Low latitude density variations in the earth's neutral atmosphere between 200 and 400km,from August 1969 to May 1970     

D.E. Knight  R. Uribe  B.E. Woodgate 《Planetary and Space Science》1973,21(2):253-271

The daily averages of the dawn and dusk observed exospheric temperatures (deduced from solar EUV attenuation measurements between 250 and 400 km) are presented for 280 days from day 227, 1969. They are compared with the empirical model of the US Standard Atmosphere Supplements 1966 and the Jacchia 35 H model. Although consistently lower temperatures than either model were found, a better fit to the latter rather than the former was observed. The exospheric response to solar and geomagnetic activity is investigated, and refinements to the models are suggested.  相似文献   

Management procedures in the US fishery conservation zone     

H. Gary Knight 《Marine Policy》1978,2(1):22-29

The author provides an overview of the management process and indicates, on the basis of experience to date, how procedures are being developed to generate and implement fishery management plans. The article includes discussion of the Fishery Conservation and Management Act of 1976 and of the structure and operation of US regional fisheries commissions. It concludes with an analysis of potential problem areas that threaten the development of a sound management programme.  相似文献   

OXFORD NEW ZEALAND ENCYCLOPEDIA. General Editor: Laura Scott; New Zealand Editor: John Pascoe.     

Colin L.  Knight 《New Zealand geographer》1966,22(1):105-106

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The environmental significance of ventifacts: A critical review     

Jasper Knight 《Earth》2008,86(1-4):89-105

Ventifacts (wind-abraded clasts or rock surfaces) are common features of many terrestrial hot and cold deserts, coastal, periglacial and mountain environments, as well as on Mars, and have a long history of investigation. This review paper discusses some of the main themes in terrestrial ventifact research including their formation and geomorphic controls. The varied morphological forms of ventifacts in terrestrial environments, and their environmental significance as indicators of past and present wind direction and sediment mobility, are critically evaluated. Future research directions are identified.  相似文献   

The crystal structure and thermal expansion tensor of MgSO<Subscript>4</Subscript>–11D<Subscript>2</Subscript>O(meridianiite) determined by neutron powder diffraction     

A. D. Fortes  I. G. Wood  K. S. Knight 《Physics and Chemistry of Minerals》2008,35(4):207-221

We have collected high-resolution neutron powder diffraction patterns from MgSO₄·11D₂O over the temperature range 4.2–250 K. The crystal is triclinic, space-group \( \text{P} \bar{1} \) (Z = 2) with a = 6.72746(6) Å, b = 6.78141(6) Å, c = 17.31803(13) Å, α = 88.2062(6)°, β = 89.4473(8)°, γ = 62.6075(5)°, and V = 701.140(6) ų at 4.2 K, and a = 6.75081(3) Å, b = 6.81463(3) Å, c = 17.29241(6) Å, α = 88.1183(3)°, β = 89.4808(3)°, γ = 62.6891(3)°, and V = 706.450(3) ų at 250 K. Structures were refined to wRp = 3.99 and 2.84% at 4.2 and 250 K, respectively. The temperature dependence of the lattice parameters over the intervening range have been fitted with a modified Einstein oscillator model which was used to obtain the coefficients of the thermal expansion tensor. The volume thermal expansion, α_V, is considerably smaller than ice Ih at all temperatures, and smaller even than MgSO₄·7D₂O (although ?α_V/?T is very similar for both sulfates); MgSO₄·11D₂O exhibits negative α_V below 55 K (compared to 70 K in D₂O ice Ih and 20 K in MgSO₄·7D₂O) The relationship between the magnitude and orientation of the principal axes of the expansion tensor and the main structural elements are discussed.  相似文献   

Comment on “The International Association of Hydrogeologists (IAH): reflecting on 60 years of contributions to groundwater science and water management”: article published in <Emphasis Type="Italic">Hydrogeology Journal</Emphasis> (2016) 24: 1069–1086, by Willi Struckmeier,Ken Howard and John Chilton     

Michael J. Knight 《Hydrogeology Journal》2016,24(8):2189-2190

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Could working less reduce pressures on the environment? A cross-national panel analysis of OECD countries, 1970–2007     

Kyle W. Knight  Eugene A. Rosa  Juliet B. Schor 《Global Environmental Change》2013,23(4):691-700

