Modelling and comparing 3-D soil stratigraphy using subsurface borings and cone penetrometer tests in coastal Louisiana,USA     

An Li  Frank T.-C. Tsai 《Georisk: Assessment and Management of Risk for Engineered Systems and Geohazards》2020,14(2):158-176

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Toward green cartography & visualization: a semantically-enriched method of generating energy-aware color schemes for digital maps     

Yangli Han  Robert Roth 《制图学和地理信息科学》2021,48(1):43-62

ABSTRACT

We introduce a semantically-enriched method of generating color schemes for various types of digital maps that reduces the energy consumption of the display device while preserving the quality of the original design. Energy-aware design intersects two important trends in cartography. First, as more maps are viewed today on mobile, battery life has become a central constraint influencing design. Second, there is increasing need for green computing, which encourages the efficient use of energy to limit environmental impacts. This paper focuses on one important aspect of energy-aware cartography: color design. Existing research on energy-aware color adjustment methods apply broadly to images or websites. However, the colors used in maps have more structured semantic relationships than most documents viewed on mobile devices, and efforts to account for these relationships while reducing energy consumption are limited. To fill this gap, we mathematically formalize energy-aware map-color adjustment as a constrained optimization problem: we define energy consumption as the objective function and model the preservation of semantic relationships as the search constraints. We evaluate our proposed method against a common color dimming method using four maps with different semantic relationships. The evaluation suggests that our proposed method better preserves the original color semantics.  相似文献   

Natural geobatteries associated with sulphide ore deposits,I. Theoretical studies     

Prokopis Sivenas  Frank W. Beales 《Journal of Geochemical Exploration》1982,17(2):123-143

Any conductive sulphide ore body can generate electrical ore potentials and this can be regarded as a geobattery, with an upper positive cathode and a lower negative anode. Two mechanisms which can occur simultaneously and which appear to explain these potentials are the oxygen concentration cell (OCC) and the sulphide galvanic cell (SGC). When there is a difference of O₂ concentration between the cathode and anode, the OCC operates by contributing oxygen to the anode, and ceases when the difference is diminished. However, gradients of pH, temperature or pressure can keep the cell operating. In the SGC the sulphides dissolve at the anode (producing metal ions, sulphur and electrons), while at the cathode, either sulphides dissolve producing metal and sulphur ions, or reaction is as in the OCC. The ore potential measured in the field is the sum of the oxygen concentration cell and at times locally dominant sulphide galvanic cells.  相似文献   

On Lyttleton's Extensions of Ramsey's Theory of the Nature of the Core of the Earth     

F. C. Frank 《Geophysical Journal International》1971,23(4):461-464

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Bending waves in Saturn's rings     

Frank H. Shu  Jeffrey N. Cuzzi  Jack J. Lissauer 《Icarus》1983,53(2):185-206

We investigate certain brightness variations seen in Saturn's A ring and find them to be due to vertical corrugations of the local ring plane caused by a spiral bending wave. This wave is resonantly excited by Mimas and propagates inward via the collective gravity of the ring particles. B. A. Smith et al. [Science212, 163–191 (1981)] had previously associated vertical relief with this feature due to its observed azimuthal variations and its proximity to an inclination resonance with Mimas. We develop the theory of forced bending waves, some aspects of which have been treated in the galactic context by C. Hunter and A. Toomre [Astrophys. J.155, 747–776 (1969)] and by G. Bertin and J.W.-K. Mark [Astron. Astrophys.88, 289–297 (1980)]. Our theory is in good agreement with the observations. In particular, the presence of these bending waves may resolve the conflict between ground-based estimates of 1–2 km for the global ring thickness [e.g., A. Brahic and B. Sicardy, Nature289, 447–450 (1981)] and Voyager stellar occultation measurements of <200 m for the local ring thickness [A. L. Lane et al., Science215, 537–543 (1982); E. A. Marouf and G. L. Tyler, Science217, 243–245 (1982)].  相似文献   

SPOT4-VEGETATION中国西北地区土地覆盖制图与验证   总被引：13，自引：0，他引：13  

卢玲  李新  董庆罕  Else Swinnen  Frank Veroustraete  王建华  王一谋 《遥感学报》2003,7(3):214-220

利用SPOT4 VEGETATION的遥感数据产品生成的NDVI与NDWI植被指数时间序列图像集 ,通过ISODATA非监督分类方法 ,编制中国西北地区土地覆盖图。以TM影像人工解译结果作为真实值 ,通过对西北五省共计 47个均匀分布且异质性强的 2 5km× 2 5km样本区内的土地覆盖类型及其面积进行统计分析 ,修正了SPOT4 VEGETATION的土地覆盖分类系统 ,建立了各省验证结果的样本统计直方图并计算其回归系数。结果表明SPOT4 VEGETATION中国西北地区土地覆盖图在总体上具有较高的准确性。影响遥感数据自动分类精度 ,造成土地覆盖误判的原因主要来源于两个方面 :即异物同谱和混合像元问题。对于前者通过叠加各种辅助数据如DEM等可以降低误判的机率 ;对于后者运用混合像元分解的各种算法可以提高分类精度  相似文献   

