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Monitoring household upgrading in unplanned settlements with unmanned aerial vehicles

INTERNATIONAL JOURNAL OF APPLIED EARTH OBSERVATION AND GEOINFORMATION 2020年 90卷 102117-102117页

作者： Gevaert, Caroline M. Persello, Claudio Sliuzas, Richard Vosselman, George Univ Twente Fac ITC NL-7500 AE Enschede Netherlands

In-situ slum upgrading projects include infrastructural improvements such as new roads, which are perceived to improve the quality of life for the residents and encourage structural improvements at a household level. Although these physical changes are easily visible in satellite imagery, it is more difficult to track incremental improvements undertaken by the residents - which are perhaps more closely linked to the socio-economic development of the households themselves. The improved detail provided by imagery obtained from Unmanned Aerial Vehicles (UAVs) has the potential to monitor these more subtle changes in a settlement. This paper provides a framework which takes advantage of high-resolution imagery and a detailed elevation model from UAVs to detect changes in informal settlements. The proposed framework leverages expert knowledge to provide training labels for deep learning and thus avoids the cost of manual labelling. The semantic classification is then used to interpret a change mask and identify: new buildings, the creation of open spaces, and incremental roof upgrading in an informal settlement. The methodology is demonstrated on UAV imagery of an informal settlement in Kigali, Rwanda, successfully identifying changes between 2015 and 2017 with an Overall Accuracy of 95 % and correctly interpreting changes with an Overall Accuracy of 91 %. Results reveal that almost half the buildings in the settlement show visible changes in the roofing material, and 61 % of these changed less than 1m(2). This demonstrates the incremental nature of housing improvements in the settlement.

关键词： change detection algorithms Image analysis Unmanned aerial vehicles Urban planning Informal settlements

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A NEW FFT-BASED DIGITAL FREQUENCY RELAY FOR LOAD SHEDDING

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IEEE TRANSACTIONS ON POWER APPARATUS AND SYSTEMS 1982年第2期101卷 433-439页

作者： GIRGIS, AA HAM, FM HARRIS CORP MELBOURNEFL 32901

A power system disturbance, or operating abnormality, can produce a severe generation and load imbalance, resulting in a rapid frequency decline. The possibility of such a disturbance has led to increased interest in the application of automatic under-frequency protection schemes to restore load/generation balance and to prevent equipment damage. In this paper a new method for detecting changes in the power system frequency, by relating it to a leakage coefficient in the FFT, is presented. The algorithm computes the deviation of the power system frequency from the fundamental component and the best estimate of its rate of change. The algorithm then predicts the percentage generation and load imbalance, and finally trips the appropriate amounts of load at the appropriate time delays.

关键词： Digital relays Power system restoration Power system protection Power system relaying change detection algorithms Frequency estimation Protective relaying Power generation Leak detection Prediction algorithms

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COMPUTER-ANALYSIS OF EEG SIGNALS WITH PARAMETRIC MODELS

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PROCEEDINGS OF THE IEEE 1981年第4期69卷 451-461页

作者： ISAKSSON, A WENNBERG, A ZETTERBERG, LH SWEDISH NATL BOARD OCCUPAT SAFETY & HLTH DEPT CLIN NEUROPHYSIOLSTOCKHOLMSWEDEN ROYAL INST TECHNOL DEPT TELECOMM THEORYS-10044 STOCKHOLM 70SWEDEN

Fifty years ago Berger made the first registrations of the electrical activity of the brain with electrodes placed on the intact skull. It immediately became clear that the frequency content of recorded signals plays an important role in describing these signals and also the state of the brain. This paper briefly surveys the main properties the electroencephalogram (EEG), and points out several influential factors. A number of methods have been developed to quantify the EEG in order to complement visual screening; these are conveniently classified as being parametric or nonparametric. The paper emphasizes parametric methods, in which signal analysis is based on a mathematical model of the observed process. The scalar or multivariate model is typically linear, with parameters being either time invariant or time variable. algorithms to fit the model to observed data are surveyed. Results from the analysis my be used to describe the spectral properties of the EEG, including the way in which characteristic variables change with time. Parametric models have successfully been applied to detect the occurrence of transients with epiliptic origin, so-called spikes and sharp waves. Interesting results have also been obtained by combining parameter estimation with classification algorithms in order to recognize significant functional states of the brain. The paper emphasizes methodology but includes also brief accounts of applications for research and clinical use. These mainly serve to illustrate the progress being made and to indicate the need for further work. The rapid advance of computer technology makes the processed EEG an increasingly viable tool in research and clinical practice.

