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1.
We give an example of a subspace K of such that , where denotes the closure with respect to convergence in probablity. On the other hand, the cone C ≔ K − L ∞ + is dense in L ∞ with respect to the weak-star topology σ( L ∞ , L 1 ) . This example answers a question raised by I. Evstigneev. The topic is motivated by the relation of the notion of no arbitrage and the existence of martingale measures in Mathematical Finance. 相似文献
2.
Jennifer G. Winter M. Catherine Eimers Peter J. Dillon Lem D. Scott Wolfgang A. Scheider Campbell C. Willox 《Journal of Great Lakes research》2007,33(2):381-396
Total phosphorus (TP) inputs to Lake Simcoe have led to hypolimnetic dissolved oxygen (DO) depletion and loss of cold water fish habitat. Since 1990, efforts have been made to reduce the total TP input to the lake below a defined target of 75 t/year, which was predicted to lead to reductions in spring TP concentration and improvements in end-of-summer hypolimnetic DO concentrations. The total TP load to the lake during the most recent period of record (1998/99-2003/04) ranged from 53 to 76 t/yr and averaged 67 t/yr, compared to an average of 114 t/yr estimated between 1990/91 and 1997/98 (range 85-157 t/yr). Reductions in TP loads from the catchment via tributary discharge (∼26 t) accounted for the majority of the decrease in total load between the two time periods. Total P concentrations decreased significantly in four out of six long-term monitored tributaries; however, concentrations in all six tributaries remain above the level recommended to avoid nuisance plant growth (30 μg/L). Although TP loads to the lake are currently below the target 75 t/yr, excessive growths of filamentous algae and macrophytes continue to be a problem in the nearshore zone. End-of-summer minimum hypolimnetic DO concentrations (average 4.3 mg/L, 1998/99-2003/04) remain substantially below the level (7 mg/L) that is considered protective of lake trout. Efforts to reduce TP loads to the lake therefore need to continue. 相似文献
3.
One hypothesis for the transcontinental and intra-Great Lakes basin transfer of round gobies (Neogobius melanostomus) has been that round gobies were pumped into the ballast water of ships. During June 2005 in Lake Erie, we obtained evidence of a vertical migration of round goby larvae, when we collected 167 round goby larvae in surface ichthyoplankton net tows at night and zero during day. These results complemented similar findings from the Muskegon River estuary of Lake Michigan during 2003 and 2004, documenting diel vertical migration for the first time in larval round gobies. We suggest vertical migration behavior may have allowed larval round gobies to be transported to and within the Great Lakes via ballast water and dispersed in the Great Lakes via advection of 6.5–8.5-mm long larvae at the surface. Based on our results, if ballast water was only taken on near the surface during daylight hours from May through September when larval round gobies were present, it would have mitigated the spread of round gobies throughout the Great Lakes. 相似文献
4.
This paper is focused on the cost of raising capital in Germany. A cross-sectional analysis of flotation cost data for 117 IPOs over the years 1993–1998 is presented. We find average flotation costs to be 7.77 percent of gross proceeds, while underwriting fees average 5.01 percent. Our results extend the literature in two important directions. First, contrary to the conventional economies of scale view we find marginal spreads to be rather constant in gross proceeds and to be higher for more risky and more complex offerings. Fixed costs amount to 5 to 9 percent of underwriting fees. Second, by applying a principal component analysis we find issue size, an issuer risk factor, and an offering method complexity factor to have an economicaly meaningful impact on underwriting fees. 相似文献
5.
