5,711 research outputs found
The Relationship between IR Effectiveness Measures and User Satisfaction
This paper presents an experimental study of users assessing the quality of Google web search results. In particular we look at how users' satisfaction correlates with the effectiveness of Google as quantified by IR measures such as precision and the suite of Cumulative Gain measures (CG, DCG, NDCG). Results indicate strong correlation between users' satisfaction, CG and precision, moderate correlation with DCG, with perhaps surprisingly negligible correlation with NDCG. The reasons for the low correlation with NDCG are examined
Users' effectiveness and satisfaction for image retrieval
This paper presents results from an initial user
study exploring the relationship between system
effectiveness as quantified by traditional
measures such as precision and recall, and users’
effectiveness and satisfaction of the results. The
tasks involve finding images for recall-based
tasks. It was concluded that no direct relationship
between system effectiveness and users’
performance could be proven (as shown by
previous research). People learn to adapt to a
system regardless of its effectiveness. This study
recommends that a combination of attributes
(e.g. system effectiveness, user performance and
satisfaction) is a more effective way to evaluate
interactive retrieval systems. Results of this
study also reveal that users are more concerned
with accuracy than coverage of the search
results
Relevance Judgments between TREC and Non-TREC Assessors
This paper investigates the agreement of relevance assessments between official TREC judgments and those generated from an interactive IR experiment. Results show that 63% of documents judged relevant by our users matched official TREC judgments. Several factors contributed to differences in the agreements: the number of retrieved relevant documents; the number of relevant documents judged; system effectiveness per topic and the ranking of relevant documents
Blade Tip Rubbing Stress Prediction
An analytical model was constructed to predict the magnitude of stresses produced by rubbing a turbine blade against its tip seal. This model used a linearized approach to the problem, after a parametric study, found that the nonlinear effects were of insignificant magnitude. The important input parameters to the model were: the arc through which rubbing occurs, the turbine rotor speed, normal force exerted on the blade, and the rubbing coefficient of friction. Since it is not possible to exactly specify some of these parameters, values were entered into the model which bracket likely values. The form of the forcing function was another variable which was impossible to specify precisely, but the assumption of a half-sine wave with a period equal to the duration of the rub was taken as a realistic assumption. The analytical model predicted resonances between harmonics of the forcing function decomposition and known harmonics of the blade. Thus, it seemed probable that blade tip rubbing could be at least a contributor to the blade-cracking phenomenon. A full-scale, full-speed test conducted on the space shuttle main engine high pressure fuel turbopump Whirligig tester was conducted at speeds between 33,000 and 28,000 RPM to confirm analytical predictions
Lamb wave near field enhancements for surface breaking defects in plates
Near field surface wave ultrasonic enhancements have previously been used to detect surface breaking defects in thick samples using Rayleigh waves. Here, we present analogous surface wave enhancements for Lamb waves propagating in plates. By tracking frequency intensities in selected regions of time-frequency representations, we observe frequency enhancement in the near field, due to constructive interference of the incident wave mode with those reflected and mode converted at the defect. This is explained using two test models; a square based notch and an opening crack, which are used to predict the contribution to the out-of-plane displacement from the reflected and mode converted waves. This method has the potential to provide a reliable method for the near field identification and characterisation of surface breaking defects in plates
Mercy killing: three's a crowd?
A defendant who has committed a so called ‘mercy killing’, meaning that they killed a loved one to end their suffering from some kind of painful or terminal illness or disease, has no direct route to a manslaughter conviction. It is a difficult situation for the courts, although such actions are acknowledged as a mitigating feature at the sentencing stage. This article discusses the controversial subject, and questions if it may be included within the scope of either diminished responsibility or loss of control since the Coroners and Justice Act 2009 came into force
Cross-shelf and seasonal variation in larval fish assemblages on the southeast United States continental shelf off the coast of Georgia
Seasonal and cross-shelf patterns were investigated in larval fish assemblages on the continental shelf off the coast of Georgia. The influence of environmental factors on
larval distributions also was examined, and larval transport processes on the shelf were considered. Ichthyoplankton and environmental data were collected approximately every other month from spring 2000 to winter
2002. Ten stations were repeatedly sampled along a 110-km cross-shelf transect, including four stations in the vicinity of Gray’s Reef National Marine Sanctuary. Correspondence analysis (CA) on untransformed community
data identified two seasonal (warm weather [spring, summer, and fall] and winter) and three cross-shelf larval assemblages (inner-, mid-, and outer-shelf ). Five environmental factors (temperature, salinity, density,
depth of the water column, and stratification) were related to larval cross-shelf distribution. Specifically,
increased water column stratification was associated with the outer-shelf assemblage in spring, summer, and fall. The inner shelf assemblage was associated with generally lower temperatures and lower salinities in the spring and summer and higher salinities in the winter. The three cross-shelf
regions indicated by the three assemblages coincided with the location of three primary water masses on the shelf. However, taxa occurring together within an assemblage were
transported to different parts of the shelf; thus, transport across the continental shelf off the coast of Georgia cannot be explained solely by twodimensional
physical factors
Arabic users' satisfaction with the online information as obtained from Google
This paper reports an experimental study that evaluates the retrieval effectiveness of Google in response to 104 Arabic queries. The study investigates Arabic users’ satisfaction with the accuracy and coverage of search results. Analysis of results indicates that Arabic users are not highly satisfied with the results of Google
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