On the problem of model validation for predictive exposure assessments     

M. B. Beck  J. R. Ravetz  L. A. Mulkey  T. O. Barnwell 《Stochastic Environmental Research and Risk Assessment (SERRA)》1997,11(3):229-254

The development and use of models for predicting exposures are increasingly common and are essential for many risk assessments of the United States Environmental Protection Agency (EPA). Exposure assessments conducted by the EPA to assist regulatory or policy decisions are often challenged to demonstrate their “scientific validity”. Model validation has thus inevitably become a major concern of both EPA officials and the regulated community, sufficiently so that the EPA's Risk Assessment Forum is considering guidance for model validation. The present paper seeks to codify the issues and extensive foregoing discussion of validation with special reference to the development and use of models for predicting the impact of novel chemicals on the environment. Its preparation has been part of the process in formulating a White Paper for the EPA's Risk Assessment Forum. Its subject matter has been drawn from a variety of fields, including ecosystem analysis, surface water quality management, the contamination of groundwaters from high-level nuclear waste, and the control of air quality. The philosophical and conceptual bases of model validation are reviewed, from which it is apparent that validation should be understood as a task of product (or tool) design, for which some form of protocol for quality assurance will ultimately be needed. The commonly used procedures and methods of model validation are also reviewed, including the analysis of uncertainty. Following a survey of past attempts at resolving the issue of model validation, we close by introducing the notion of a model having maximum relevance to the performance of a specific task, such as, for example, a predictive exposure assessment.  相似文献   

Regionalization of unit hydrograph parameters: 1. Comparison of regression analysis techniques     

Y. -K. Tung  K. -C. Yeh  J. -C. Yang 《Stochastic Hydrology and Hydraulics》1997,11(2):145-171

Hydrologic regionalization is a useful tool that allows for the transfer of hydrological information from gaged sites to ungaged sites. This study developed regional regression equations that relate the two parameters in Nash's IUH model to the basin characteristics for 42 major watersheds in Taiwan. In the process of developing the regional equations, different regression procedures including the conventional univariate regression, multivariate regression, and seemingly unrelated regression were used. Multivariate regression and seeming unrelated regression were applied because there exists a rather strong correlation between the Nash's IUH parameters. Furthermore, a validation study was conducted to examine the predictability of regional equations derived by different regression procedures. The study indicates that hydrologic regionalization involving several dependent variables should consider their correlations in the process of establishing the regional equations. The consideration of such correlation will enhance the predictability of resulting regional equations as compared with the ones from the conventional univariate regression procedure.  相似文献   

Age determination, validation and growth of Grand Bank yellowtail flounder (Limanda ferruginea)     

Dwyer  Karen S; Walsh  Stephen J; Campana  Steven E 《ICES Journal of Marine Science》2003,60(5):1123-1138

  相似文献   

Age validation in horse mackerel (Trachurus trachurus) otoliths   总被引：1，自引：0，他引：1  

Waldron  Miranda E.; Kerstan  Michael 《ICES Journal of Marine Science》2001,58(4):806-813

  相似文献   

Age validation of walleye pollock (Theragra chalcogramma) from the Gulf of Alaska using the disequilibrium of Pb-210 and Ra-226     

Kastelle  Craig R.; Kimura  Daniel K. 《ICES Journal of Marine Science》2006,63(8):1520-1529

  相似文献   

Validation of GLI and other satellite-derived sea surface temperatures using data from the Rottnest Island ferry, Western Australia   总被引：3，自引：0，他引：3  

Ian Barton  Alan Pearce 《Journal of Oceanography》2006,62(3):303-310

An accurate platinum resistance thermometer (PRT) has been installed on a commercial ferry that operates between Hillarys Marina, some 15 km north of Fremantle, and Rottnest Island off the Western Australian coast. The PRT is located in the engine intake system and provides continuous under-way measurements of the bulk sea surface temperature (SST) at a depth of 1 m. The “SeaFlyte” ferry makes the trip to Rottnest Island between 3 and 5 times daily and so a wealth of data is available for comparison with the SST derived using data from the GLI instrument on ADEOS-II. Analyses of the ferry and satellite data confirm the excellent quality of SST estimates from the GLI as well as four other satellite instruments—AVHRR on NOAA-16, AATSR on ENVISAT, and the MODIS instruments on TERRA and AQUA. All satellite instruments showed a comparison standard deviation of better than 0.6°C with GLI being better than 0.4°C. The number of ferry-satellite data coincidences used in this study demonstrates one of the advantages of installing measurement systems on commercial ships that operate regular passenger or freight services rather than infrequent deployments on research vessels. The analyses also demonstrate that satellite-derived SST estimates obtained under low surface wind conditions must be treated with care.  相似文献   

