59,719 research outputs found
KULTUR: showcasing art through institutional repositories
Showcasing work has always been at the heart of the arts community, whether it be through an exhibition, site-specific installation or performance. Representation of the original work has also been important and use of print-based options like exhibition catalogues is now complemented by websites and multi-media friendly services like Flickr and YouTube and Vimeo. These services also provide options for sharing born-digital material. For those working in higher education there is a need to profile both the personal and the institutional aspects of creative outputs. The KULTUR project created a model for arts-based institutional repositories and it is hoped that this approach will be useful for other arts institutions
The effects of centrifuge radius on the performance of entry tasks
Effects of centrifuge radius on entry task performance - discrete response task, tracking task, and transfer of training effect
A Method for Establishing Outdoor Recreation Project Priorities in Alaska
The authors thank Theodore Smith, Edward Kramer and Nat Goodhue
of the Division of Parks for information and comments supplied during this
study, and Frank Orth, Charles Marsh, Ed Kramer, C.E. Logsdon, and Frank
Wooding for reviewing the manuscript.
Thanks is also due the Department of Business Administration,
University of Alaska, Fairbanks, Dale Swanson, Head, for their cooperation
in this research project.The objectives of this study are to define outdoor recreation benefits to
the public and to develop a priority ranking method for proposed outdoor
recreation projects. A careful analysis of the benefits which people derive
from outdoor recreation provides a frame of reference for evaluating a
recreational facility. A project should supply those benefits which are most
highly demanded by the public. Fifteen benefits of recreation are defined
and discussed. They are divided into two major categories; those which
accrue to recreational participants and those which accrue to
non-participants.This research was supported by a grant from the Division of Parks,
State of Alaska
Demand and Pricing in Electricity Markets: Evidence from San Diego During California's Energy Crisis
We study the electricity consumption of San Diego-area households following a series of price changes and related events during California's energy crisis in 2000-01. The analysis uses a five-year panel of disaggregate billing and weather data for a random sample of 70,000 households. In contrast to prior work, these data allow us to proceed without behavioral assumptions regarding a consumer's knowledge of energy prices. We find that after a rapid price increase in summer 2000, consumption fell substantially over about 60 days, averaging 12% per household; consumption then rebounded to within 3% of pre-crisis levels after a price cap was imposed. Under the price cap public appeals for energy conservation and a remunerative voluntary conservation program had significant, but transitory, effects. Further, a large share of households reduced electricity consumption substantially (over 10%) but saved small monetary amounts ($10 or less). Overall, the results indicate consumers may be far more responsive to pecuniary and non-pecuniary incentives for altering their energy use than is commonly believed.
Household Electricity Demand, Revisited
Recent efforts to restructure and partially deregulate electricity markets have renewed interest in understanding how consumers respond to price changes. Several interrelated problems complicate demand analyses of these markets, including nonlinear pricing, heterogeneity in households' price sensitivities, and data aggregation. This paper formulates a model of household electricity demand that addresses these difficulties. We estimate the model using data for a representative sample of California households, and summarize how electricity demand elasticities vary in that state. We then use the model to analyze the electricity consumption and expenditure effects of recent tariff structure changes in California.
Evaluating Welfare with Nonlinear Prices
This paper examines how to evaluate consumer welfare when consumers face nonlinear prices. This problem arises in many settings, such as devising optimal pricing strategies for firms, assessing how price discrimination affects consumers, and evaluating the efficiency costs of many transfer programs in the public sector. We extend prior methods to accommodate a broad range of modern pricing practices, including menus of pricing plans. This analysis yields a simpler and more general technique for evaluating exact consumer surplus changes in settings where consumers face nonlinear prices. We illustrate our method using recent changes in mobile phone service plans.
