The data management and archiving activities of the Pacific 2001 Air Quality Study were handled by the Pacific 2001 Data Centre which was run by the National Atmospheric Chemistry (NAtChem) Database and Analysis Facility of Environment Canada. To ensure that the Pacific 2001 Air Quality Study data were archived in a common way, the NARSTO Data Exchange Standard (DES) was used as the mandatory format for the data files, partially because it allowed for the inclusion of metadata within the data files and partially because it provided the necessary flexibility for handling the many measurement types used in the study. Described in detail in the paper, the DES is now readily available to the scientific community. After each DES data file was submitted to the Data Centre, a read-and-verify program was run to check its conformity to the DES and to detect incorrect and problematic data. The errors detected by the read-and-verify program were automatically documented and an error report was sent to the data originators for data correction and resubmission. Statistical summaries and data plots were created for all data files and subsequently sent to the data originators for review and further error detection. Of the 125 data files submitted to the Data Centre, only 5 were error-free upon first submission. A test of 17 randomly selected files determined that all but two required at least four iterations of the submission-error checking-resubmission cycle in order to produce final error-free files. It was therefore concluded that both data originators and data centres alike should assume that errors exist in all submitted data files until proven differently by a set of automated error-checking programs. It was also concluded that data visualization plots and statistical summaries are highly effective tools for detecting errors in data files. Metadata associated with the measurement data were documented in Quality Assurance Project Plans that were archived in the Data Centre with the DES data files. (c) 2006 Elsevier Ltd. All rights reserved.
Observation equivalence holds in the hyperbolic discounting models such as Laibson (1996), Barro (1999), and Krusell et al (2002). We study a hyperbolic discounting model where the policy function cannot be replicated by a geometric discounting model. Under the logarithmic utility and Cobb-Douglas production, we obtain the explicit solution for consumer's consumption-saving decision. Different from the literatures of exponential discounting, our model shows that the habit persistence affects consumer''s consumption-saving decision. Therefore, observational equivalence does not hold in our hyperbolic discounting model.
Lake eutrophication caused by excess phosphorus (P) loading from point sources (PS) and nonpoint sources (NPS) is a persistent and serious ecological problem in China. A phosphorus budget, based on material flow analysis(MFA) and system dynamic (SD), is proposed and applied for the agriculture-dominated Qionghai Lake watershed located in southwestern China. The MFA-SD approach will not only cover the transporting process of P in the lake-watershed ecosystems, but also can deal with the changes of P budget due to the dynamics of watershed. P inflows include the fertilizer for agricultural croplands, soil losses, domestic sewage discharges, and the atmospheric disposition such as precipitation and dust sinking. Outflows are consisted of hydrologic export, water resources development, fishery and aquatic plants harvesting. The internal P recycling processes are also considered in this paper. From 1988 to 2015, the total P inflows for Lake Qionghai are in a rapid increase from 35.65 to 78.73 t/a, which results in the rising of P concentration in the lake. Among the total P load 2015, agricultural loss and domestic sewage account for 70.60% and 17.27% respectively, directly related to the rapid social-economic development and the swift urbanization. Future management programs designed to reduce P inputs must be put into practices in the coming years to ensure the ecosystem health in the watershed.