27,200 research outputs found
Land use of northern megalopolis
The major objective is to map and digitize the land use of northern megalopolis, the states of Massachusetts, Connecticut, and Rhode Island, and to evaluate ERTS as a planning tool for megalopolitan areas. The southern New England region provides a good test ERTS's capabilities because of its complex landscape. Not only are there great differences in the degree of urban development, but in relief and vegetative cover as well
Recognition of settlement patterns against a complex background
Photointerpretation of aerial color infrared photography for analysis of urban land us
Fire and rescue service community safety initiatives: measuring impact
Purpose - The purpose of this paper is to discuss methods of capturing the impact of fire and rescue service (FRS) community safety work which directly aims to reduce the occurrence of specific incidents. Design/methodology/approach - The impact assessment method described focuses on addressing one of the major problems with regards to attributing outcomes to FRS community safety work; the influence of external factors. This paper looked to assess the incident trends within a case study UK FRS within the context of the following external data sets: first, incident trends within other UK FRSs; second, demographic trends; and third, incident data from other public services. Findings - There were instances, either across the whole region served by the case study FRS, or within specific districts, where evidence suggested a strong likelihood of the community safety work of the case study FRS contributing towards an observed reduction in incidents. These findings were established through filtering the impact of widespread external factors, which could impact upon incident figures. Research limitations/implications - The utility of this impact assessment relies upon FRS consistently recording the specific aims and focus of individual community safety activity, so that any positive outcomes can be attributed to a particular group of community safety initiatives. Originality/value - This paper discusses how an evaluation process, to deter mine the likelihood of community safety impacting upon incident numbers, can be practically applied to a FRS
Stochastic Perturbations of Periodic Orbits with Sliding
Vector fields that are discontinuous on codimension-one surfaces are known as
Filippov systems and can have attracting periodic orbits involving segments
that are contained on a discontinuity surface of the vector field. In this
paper we consider the addition of small noise to a general Filippov system and
study the resulting stochastic dynamics near such a periodic orbit. Since a
straight-forward asymptotic expansion in terms of the noise amplitude is not
possible due to the presence of discontinuity surfaces, in order to
quantitatively determine the basic statistical properties of the dynamics, we
treat different parts of the periodic orbit separately. Dynamics distant from
discontinuity surfaces is analyzed by the use of a series expansion of the
transitional probability density function. Stochastically perturbed sliding
motion is analyzed through stochastic averaging methods. The influence of noise
on points at which the periodic orbit escapes a discontinuity surface is
determined by zooming into the transition point. We combine the results to
quantitatively determine the effect of noise on the oscillation time for a
three-dimensional canonical model of relay control. For some parameter values
of this model, small noise induces a significantly large reduction in the
average oscillation time. By interpreting our results geometrically, we are
able to identify four features of the relay control system that contribute to
this phenomenon.Comment: 44 pages, 9 figures, submitted to: J Nonlin. Sc
Deep Remix: Remixing Musical Mixtures Using a Convolutional Deep Neural Network
Audio source separation is a difficult machine learning problem and
performance is measured by comparing extracted signals with the component
source signals. However, if separation is motivated by the ultimate goal of
re-mixing then complete separation is not necessary and hence separation
difficulty and separation quality are dependent on the nature of the re-mix.
Here, we use a convolutional deep neural network (DNN), trained to estimate
'ideal' binary masks for separating voice from music, to perform re-mixing of
the vocal balance by operating directly on the individual magnitude components
of the musical mixture spectrogram. Our results demonstrate that small changes
in vocal gain may be applied with very little distortion to the ultimate
re-mix. Our method may be useful for re-mixing existing mixes
Evaluation of ERTS-1 data for acquiring land use data of northern Megalopolis
State planners are increasingly becoming interested in ERTS as a possible method for acquiring land use data. An important consideration to them is whether ERTS can provide such data at a savings in both time and money over alternative systems. A preliminary evaluation of ERTS as a planning tool is given
The flow over delta wings at low speeds with leading edge separation
A low speed investigation of the flow over a 40 degree apex angle delta wing with sharp leading edges had been made in order to ascertain details of the flow in the viscous region near the leading edge of the suction surface of the wing. A physical picture of the flow was obtained from the surface flow and a smoke technique of flow visualization, combined with detailed measurements of total head, dynamic pressure, flow directions and vortex core positions in the flow above the wing
A digital technique to compensate for time- base error in magnetic tape recording
Digital technique for compensation of time base error in magnetic tape recorder dat
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