High frequency, high power capacitor development
A program to develop a special high energy density, high power transfer capacitor to operate at frequency of 40 kHz, 600 V rms at 125 A rms plus 600 V dc bias for space operation. The program included material evaluation and selection, a capacitor design was prepared, a thermal analysis performed on the design. Fifty capacitors were manufactured for testing at 10 kHz and 40 kHz for 50 hours at Industrial Electric Heating Co. of Columbus, Ohio. The vacuum endurance test used on environmental chamber and temperature plate furnished by Maxwell. The capacitors were energized with a special power conditioning apparatus developed by Industrial Electric Heating Co. Temperature conditions of the capacitors were monitored by IEHCo test equipment. Successful completion of the vacuum endurance test series confirmed achievement of the main goal of producing a capacitor or reliable operation at high frequency in an environment normally not hospitable to electrical and electronic components. The capacitor developed compared to a typical commercial capacitor at the 40 kHz level represents a decrease in size and weight by a factor of seven
Mesoscale variability of free tropospheric humidity near San Nicolas Island during FIRE
Humidity variability at the top of the marine boundary layer (MBL) and in the free troposphere was examined using a variety of measurements taken on and around San Nicolas Island (SNI) during the FIRE IFO in July, 1987. Doppler wind profiler reflectivity recorded at two minute time resolution has provided the most continuous record and detail of small scale humidity fluctuations. Rawinsonde data were available from both an island site and the research vessel Point Sur. The information extractable from these sources is somewhat limited due to the frequency of launches (3 to 4/day at SNI and 6/day on the Point Sur). Some additional data were available from instrumented aircraft although scheduling flights in the neighborhood of the island was difficult due to restrictions on the air space. Other relevant data were collected at SNI near the radar and rawinsonde launch sites. A continuous record of cloud base altitude was logged by a ceilometer. Doppler acoustic sounder (sodar) reflectivity data provided a good record of inversion height. The sodar also monitored turbulent temperature fluctuations in the MBL. A small ground station recorded hourly averages of solar irradiance and downward longwave irradiance. The analysis in progress of the various data sets for two adjacent two day periods from 11 July to 14 July is described. The earlier period was chosen because the marine inversion was unusually high and there was increased frequency of rawinsonde launches at SNI. The later period was chosen because of the significant descent with time of an elevated inversion indicated by the radar data. Throughout the four day period, but especially in the first half, the turbulent humidity structure calculated from Doppler radar reflectivity shows excellent agreement with humidity profiles evaluated from rawinsonde data
Evaluating implicit feedback models using searcher simulations
In this article we describe an evaluation of relevance feedback (RF) algorithms using searcher simulations. Since these algorithms select additional terms for query modification based on inferences made from searcher interaction, not on relevance information searchers explicitly provide (as in traditional RF), we refer to them as implicit feedback models. We introduce six different models that base their decisions on the interactions of searchers and use different approaches to rank query modification terms. The aim of this article is to determine which of these models should be used to assist searchers in the systems we develop. To evaluate these models we used searcher simulations that afforded us more control over the experimental conditions than experiments with human subjects and allowed complex interaction to be modeled without the need for costly human experimentation. The simulation-based evaluation methodology measures how well the models learn the distribution of terms across relevant documents (i.e., learn what information is relevant) and how well they improve search effectiveness (i.e., create effective search queries). Our findings show that an implicit feedback model based on Jeffrey's rule of conditioning outperformed other models under investigation
Stripping of gas and dust from the elliptical galaxy M86
Past observations of the x ray morphology of M86 have revealed that the galaxy is experiencing ram-pressure stripping due to its large velocity (1500 km s(-1)) relative to the intracluster medium of Virgo (Forman et al. 1979, Fabian, Schwartz, and Forman 1980). Observations indicate that the x ray emitting gas in the plume of M86 is still being produced from the continual heating of gas and dust stripped from nearer the galaxy's center. Researchers obtained two-dimensional Infrared Astronomy Satellite (IRAS) images of M86 which have revealed that there are two spatially separated regions of emission, one at 60 microns and the other at 100 microns of the IRAS wavebands. The 100 microns emission, presumably from cool dust (at approximately 20 K), appears to be located near the center of the galaxy together with HI (detected by Bregman, Roberts and Giovanelli 1988), while the 60 microns emission appears to lie more than 3 arcminutes away from the optical center in a direction slightly south of the center of the plume. Optical images produced by scanning U.K. Schmidt plates, reveal asymmetric isophotal contours along the major axis of the galaxy (first reported by Nulsen and Carter in 1987, which they propose as excess emission due to star formation). This excess optical emission is co-incident with the direction of the 60 micron infra-red emission
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