关键词： Signal analysis Electroencephalography Parametric statistics Brain modeling change detection algorithms Electrodes Skull Frequency Mathematical model Parameter estimation

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COVID-19 PANDEMIC ASSESSMENT BY NIGHT-LIGHTS

COVID-19 PANDEMIC ASSESSMENT BY NIGHT-LIGHTS

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IEEE International Geoscience and Remote Sensing Symposium (IGARSS)

作者： Stathakis, Demetris Liakos, Leonidas Baltas, Pavlos Univ Thessaly Planning & Reg Dev Dept Volos 38334 Greece Natl Ctr Social Res Athens Greece

ISBN: (纸本)9781665403696

Visible Infrared Imaging Radiometer Suite (VIIRS) Day/Night Band (DNB) images have been used as an indicator of socioeconomic activity in annual time-series as well as within a year, given the availability of monthly composites. The capacity of VIIRS monthly data to reveal the socioeconomic activity disruption caused by the COVID-19 pandemic is explored here. The light emissions for each municipality in Greece are examined. In specific, monthly 2020 values are compared to the corresponding 2017-9 monthly average values, taken to represent the 'normality'. Two interesting results are derived. First, the impact of the pandemic is actually visible despite the fine spatial scale. Second, and less expected, the magnitude of night-lights dimming is not proportional to the magnitude of the pandemic impact. Dense urbanized areas tend to fluctuate less than sparse urban areas. At the same time it is shown that tourism-dependent areas, that normally attract a high amount of seasonal population and activity, are substantially more affected.

关键词： Optical imaging Image processing Urban areas change detection algorithms

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Detecting a Suddenly Arriving Dynamic Profile of Finite Duration

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IEEE TRANSACTIONS ON INFORMATION THEORY 2017年第5期63卷 3039-3052页

作者： Guepie, Blaise Kevin Fillatre, Lionel Nikiforov, Igor Univ Technol Troyes Inst Charles Delaunay UMR CNRS 6281 LM2S F-10004 Troyes France Univ Cote Azur CNRS Lab I3S UMR 7271 CS 40121 F-06903 Sophia Antipolis France

This paper addresses the detection of a suddenly arriving dynamic profile of a finite duration often called a transient change. In contrast to the traditional abrupt change detection, where the post-change period is assumed to be infinitely long, the detection of a suddenly arriving transient change should be done before it disappears. The detection of transient changes after their disappearance is considered as missed. Hence, the traditional quickest change detection criterion, minimizing the average detection delays provided a prescribed false alarm rate, is compromised. The proposed optimality criterion minimizes the worst case probability of missed detection provided that the worst case probability of false alarm during a certain period is upper bounded. A suboptimal CUSUM-type transient change detection algorithm, based on a subclass of truncated Sequential Probability Ratio Tests, is proposed. The optimization of the proposed algorithm in this subclass leads to a specially designed Finite Moving Average Test. The proposed method is analyzed theoretically and by simulation. A special attention is paid to the case of Gaussian observations with a dynamic profile.

关键词： change detection algorithms fault detection sequential analysis signal detection

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GLR detection AND ESTIMATION OF UNEXPECTED INPUTS IN LINEAR DISCRETE-SYSTEMS

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IEEE TRANSACTIONS ON AUTOMATIC CONTROL 1979年第3期24卷 499-501页

作者： CHANG, CB DUNN, KP M I T Lincoln Laboratory Lexington MA USA

In this paper, we present a recursive generalized likelihood ratio (GLR) test algorithm for detecting sudden changes in linear discrete systems. We demonstrate the application of linear filtering techniques to obtain a recursive GLR algorithm so that the requirement for matrix inversions in the previously known GLR algorithms can be reduced or avoided. Furthermore, the GLR algorithm is extended to the case when the sudden change follows known linear dynamics. An adaptive filtering scheme which uses the input estimate to correct the state estimate is also presented for the time-varying input case.

关键词： State estimation System testing change detection algorithms Vehicle dynamics Maximum likelihood estimation Filters Maximum likelihood detection Filtering algorithms Linear systems Vehicle detection

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An OSPF based load sensitive QoS routing algorithm using alternate paths 11

An OSPF based load sensitive QoS routing algorithm using alt...

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11th International Conference on Computer Communications and Networks

作者： Sahoo, A 1001 S. Main Street Milpitas 95035 CA United States

ISBN: (纸本)078037553X

Real-time applications such as Voice over IP, audio and video streaming require Quality of Service (QoS). Such applications are being executed over the public Internet. Since today's Internet largely supports best effort traffic, QoS routing in the best effort environment is required to support real-time applications. Some QoS routing use source routing and others use flooding of some QoS attibutes of the nodes. There were also some variants of shortest path algorithm reported in the literature. But those algorithms require changes to packet forwarding engine and logic for loop detection. We believe a better way of implementing QoS routing is to localize the QoS routing changes to the region where QoS has deteriorated and choose loop-free alternate paths. We present such an algorithm based on OSPF called LSR algorithm. In LSR algorithm, congestion notification is limited to neighbors of the congested node and the neighbors try to use alternate next hops to route packets. Alternate LSR next hop is chosen in such a way that it preserves the next hop property of OSPF routing which enables LSR algorithm to avoid loop. We present three such methods to choose an alternate LSR next hop and prove that these methods provide loop free routing. Our simulation results based on the three methods show that on an average LSR algorithm performs better than OSPF algorithm in terms of delay and jitter.

