997 resultados para Navegación aérea


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The Pacoima area consists of Miocene (sediments and basalts) rocks underlain by a quartz diorite basement complex of Jurassic age. The stratigranhic units range from 25 feet to more than 600 feet in thickness. The lower sediments are arkosic land- laid deposits while the Modelo formation, shallow marine in origin, consists of thinly bedded sandstones, shales, volcanic ash and calcareous members. An andesitic mass, possibly a volcanic plug, outcrops near the summit of one of the hills.

An anticline, and possibly an associated syncline, has been developed by compressional folding. Small scale contortion is locally exposed. Regional dip is northward, decreasing from south to north in the area. Faulting is common, most faults trending nearly north-south. Movement along these faults ranges from a few feet to several hundred feet.

There are no important mineral deposits in the area. Quarrying of the basement rocks has been abandoned.

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The region treated in the following report is a small area of about one square mile near Pacoima, California. It consists of a group of small hills that that form the western abutment of the Hansen Dam. It is underlain by a section of intrusives, sediments, and extrusives, which may be subdivided into four groups.

The oldest rocks form the Dimebere complex of Jurassic (?) plutonic rocks, pegmatites, and schists. Lying uncomformably on this is a series of alternating terrestrial sandstones and bassalts of Tertiary age. These are unconformably overlain in turn by the Hansen Dam formation, a series of marine shales and sandstone correlated with the Temblor by the fossil contact. Finally into these strata was intruded the Munglish andesite.

These strata form a shallow, plunging anticline, whose axis trends slightly east of north and lies in the center of the hills. The unconformities have been offset in several places by a series of faults apparently related to the anticline.

A complete outline of the geologic history is included in the report.

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To be able to carry out physical, chemical and biological investigations on a lake, one needs a thorough knowledge of the volume of water and the shape of the lake basin. Little is known about the about the morphology of the lakes in Schleswig-Holstein and its ecological consequences. For this research a 30 KHz echo sounder with sediment transceiver was used to carry out profile determinations (echo soundings). This apparatus continuously records on paper the different reflexions and absorptions of the sediment and water body in the corresponding depth. By this, acoustically noticeable layers and different densities in the sediment and 'scattering layers' in the water body due to physical, chemical and biological reasons (e.g. plans and single fish) are made visible. Result are summarised here regarding the echo soundings in Blunker See.

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A new supervised burned area mapping software named BAMS (Burned Area Mapping Software) is presented in this paper. The tool was built from standard ArcGIS (TM) libraries. It computes several of the spectral indexes most commonly used in burned area detection and implements a two-phase supervised strategy to map areas burned between two Landsat multitemporal images. The only input required from the user is the visual delimitation of a few burned areas, from which burned perimeters are extracted. After the discrimination of burned patches, the user can visually assess the results, and iteratively select additional sampling burned areas to improve the extent of the burned patches. The final result of the BAMS program is a polygon vector layer containing three categories: (a) burned perimeters, (b) unburned areas, and (c) non-observed areas. The latter refer to clouds or sensor observation errors. Outputs of the BAMS code meet the requirements of file formats and structure of standard validation protocols. This paper presents the tool's structure and technical basis. The program has been tested in six areas located in the United States, for various ecosystems and land covers, and then compared against the National Monitoring Trends in Burn Severity (MTBS) Burned Area Boundaries Dataset.

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An atomic force microscope (AFM) assisted surface plasmons leakage radiation photolithography technique has been numerically demonstrated by using two-dimensional finite-difference time-domain (2D-FDTD) method. With the aid of a metallic AFM tip, particular characteristic of the Kretstchmann configuration to excite surface plasmons (SPs) is utilized to achieve large-area patterns with high spatial resolution and contrast, the photoresist could be exposed with low power laser due to the remarkable local field enhancement at the metal/dielectric interface and the resonant localized SPs modes near the tip. Good tolerance on the film thickness and incident angle has been obtained, which provides a good practicability for experiments. This photolithography technique proposed here can realize large-area, high-resolution, high-contrast, nondestructive, arbitrary-structure fabrication of nanoscale devices. (c) 2007 Elsevier B.V. All rights reserved.

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Objective: to analyze what nursing models and nursing assessment structures have been used in the implementation of the nursing process at the public and private centers in the health area Gipuzkoa (Basque Country). Method: a retrospective study was undertaken, based on the analysis of the nursing records used at the 158 centers studied. Results: the Henderson model, Carpenito's bifocal structure, Gordon's assessment structure and the Resident Assessment Instrument Nursing Home 2.0 have been used as nursing models and assessment structures to implement the nursing process. At some centers, the selected model or assessment structure has varied over time. Conclusion: Henderson's model has been the most used to implement the nursing process. Furthermore, the trend is observed to complement or replace Henderson's model by nursing assessment structures.

