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11.
NANCY J. OBERMEYER 《Geographical review》2007,97(3):351-364
ABSTRACT. This article draws from the foundation provided by the ongoing debate about geosurveillance to frame a discussion of the use of tracking technologies in public transit. Specifically, it uses the case of public transit to illustrate the uncomfortable debate about compromises that come with increased surveillance to enhance public safety and security. The article begins with a discussion of the evolution of the debate about geosurveillance, casting the use of surveillance technologies in public transit within this framework. Next, it describes and discusses the implementation of automatic vehicle locators and closed‐circuit television in public transit. The following sections focus on the risks to individual privacy that accompany implementation of these technologies, then describe an unusual effort to draw attention to the prevalence of increased surveillance in public spaces in an effort to expose the risks. The article concludes by making the case that public transit is a place where surveillance provides clear benefits but where the humans who review the surveillance data must interpret and use them responsibly to minimize the risks to individual privacy. 相似文献
12.
ABSTRACT. The purchase and subsequent demolition of Cheshire, Ohio‐located in the shadow of the General James M. Gavin Power Plant‐has attracted national attention. According to a New York Times report, “the deal … is believed to be the first by a company to dissolve an entire town.” In this article we consider historical precedents for the case, explore the thirty‐year history of community‐plant relations in Cheshire, and recount the series of incidents that ultimately led to the town's sale. We discuss the impact that the town's sale has had on the local community and the larger implications of American Electric Power's actions. 相似文献
13.
Meridional zonation of the Barents Sea ecosystem inferred from satellite remote sensing and in situ bio-optical observations 总被引:2,自引:0,他引:2
B. GREG MITCHELL ERIC A. BRODY EUENG-NAN YEH CHARLES MCCLAIN JOSEFINO COMISO NANCY G. MAYNARD 《Polar research》1991,10(1):147-162
The Barents Sea is a productive, shallow, high-latitude marine ecosystem with complex hydrographic conditions. Zonal hydrographic bands defined by a coastal current. North Atlantic Water, the Polar Front, and the seasonally variable marginal ice edge zone create a meridional zonation of the ecosystem during the spring-summer transition. The features reveal themselves in satellite imagery and by high-resolution (vertical and horizontal) physical-optical-biological sampling.
Surprisingly, the long-term (7-year) mean of Coastal Zone Color Scanner (CZCS) imagery reveals the Barents Sea as an anomalous "blue-water" regime at high latitudes that are otherwise dominated by satellite-observed surface blooms. A combination of satellite imagery and in situ bio-optical analyses indicate that this pattern is caused by strong stratification in summer with surface nutrient depletion. The onset of stratification of the entire region is linked to the extent of the winter ice edge: cold years with extensive sea ice apparently stratify early due to ice melt; warm years stratify later, perhaps due to weaker thermal stratification of the Atlantic waters (e.g. Skjoldal et al. 1987). The apparent "low chlorophyll" indicated by the CZCS 7-year mean is partly due to sampling error whereby the mean is dominated by images taken later in the summer. In fact, massive blooms of subsurface phytoplankton embedded in the pycnocline persist throughout the summer and maintain substantial rates of primary production. Further, these subsurface blooms that are not observed by satellite are responsible for dramatic gradients in the beam (c1 ) and spectral diffuse (k) attenuation coefficients. The Barents Sea exemplifies the need to couple satellite observations with spatially and temporally resolved biogeographic ecosystem models in order to estimate the integrated water column primary production, mass flux or spectral light attenuation coefficients. 相似文献
Surprisingly, the long-term (7-year) mean of Coastal Zone Color Scanner (CZCS) imagery reveals the Barents Sea as an anomalous "blue-water" regime at high latitudes that are otherwise dominated by satellite-observed surface blooms. A combination of satellite imagery and in situ bio-optical analyses indicate that this pattern is caused by strong stratification in summer with surface nutrient depletion. The onset of stratification of the entire region is linked to the extent of the winter ice edge: cold years with extensive sea ice apparently stratify early due to ice melt; warm years stratify later, perhaps due to weaker thermal stratification of the Atlantic waters (e.g. Skjoldal et al. 1987). The apparent "low chlorophyll" indicated by the CZCS 7-year mean is partly due to sampling error whereby the mean is dominated by images taken later in the summer. In fact, massive blooms of subsurface phytoplankton embedded in the pycnocline persist throughout the summer and maintain substantial rates of primary production. Further, these subsurface blooms that are not observed by satellite are responsible for dramatic gradients in the beam (c
14.
ABSTRACT. In the nineteenth century, local‐scale roads in central Kentucky were built subject to local knowledge and cultural tradition but within the context of legal authority and folk‐ or science‐based engineering precepts. This study demonstrates how legal and engineering standards‐though conceived as transcendent and objective‐were in fact contingent on the region's physical attributes as well as its cultural traditions and character. Thus local road alignment and construction have been influenced by and contingent on local knowledge, dialogue, and debate since frontier times. 相似文献
15.
Estimation of observation impact using the NRL atmospheric variational data assimilation adjoint system 总被引:2,自引:0,他引:2
An adjoint-based procedure for assessing the impact of observations on the short-range forecast error in numerical weather prediction is described. The method is computationally inexpensive and allows observation impact to be partitioned for any set or subset of observations, by instrument type, observed variable, geographic region, vertical level or other category. The cost function is the difference between measures of 24-h and 30-h global forecast error in the Navy Operational Global Atmospheric Prediction System (NOGAPS) during June and December 2002. Observations are assimilated at 00 utc in the Naval Research Laboratory (NRL) Atmospheric Variational Data Assimilation System (NAVDAS). The largest error reductions in the Northern Hemisphere are produced by rawinsondes, satellite wind data, and aircraft observations. In the Southern Hemisphere, the largest error reductions are produced by Advanced TIROS Operational Vertical Sounder (ATOVS) temperature retrievals, satellite wind data and rawinsondes. Approximately 60% (40%) of global observation impact is attributed to observations below (above) 500 hPa. A significant correlation is found between observation impact and cloud cover at the observation location. Currently, without consideration of moisture observations and moist processes in the forecast model adjoint, the observation impact procedure accounts for about 75% of the actual reduction in 24-h forecast error. 相似文献
16.
Effect of source width and tidal elevation changes on aeolian transport on an estuarine beach 总被引:1,自引:0,他引:1
Data from a moderate energy, meso-tidal beach on the east side of Delaware Bay, New Jersey, USA, revealed the significance of both beach width as a source for aeolian transport and the effect of tidal rise on source width. Wind speeds averaged over 17·1 min, recorded 6 m above the crest of a 0·5 m high dune, ranged from 11·6 to 12·7 m s?1 during the experiment. The highest observed rate of transport on the beach was 0·0085 kg m?1 s?1, monitored at rising low tide when the average wind speed was 11·6 m s?1 across 0·35 mm diameter surface sediments. The wind direction was oblique to the shoreline, creating a source width of 34 m. The reduction in the width of the beach as a source for aeolian transport during rising tide was approximately arithmetic, whereas the reduction in volume of sediment trapped was exponential. Aeolian transport effectively ceased when source width was less than 8 m. Wind conditions, moisture content of the surface sediments and presence of binding salts did not appear to vary dramatically, and no coarse grained lag deposit formed on the surface of the beach. The decrease in rate of sediment trapped through time in the tidal cycle is attributed to differences in source width. Sediment deposited in the litter behind the active beach by strong winds during the rising tide was eroded during the high water period by the high waves and storm surge generated by these winds, and net losses of sediment were observed despite initial aeolian accretion. 相似文献