482,303 research outputs found
Farming Differentiation in the Rural-urban Interface of the Middle Mountains, Nepal: Application of Analytic Hierarchy Process (AHP)Modeling
This article investigates the dominant factors of farming differentiation in the rural-urban interface of the densely
populated Kathmandu Valley, using the Analytic Hierarchy Process (AHP) modeling. The rural-urban interface in the Kathmandu Valley is an important vegetable production pocket which supplies a large amount of the vegetables in the city core. While subsistence farming in the rural area is characterized by a system which integrates livestock and forestry with agriculture, the intensification in the urban fringe is characterized by triple crop rotations and market-oriented intensive vegetable production. Seven factors which were supposed to cause farming variation in the interface were incorporated in the AHP framework and then subjected to the farmers’ judgment in distinctly delineated three farming zones. These factors played crucial yet differing roles in different farming zones. Inaccessibility and use of local resources; higher yield and accessibility and agro-ecological consideration and quality production are the key impacting factors of subsistence, commercial inorganic and smallholder organic farming respectively. The quantification of such factors of farming differentiation through AHP is an important piece of information that will contribute in modeling farming in the rural-urban interface of developing countries which are characterized by a high diversity of farming practices and are undergoing a rapid
change in the land use pattern
MU670 Chamber Music Recital, December 7, 1988
This is the concert program of the MU670 Chamber Music Recital performance on Wednesday, December 7, 1988 at 7:00 p.m., at the Marshall Room, 855 Commonwealth Avenue, Boston, Massachusetts. Works performed were Sonate pour Flute, Alto et Harpe by Claude Debussy, Piano Trio in C Major, opus 87 by Johannes Brahms, Andante and Rondo by Doppler, Mystery Quintet by Unknown, Trio, No. 2 in B-flat Major by Francois Devienne, Mysery Quintety by Unknown, Trois Pieces Breves by Jacques Ibert, Trio by Darius Milhaud, and Trio in d minor by Felix Mendelssohn. Digitization for Boston University Concert Programs was supported by the Boston University Humanities Library Endowed Fund
SOCIO-ECONOMIC AND ENVIRONMENTAL ASPECTS OF FARMING PRACTICES IN THE PERI-URBAN HINTERLANDS OF NEPAL
Spatial location of the farm households shapes farming practices and livelihoods of the farmers. Many socio-economic variables have strong spatial relations that would otherwise be missed by data aggregation at household level. Geographic Information System (GIS)provides display and analysis of socio-economic data that may be fundamental for many social scientists to understand socio-economic reality influenced by geographical position of the farm households. Present article aims at integrating socio-economic data into GIS environment to examine spatial relation in the resource availability and use employing spatial and random sampling techniques. Result demonstrates the variation in the socioeconomic attributes along the spatial gradient which is mainly related to the infrastructures such as road, market and improved agro-inputs. While households with better access to these infrastructures have tendency to use more agro-chemicals, have larger family, land holding and livestock units, better off-farm opportunities, commercial farming orientation and hence higher family income; opposite is true for the households with poor access to these infrastructures. Peri-urban farmlands, wherever agro-chemicals are applied imprudently, faces the problems of agro-ecological degradation while rural subsistence farming faces the problem of spatial poverty
Planetary Radio Interferometry and Doppler Experiment (PRIDE) Technique: a Test Case of the Mars Express Phobos Fly-by. 2. Doppler tracking: Formulation of observed and computed values, and noise budget
Context. Closed-loop Doppler data obtained by deep space tracking networks
(e.g., NASA's DSN and ESA's Estrack) are routinely used for navigation and
science applications. By "shadow tracking" the spacecraft signal, Earth-based
radio telescopes involved in Planetary Radio Interferometry and Doppler
Experiment (PRIDE) can provide open-loop Doppler tracking data when the
dedicated deep space tracking facilities are operating in closed-loop mode
only. Aims. We explain in detail the data processing pipeline, discuss the
capabilities of the technique and its potential applications in planetary
science. Methods. We provide the formulation of the observed and computed
values of the Doppler data in PRIDE tracking of spacecraft, and demonstrate the
quality of the results using as a test case an experiment with ESA's Mars
Express spacecraft. Results. We find that the Doppler residuals and the
corresponding noise budget of the open-loop Doppler detections obtained with
the PRIDE stations are comparable to the closed-loop Doppler detections
obtained with the dedicated deep space tracking facilities
Measurement-based analysis of delay-Doppler characteristics in an indoor environment
