55,376 research outputs found
Skylab A proposal aerotriangulation with very small scale photography
There are no author-identified significant results in this report
Skylab A proposal aerotriangulation with very small scale photography
There are no author-identified significant results in this report
Skylab A proposal aerotriangulation with very small scale photography
There are no author-identified significant results in this report
Skylab: A proposal aerotriangulation with very small scale photography
There are no author-identified significant results in this report
Exponential ergodicity of the jump-diffusion CIR process
In this paper we study the jump-diffusion CIR process (shorted as JCIR),
which is an extension of the classical CIR model. The jumps of the JCIR are
introduced with the help of a pure-jump L\'evy process . Under
some suitable conditions on the L\'evy measure of , we derive a
lower bound for the transition densities of the JCIR process. We also find some
sufficient condition guaranteeing the existence of a Forster-Lyapunov function
for the JCIR process, which allows us to prove its exponential ergodicity.Comment: 14 page
Machine learning regression on hyperspectral data to estimate multiple water parameters
In this paper, we present a regression framework involving several machine
learning models to estimate water parameters based on hyperspectral data.
Measurements from a multi-sensor field campaign, conducted on the River Elbe,
Germany, represent the benchmark dataset. It contains hyperspectral data and
the five water parameters chlorophyll a, green algae, diatoms, CDOM and
turbidity. We apply a PCA for the high-dimensional data as a possible
preprocessing step. Then, we evaluate the performance of the regression
framework with and without this preprocessing step. The regression results of
the framework clearly reveal the potential of estimating water parameters based
on hyperspectral data with machine learning. The proposed framework provides
the basis for further investigations, such as adapting the framework to
estimate water parameters of different inland waters.Comment: This work has been accepted to the IEEE WHISPERS 2018 conference. (C)
2018 IEE
Fuzzy set methods for object recognition in space applications
Progress on the following tasks is reported: (1) fuzzy set-based decision making methodologies; (2) feature calculation; (3) clustering for curve and surface fitting; and (4) acquisition of images. The general structure for networks based on fuzzy set connectives which are being used for information fusion and decision making in space applications is described. The structure and training techniques for such networks consisting of generalized means and gamma-operators are described. The use of other hybrid operators in multicriteria decision making is currently being examined. Numerous classical features on image regions such as gray level statistics, edge and curve primitives, texture measures from cooccurrance matrix, and size and shape parameters were implemented. Several fractal geometric features which may have a considerable impact on characterizing cluttered background, such as clouds, dense star patterns, or some planetary surfaces, were used. A new approach to a fuzzy C-shell algorithm is addressed. NASA personnel are in the process of acquiring suitable simulation data and hopefully videotaped actual shuttle imagery. Photographs have been digitized to use in the algorithms. Also, a model of the shuttle was assembled and a mechanism to orient this model in 3-D to digitize for experiments on pose estimation is being constructed
Building the Scientific Modeling Assistant: An interactive environment for specialized software design
The construction of scientific software models is an integral part of doing science, both within NASA and within the scientific community at large. Typically, model-building is a time-intensive and painstaking process, involving the design of very large, complex computer programs. Despite the considerable expenditure of resources involved, completed scientific models cannot easily be distributed and shared with the larger scientific community due to the low-level, idiosyncratic nature of the implemented code. To address this problem, we have initiated a research project aimed at constructing a software tool called the Scientific Modeling Assistant. This tool provides automated assistance to the scientist in developing, using, and sharing software models. We describe the Scientific Modeling Assistant, and also touch on some human-machine interaction issues relevant to building a successful tool of this type
Knowledge-intensive software design systems: Can too much knowledge be a burden?
While acknowledging the considerable benefits of domain-specific, knowledge-intensive approaches to automated software engineering, it is prudent to carefully examine the costs of such approaches, as well. In adding domain knowledge to a system, a developer makes a commitment to understanding, representing, maintaining, and communicating that knowledge. This substantial overhead is not generally associated with domain-independent approaches. In this paper, I examine the downside of incorporating additional knowledge, and illustrate with examples based on our experience in building the SIGMA system. I also offer some guidelines for developers building domain-specific systems
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