1 

Graph Augmentation: a Quantum Algorithm for Maximising Robustness

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2 

Retrieval of Aerosol Optical Depth over Land using twoangle view Satellite Radiometry during TARFOX
A new aerosol optical depth retrieval algorithm is presented that uses the twoangle view capability of the Along Track Scanning Radiometer 2 (ATSR2). By combining the twoangle view and the spectral information this socalled dual view algorithm separates between aerosol and surface contributions to the top of the atmosphere radiance. First validation of the dual view algorithm was performed during the Tropospheric Aerosol Radiative Forcing Observational Experiment (TARFOX), which was conducted at the midAtlantic coast of the United States in July 1996. The satellite retrieved spectral aerosol optical depth is in good agreement with the aerosol optical depth from groundbased Sun/sky radiometers in three out of four cases. This shows the potential of aerosol retrieval over land using twoangle view satellite radiometry. Copyright 1998 by the American Geophysical Union.

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3 

Aerosol optical thickness retrieval over land and water using Global Ozone Monitoring Experiment (GOME) data
An algorithm for the retrieval of the aerosol optical thickness over land and over water from Global Ozone Monitoring Experiment (GOME) data is presented. The cloud fraction in the GOME pixels is determined using the Fast Retrieval Scheme for Clouds From the Oxygen A Band (FRESCO) algorithm. Surface contributions to the top of atmosphere reflectance are determined from the GOME surface reflectance database. The aerosol retrieval algorithm uses lookup tables that were created using the radiative transfer model 6S. The algorithm allows retrieving the aerosol types characterized by Angstrom coefficients in the range from 0.1 to 2.8; i.e., the range of values observed by the AERONET groundbased measurements. Validation of the algorithm done using the AERONET Sun photometer data for 12 sites in Europe and Africa, for the year 1997, shows very good agreement. The correlation coefficient between the satellite retrieval and AERONET data for the wavelength of 440 nm is 97%, and for 670 nm it is 94%. Validation of the algorithm for the year 2000 was done for a few sites with similar results. The algorithm has been successfully tested over an island influenced by Saharan dust (i.e., Cape Verde, 16oN, 22oW and over a site located near the Saharan desert (i.e., Bondoukoui, 11oN, 3oW). For other sites located near the Saharan desert such as Bidi Bahn (14oN, 2oW) and Banizombou (13oN, 2oE), the agreement was very good at 440 nm. The algorithm has not been tested over other bright surfaces such as icecovered regions. Examples of the spatial distribution of the aerosol optical thickness over Europe, north Africa, and the North Atlantic for the year 1997 and 2000 are presented.

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4 

A case study of a multiobjective recombinative genetic algorithm with coevolutionary sharing
We present a multiobjective genetic algorithm that incorporates various genetic algorithm techniques that have been proven to be efficient and robust in their problem domain. More specifically, we integrate rank based selection, adaptive niching through coevolutionary sharing, elitist recombination, and nondominated sorting into a multiobjective genetic algorithm called ERMOCS. As a proof of concept we test the algorithm on a softkillscheduling problem

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5 

A splitplot experiment with factordependent wholeplot sizes
Problem: The dairy company FrieslandCampina had an opportunity to redesign the production process for its coffee cream. This product has a very specific viscosity, and the redesigned process had to result in the same viscosity as the old one. Approach: For an effective redesign, the investigators wanted to obtain a simple model linking the settings of nine controllable factors to the viscosity of the product. They decided to use the results of a statistically designed experiment to build such a model. Two factors were hard to change (HTC) and could only be set six times; the remaining factors were easy to change (ETC). The presence of HTC and ETC factors calls for a splitplot experiment with whole plots defined by the six settings of the HTC factors. However, the number of runs within a whole plot depended on the level of one of the wholeplot factors. Commercial software fails to produce designs for this situation. In this paper, we detail orthogonal and nonorthogonal wholeplot designs for each of three total run sizes and discuss how three existing algorithms to construct optimal splitplot designs can be modified to handle factordependent wholeplot sizes. Results: The experiment was conducted according to one of the designs and viscosity measurements of the products were made. A secondorder model, fitted using generalized least squares and restricted maximum likelihood, was used to study the effect of changes to the process design on the viscosity.

