985 research outputs found
Recommended from our members
Plethodon welleri
Number of Pages: 2Place of Publication: Kensington, MarylandIntegrative BiologyGeological Science
Functional Sequential Treatment Allocation
Consider a setting in which a policy maker assigns subjects to treatments,
observing each outcome before the next subject arrives. Initially, it is
unknown which treatment is best, but the sequential nature of the problem
permits learning about the effectiveness of the treatments. While the
multi-armed-bandit literature has shed much light on the situation when the
policy maker compares the effectiveness of the treatments through their mean,
much less is known about other targets. This is restrictive, because a cautious
decision maker may prefer to target a robust location measure such as a
quantile or a trimmed mean. Furthermore, socio-economic decision making often
requires targeting purpose specific characteristics of the outcome
distribution, such as its inherent degree of inequality, welfare or poverty. In
the present paper we introduce and study sequential learning algorithms when
the distributional characteristic of interest is a general functional of the
outcome distribution. Minimax expected regret optimality results are obtained
within the subclass of explore-then-commit policies, and for the unrestricted
class of all policies
Australian and US Experiences with Transfer of Rangeland Improvement Technologies: A Comparative Analysis
American and Australian range economists work in tandem with range ecologists and management specialists to develop and analyze strategies for technology transfer. Historically, this process has developed around a model aimed at communication with a narrow target group (ranchers) with easily-defined and homogeneous goals (continuously improving income). In accord with this traditional model of technology transfer, the focus of range economists’ inquiries was once to assess the cost-effectiveness of grazing improvement technologies (Conner, 1985). It is a relatively recent phenomenon that both American and Australian range technology transfer agents are encountering an increasingly broad social and ecological agenda. Ranchers recognize and respond to a variety of goals and motivations. This has implications for their decisions considering whether and when to adopt certain grazing improvement technologies. The analysis of technology transfer now involves taking a systems approach, considering a larger arena of stakeholders and their expectations concerning the sustainable use of rangelands, and, accordingly, accounting for increasingly complex and diverse ecological and social issues (Brown and MacLeod, 1996). Range economists in Texas and Australia face similar challenges and have pursued concentric paths in analyzing and participating in technology transfer. Three topics are developed: a portrayal of the parallelism in demographics and trends associated with range technology transfer in Texas and Australia, a discussion of the empirical and methodological issues raised in recent and current projects underway in Texas and Australia, and a brief synthesis identifying possible complementarities in these research agendas
Recommended from our members
Summary and results of the comprehensive environmental monitoring program at the INEL's Raft River geothermal site
The Raft River Geothermal Program was designed to demonstrate that moderate temperature (approx. 150/sup 0/C) geothermal fluids could be used to generate electricity and provide an alternate energy source for direct-use applications. The environmental program was initiated soon after drilling began. The major elements of the monitoring program were continued during the construction and experimental testing of the 5-MW(e) power plant. The monitoring studies established pre-development baseline conditions of and assessed changes in the physical, biological, and human environment. The Physical Environmental Monitoring Program collected baseline data on geology, subsidence, seismicity, meteorology and air quality. The Biological Environmental Monitoring Program collected baseline data on the flora and fauna of the terrestrial ecosystem, studied raptor disturbances, and surveyed the aquatic communities of the Raft River. The Human Environmental Monitoring Program surveyed historic and archaeological sites, considered the socioeconomic environment, and documented incidences of fluorosis in the Raft River Valley. In addition to the environmental monitoring programs, research on biological direct applications using geothermal water was conducted at Raft River. Areas of research included biomass production of wetland and tree species, aquaculture, agricultural irrigation, and the use of wetlands as a treatment or pretreatment system for geothermal effluents
Killing-Yano tensors and some applications
The role of Killing and Killing-Yano tensors for studying the geodesic motion
of the particle and the superparticle in a curved background is reviewed.
Additionally the Papadopoulos list [74] for Killing-Yano tensors in G
structures is reproduced by studying the torsion types these structures admit.
The Papadopoulos list deals with groups G appearing in the Berger
classification, and we enlarge the list by considering additional G structures
which are not of the Berger type. Possible applications of these results in the
study of supersymmetric particle actions and in the AdS/CFT correspondence are
outlined.Comment: 36 pages, no figure
Paleoproductivity, ventilation, and organic carbon burial in the Santa Barbara Basin (ODP Site 893, off California) since the last glacial
Biogenic burial rates and coccolith assemblage data were generated for the past 16 ka at ODP Site 893 in the Santa Barbara Basin, off California, to determine if dysoxic events in the basin were related to changes in marine productivity. Coccolith abundance data show that changes in surface water conditions did indeed change in concert with oxygen levels at the sea floor. However, organic carbon burial rates varied independently, indicating that oxygenation of the water column is related mainly to intermediate water ventilation. A strong correlation of organic carbon burial rates with lithogenic, and to a lesser extent with carbonate and opal accumulation rates confirms recent conclusions that the export of organic carbon from the sea surface is largely controlled by the presence of ballast minerals
Synthesis of bis(indolyl)methanes using silica gel as an efficient and recyclable surface
AbstractHere we describe a simple, clean, and efficient solvent-free protocol for the synthesis of bis(indolyl)methanes promoted by silica gel. The products were obtained in good to excellent yields through the reaction of indoles with cyclohexanone and a range of aldehydes. The silica gel was easily recovered and utilized for further reactions without loss of activity
Impact of age norms and stereotypes on managers' hiring decisions of retirees
Purpose -Our study investigates the role of managers in the re-employment of early retirees and asks what the effect is of managers’ age norms and stereotypes on managers’ employment decisions.
Design/methodology/approach- A combination of a factorial study and a survey was conducted. First, information on the age norms and stereotypes was collected. Secondly, profiles of hypothetical retired job applicants were presented to the employers, who were asked to make a specific hiring decision. The information collected during both studies was combined in the analysis and multilevel models were estimated.
Findings -The results indicate that higher age norms result in a higher propensity to hire an early retiree. Stereotypes, by contrast, do not influence managers’ decisions. Early retirees’ chances for re-employment are also related to their own circumstances (physical appearance and relevant experience) and organisational forces, as they are hired when organisations face labour force shortages.
Research limitation / implications – with the use of vignettes study we deal with hypothetical hiring situation.
Originality value- Although the effect of age norms and age stereotypes has been often suggested, not much empirical evidence was presented to support this notion. Our study estimates the effect of age norms and stereotypes on hiring decision.
key words: bridge employment; early retirees; age norms; age stereotypes; multilevel models.
- …