944 resultados para Astronomical Data Bases : Miscellaneous


Relevância:

20.00% 20.00%

Publicador:

Resumo:

This paper reports an empirical study on measuring transit service reliability using the data from a Web-based passenger survey on a major transit corridor in Brisbane, Australia. After an introduction of transit service reliability measures, the paper presents the results from the case study including study area, data collection, and reliability measures obtained. This includes data exploration of boarding/arrival lateness, in-vehicle time variation, waiting time variation, and headway adherence. Impacts of peak-period effects and separate operation on service reliability are examined. Relationships between transit service characteristics and passenger waiting time are also discussed. A summary of key findings and an agenda of future research are offered in conclusions.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This paper discusses the statistical analyses used to derive bridge live loads models for Hong Kong from a 10-year weigh-in-motion (WIM) data. The statistical concepts required and the terminologies adopted in the development of bridge live load models are introduced. This paper includes studies for representative vehicles from the large amount of WIM data in Hong Kong. Different load affecting parameters such as gross vehicle weights, axle weights, axle spacings, average daily number of trucks etc are first analyzed by various stochastic processes in order to obtain the mathematical distributions of these parameters. As a prerequisite to determine accurate bridge design loadings in Hong Kong, this study not only takes advantages of code formulation methods used internationally but also presents a new method for modelling collected WIM data using a statistical approach.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Throughout the world, state and nation standardised testing of children, has become a "huge industry" (English, 2002). Although English is referring to the American system which has been involved in standardised testing for over half a century, the same could be said of many other countries, including Australia. It has been only in recent years that Australia has embraced national testing as part of a wider reform effort to bring about increased accountability in schooling. The results of high-stakes tests in Australia are now published in newspapers and electronically on the Australian federal government's MySchool website (www.myschoold.edu.au). MySchool provides results on the National Assessment Program - Literacy and Numeracy (NAPLAN) for students in Years 3,5, 7 and 9. Data are available that compare schools to statistically similar schools. This more recent publication of national testing results in Australia is a visible example of "contractual accountability", described by Mulford, Edmunds, Kendall, Kendall and Bishop (2008) as " the degree to which [actors] are fulfilling the expectations of particular audiences in terms of standards, outcomes and results" (p.20).

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The use of stable isotope ratios δ18O and δ2H are well established in assessment of groundwater systems and their hydrology. The conventional approach is based on x/y plots and relation to various MWL’s, and plots of either ratio against parameters such as Clor EC. An extension of interpretation is the use of 2D maps and contour plots, and 2D hydrogeological vertical sections. An enhancement of presentation and interpretation is the production of “isoscapes”, usually as 2.5D surface projections. We have applied groundwater isotopic data to a 3D visualisation, using the alluvial aquifer system of the Lockyer Valley. The 3D framework is produced in GVS (Groundwater Visualisation System). This format enables enhanced presentation by displaying the spatial relationships and allowing interpolation between “data points” i.e. borehole screened zones where groundwater enters. The relative variations in the δ18O and δ2H values are similar in these ambient temperature systems. However, δ2H better reflects hydrological processes, whereas δ18O also reflects aquifer/groundwater exchange reactions. The 3D model has the advantage that it displays borehole relations to spatial features, enabling isotopic ratios and their values to be associated with, for example, bedrock groundwater mixing, interaction between aquifers, relation to stream recharge, and to near-surface and return irrigation water evaporation. Some specific features are also shown, such as zones of leakage of deeper groundwater (in this case with a GAB signature). Variations in source of recharging water at a catchment scale can be displayed. Interpolation between bores is not always possible depending on numbers and spacing, and by elongate configuration of the alluvium. In these cases, the visualisation uses discs around the screens that can be manually expanded to test extent or intersections. Separate displays are used for each of δ18O and δ2H and colour coding for isotope values.