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6 

A KaBand Backscatter Model Function and an Algorithm for Measurement of the Wind Vector Over the Sea Surface
A Kaband backscatter model and an algorithm for measurement of the wind speed and direction over the sea surface by a frequencymodulated continouswave radar demonstrator system operated in scatterometer mode have been developed. To evaluate the proposed algorithm, a simulation of the wind vector retrieval has been performed.

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7 

An evaluation of the accuracy of shallow water matched field inversion results
In this article the accuracy of geoacoustic and geometric parameter estimates obtained through matched field inversion (MFI) was assessed. Multifrequency MFI was applied to multitone data (200600 Hz) received at a 2km source/receiver range. The acoustic source was fixed and the signals were received at a vertical array. Simultaneously with the acoustic transmissions, a CTD (conductivity, temperature and depth)chain was towed along the acoustic track. A genetic algorithm was used for the global optimization, whereas a normal mode model was applied for the forward acoustic calculations. Acoustic data received at consecutive times were inverted and the stability of the inverted parameters was determined. Also, the parameter estimates were compared with independent measurements, such as multichannel seismic surveys (for geoacoustic parameters). The obtained uncertainty in the inversion results was assumed to have two distinct origins. The first origin is the inversion method itself, since each optimization will come up with some solution close to the exact optimum. Parameter coupling and the fact that some parameters hardly influence the acoustic propagation further contribute to this uncertainty. The second is due to oceanographic variability. Both contributions were evaluated through simulation. The contribution of oceanographic variability was evaluated through synthetic inversions that account for the actual sound speed variations as measured by the towed CTDchain.

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8 

Aerosol Optical Depth Retrieval over Land from Two Angle View Satellite Radiometry
Atmospheric aerosol particles play an important role in the Earth’s radiation balance.

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9 

Optimal placement of imperfect water quality sensors in water distribution networks
Water Distribution Networks (WDNs) are often susceptible to either accidental or deliberate contamination which can lead to poisoned water, many fatalities and large economic consequences. In order to protect against these intrusions or attacks, an efficient sensor network with a limited number of sensors should be placed in a WDN. In this paper, we focus on optimal sensor placements by introducing two greedybased algorithms in which the imperfection of sensors and multiple objectives can be taken into account. The algorithms were tested using a medium scale urban WDN. It is shown that our algorithms are able to find sensor placements in reasonable time and that its solutions are close to optimal. Furthermore, relaxing the often used assumption that sensors work perfectly results in different sensor placements than were found before, indicating the importance to take sensor imperfection into account when placing sensors. © 2018 Elsevier Ltd

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10 

The accuracy of DERM may be a selffulfilling DREAM


11 

Secure and selfstabilizing clock synchronization in sensor networks
In sensor networks, correct clocks have arbitrary starting offsets and nondeterministic fluctuating skews. We consider an adversary that aims at tampering with the clock synchronization by intercepting messages, replaying intercepted messages (after the adversary's choice of delay), and capturing nodes (i.e., revealing their secret keys and impersonating them). We present the first selfstabilizing algorithm for secure clock synchronization in sensor networks that is resilient to such an adversary's attacks. Our algorithm tolerates random media noise, guarantees with high probability efficient communication overheads, and facilitates a variety of masking techniques against pulsedelay attacks in the presence of captured nodes. © SpringerVerlag Berlin Heidelberg 2007.

