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41.
Optimization Model and Algorithm for Crew Management During Airline Irregular Operations 总被引:4,自引:0,他引:4
Airline irregular operations have long been a realm where human experience and judgement are the most important tools to utilize. Crew management during irregular operations is usually the bottleneck of the whole system-recovering process due to complicated crew schedules and restrictive crew legalities as well as the size and scope of the hub-and-spoke networks adopted by major carriers. A system-wide multi-commodity integer network flow model and a heuristic search algorithm for the above purpose are presented and discussed in this paper. The computational experiences show that the algorithm is efficient enough to solve problems of realistic size and also has the flexibility to accommodate practical business requirements. 相似文献
42.
The MENTOR project, based at the University of Strathclyde, is producing multimedia computer based learning materials with the aim of improving both the effectiveness and the efficiency of teaching Operational Research/Management Science in higher education. The process of development has been carefully designed to encourage ownership of and commitment to the materials amongst lecturing staff in Universities, with the aim of ensuring widespread use. The paper outlines this process of development and design of materials. Experiences in introducing students to the use of these materials as an integrated part of a Management Science class are reported. Feedback from students has been very positive but also indicates the need for ongoing support and direction. 相似文献
43.
44.
This paper examines recent changes in weekly income levels and dispersion for Māori, New Zealand’s indigenous ethnic group.
Changes in the Māori income distribution between 1997 and 2003 reflect rapid increases in economic growth and employment rate.
A reduced proportion of people had zero or benefit-level incomes and a higher proportion had high incomes. Income inequality
declined for working-aged Māori and was stable for employed Māori. The average income gap between Māori and Europeans declined.
The increased Māori employment rate during this period was the single most important driver of changes in the Māori income
distribution.
相似文献
David C. Maré (Corresponding author)Email: |
45.
Demographic and Health Survey data from nine African countries make it clear that HIV/AIDS prevention knowledge has been increasing.
Still, in many cases, fewer than half of adult respondents can identify specific prevention behaviors. Knowledge is lowest
in rural areas and among women. HIV testing generally remains rare but is highly variable across countries, likely reflecting
differences in the supply of testing services. In most cases, schooling and wealth impacts on prevention knowledge have either
been stable or have increased; hence, in the majority of contexts, initial disparities in knowledge by education and wealth
levels have persisted or widened.
相似文献
David E. SahnEmail: |
46.
Anders?Bj?rklund Donna?K.?Ginther Marianne?Sundstr?mEmail author 《Journal of population economics》2007,20(1):183-201
Previous research shows that living in a non-intact family is associated with educational disadvantages. This paper compares the relationships between childhood family structure, schooling, and earnings in Sweden and the USA. This comparison is interesting because both family structure and public policies differ significantly. We find a negative relationship between living in a non-intact family and child outcomes, and the estimates are remarkably similar in both countries. After using sibling-difference models, the correlation with family structure is no longer significant. These results cast doubt on the causal interpretation of the negative relationship between non-intact family structures and child outcomes. 相似文献
47.
Statistics and Computing - 相似文献
48.
Summary ‘Predator-foolhardiness’ (Lloyd andDybas, 1966b) in an epidemic population of the sugarcane cicada,Mogannia minuta was tested by counting the number of successful and failed trials of hand-capturing of adults in the centre and periphery
of a heavily infested area. Males frequently failed to escape from capture in the outbreak area but they did not in the peripheral
zone. Females could escape well irrespective of the density. It was considered that the ‘predator-foolhardiness’ of males
is not due to genetic differentiation through the process of outbreak but to the effect of massive chorus on the escape behaviour.
The work was supported in part by Grant-in-Aid No. 439017 from the Ministry of Education, Science and Culture. 相似文献
49.
50.
Nils Chr Stenseth Ottar N. Bj?rnstad Takashi Saitoh 《Researches on Population Ecology》1998,40(1):85-95
We interpret gradients in population dynamics of the gray-sided vole from the southwestern part of the island of Hokkaido
to its northeastern part within the framework of a phenomenological model involving the relative length of summer and winter.
In Hokkaido, as in other northern regions, both spring and fall is considered as short transition periods between the two
main seasons — summer (the primary breeding season) and winter (the non-reproductive or secondary breeding season). We show
that the geographic transition in dynamics may be understood as the combined consequence of different patterns of density-dependence
during summer and winter, and geographically varying season lengths. Differences are shown to exist between summer and winter
with respect to strength of density-dependence. Direct density-dependence, in particular, is stronger during winter than during
summer. A model is presented to show how relative lengths of seasons can induce both stable and periodically fluctuating population
dynamics. The results are compared and contrasted with what is otherwise known about the gradient in rodent dynamics in Fennoscandia. 相似文献