关键词： change detection algorithms Costs Floods Internet telephony IP networks Quality of service Routing Search engines Streaming media Web and internet services

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Dynamic Multi-Objective Optimization using Charged Vector Evaluated Particle Swarm Optimization

Dynamic Multi-Objective Optimization using Charged Vector Ev...

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IEEE Congress on Evolutionary Computation (CEC)

作者： Harrison, Kyle Robert Ombuki-Berman, Beatrice M. Engelbrecht, Andries P. Brock Univ Dept Comp Sci St Catharines ON L2S 3A1 Canada Univ Pretoria Dept Comp Sci ZA-0002 Pretoria South Africa

ISBN: (纸本)9781479914883

The vector evaluated particle swarm optimization (VEPSO) algorithm is a multi-swarm variation of the traditional particle swarm optimization (PSO) used to solve static multi-objective optimization problems (MOOPs). Recently, the dynamic VEPSO (DVEPSO) algorithm was proposed as an extension to VEPSO enabling the algorithm to handle dynamic MOOPs (DMOOPs). While DVEPSO has been successful at handling DMOOPs, the change detection mechanism relied on observing changes in objective space. An alternative strategy is proposed by using charged PSO (CPSO) sub-swarms with decision space change detection to address the outdated memory issue observed in vanilla PSO. This dynamic PSO variant allows for (implicit) decision space tracking not seen in DVEPSO while implicitly handling the diversity issue seen in dynamic environments. The proposed charged VEPSO is compared to DVEPSO on a wide variety of dynamic environment types. Results indicated that, in general, the proposed charged VEPSO outperformed the existing DVEPSO. Further, charged VEPSO exhibited better front-tracking abilities, while DVEPSO was superior with regards to locating the Pareto front.

关键词： change detection algorithms Heuristic algorithms Pareto optimization Particle swarm optimization Standards Vectors

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A flexible dynamic partitioning algorithm for optimistic distributed simulation 07

A flexible dynamic partitioning algorithm for optimistic dis...

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21st International Workshop on Principles of Advanced and Distributed Simulation (PADS 2007)

作者： Peschlow, Patrick Honecker, Tobias Martini, Peter Univ Bonn Dept Comp Sci 4 Roemerstr 164 D-53117 Bonn Germany

ISBN: (纸本)9780769528984

The performance of distributed simulation depends very much on the partitioning of the simulation model among the participating hosts. Usually, when starting a simulation run, an initial partitioning is determined by taking into account the available computing resources as well as the expected workload and the communication structure of the simulation model. However as hosts can be subject to background load or the model behavior can change in the course of the simulation, a dynamic partitioning mechanism is required to avoid inefficiencies. In this paper we introduce a new dynamic partitioning algorithm for optimistic distributed simulation. The algorithm is generally applicable but can also be configured to meet the requirements of specific scenarios. It is based on performance estimates for both computation and communication workload, the calculation of which is completely platform-independent. Our experiments show that the algorithm has low overhead and reacts reliably to changes of both model behavior and external resources.

关键词： Heuristic algorithms Partitioning algorithms Computational modeling Computer simulation Measurement Computer science Load modeling Clocks Degradation change detection algorithms

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Novelty detection Using Growing Neural Gas for Visuo-Spatial Memory

Novelty Detection Using Growing Neural Gas for Visuo-Spatial...

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IEEE/RSJ International Conference on Intelligent Robots and Systems

作者： Kit, Dmitry Sullivan, Brian Ballard, Dana Univ Texas Austin Austin TX 78712 USA

ISBN: (纸本)9781612844558

Detecting visual changes in environments is an important computation with many applications in robotics and computer vision. Security cameras, remotely operated vehicles, and sentry robots could all benefit from robust change detection capability. We conjecture that if one has a mobile camera system the number of visual scenes that are experienced is limited (compared to the space of all possible scenes) and that the scenes do not frequently undergo major changes between observations. These assumptions can be exploited to ease the task of change detection and reduce the computational complexity of processing visual information by utilizing memory to store previous computations. We demonstrate a method to learn the distribution of visual features in an environment via a self-organizing map. Additionally, the spatial distribution of these features can be learned if a positional signal is available. Our method uses a low dimensional representation of visual features to rapidly detect changes in current visual inputs. The model encodes spatially-distributed color histograms of real world visual scenes captured by a camera moved through an environment. The distribution of the color histograms is learned using a self-organizing map with location (when available) and color data. We present tests of the model on detecting changes in an indoor environment.

关键词： Cameras change detection algorithms Histograms Image color analysis Robots Training Visualization

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