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12 

Mapping of synchronous dataflow graphs on MPSoCs based on parallelism enhancement
Multiprocessor systemsonchips are widely adopted in implementing modern streaming applications to satisfy the ever increasing computation requirements. To take advantage of this kind of platform, it is necessary to map tasks of the application properly to different processors, so as to fully exploit the inherent tasklevel parallelism and satisfy the stringent timing requirements. We propose the Parallelism Graph to capture the tasklevel parallelism of the application and transform the mapping problem to a graph partitioning problem. The graph partitioning problem is formulated as an Integer Linear Programming problem, which is solved optimally using the ILP solver. To reduce the complexity, a twostep local search algorithm, i.e., the greedy partition and refinement algorithm, is proposed. Since oneshot heuristics cannot guarantee the solution quality, evolutionary algorithms are widely used to search the solution space such that better results can be found. We also integrate the idea of parallelism enhancement into the genetic algorithm and propose a hybrid genetic algorithm to improve the performance. Sets of synthesized Synchronous Data Flow Graphs and some practical applications are used to evaluate the performance of the proposed algorithms. Experiment results demonstrate that the proposed algorithms outperform available algorithms.

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13 

Speaker linking in large data sets
This paper investigates the task of linking speakers across multiple recordings, which can be accomplished by speaker clustering. Various aspects are considered, such as computational complexity, on/offline approaches, and evaluation measures but also speaker recognition approaches. It has not been the aim of this study to optimize clustering performance, but as an experimental exercise, we perform speaker linking on all '1conv4w' conversation sides of the NIST2006 evaluation data set. This set contains 704 speakers in 3835 conversation sides. Using both online and offline algorithms, equalpurity figures of about 86 % are obtained. © Odyssey 2010: Speaker and Language Recognition Workshop. All rights reserved.

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14 

Future scenarios of variable renewable energies and flexibility requirements for thermal power plants in China
In 2017 about 37% of the world's wind turbines and 50% of the world's photovoltaic (PV) panels are installed in China. But at the same time a huge amount of wind power and PV power is wasted mainly because of insufficient flexibility of thermal power which is the dominant source in China's electricity system. This paper aims to assess the flexibility requirements for thermal power plants to accommodate largescale variable renewable energies (VREs). This paper constructs three scenarios for the reference year of 2030, where VREs account for 16%, 19% and 22% in the electricity system respectively, and simulates corresponding residual load time series (residual load = load − hydropower − nuclear power − wind power − PV power). We find that the current average 1%/min ramp rate of thermal power plants is basically sufficient to deal with ramps in residual load in the future. But the current average 60% minimum load level of thermal power plants has to be improved to 40% or even 30%, otherwise the economic losses of VREs curtailment will be as high as 947.2×108 – 1632.0×108 CNY per year in the future. It is necessary and beneficial for the central authority to invest in retrofitting the existing huge thermal power plants to improve their minimum load level. © 2018 Elsevier Ltd

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15 

Use of neural networks in groundbased aerosol retrievals from multiangle spectropolarimetric observations
article 
2015

Author: 
Di Noia, A.
·
Hasekamp, O.P.
·
Harten, G. van
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Rietjens, J.H.H.
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Smit, J.M.
·
Snik, F.
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Henzing, J.S.
·
Boer, J. de
·
Keller, C.U.
·
Volten, H.

Keywords: 
Environment · Aerosol property · Algorithm · Atmospheric modeling · Groundbased measurement · Urban Development · Built Environment · Earth & Environment · UES  Urban Environment & Safety · ELSS  Earth, Life and Social Sciences

In this paper, the use of a neural network algorithm for the retrieval of the aerosol properties from groundbased spectropolarimetric measurements is discussed. The neural network is able to retrieve the aerosol properties with an accuracy that is almost comparable to that of an iterative retrieval. By using the outcome of the neural network as first guess in the iterative retrieval scheme, the accuracy of the retrieved fine and coarsemode optical thickness is further improved, while for the other parameters the improvement is small or absent. The resulting scheme (neural network + iterative retrieval) is compared to the original one (lookup table + iterative retrieval) on a set of simulated groundbased measurements, and on a small set of real observations carried out by an accurate groundbased spectropolarimeter. The results show that the use of a neuralnetworkbased first guess leads to an increase in the number of converging retrievals, and possibly to more accurate estimates of the aerosol effective radius and complex refractive index.

