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See detailAn Optimization-Based Iterative Learning Method for Anticipatory Network Traffic Control
Huang, Wei; Ma, Wanjing; Viti, Francesco UL et al

in Proceedings of the 16th COTA International Conference of Transportation Professionals (2016)

Detailed reference viewed: 54 (3 UL)
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See detailOptimized Coordinated Checkpoint/Rollback Protocol using a Dataflow Graph Model
Besseron, Xavier UL; Gautier, Thierry

Presentation (2009, January 22)

Fault-tolerance protocols play an important role in today long runtime scienti\ufb01c parallel applications. The probability of a failure may be important due to the number of unreliable components ... [more ▼]

Fault-tolerance protocols play an important role in today long runtime scienti\ufb01c parallel applications. The probability of a failure may be important due to the number of unreliable components involved during an execution. We present our approach and preliminary results about a new checkpoint/rollback protocol based on a coordinated scheme. The application is described using a dataflow graph, which is an abstract representation of the execution. Thanks to this representation, the fault recovery in our protocol only requires a partial restart of other processes. Simulations on a domain decomposition application show that the amount of computations required to restart and the number of involved processes are reduced compared to the classical global rollback protocol. [less ▲]

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See detailOptimized event notification in CAN through in-frame replies and Bloom filters
Bloom, Gadare; Cena, Gianluca; Cibrario Bertolotti, Ivan et al

in 2017 IEEE 13th International Workshop on Factory Communication Systems (WFCS) (2017)

Thanks to its distributed and asynchronous medium access control mechanism, CAN is the ideal choice for interconnecting devices in event-driven systems. When timing requirements of applications are not ... [more ▼]

Thanks to its distributed and asynchronous medium access control mechanism, CAN is the ideal choice for interconnecting devices in event-driven systems. When timing requirements of applications are not particularly demanding, as in the case of, e.g., reactive and proactive maintenance, constraints on event delivery can be relaxed, so that their notification may rely on best-effort approaches. In this paper, a number of techniques are taken into account for notifying events in such a kind of systems, and their performance has been evaluated. Besides conventional CAN, a recent proposal for extending this protocol, termed CAN XR, is considered. Moreover, the adoption of Bloom filters to cope with rare events in very large systems has also been evaluated. [less ▲]

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See detailOptimized Link Adaptation for DVB-S2X Precoded Waveforms based on SNIR Estimation
Andrenacci, Stefano UL; Spano, Danilo UL; Christopoulos, Dimitrios et al

in Asilomar Conference on Signals, Systems, and Computers 2016 (2016)

The present work deals with optimized strategies to address the issue of link adaptation (Adaptive Coding and Modulation - ACM) in a multi-user multi-beam satellite system employing precoding at the ... [more ▼]

The present work deals with optimized strategies to address the issue of link adaptation (Adaptive Coding and Modulation - ACM) in a multi-user multi-beam satellite system employing precoding at the gateway side. Accordingly, the focus is on the forward link of a multi-beam satellite system employing a full frequency reuse configuration. In such an interference limited setting, the Super-Framing structure of DVB-S2X air interface (format specification 2 and 3) enables the use of precoding techniques. The aim herein is to investigate the Signal-to-Noise-plus- Interference (SNIR) estimation error given by the User Terminals (UTs) through the so-called P2 pilots is taken into account to optimize the ACM margins. [less ▲]

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See detailOptimized non-orthogonal multiplexing in Peak Power Limited Channels
Alagha, Nader; Kayhan, Farbod UL; Montorsi, Guido

Scientific Conference (2017, October)

In this paper, we investigate the performance of optimized overlay modulation schemes and compare the results with both time division multiplexing and superposition modulation assuming a peak power ... [more ▼]

In this paper, we investigate the performance of optimized overlay modulation schemes and compare the results with both time division multiplexing and superposition modulation assuming a peak power limited AWGN channel. We show that significant gains can be achieved by properly designing the constellation set, specially in the presence of large SNIR imbalance between the user's link quality. We introduce two realistic case studies and present the results for each scenario. [less ▲]

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See detailAn optimized short-arc approach: methodology and application to develop refined time series of Tongji-Grace2018 GRACE monthly solutions
Chen, Qiujie; Shen, Yunzhong; Chen, Wu et al

in Journal of Geophysical Research. Solid Earth (2019)

Abstract Considering the unstable inversion of ill-conditioned intermediate matrix required in each integral arc in the short-arc approach presented in Chen et al. (2015), an optimized short-arc method ... [more ▼]