Many scholars and activists are now advocating a program of economic degrowth for developed countries in order to mitigate demands on the global environment. An increasingly prominent idea is that developed countries could achieve slower or zero economic growth in a socially sustainable way by reducing working hours. Research suggests that reduced working hours could contribute to sustainability by decreasing the scale of economic output and the environmental intensity of consumption patterns. Here, we investigate the effect of working hours on three environmental indicators: ecological footprint, carbon footprint, and carbon dioxide emissions. Using data for 1970–2007, our panel analysis of 29 high-income OECD countries indicates that working hours are significantly associated with greater environmental pressures and thus may be an attractive target for policies promoting environmental sustainability.  相似文献   

Palaeoglaciology of the last Irish ice sheet reconstructed from striae evidence     

M.J. Smith  J. Knight 《Quaternary Science Reviews》2011,30(1-2):147-160

A database comprising some ～5200 individual striation measurements on bedrock surfaces across the island of Ireland was used to produce maps of flowsets corresponding to individual ice flow events during the last (late Devensian) glacial cycle. These flowsets were identified on the basis of regional-scale correspondence between striae orientations which, when linked together spatially, are able to identify consistent ice flow vectors. Four main chronological stages are identified on the basis of this evidence: (i) incursion of Scottish ice into Ireland; (ii) glacial maximum conditions; (iii) ice retreat and dissolution; and (iv) development of localised ice domes. Striae-based reconstructions of the glaciology of the last Irish ice sheet are qualitatively different from those based on bedform (mainly drumlin and ribbed moraine) evidence. Significant differences are apparent in upland areas which have fewer preserved bedforms and a higher concentration of striae. Combining bedform and striae datasets will enable a better understanding of the temporal evolution of the ice sheet. It is likely that both datasets record a snapshot of ice flow direction and subglacial conditions and environments immediately prior to preservation of this directional evidence.  相似文献   

Assessing the ‘usability’ of climate change research for decision-making: A case study of the Canadian International Polar Year     

James D. Ford  Maggie Knight  Tristan Pearce 《Global Environmental Change》2013,23(5):1317-1326

The creation of ‘usable science’ is widely promoted by many environmental change focused research programs. Few studies however, have examined the relationship between research conducted as part of such programs and the decision-making outcomes that the work is supposed to advance, and is constrained by limited methodological development on how to empirically assess the ‘usability’ of science. Herein, this paper develops a conceptual model and assessment rubric to quantitatively and systematically evaluate the usability of climate change research for informing decision-making. We focus on the process through which data is collected, analyzed and reported and examine the extent to which key principles of usable science are integrated into project design, using grant proposals as our data source. The approach is applied to analyze climate change research conducted as part of the International Polar Year in Canada, with 23 projects identified as having explicit goals to inform decision-making.While the creation of usable science was promoted by funded projects in the International Polar Year, this was not generally reflected in research design: fewer than half determined objectives with input of decision makers, decision context was not widely considered, and knowledge users were not widely reported to be engaged in assessing the quality of data or in resolving conflict in evidence. The importance of science communication was widely emphasized, although only 8/23 projects discussed tailoring specific results for end user needs. Thus while International Polar Year research has made significant advances in understanding the human dimensions of Arctic climate change, key attributes necessary for determining success in linking science to decision-making (pertinence, quality, timeliness) were not captured by many projects. Integrating these attributes into research design from the outset is essential for creating usable science, and needs to be at the forefront of future research programs which aim to advance societal outcomes. The framework for assessing usability here, while developed and tested in an Arctic climate change context, has broader applicability in the general environmental change field.  相似文献   

A locally-constrained YOLO framework for detecting small and densely-distributed building footprints     

Yiqun Xie  Jiannan Cai  Rahul Bhojwani  Shashi Shekhar  Joseph Knight 《International journal of geographical information science》2020,34(4):777-801

ABSTRACT

Building footprints are among the most predominant features in urban areas, and provide valuable information for urban planning, solar energy suitability analysis, etc. We aim to automatically and rapidly identify building footprints by leveraging deep learning techniques and the increased availability of remote sensing datasets at high spatial resolution. The task is computationally challenging due to the use of large training datasets and large number of parameters. In related work, You-Only-Look-Once (YOLO) is a state-of-the-art deep learning framework for object detection. However, YOLO is limited in its capacity to identify small objects that appear in groups, which is the case for building footprints. We propose a LOcally-COnstrained (LOCO) You-Only-Look-Once framework to detect small and densely-distributed building footprints. LOCO is a variant of YOLO. Its layer architecture is determined by the spatial characteristics of building footprints and it uses a constrained regression modeling to improve the robustness of building size predictions. We also present an invariant augmentation based voting scheme to further improve the precision in the prediction phase. Experiments show that LOCO can greatly improve the solution quality of building detection compared to related work.  相似文献