An analysis of delay-Doppler characteristics in the presence of moving people is presented for short-range communication in an indoor environment. Channel-sounding measurements have been carried out at 3.6 GHz in a crowded university hall during several short and long breaks in-between courses. During three consecutive days, the measurements were repeated with different positions for the transmit and receive antennas. In this study, the behavior of the maximum Doppler shift and the Doppler spread was analyzed in the time-delay domain as a function of the occupation of the hall, the polarizations of the 2 x 2 MIMO antennas, and their positions in the hall. The measurements reveal a clear distinction between the Doppler spread of the short and long breaks in the campaign, indicating a distinctive power distribution of their Doppler spectra. In addition, there is a significant contrast between the Doppler characteristics of the co- and cross-polarizations. Measurements at several positions reveal the importance of characterizing multipaths and show that the Doppler effect depends on the position of the antennas in the environment. In addition, this work also shows that the Doppler spectrum can be accurately modeled by a Cauchy distribution, allowing for the generation of parameters to describe Doppler characteristics
Radar High Resolution Range & Micro-Doppler Analysis of Human Motions
In radar imaging it is well known that relative motion or deformation of parts of illuminated objects induce additional features in the Doppler frequency spectra. These features are called micro-Doppler effect and appear as sidebands around the central Doppler frequency. They can provide valuable information about the structure of the moving parts and may be used for identification purposes [1]. Previous papers have mostly focused on ID micro-Doppler analysis [2-4]. In this paper, we propose to emphasize the analysis of such "non stationary targets" using a 2D imaging space, using both the micro-Doppler and a high range resolution analysis. As in 2D-ISAR imaging, range separation enables us to better discriminate the various effects caused by the time varying reflectors. We will focus our study on human motion. We will see how micro-Doppler signature can be used to extract information on pedestrians gait. We will show examples on simulated and experimental data
Photonic superdiffusive motion in resonance line radiation trapping - partial frequency redistribution effects
The relation between the jump length probability distribution function and
the spectral line profile in resonance atomic radiation trapping is considered
for Partial Frequency Redistribution (PFR) between absorbed and reemitted
radiation. The single line Opacity Distribution Function [M.N. Berberan-Santos
et.al. J.Chem.Phys. 125, 174308 (2006)] is generalized for PFR and used to
discuss several possible redistribution mechanisms (pure Doppler broadening,
combined natural and Doppler broadening and combined Doppler, natural and
collisional broadening). It is shown that there are two coexisting scales with
a different behavior: the small scale is controlled by the intricate PFR
details while the large scale is essentially given by the atom rest frame
redistribution asymptotic. The pure Doppler and combined natural, Doppler and
collisional broadening are characterized by both small and large scale
superdiffusive Levy flight behaviors while the combined natural and Doppler
case has an anomalous small scale behavior but a diffusive large scale
asymptotic. The common practice of assuming complete redistribution in core
radiation and frequency coherence in the wings of the spectral distribution is
incompatible with the breakdown of superdiffusion in combined natural and
Doppler broadening conditions
Doppler-Free Spectroscopy of Weak Transitions: An Analytical Model Applied to Formaldehyde
Experimental observation of Doppler-free signals for weak transitions can be
greatly facilitated by an estimate for their expected amplitudes. We derive an
analytical model which allows the Doppler-free amplitude to be estimated for
small Doppler-free signals. Application of this model to formaldehyde allows
the amplitude of experimentally observed Doppler-free signals to be reproduced
to within the experimental error.Comment: 7 pages, 7 figures, 1 table, v2: many small improvements + corrected
line assignmen
Doppler lidar results from the San Gorgonio Pass experiments
During FY-84, the Doppler Lidar data from the San Gorgonio Pass experiments were analyzed, evaluated, and interpreted with regard to signal strength, signal width, magnitude and direction of velocity component and a goodness parameter associated with the expected noise level of the signal. From these parameters, a screening criteria was developed to eliminate questionable data. For the most part analysis supports the validity of Doppler Lidar data obtained at San Gorgonio Pass with respect to the mean velocity magnitude and direction. The question as to whether the Doppler width could be interpreted as a measure of the variance of the turbulence within the Doppler Lidar System (DLS) focal volume was not resolved. The stochastic nature of the Doppler broadening from finite residence time of the particles in the beam as well as other Doppler broadening phenomenon tend to mask the Doppler spread associated with small scale turbulence. Future tests with longer pulses may assist in better understanding
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