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A master-oscillator fiber power amplifier (MOPA) system with a 4-m-long Yb3+-doped homemade large mode area (LMA) double-clad fiber is reported. The system emits up to 133.8 W of amplified radiation at a wavelength of 1064 nm and a repetition rate of 100 kHz, limited only by the available pump power. Peak power of 300 kW at 20 kHz with a pulse duration of 15 ns is obtained. (c) 2006 Society of Photo-Optical Instrumentation Engineers.

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A master-oscillator fiber power amplifier (MOPA) system with a 4-m-long Yb3+-doped homemade large mode area (LMA) double-clad fiber is reported. The system emits up to 133.8 W of amplified radiation at a wavelength of 1064 nm and a repetition rate of 100 kHz, limited only by the available pump power. Peak power of 300 kW at 20 kHz with a pulse duration of 15 ns is obtained. (c) 2006 Society of Photo-Optical Instrumentation Engineers.

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To get high output power with good beam quality, a tapered section is introduced to large-mode-area (LMA) Yb-doped fiber laser. Output characteristics of the fiber laser without tapered section and with tapered section are compared experimentally. When the launched pump power is 119.1 W, 77.9 W with M-2 3.08 and 56.4 W with M-2 1.14 can be obtained, respectively. The corresponding slope efficiencies are 71.8% and 54.1%, respectively. Although output power of the tapered fiber laser has 30.6% penalty, brightness of it is as much as 5.28 times of the fiber laser without tapered section. Moreover, spectra of them are measured. It is found that tapered section makes lasing wavelength of the fiber laser shorter. (c) 2007 Elsevier B.V. All rights reserved.

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The Inter-American Tropical Tuna Commission (IATTC) staff has been sampling the size distributions of tunas in the eastern Pacific Ocean (EPO) since 1954, and the species composition of the catches since 2000. The IATTC staff use the data from the species composition samples, in conjunction with observer and/or logbook data, and unloading data from the canneries to estimate the total annual catches of yellowfin (Thunnus albacares), skipjack (Katsuwonus pelamis), and bigeye (Thunnus obesus) tunas. These sample data are collected based on a stratified sampling design. I propose an update of the stratification of the EPO into more homogenous areas in order to reduce the variance in the estimates of the total annual catches and incorporate the geographical shifts resulting from the expansion of the floating-object fishery during the 1990s. The sampling model used by the IATTC is a stratified two-stage (cluster) random sampling design with first stage units varying (unequal) in size. The strata are month, area, and set type. Wells, the first cluster stage, are selected to be sampled only if all of the fish were caught in the same month, same area, and same set type. Fish, the second cluster stage, are sampled for lengths, and independently, for species composition of the catch. The EPO is divided into 13 sampling areas, which were defined in 1968, based on the catch distributions of yellowfin and skipjack tunas. This area stratification does not reflect the multi-species, multi-set-type fishery of today. In order to define more homogenous areas, I used agglomerative cluster analysis to look for groupings of the size data and the catch and effort data for 2000–2006. I plotted the results from both datasets against the IATTC Sampling Areas, and then created new areas. I also used the results of the cluster analysis to update the substitution scheme for strata with catch, but no sample. I then calculated the total annual catch (and variance) by species by stratifying the data into new Proposed Sampling Areas and compared the results to those reported by the IATTC. Results showed that re-stratifying the areas produced smaller variances of the catch estimates for some species in some years, but the results were not significant.

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Muchos de los servicios que hasta hace relativamente poco tiempo eran ofertados únicamente por los operadores de telecomunicaciones, han pasado en la actualidad a ser prestados por terceros gracias al modelo de servicios en la nube, impulsando el auge de este modelo frente al tradicional. Esto trae consigo un incremento en la complejidad en la implantación por parte del proveedor de políticas para la gestión de la QoS demandada por el cliente.En este nuevo escenario, el concepto de calidad de servicio ha venido evolucionando desde su definición clásica, entendida como el análisis objetivo de los indicadores intrínsecos de calidad que definen el rendimiento de un servicio, hacia una visión subjetiva centrada en el punto de vista del cliente respecto a dicho servicio. En este contexto, organismos de estandarización como la ITU, a través de sus grupos de trabajo, están fomentando el interesante planteamiento de abordar los servicios de telecomunicaciones ampliamente asentados y más que estudiados desde la vertiente clásica de la QoS, desde este nuevo prisma enfocado al cliente, en el que poder establecer una metodología de estudio de la QoE en dichos servicios. En particular, el trabajo presentado en este documento se asienta en la validación del draft de la recientemente aprobada recomendación ITU-T P.1501 (Metodología de test subjetiva para el servicio de navegación web), así como en la contribución a la recomendación G.1031 (Factores de QoE en el servicio de navegación web).