Diana Hurdowar-Castro Ioannis Tsanis Ilmar Simanovskis 《Journal of Great Lakes research》2007,33(1):232-252
A 3D transport model is used to perform a comparative analysis of several potential drinking water intakes located along the northwest shore of Lake Ontario between Toronto and Oshawa. The model is specifically used to assess each intake under both long- and short-term transport of a potential pollutant release from the Pickering Nuclear Generating Station and potential and actual pollutant releases from local land sources respectively. A model based on a 500 m grid resolution is calibrated using data collected in the aftermath of the 1992 tritium spill at the Pickering Nuclear Generation Station and subsequently used to simulate long-term transport. A model based on a 100 m grid resolution is verified using drogue studies and used to simulate short-term transport events. Both models are used to assess pollutant levels at each of nine potential intake locations under different wind scenarios and pollutant releases. Field data for the study included water quality and flow measurements from local sewers and rivers, and estimates of pollutant levels from the local waste water treatment plants. This paper describes the model setup for both the long-term and short-term transport models, calibration using field data, long-term transport modeling, short-term transport modeling, and the comprehensive analysis approach used to evaluate the nine potential intake locations proposed. Results indicated that four intakes in particular outperformed other intake locations by maintaining bottom pollutant levels within governmental standards and warning times that exceeded 20 hours. 相似文献
6.
Johan Lagerlöf 《The Scandinavian journal of economics》2004,106(1):123-142
The model of public policy studied in this paper has heterogeneous citizens/voters and two public goods: one (roads) chosen directly by an elected policy‐maker, and the other (pollution) stochastically dependent on the amount of roads. Both a one‐country and a two‐country version of the model are analyzed; the latter displays externalities across the countries which create incentives for free riding and strategic delegation. The welfare effects of providing the policy‐maker with information about the relationship between roads and pollution are investigated, and it is shown that more information hurts some—sometimes even all—citizens. In particular, the opportunity not to create an institution for information gathering can serve as a commitment device for a country, although with the unfortunate effect of making the overall outcome even worse. Implications for the welfare effects of “informational lobbying” are also discussed. 相似文献
7.
Brigitte Eierle 《Accounting, Business & Financial History》2005,15(3):279-315
Based on a contingent perspective of accounting change, this paper reviews the historical development of differential reporting in Germany, by drawing on primary and secondary sources. The main objective of the paper is to shed light on the driving forces and main influential parameters that have shaped the existing differential reporting framework. This historical approach supplies interesting insights for the current discussion on differential reporting in Germany produced by the EU Regulation on the application of International Accounting Standards. 相似文献
8.
The comparison of true cost of living indices between demographically different households (relative equivalence scale) is argued to be sensitive to the way demographic characteristics enter demand analysis. In particular, parameters reflecting the cost of demographic characteristics at base prices, though themselves do not have welfare (equivalence scale) interpretation, can alter the benchmark from which demographically varying inflation effects are measured. The empirical analysis, based on a rank‐3 demand system applied to UK individual household data, shows that the inflation adjustment of child benefits can vary with the way demographic costs at base period prices are specified. 相似文献
9.
僧海霞 《四川商业高等专科学校学报》2006,14(1):57-59,64
唐代的法制思想,主要有两大特征,即仁刑恤典和厉行法制。对此,学者们多从正史的角度加以探讨和分析。而从敦煌所出唐代蒙书《百行章》所述内容同样清楚地显示了唐初的法制思想的以上特点。这一研究可以起到补充正史的作用。 相似文献
10.
Jan A. Derecki 《Journal of Great Lakes research》1985,11(3):201-207
Periodic man-made changes in the outlet of Lake Huron through the St. Clair River date back to the middle of the last century. These artificial channel changes have been well documented during the present century. They consist of dredging for commercial gravel removal in the upper river during 1908–25 and uncompensated navigation improvements for the 7.6-m (25-ft) and 8.2-m (27-ft) projects completed in 1933 and 1962, respectively. The total effect of these changes on the levels of Lakes Michigan and Huron (hydraulically one lake) and on the upper St. Clair River profile was determined with dynamic flow models. The ultimate effect of the above dredging was a permanent lowering of the Lake Michigan-Huron levels 0.27 m (0.89 ft), which represents a tremendous loss of freshwater resource [32 km3 (7.7 mi3)]. 相似文献