Validated age, growth, and mortality estimates of the ocean quahog (Arctica islandica) in the western Atlantic     

Kilada  Raouf W.; Campana  Steven E.; Roddick  Dale 《ICES Journal of Marine Science》2007,64(1):31-38

  相似文献   

Comparison of downward surface solar radiation derived from GMS5/VISSR and of reanalysis products     

Huiling Qin  Yoshimi Kawai  Hiroshi Kawamura 《Journal of Oceanography》2006,62(4):577-586

A high-resolution downward surface solar radiation (DSSR) dataset has been produced using geostationary meteorological satellite measurements. Its validation with in situ observations shows that the daily satellite DSSRs are highly accurate. Comparing the satellite DSSRs with reanalysis DSSR datasets, the former has higher probability density in a low value range, and lower density in a high value range. Overestimations of the reanalysis DSSR are significant in the low range. Correlations between the reanalysis DSSRs and the satellite DSSR are relatively low in the tropics. It is suggested that the satellite DSSRs have good potential to capture cloud behavior in the tropics.  相似文献   

Validation of ERS-1 and High-Resolution Satellite Gravity with in-situ Shipborne Gravity over the Indian Offshore Regions: Accuracies and Implications to Subsurface Modeling     

Sirsendu Chatterjee  Rudradeb Bhattacharyya  Laju Michael  Kolluru Sree Krishna  Tapan Jyoti Majumdar 《Marine Geodesy》2007,30(3):197-216

Geoid and gravity anomalies derived from satellite altimetry are gradually gaining importance in marine geoscientific investigations. Keeping this in mind, we have validated ERS-1 (168 day repeat) altimeter data and very high-resolution free-air gravity data sets generated from Seasat, Geosat GM, ERS-1 and TOPEX/POSEIDON altimeters data with in-situ shipborne gravity data of both the Bay of Bengal and the Arabian Sea regions for the purpose of determining the consistencies and deviations. The RMS errors between high resolution satellite and ship gravity data vary from 2.7 to 6.0 mGal, while with ERS-1 data base the errors are as high as 16.5 mGal. We also have generated high resolution satellite gravity maps of different regions over the Indian offshore, which eventually have become much more accurate in extracting finer geological structures like 85° E Ridge, Swatch of no ground, Bombay High in comparison with ERS-1satellite-derived gravity maps. Results from the signal processing related studies over two specific profiles in the eastern and western offshore also clearly show the advantage of high resolution satellite gravity compared to the ERS-1 derived gravity with reference to ship gravity data.  相似文献   

Validating a Tsunami Vulnerability Assessment Model (the PTVA Model) Using Field Data from the 2004 Indian Ocean Tsunami   总被引：2，自引：1，他引：2  

Dale Dominey-Howes  Maria Papathoma 《Natural Hazards》2007,40(1):113-136

The “PTVAM” tsunami vulnerability assessment model [Papathoma and Dominey-Howes: 2003, Nat. Hazards Earth Syst. Sci. 3, 733–744; Papathoma et al.: 2003, Nat. Hazards Earth Syst. Sci. 3, 377–389], like all models, requires validation. We use the results from post-tsunami surveys in the Maldives following the December 26, 2004 Indian Ocean tsunami to ‘evaluate’ the appropriateness of the PTVAM attributes to understanding spatial and temporal vulnerability to tsunami damage and loss. We find that some of the PTVAM attributes are significantly important and others moderately important to understanding and assessing vulnerability. Some attributes require further investigation. Based upon the ground-truth data, we make several modifications to the model framework and propose a revised version of the PTVAM (PTVAM 2).  相似文献