This thesis addresses problems of optimization and estimation encountered in the process of airline yield management, also called airline seat inventory control. Optimality conditions are given for the problem of setting booking limits for multiple, stochastically independent demand classes that are booked in a nested fashion into a fixed pool of airline seats. These optimality conditions are compared with the approximations given by the EMSR method. Additional conditions are given for two stochastically dependent fare classes, and extensions are made that allow for incorporation of passenger goodwill and upgrades of passengers between fare classes. The model developed for the dependent demand case is also applied to the problem of determining an optimal overbooking limit in a single fare class. Finally, a methodology is developed for using multivariate multiple regression in conjunction with the EM method to estimate the parameters of demand distributions on the basis of historical demand data that have been censored by the presence of booking limits. / Business, Sauder School of / Operations and Logistics (OPLOG), Division of / Graduate

The purpose of this thesis is to examine what motivates nonindustrial private forest landowners to accept bids of various levels for harvesting. Through the use of a survey we specifically consider what preferences and landowner characteristics effect these decisions. Landowners were randomly selected from counties in Southwest Virginia. The participants were presented a payment table in which they were asked to indicate the level of certainty with which they would accept bids of various levels for their timber. The information obtained for the survey was used in a LOGIT model to examine which variables were most important both in determining the certainty respondents attached to different bid levels, and the likelihood of accepting a bid of any size. Our most important results show that factors such as bequest motives, tract size, absentee status, and environmental preferences influence the bid acceptance decision for landowners in the sample. / Master of Science

Thesis (M.B.A.)--University of Hong Kong, 1996. / Includes bibliographical references (leaf 54-55).

No description available.

published_or_final_version / abstract / Transport Policy and Planning / Master / Master of Arts in Transport Policy and Planning

4 pp. / This fact sheet explores the socioeconomic and cultural aspects of the Hualapai reservation, and includes the extension program methods which work well on the reservation as well as collaborators who work with extension.

2 pp. / This fact sheet briefly describes the socioeconomic and cultural aspects of the Hualapai reservation.

2 pp. / This fact sheet briefly describes research protocol on the Hualapai reservation.

This dissertation adopts the perspective of Cognitive Ethnography to examine the work of a grassroots, Navajo environmental organization called Diné Citizens Against Ruining our Environment. Specifically, I will examine the work and the challenges facing the members of this organization in order to evaluate how new communications and information technologies may be of use to them. This analysis begins, as Cognitive Ethnography mandates, with a general description of the tasks which constitute the work of Diné CARE. As will be discussed, these consist primarily in attempts to reassert what the organization's members consider to be traditional Navajo perspectives on economic development and the human relationship with the natural environment. Subsequently, I analyze the representations, measurements of work, and forms of organization required to accomplish Diné CARE's tasks. In all aspects of the work, members were constantly required to manage a dialogue between their preferred means of organizing or representing work, and the means required by the operating environment in which they found themselves, characterized primarily by relationships with various outside sources of legal, technical or financial support. The work of Diné CARE is thus extensively "dialogic." While members continually drew on Navajo traditions for viewing the relationship of human beings to the natural environment, for representing their work, and for building cooperative access to resources for resistance, they were nonetheless required at the same time to position these "traditional" approaches against approaches whose history of development have political, social and cultural roots in Western Europe and modem America. Often, this dialogue brought with it tension and even morally charged conflict for the members of Diné CARE. This tension extended to emerging technologies as well. In spite of many claims to the contrary, new communications and information technologies did little to alleviate the mismatch between "local" and "foreign" ways of doing work. Instead of "empowering" local communities by providing them access to information or the chance to be heard on their own terms, new technologies complicated the scenario of local resistance by requiring practices for representing work which were both difficult to master and often inappropriate.

The Gila River Indian Reservation lies in the Sonoran Desert of south-central Arizona, with an elevation range from 941 to 4512 feet (287 to 1375 m). Three major desert streams (the Salt, Gila, and Santa Cruz Rivers) have their confluences on the reservation. The human occupancy of the Gila floodplain is believed to have been continuous for the past two millenia. In the past century loss of stream flow and deterioration of riparian and marsh habitats have resulted from drastic changes in hydrologic regimes of the major streams. Documentation of original habitat conditions is based on Hispanic accounts (1694-1821) and subsequent Anglo accounts, together with oral history from the Pima Indians. Riparian timber and emergent vegetation were gone by 1950 due to destructive floods and lowered water table. Irrigation run-off and Phoenix sewage effluent have reestablished locally riparian communities and marshes. Eleven major habitats occur today on the reservation. Their predominant vegetation is described. Field work on the reservation was conducted from 1963 to 1976. Modern distributional data are compared with evidence from archaeological, ethnographic, and historical sources. The total avifauna (all time horizons) consists of 232 species, of which 207 are supported by specimen evidence. At least 101 species are breeding or have bred in the past; five other species are probably breeding. On geographic grounds an additional seven species are suspected of having bred aboriginally. The taxonomy and migration are discussed in accounts of 46 species with two or more subspecies occurring on the study area. The Piman ethno-taxonomy of birds distinguishes 67 taxa, most of which correspond to Linnaean (biological) species. In the past 100 years 28 species (21 as breeding species) have been extirpated from the reservation. Of these 24 are directly related to loss of riparian woodlands or open water and marshes. Since 1958 at least 13 species have recolonized as a result of the redevelopment of riparian communities with willow, cottonwood, and cattail. The present reservation habitat and avifauna are contrasted with two modern analogs with perennial surface water and intact riparian communities. These are at similar elevations, less than 30 miles (48 km) from the reservation. Ten Neotropical species have colonized Arizona within the 20th century and an additional eight have extended their breeding ranges northward. Four Neotropical species have occupied the reservation during this period. Formerly allopatric subspecies of two species (Great-tailed Grackle, Quiscalus mexicanus, and Horned Lark, Eremophila alpestris) are now interbreeding on the reservation in areas of secondary intergradation. The northward movements are attributed to post- Pleistocene recolonizations, in part facilitated by human modifications of habitats. At least 15 wintering species are departing earlier in spring than they did at the turn of the century. This is attributed to habitat deterioration. The habitats with the greatest avifaunal diversity, both summer and winter, are the traditional Pima farms (rancherlas) and the recently redeveloped riparian communities along the Salt River. The least diversified and most disturbed habitats are the Gila River channel and the large-scale mechanized farms on lands leased to non-Indians. The future of both the natural habitats and the avifauna of the reservation is in the hands of tribal leaders.