvement and widening of Washington-Gettysburg highway. Hearings, Seventy-first Congress, second session.

Mode of access: Internet.

East River, N.Y. : hearings before the Committee on Rivers and Harbors, House of Representatives, Seventy-seventh Congress, first session, on the subject of the improvement of the East River, N.Y. March 5-7, 1941.

Mode of access: Internet.

Central Valley Project Improvement Act : hearings before the Subcommittee on Water and Power of the Committee on Energy and Natural Resources, United States Senate, One Hundred Second Congress, first session, on S. 484 ... Los Angeles, CA, March 18, 1991; Washington, DC, May 6, 1991; Sacramento, CA, May 30, 1991.

"San Francisco, CA, September 4, 1991"--Pt. 2.

Public Lands Management Improvement Act of 1997 : hearings before the Subcommittee on Forests and Public Land Management of the Committee on Energy and Natural Resources, United States Senate, One Hundred Fifth Congress, first session, on S. 1253, to provide to the federal land management agencies the authority and capability to manage effectively the federal lands in accordance with the principles of multiple use and sustained yield, and for other purposes, October 30, 1997, December 15, 1997, February 3, 1998.

"April 23,1998, April 30, 1998, May 5, 1998, June 4, 1998, June 17, 1998"--Pt. 2.

Performance improvement of broadband distributed Raman amplifier using bidirectional pumping with first and dual order forward pumps

In this paper, a new bidirectional pumping scheme with dual order forward pumps is proposed. Performance is compared numerically with conventional bidirectional and backward only pumping schemes for a 70 nm bandwidth, 61.5 km distributed Raman amplifier. We demonstrate that it is possible to design a flat gain spectrum with improved noise figure and OSNR, as well as a low gain ripple (<1 dB).

Ethyl-eicosapentaenoic acid in first-episode psychosis : a 1H-MRS study

Ethyl-eicosapentaenoic acid (E-EPA) is an omega-3 fatty acid that has been used in a range of neuropsychiatric conditions with some benefits. However, its mechanism of action is unknown. Here, we investigate its effects on in vivo brain metabolism in first-episode psychosis (FEP). Proton magnetic resonance spectroscopy at 3 T was performed in the temporal lobes of 24 FEP patients before and after 12 weeks of treatment in the context of a larger double-blind, placebo-controlled E-EPA augmentation study. Treatment group effects for glutathione (F1,12=6.1, p=0.03), and a hemisphere-by-group interaction for glutamine/glutamate (F1,20=4.4, p=0.049) were found. Glutathione increased bilaterally and glutamate/glutamine increased in the left hemisphere following E-EPA administration. Improvement in negative symptoms correlated with metabolic brain changes, particularly glutathione (r=-0.57). These results suggest that E-EPA augmentation alters glutathione availability and modulates the glutamine/glutamate cycle in early psychosis, with some of the metabolic brain changes being correlated with negative symptom improvement. Larger confirmatory studies of these postulated metabolic brain effects of E-EPA are warranted.