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16 

Avoiding simplification strategies by introducing multiobjectiveness in real world problems
In business analysis, models are sometimes oversimplified. We pragmatically approach many problems with a single financial objective and include monetary values for nonmonetary variables. We enforce constraints which may not be as strict in reality. Based on a case in distributed energy production, we illustrate how we can avoid simplification by modeling multiple objectives, solving it with an NSGAII algorithm with a novel comparison operator. Advantages include a strengthened focus on the tradeoff relation between financial and nonmonetary objectives. We conclude that this approach is very applicable in a business analysis setting. © 2010 IEEE.

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17 

Nonlinear Frequency Scaling Algorithm for FMCW SAR Data
This paper presents a novel approach for processing data acquired with Frequency Modulated Continuous Wave (FMCW) dechirponreceive systems by using a nonlinear frequency scaling algorithm. The range frequency nonlinearity correction, the Doppler shift induced by the continuous motion and the range migration removal are performed at the same time in the wavenumber domain with a very efficient solution. The crossrange focusing is then achieved with conventional matched filtering. Real data have been acquired with the FMCW SAR demonstrator system built at the Delft University of Technology. Stripmap images processed with the proposed method are presented in order to show the validity of the nonlinear frequency scaling algorithm. © 2006 EuMA.

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18 

Sonar target enhancement by shrinkage of incoherent wavelet coefficients
Background reverberation can obscure useful features of the target echo response in broadband lowfrequency sonar images, adversely affecting detection and classification performance. This paper describes a resolution and phasepreserving means of separating the target response from the background reverberation noise using a coherencebased wavelet shrinkage method proposed recently for denoising magnetic resonance images. The algorithm weights the image wavelet coefficients in proportion to their coherence between different looks under the assumption that the target response is more coherent than the background. The algorithm is demonstrated successfully on experimental synthetic aperture sonar data from a broadband lowfrequency sonar developed for buried object detection. © 2014 Acoustical Society of America.

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19 

Convergence analysis of the FilteredU LMS algorithm for active noise control in case perfect cancellation is not possible
The FilteredU LMS algorithm, proposed by Eriksson for active noise control applications, adapts the coefficients of an infiniteimpulse response controller. Conditions for global convergence of the FilteredU LMS algorithm were presented by Wang and Ren (Signal Processing, 73 (1999) 3) and Mosquera and PérezGonzález (Signal Processing, 80 (2000) 5) for the case where perfect noise cancellation is achievable, which means only measurement noise remains. This paper shows that the assumption of perfect cancellation is not necessary. In real situations perfect cancellation is often not achievable due to delays and nonminimum phase zeros. The conclusion is derived by analysis of the structure of the Wiener optimal solution. This also leads to the suggestion of preconditioning filters in the FilteredU LMS updating. The preconditioning has shown considerable increase of the convergence rate in a realistic simulation study.

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20 

Aerosol properties over the Indian Ocean Experiment (INDOEX) campaign area retrieved from ATSR2
Aerosol retrieved algorithms for ATSR2 have been applied over land and water using data from the Indian Ocean Experiment (INDOEX) Intensive Field Phase (IFP) in February and March 1999. The goal was the extension of the ATSR2 algorithms, developed for application over the U.S. east coast and Europe, to other areas with different types of aerosols and to explore the feasibility of deriving spatial variations in the aerosol composition. The ATSR2 algorithm was extended with absorbing aerosols, and AERONET data were used to test the retrieved spectral aerosol optical depth (AOD). The resulting maps of AOD at 0.659 μm, Ångström coefficient and urban/industrial aerosol contribution to the AOD over the ocean are evaluated by comparison with in situ data. AOD over land is in the range 0.180.45 with values up to 0.7 when biomass burning aerosol is present and decreases gradually over water with increasing fetch to 0.15 near the Intertropical Convergence Zone (ITCZ). Ångström coefficients over land are in the range 1.52.0. Over water these values gradually decrease to almost zero. Over land urban/industrial aerosol dominates, and, as expected, over water the anthropogenic influence gradually decreases with fetch and the relative contribution of marine aerosol increases. South of the ITCZ the anthropogenic effect is negligible. Copyright 2006 by the American Geophysical Union.

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