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How can teams of artificial agents localize and position themselves in GPS-denied environments? How can each agent determine its position from pairwise ranges, own velocity, and limited interaction with neighbors? This paper addresses this problem from an optimization point of view: we directly optimize the nonconvex maximum-likelihood estimator in the presence of range measurements contaminated with...
In polar region operations, drift sea ice positioning and tracking is useful for both scientific and safety reasons. Modeling ice movements has proven difficult, not least due to the lack of information of currents and winds of high enough resolution. Thus, observations of drift ice is essential to an up-to-date ice-tracking estimate. As an inverse problem, it is possible to extract current and wind...
The statistics of extreme wave heights is of great importance in many ocean and coastal engineering applications and is an important part of physical oceanography. For example, in the design and operation of marine structures one needs to take the influence of extreme ocean environments into account and estimates of very large return values of wave heights are often needed. However, due to the limited...
Real-time quality control (qc) of oceanographic data is usually accomplished by testing data points against a variety of conditions to identify the quality of the data. Since 2012, the U.S. Integrated Observing System (U.S IOOS®) Program Office Quality Assurance/Quality Control of Real-Time Oceanographic Data (Qartod) Project has worked with the ocean-observing community both nationally and internationally...
Oceanographic applications increasingly rely on the integration of multivariate data from diverse observational platforms, the coupling of remote sensing and field data being integral to analysis workflows. However, the inherent heterogeneity of in situ datasets and their variable adherence to meta/data standards poses a significant impediment to interoperability and long-term data stewardship. Here...
Alaska's coastal waters exhibit a rich variety of sea-level fluctuations, driven by multiple processes and encompassing a wide range of timescales. Water level data from a set of stations along the Alaska coast are examined from different perspectives to isolate portions of the variability with different periods or subranges of timescales. The approach is exploratory, addressing selected aspects of...
The use of elevation changes in an undulating terrain surface can be an effective alternative for vehicle navigation in GPS-denied underwater environments, since subsea terrain elevation data can be obtained using sonar systems. The performance of terrain-referenced navigation varies significantly depending on how informative a given terrain is, however it is not straightforward to quantify the amount...
The QARTOD methodology of a standard sequential string of tests on individual measurements has high applicability to constrained data systems. The QARTOD methodology has the benefit of a coherent and replicable test structure that enables relatively easy expansion into new measurements. However, as data streams become more complex the series of tests described becomes increasingly difficult to analyse...
Refraction of light underwater is a major source of error for 3D reconstruction. Use of a physically correct camera model taking into account properties of the optical system is essential for understanding the reasons why errors occur and obtaining quantitative estimates of errors. It was proven that use of the single viewpoint model of the camera leads to significant distortions in reconstruction...
Ocean Networks Canada (ONC) is a not-for-profit society that operates and manages innovative cabled observatories which supply continuous power and Internet connectivity to scientific instruments located in coastal, deep-ocean, and Arctic environments. The data from the instruments are archived, quality-controlled, and made freely available to researchers, educators, and the public. The Oceans 2.0...
Traditionally unmanned undersea vehicles (UUVs) have been large, complex and expensive. Development of UUVs has been driven by defense and commercial requirements. This has allowed for extensive research and development budgets and long development cycles. This paper briefly discuses these historic drivers and how this situation has changed. It focuses on a new compact affordable UUV. In 2015, several...
With the increasing needs for long-term fossil fuels, the Arctic regions of the world have opened up to opportunities in oil/gas development, Northern transportation, and sea routes to reduce travel times between Europe and Asia are also increasing interest in commerce along those routes. The increased number of drilling rigs, production platforms, accommodation ships and support /supply vessels working...
Traditional methods of system verification call for the repeated exercise of that system in its intended environment to give confidence that it will operate as designed. Autonomous systems, however, are systems designed for sophisticated operation in stochastic environments that specifically handle the unexpected; testing all possible operational scenarios for such systems is intractably complex....
Short range ad-hoc wireless networks can be used to deliver streaming multimedia for information, entertainment and advertisement purposes. To enable short-range communication between various devices, the Wi-Fi Alliance proposed an extension to the IEEE802.11 Wi-Fi standard called Wi-Fi Peer-to-Peer (P2P). It allows compliant devices to form ad-hoc communication groups without interrupting conventional...
In this paper, we describe the LFM-1b User Genre Profile dataset. It provides detailed information on musical genre preferences for more than 120,000 listeners and links to the LFM-1b dataset. We created the dataset by exploiting social tags, indexing them using two genre term sets, and aggregating the resulting annotated listening events on the user level. We foresee several applications of the dataset...
With the rapid growth of online content consumption, knowing end-users and having actionable content insights has become extremely important for any online content provider. Insights from user segment identification could help in developing a content recommendation as well as new content acquisition. For advertisers, identifying segments could assist in designing ad campaigns with greater target accuracy...
Privacy for mobile devices will be more and more important, while data in the devices are easily be hacked. Traditional mobile unlocking systems such as inner password unlock and graphics unlock are unsecure so that this study is based on fingerprint with touch identify and Advanced Encryption Standard (AES) to effectively secure mobile privacy data and to reduce the risk of data leaking.
In this paper, we consider the energy-efficient coordination of a set of appliances in a smart-building. We introduce a theoretical formulation of the coordination problem and an Integer Linear Programming model for its resolution. Our formalization is complemented by an analysis of the properties and limits of the model. We also define a practical smart-building setting in which our formalization...
Linear-quadratic problem for a time-invariant scalar continuous time system and a bound spectrum disturbance is considered. The problem is shown to be degenerate; and an algorithm of the regulator synthesis is presented.
Formal verification has become very useful and popular in last decade in area of embedded systems design and in analysis of critical systems. It can reveal common errors like deadlocks, starvation, check system invariants, but also verify more complex properties defined by LTL formulas whose writing may be very error prone for non expert users. To reduce the time-to-market for embedded systems and...
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