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871.
The Myth of Location Privacy in the United States: Surveyed Attitude Versus Current Practices 总被引:1,自引:0,他引:1
In the United States, legal steps have been taken to protect personal privacy, which is viewed as an individual's fundamental right. Location privacy (i.e., protection of personal and location information), however, has not received equal attention in the legal system. Given the recent popularity of location-based services (e.g., cell phones), it is possible to obtain an individual's location information easily and precisely. An investigation of public perception of privacy in the United States indicated that survey responders (1) were unaware of legal implications of location privacy violation and (2) believed that there should be location privacy protection similar to that provided by the Health Insurance Portability and Accountability Act and the Family Educational Rights and Privacy Act. 相似文献
872.
Jennifer L. Rice 《The Professional geographer》2013,65(2):333-344
A survey of local governments participating in two urban climate change programs is presented to determine the mechanisms used to reach emissions reduction goals and the motivations for participation. Results support previous research that shows a preference for policies that rely on changes in individual behavior, while also providing new insights into how mitigation responsibilities are distributed among the public and private sector and the relative importance of scientific consensus, economic incentives, and federal inaction on local government justification for climate-related policies. The article concludes with a discussion of urban climate governance as part of a wider system of neoliberal climate governance. 相似文献
873.
Jason C. Senkbeil David A. Scott Pilar Guinazu-Walker Meganne S. Rockman 《The Professional geographer》2013,65(4):610-620
The 27 April 2011 EF4 Tuscaloosa tornado directly impacted more than 50,000 residents, causing forty-five fatalities within the city and sixty-five in total. It was a rare urban tornado with varying impacts on the three major ethnic and racial groups within the city. A hybrid survey and interview of open-ended and closed questions was conducted with 211 Tuscaloosa area residents in a two-week period after the tornado. Results indicate significant differences in risk perception, preparedness, and shelter lead time among the three ethnic and racial groups. Furthermore, results were still significant for perception after controlling for the effects of age, education, and experience. 相似文献
874.
D. C. OVADIA 《International journal of geographical information science》2013,27(2):190-191
875.
准噶尔盆地南缘荒漠区梭梭维持水源初步研究 总被引:2,自引:0,他引:2
为了了解沙漠植物梭梭维持水源的利用情况,探明其对水源的利用策略,利用稳定性同位素技术定位取样,对准噶尔盆地南缘荒漠区梭梭进行了研究.结果表明,冬季,梭梭基本没有直接利用降雪;随着融雪后浅层土壤含水率的上升,梭梭明显利用浅层土壤水;梭梭利用水源中,地下水占有很大比例,这种比例在冬季和夏季最高,最高幅度可达到80%,平均占到30%左右;降雨也是梭梭利用的水源之一,在降雨后的3~5 d内,梭梭木质部δ18O值有明显趋近降雨δ18O值的趋势.因此,本研究区的梭梭维持水源有多个途径,地下水、融雪形成的浅层土壤水是其主要水源,中、大量降雨也是其利用的水源之一. 相似文献
876.
A whole-basin, mass-balance approach to paleolimnology 总被引:1,自引:0,他引:1
Lake sediments record the flux of materials (nutrients, pollutants, particulates) through a lake system both qualitatively, as changes in the composition of geochemical and biological tracers, as well as quantitatively, through changes in their rate of burial. Burial rates provide a direct link to contemporary (neo-) limnological studies as well as management efforts aimed at load reductions, but are difficult to reconstruct accurately from single cores owing to the spatial and temporal variability of sediment deposition in most lakes. The accurate determination of whole-lake burial rates from analysis of multiple cores, though requiring more effort per lake, can help resolve such problems and improve our understanding of sediment heterogeneity at multiple scales. Partial solutions to these problems also include focusing corrections based on 210Pb flux, co-evaluation of concentration profiles, trend analysis using multiple lakes, and trend replication based on a small number of cores from the same lake. Recent multi-core studies demonstrate that no single core site faithfully records the whole-lake time-resolved input of materials, but that as few as five well-placed cores can provide a reliable record of whole-lake sediment flux for morphometrically simple basins. Lake-wide sediment fluxes can be coupled with reconstructed outflow losses to calculate historical changes in watershed and atmospheric loading of nutrients, metals, and other constituents. The ability of paleolimnology to accurately assess the sedimentary flux and extend the period of reference into the distant past represents an important contribution to the understanding of biogeochemical processes and their response to human and natural disturbance. 相似文献
877.
Following deglaciation, the long-term pattern of change in diatom communities and the inferred history of the aquatic environment are affected by a hierarchy of environmental controls. These include direct climate impacts on a lake’s thermal and hydrologic budgets, as well as the indirect affects of climate on catchment processes, such as weathering, soil development, microbial activity, fire, and vegetation composition and productivity, which affect the transfer of solutes and particulates from the terrestrial ecosystem into the lake. Some of these catchment influences on lacustrine systems operate as time-dependent patterns of primary succession that are set in motion by glacier retreat. This paper provides a conceptual model of some dominant pathways of catchment influence on long-term lake development in glaciated regions and uses a series of paleolimnological examples from arctic, boreal, and temperate regions to evaluate the relative role of direct climate influences and of catchment processes in affecting the trajectory of aquatic ecosystems during the Holocene in different environmental contexts. 相似文献
878.
Hourly precipitation data were collected from 143 first-order US weather stations during the period from 1980 to 2009 to assess the internal distribution of precipitation events lasting at least three hours. A total of 46,595 individual precipitation events were identified and evaluated using the mean, standard deviation, skewness, kurtosis, and the number of peaks occurring within an event. Mean event duration is longest along the West and Northwest coasts, the Mid-South, the Mid-Atlantic, and the Northeast; while shorter-duration events are more frequent in the Rocky Mountains, the Southwest, and the Great Plains. Mean event precipitation and standard deviation are greatest along the Gulf Coast and decrease inland. Precipitation events are positively skewed, indicating that more precipitation tends to occur earlier in the event. The most positively-skewed events are also located in regions flanking the Gulf of Mexico, while less-skewed events are common in the Northwest and Rocky Mountain regions. Event kurtosis is negative throughout the entire USA, with the highest negative values generally west of the Front Range, where cyclonic development and transition produce more evenly distributed precipitation within storms. Intra-event precipitation maxima were also evaluated, with western Florida and the desert Southwest having the greatest number per event. 相似文献
879.
880.
Carlos López 《International journal of geographical information science》2013,27(6):589-607
Gathering data accounts for more than 80% of the cost of any GIS project. Fast Internet connections and digital datasets threaten the investments of data producers through data piracy. Outside the GIS community this problem has been known for a long time, and possible solutions exist for digital imagery, formatted text, 3D meshes and so on, showing possible links to typical spatial data. This is largely achieved through embedding hidden information in a dataset without producing perceptible changes in the data, a process known as watermarking. The producer can recover the embedded information on request in order to produce evidence of ownership in a court, so the overall strategy relies on a legal basis rather than technical ones. This paper analyses the state-of-the-art for watermarking protection in digital geographical datasets. Digital imagery is demonstrably a more mature area than geographical information, even with multiple commercial vendors offering watermarking protection. 2D vector and point datasets have received less attention from the research community; however, 3D meshes have been considered by the CAD community and a handful of techniques are available for that case, and they are reviewed here. 相似文献