Abstract Considering the unstable inversion of ill-conditioned intermediate matrix required in each integral arc in the short-arc approach presented in Chen et al. (2015), an optimized short-arc method via stabilizing the inversion is proposed. To account for frequency-dependent noise in observations, a noise whitening technique is implemented in the optimized short-arc approach. Our study shows the optimized short-arc method is able to stabilize the inversion and eventually prolong the arc length to 6 hours. In addition, the noise whitening method is able to mitigate the impacts of low-frequency noise in observations. Using the optimized short-arc approach, a refined time series of GRACE monthly models called Tongji-Grace2018 has been developed. The analyses allow us to derive the following conclusions: (a) during the analyses over the river basins (i.e. Amazon, Mississippi, Irrawaddy and Taz) and Greenland, the correlation coefficients of mass changes between Tongji-Grace2018 and others (i.e. CSR RL06, GFZ RL06 and JPL RL06 Mascon) are all over 92 and the corresponding amplitudes are comparable; (b) the signals of Tongji-Grace2018 agree well with those of CSR RL06, GFZ RL06, ITSG-Grace2018 and JPL RL06 Mascon, while Tongji-Grace2018 and ITSG-Grace2018 are less noisy than CSR RL06 and GFZ RL06; (c) clearer global mass change trend and less striping noise over oceans can be observed in Tongji-Grace2018 even only using decorrelation filtering; and (d) for the tests over Sahara, over 36 and 19 of noise reductions are achieved by Tongji-Grace2018 relative to CSR RL06 in the cases of using decorrelation filtering and combined filtering, respectively. [less ▲]

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See detailOptimizing AEDB Broadcasting Protocol with Parallel Multi-objective Cooperative Coevolutionary NSGAII
Dorronsoro, Bernabé UL; Ruiz, Patricia UL; Talbi, El-Ghazali et al

in Optimizing AEDB Broadcasting Protocol with Parallel Multi-objective Cooperative Coevolutionary NSGAII (2014)

Detailed reference viewed: 74 (1 UL)
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See detailOptimizing algebraic petri net model checking by slicing
Khan, Yasir Imtiaz UL; risoldi, matteo

in International Workshop on Modeling and Business Environments (ModBE’13) in Milano, Italy, June 24, 2013. (2013)

High-level Petri nets make models more concise and read- able as compared to low-level Petri nets. However, usual verification techniques such as state space analysis remain an open challenge for both ... [more ▼]

High-level Petri nets make models more concise and read- able as compared to low-level Petri nets. However, usual verification techniques such as state space analysis remain an open challenge for both because of state space explosion. The contribution of this paper is to propose an approach for property based reduction of the state space of Algebraic Petri nets (a variant of high-level Petri nets). To achieve the objective, we propose a slicing algorithm for Algebraic Petri nets (APNSlicing). The proposed algorithm can alleviate state space even for certain strongly connected nets. By construction, it is guaranteed that the state space of sliced net is at most as big as the original net. We exemplify our technique through the running case study of car crash management system. [less ▲]

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See detailOptimizing algebraic petri net model checking by slicing
Khan, Yasir Imtiaz UL

Report (2013)

Detailed reference viewed: 45 (4 UL)
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See detailOptimizing communication satellites payload configuration with exact approaches
Stathakis, Apostolos UL; Danoy, Grégoire UL; Bouvry, Pascal UL et al

in Engineering Optimization (2015), 0(0), 1-26

Detailed reference viewed: 116 (23 UL)
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See detailOptimizing Distributed Collaborative Filtering in Mobile Networks
Gratz, Patrick UL; Andronache, Adrian UL

in Proceedings of the 2008 High Performance Computing & Simulation Conference (2008)

Collaborative filtering mechanisms filter information by using collaboration among multiple data sources, typically involving large data sets. In this work we optimize the communication and computational ... [more ▼]

Collaborative filtering mechanisms filter information by using collaboration among multiple data sources, typically involving large data sets. In this work we optimize the communication and computational load of a distributed collaborative filtering protocol designed to augment the information exchange in mobile networks. [less ▲]

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See detailOptimizing Multi-Objective Evolutionary Algorithms to Enable Quality-Aware Software Provisioning
El Kateb, Donia UL; Fouquet, François UL; bourcier, Johann et al

Scientific Conference (2014, October)

Detailed reference viewed: 100 (5 UL)
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See detailOptimizing Trading Decisions for Hydro Storage Systems using Approximate Dual Dynamic Programming
Löhndorf, Nils UL; Wozabal, David; Minner, Stefan

in Operations Research (2013)

Detailed reference viewed: 68 (2 UL)
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See detailOptimizing verification of structurally evolving algebraic petri nets
Khan, Yasir Imtiaz UL

in Software Engineering for Resilient Systems Lecture Notes in Computer Science Volume (2013, September 08), 8166

System models are subject to evolve during the development life cycle, along which an initial version goes through a series of evolutions, generally aimed at progressively reaching all the requested ... [more ▼]

System models are subject to evolve during the development life cycle, along which an initial version goes through a series of evolutions, generally aimed at progressively reaching all the requested qualities (completeness, correctness etc.). Among the existing development methodologies the iterative and incremental one has been proved to be efficient for system development but lacks of support for an adequate verification process. When considering Algebraic Petri nets (APNs) for modeling and model checking for verification, all the proofs must be redone after each iteration which is impractical both in terms of time and space. In this work, we introduce an Algebraic Petri net slicing technique that optimizes the model checking of static or structurally evolving APN models. Furthermore, our approach is proposing a classification of evolutions dedicated to the improvement of model checking. [less ▲]

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See detailOptimum stochastic modeling for GNSS tropospheric delay estimation in real-time
Hadas, Tomasz; Teferle, Felix Norman UL; Kazmierski, Kamil et al

in GPS Solutions (2016)