In-situ reflectance spectroscopy – analysing techniques for high-resolution pigment logging in sediment cores     

Bert Rein  Frank Sirocko 《International Journal of Earth Sciences》2003,92(1):143-143

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Late Holocene annual growth in three Alpine stalagmites records the influence of solar activity and the North Atlantic Oscillation on winter climate   总被引：3，自引：0，他引：3  

Silvia Frisia  Andrea Borsato  Frank McDermott 《Earth and Planetary Science Letters》2003,216(3):411-424

Annual growth rates and the ratio of dark to light-colored calcite within single annual laminae in three contemporaneously deposited Holocene speleothems from Grotta di Ernesto, an Alpine cave in northern Italy, respond to changes in surface temperature rather than precipitation. Based on monitoring of present-day calcite growth, and correlation with instrumental data for surface climatic conditions, we interpret a higher ratio of dark to light-colored calcite and the simultaneous thinning of annual laminae as indicative of colder-than-present winters. Such dark and thin laminae occur in those parts of the three stalagmites deposited from AD 1650 to 1713 and from AD 1798 to 1840, as reconstructed through lamina counting. These periods correspond to the well-known Maunder and Dalton Minima of solar activity. An 11-yr cyclicity in growth rate, coupled with reduced calcite deposition during the historic minima of solar activity, is indicative of a solar influence on lamina thickness. Spectral analysis of the lamina thickness data also suggests that the North Atlantic Oscillation variability influenced winter temperatures. Based on the present-day controls on cave calcite formation, we infer that high-frequency changes in solar activity modulated the seasonal duration of soil CO₂ production.  相似文献   

20th Century Climate Change in the Tropical Andes: Observations and Model Results   总被引：7，自引：0，他引：7  

Mathias Vuille  Raymond S. Bradley  Martin Werner  Frank Keimig 《Climatic change》2003,59(1-2):75-99

Linear trend analysis of observational data combined with model diagnostics from an atmospheric general circulation model are employed to search for potential mechanisms related to the observed glacier retreat in the tropical Andes between 1950 and 1998. Observational evidence indicates that changes in precipitation amount or cloud cover over the last decades are minor in most regions and are therefore rather unlikely to have caused the observed retreat. The only exception is in southern Peru and western Bolivia where there is a general tendency toward slightly drier conditions. Near-surface temperature on the other hand has increased significantly throughout most of the tropical Andes. The temperature increase varies markedly between the eastern and western Andean slopes with a much larger temperature increase to the west. Simulations with the ECHAM-4 model, forced with observed global sea surface temperatures (SST) realistically reproduce the observed warming trend as well as the spatial trend pattern. Model results further suggest that a significant fraction of the observed warming can be traced to a concurrent rise in SST in the equatorial Pacific and that the markedly different trends in cloud cover to the east and west of the Andes contributed to the weaker warming east of the Andes in the model. The observed increase in relative humidity, derived from CRU 05 data, is also apparent in the model simulations, but on a regional scale the results between model and observations vary significantly. It is argued that changes in temperature and humidity are the primary cause for the observed glacier retreat during the 2nd half of the 20th century in the tropical Andes.  相似文献   

Aqueous Phase Reaction of HNO4: The Impact on Tropospheric Chemistry     

Frank Dentener  Jason Williams  Swen Metzger 《Journal of Atmospheric Chemistry》2002,41(2):109-133

We use a global atmospheric chemistry transport model to study the possible influence of aqueous phase reactions of peroxynitric acid (HNO₄) on the concentrations and budgets of NO_x, SO_x, O₃ and H₂O₂. Laboratory studies have shown that the aqueous reaction of HNO_4aq withHSO^– _3aq, and the uni-molecular decomposition of the NO₄ ^– anion to form NO₂ ^– (nitrite) occur on a time scale of about a second. Despite a substantial contribution of the reaction of HSO^– _3aq with HNO_4aq to the overall in-cloud conversion of SO₂ to SO₄ ^2–, a simultaneous decrease of other oxidants (most notably H₂O₂) more than compensated the increase in SO₄ ^2– production. The strongest influence of heterogeneous HNO₄ chemistry was found in the boundary layer, where calculated monthly average ozone concentrations were reduced between 2% to 10% andchanges of H₂O₂ between –20% to +10%compared to a simulation which ignores this reaction. Furthermore, SO₂ was increased by 10% to 20% and SO₄ ^2–depleted by up to 10%. Since the resolution of our global model does not enable a detailed comparison with measurements in polluted regions, it is not possible to verify whether considering heterogeneous HNO₄ reactions results in a substantial improvement of atmospheric chemistry transport models. However, the conversion of HNO₄ in the aqueous phase seems to be efficient enough to warrant further laboratory investigations and more detailed model studies on this topic.  相似文献