431 research outputs found
Identification of hammerstein-wiener systems including backlash input nonlinearities
Postprint (published version
Data filtering-based least squares iterative algorithm for Hammerstein nonlinear systems by using the model decomposition
This paper focuses on the iterative identification problems for a class of Hammerstein nonlinear systems. By decomposing the system into two fictitious subsystems, a decomposition-based least squares iterative algorithm is presented for estimating the parameter vector in each subsystem. Moreover, a data filtering-based decomposition least squares iterative algorithm is proposed. The simulation results indicate that the data filtering-based least squares iterative algorithm can generate more accurate parameter estimates than the least squares iterative algorithm
Ecosystem Monitoring and Port Surveillance Systems
International audienceIn this project, we should build up a novel system able to perform a sustainable and long term monitoring coastal marine ecosystems and enhance port surveillance capability. The outcomes will be based on the analysis, classification and the fusion of a variety of heterogeneous data collected using different sensors (hydrophones, sonars, various camera types, etc). This manuscript introduces the identified approaches and the system structure. In addition, it focuses on developed techniques and concepts to deal with several problems related to our project. The new system will address the shortcomings of traditional approaches based on measuring environmental parameters which are expensive and fail to provide adequate large-scale monitoring. More efficient monitoring will also enable improved analysis of climate change, and provide knowledge informing the civil authority's economic relationship with its coastal marine ecosystems
Research on optimal control, stabilization and computational algorithms for aerospace applications
The research carried out in the areas of optimal control and estimation theory and its applications under this grant is reviewed. A listing of the 257 publications that document the research results is presented
Characterising the ocean frontier : a review of marine geomorphometry
Geomorphometry, the science that quantitatively describes terrains, has traditionally focused on the investigation
of terrestrial landscapes. However, the dramatic increase in the availability of digital bathymetric data and the increasing
ease by which geomorphometry can be investigated using Geographic Information Systems (GIS) has prompted interest in
employing geomorphometric techniques to investigate the marine environment. Over the last decade, a suite of
geomorphometric techniques have been applied (e.g. terrain attributes, feature extraction, automated classification) to investigate the characterisation of seabed terrain from the coastal zone to the deep sea. Geomorphometric techniques are,
however, not as varied, nor as extensively applied, in marine as they are in terrestrial environments. This is at least partly due
to difficulties associated with capturing, classifying, and validating terrain characteristics underwater. There is nevertheless
much common ground between terrestrial and marine geomorphology applications and it is important that, in developing the
science and application of marine geomorphometry, we build on the lessons learned from terrestrial studies. We note, however, that not all terrestrial solutions can be adopted by marine geomorphometric studies since the dynamic, four-
dimensional nature of the marine environment causes its own issues, boosting the need for a dedicated scientific effort in
marine geomorphometry.
This contribution offers the first comprehensive review of marine geomorphometry to date. It addresses all the five main
steps of geomorphometry, from data collection to the application of terrain attributes and features. We focus on how these steps are relevant to marine geomorphometry and also highlight differences from terrestrial geomorphometry. We conclude
with recommendations and reflections on the future of marine geomorphometry.peer-reviewe
A review of marine geomorphometry, the quantitative study of the seafloor
Geomorphometry, the science of quantitative terrain characterization, has traditionally focused on the investigation of terrestrial landscapes. However, the dramatic increase in the availability of digital bathymetric data and the
increasing ease by which geomorphometry can be investigated using geographic information systems (GISs) and spatial analysis software has prompted interest in employing geomorphometric techniques to investigate the marine environment. Over the last decade or so, a multitude of geomorphometric techniques (e.g. terrain attributes, feature extraction,
automated classification) have been applied to characterize
seabed terrain from the coastal zone to the deep sea. Geomorphometric techniques are, however, not as varied, nor as
extensively applied, in marine as they are in terrestrial environments. This is at least partly due to difficulties associated with capturing, classifying, and validating terrain characteristics underwater. There is, nevertheless, much common
ground between terrestrial and marine geomorphometry applications and it is important that, in developing marine geomorphometry, we learn from experiences in terrestrial studies. However, not all terrestrial solutions can be adopted by
marine geomorphometric studies since the dynamic, four-dimensional (4-D) nature of the marine environment causes
its own issues throughout the geomorphometry workflow.
For instance, issues with underwater positioning, variations
in sound velocity in the water column affecting acousticbased mapping, and our inability to directly observe and
measure depth and morphological features on the seafloor
are all issues specific to the application of geomorphometry in the marine environment. Such issues fuel the need for
a dedicated scientific effort in marine geomorphometry.
This review aims to highlight the relatively recent growth
of marine geomorphometry as a distinct discipline, and offers
the first comprehensive overview of marine geomorphometry
to date. We address all the five main steps of geomorphometry, from data collection to the application of terrain attributes
and features. We focus on how these steps are relevant to marine geomorphometry and also highlight differences and similarities from terrestrial geomorphometry. We conclude with
recommendations and reflections on the future of marine geomorphometry. To ensure that geomorphometry is used and
developed to its full potential, there is a need to increase
awareness of (1) marine geomorphometry amongst scientists already engaged in terrestrial geomorphometry, and of
(2) geomorphometry as a science amongst marine scientists
with a wide range of backgrounds and experiences.peer-reviewe
Recommended from our members
Implementation and application of fracture diagnostic tools : fiber optic sensing and diagnostic fracture injection test (DFIT)
Shale reservoirs have drawn much attention in recent years in the oil and gas industry. Hydraulic fracturing is a key technology to extract the trapped hydrocarbon in the shale reservoirs. The complex hydraulic and natural fracture networks enable large contact area between fracture and low-permeability reservoir to enhance the production. The characterization of complex fracture geometry and evaluation of fracture properties are crucial to the fracturing operation design and fractured reservoir simulation. The main approach to a better understanding of fracture and shale reservoir matrix is fracture diagnosis. There are mainly five fracture diagnostic technologies: Distributed Temperature Sensing (DTS), Distributed Acoustic Sensing (DAS), Diagnostic Fracture Injection Test (DFIT), microseismic, and tracer flow-back test. In this study, we mainly focus on the data interpretation model of DTS and DFIT.
The current interpretation of DTS data is mostly limited to the qualitative analysis. To enable the quantitative interpretation of DTS data, an in-house comprehensive model is developed to evaluate the fracture properties and geometry. Our model couples fracture, wellbore, and reservoir domain together to capture the full physical process during the production stage. The effects of reservoir parameters, fracture parameters, and fracture geometries on temperature profiling along the wellbore are analyzed with our model. Our forward model could be potentially used to characterize fracture parameters or fracture geometry with history matching.
DFIT is consisted of before closure analysis and after closure analysis. The leak-off coefficient, injection efficiency, reservoir matrix permeability, and initial pore pressure can be obtained from DFIT data analysis. In this study, several models for DFIT data interpretation were integrated. A Marcellus shale gas DFIT data is successfully analyzed with our workflow.Petroleum and Geosystems Engineerin
New Approaches in Automation and Robotics
The book New Approaches in Automation and Robotics offers in 22 chapters a collection of recent developments in automation, robotics as well as control theory. It is dedicated to researchers in science and industry, students, and practicing engineers, who wish to update and enhance their knowledge on modern methods and innovative applications. The authors and editor of this book wish to motivate people, especially under-graduate students, to get involved with the interesting field of robotics and mechatronics. We hope that the ideas and concepts presented in this book are useful for your own work and could contribute to problem solving in similar applications as well. It is clear, however, that the wide area of automation and robotics can only be highlighted at several spots but not completely covered by a single book
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