In GNSS data processing, the station height, receiver clock and tropospheric delay (ZTD) are highly correlated to each other. Although the zenith hydrostatic delay of the troposphere can be provided with ... [more ▼]

In GNSS data processing, the station height, receiver clock and tropospheric delay (ZTD) are highly correlated to each other. Although the zenith hydrostatic delay of the troposphere can be provided with sufficient accuracy, zenith wet delay (ZWD) has to be estimated, which is usually done in a random walk process. Since ZWD temporal variation depends on the water vapor content in the atmosphere, it seems to be reasonable that ZWD constraints in GNSS processing should be geographically and/or time dependent. We propose to take benefit from numerical weather prediction models to define optimum random walk process noise. In the first approach, we used archived VMF1-G data to calculate a grid of yearly and monthly means of the difference of ZWD between two consecutive epochs divided by the root square of the time lapsed, which can be considered as a random walk process noise. Alternatively, we used the Global Forecast System model from National Centres for Environmental Prediction to calculate random walk process noise dynamically in real-time. We performed two representative experimental campaigns with 20 globally distributed International GNSS Service (IGS) stations and compared real-time ZTD estimates with the official ZTD product from the IGS. With both our approaches, we obtained an improvement of up to 10% in accuracy of the ZTD estimates compared to any uniformly fixed random walk process noise applied for all stations. [less ▲]

Detailed reference viewed: 127 (1 UL)
See detailOptimum structure and equity in a city with local traffic-induced air pollution
Schindler, Mirjam UL

Scientific Conference (2015, November 12)

Traffic-induced air pollution causes environmental and health concerns, which affect households differently depending on where they live within the city and in turn influence residential choices ... [more ▼]

Traffic-induced air pollution causes environmental and health concerns, which affect households differently depending on where they live within the city and in turn influence residential choices. Contrasting spatial implications of environmental consciousness and valuation of local air quality as residential preferences, raises questions of equity in terms of evaluating responsibility for and exposure to air pollution within the city. With an analytical urban economics model, we aim at investigating the effects of households' perception of local air quality and different policies on the two-way interactions between the location of households and the distribution of pollution and, thus, on intra-urban equity. This work contributes to theoretical research by extending the standard urban economics model with endogenous local pollution externalities arising from passing traffic. A closed city equilibrium is solved analytically and comparative statics serve as impact analysis of various policies on intra-urban structure and equity. Further, first-best and second-best optimum city structures are defined and analysed with regard to distance-related equity concerns and their impact on the tension between environmental and health concerns due to air pollution from traffic. The different regimes are more beneficial in either reducing the generation of emissions or reducing the level of exposure across locations. Optimum structures improve equity across the city due to concentration of density in central and outer locations. Findings suggest that a cordon toll may approximate first-best structures well and be preferable over an urban growth boundary, since the latter fails to concentrate densification on central locations, as advised by the first-best. Residential preferences as well as regional and urban framework conditions play key roles in seeking optimum densities with respect to environmental, health and equity concerns of air pollution. [less ▲]

Detailed reference viewed: 88 (3 UL)
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See detailOptinization of wireless energy transfer for mid-range distances
Ripp, Pascal UL

Doctoral thesis (2017)

This thesis deals with the optimization of resonators for wireless power transfer by resonant magnetic coupling, where loosely coupled LC resonators are used for wireless power transmission. While systems ... [more ▼]

This thesis deals with the optimization of resonators for wireless power transfer by resonant magnetic coupling, where loosely coupled LC resonators are used for wireless power transmission. While systems that are currently available use discrete capacitors for frequency tuning, this work proposes self-resonating coils on a printed circuit board. For these coils, different three-dimensional (3D) Computer Aided Design (CAD) models are created and investigated using the method of finite elements. Finally, a set of inductively coupled and capacitively coupled self-resonant coils for the 6.78 MHz ISM band is found. Furthermore, the shielding of the coils with ferrite materials is discussed to maintain a high efficiency for any application. For both types, equivalent circuit models are derived and analyzed. Besides the coil optimization, a power amplifier is also proposed. During operation the optimal operational frequency is maintained by frequency tracking. The theoretical results are verified using a demonstrator circuit. [less ▲]

Detailed reference viewed: 78 (3 UL)
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See detailThe Optional Protocol to the Convention on the Rights of the Child on the Involvement of Children in Armed Conflict
Happold, Matthew UL

in Yearbook of International Humanitarian Law (2000), 3

Detailed reference viewed: 142 (0 UL)
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See detailLes options législatives prises par la Belgique, la France et le Luxembourg à l'occasion de la transposition de la directive "fusions transfrontalières"
Corbisier, Isabelle UL

in Conac, Pierre-Henri (Ed.) Fusions transfrontalières de sociétés - Droit luxembourgeois et droit comparé (2011)

Detailed reference viewed: 25 (4 UL)
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See detailOptoelectronic Analysis of Kesterite Based Solar Cells
Robert, Erika UL

Bachelor/master dissertation (2013)

Detailed reference viewed: 44 (4 UL)