96 research outputs found
Producción y uso de las grandes hojas de sílex durante el Calcolítico del Noreste de Bulgaria
The Chalcolithic sites of Bulgaria are characterized by a large number of tools from Dobrudjian flint. Results of studying of flint items the main blank for which was the long blade, existence of workshops, a wide circulation of the same products in different regions of the country testify to high technological level of processing of flint raw materials, professionalism of craftsmen and specialization of flint production in economy of this time. Archaeological materials were studied by means of technical- morphological and experimental-traceological methods and ethnographic data were also used.Los yacimientos calcolíticos de Bulgaria se caracterizan por presentar una gran cantidad de piezas de sílex de Dobrudjian. Los resultados del estudio de los artefactos de sílex, materia sobre la que se elaboraron las grandes hojas, la existencia de talleres, y de una amplia circulación de los mismos productos en diferentes regiones del país dan testimonio del alto nivel tecnológico del procesado de las materias primas silíceas, de la capacidad de los artesanos y de la especialización de la producción de artefactos sílex en la economía de esa época. Los materiales arqueológicos se han estudiado mediante métodos tecno-morfológicos y experimental-traceológicos, y también se tuvieron en cuenta datos etnográficos
Capillary Bridges — A Tool for Three-Phase Contact Investigation
Subject of investigation are capillary bridges (CB) between two parallel solid plates normally oriented to the gravity field. Presented are results of study of CB with negligible gravity effects and CB undergoing observable gravitational deformations. Among the discussed problems some new aspects of the CB behavior are formulated. One of them is the so-called stretching thickness limit, i.e. the maximal thickness above which a CB of given volume and contact angles cannot exist. It is shown that the stretching thickness limit of a concave CB substantially differs from that of a convex one. Analysis of the forces acting on CB plates is presented. It clearly demonstrates that the gravity part of the forces, relative to the part of capillary forces, increases with stretching. Most of the observed effects are interpreted on the basis of the two CB radii of curvature analysis, thus avoiding the ponderous procedures of obtaining (integrating) the CB generatrix profile. The success of this approach lies in its combination with image analysis of CB profile. Discussed are the contact angle hysteresis effects at CB stretching and pressing
Crop Acreage Estimation: Landsat TM and Resourcesat-1 AWiFS Sensor Assessment of the Mississippi River Delta, 2005
AWiFs data are appropriate for crop acreage estimation over large, spectrally homogenous, crop areas such as the Mid-West, the Delta and the Northern Great Plains. Regression and Kappa statistics for soybean, corn, cotton, rice and sorghum produced using both the Landsat TM and AWiFS data are very similar. AWiFS data appear to be a suitable alternative or supplement to Landsat TM data for production of NASS'Cropland Data Layer product
Table 2: Example applications of the use of remote sensing technologies to detect change in vegetation.
In order to understand the distribution and prevalence of Ommatissus lybicus (Hemiptera: Tropiduchidae) as well as analyse their current biographical patterns and predict their future spread, comprehensive and detailed information on the environmental, climatic, and agricultural practices are essential. The spatial analytical techniques such as Remote Sensing and Spatial Statistics Tools, can help detect and model spatial links and correlations between the presence, absence and density of O. lybicus in response to climatic, environmental, and human factors. The main objective of this paper is to review remote sensing and relevant analytical techniques that can be applied in mapping and modelling the habitat and population density of O. lybicus. An exhaustive search of related literature revealed that there are very limited studies linking location-based infestation levels of pests like the O. lybicus with climatic, environmental, and human practice related variables. This review also highlights the accumulated knowledge and addresses the gaps in this area of research. Furthermore, it makes recommendations for future studies, and gives suggestions on monitoring and surveillance methods in designing both local and regional level integrated pest management strategies of palm tree and other affected cultivated crops
A new land cover classification based stratification method for area sampling frame construction
This paper proposes a new automated USDA National
Agricultural Statistics Service (NASS) Cropland Data Layer
(CDL) based method for stratifying U.S. land cover. The
proposed method is used to stratify the NASS state level Area
Sampling Frames (ASFs) by automatically calculating percent
cultivation at the Primary Sampling Unit (PSU) level based on
the CDL data. The CDL based stratification experiment was
successfully conducted for Oklahoma, Ohio, Virginia, Georgia,
and Arizona. The stratification accuracies of the traditional and
new automated CDL stratification methods were compared
based on 2010 June Area Survey (JAS) data. Experimental
results indicated that the CDL based stratification method
achieved higher accuracies in the intensively cropped areas while
the traditional method achieved higher accuracies in low or non
agricultural areas. The differences in the accuracies were
statistically significant at a 95% confidence level. It is concluded
that the CDL based stratification method will improve efficiency
and reduce cost in NASS ASF construction, and improve the
precision of NASS JAS estimates
Integration of the Cropland Data Layer Based Automatic Stratification Method into the Traditional Area Frame Construction Process
A new automatic stratification method utilizing United States Department of Agriculture (USDA) National Agricultural Statistics Service (NASS) geospatial Cropland Data Layers (CDLs) was recently implemented in NASS operations. Recent research findings indicated that using the automated stratification method significantly improved Area Sampling Frame (ASF) stratification accuracies in intensively cropped areas (>15% cultivation) and overall stratification accuracies when compared to traditional stratification based on visual analysis of aerial photography or satellite data , while reducing the cost of ASF construction (Boryan et al., 2014). Though the new automated stratification method has improved stratification efficiency, objectivity, accuracy in the intensively cropped areas it inherits the CDL classification errors and has lower accuracies in low or non-agricultural areas. This implies that the automated stratification process is not a perfect solution to directly replace the NASS traditional stratification method for ASF construction operationally. This paper describes a hybrid approach: an operational ASF construction process that integrates the automated stratification results with ASF editing/review methods. New 2014 - 2015 NASS ASFs for South Dakota, Oklahoma, Arizona, New Mexico, Georgia, Alabama and North Carolina were successfully built using the new integrated operational process. The seven updated ASFs delivered significant improvements in objectivity, operational efficiency, and frame accuracy, based on 2014 and 2015 June Area Survey (JAS) reported data
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