| 1. |
- Marconato, A., et al.
(författare)
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Identification of the Silverbox Benchmark Using Nonlinear State-Space Models
- 2012
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Ingår i: IFAC Proceedings Volumes (IFAC-PapersOnline). - 2405-8963. - 9783902823069 ; 16:1, s. 632-637
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Konferensbidrag (refereegranskat)abstract
- This work presents the application of an initialization scheme for nonlinear state-space models on a real data benchmark example: the Silverbox problem. The goal of the proposed approach is to transform the identification of a nonlinear dynamic system into an approximate static problem, so that system dynamics and nonlinear terms are identified separately. Classic identification techniques are used to handle dynamics, while regression methods from the statistical learning community are introduced to estimate the nonlinearities in the model. Results obtained on the Silverbox problem are discussed and compared with the performance of other related methods.
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| 2. |
- Marconato, A., et al.
(författare)
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Improved Initialization for Nonlinear State-Space Modeling
- 2014
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Ingår i: IEEE Transactions on Instrumentation and Measurement. - 1557-9662 .- 0018-9456. ; 63:4, s. 972-980
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Tidskriftsartikel (refereegranskat)abstract
- This paper discusses a novel initialization algorithmfor the estimation of nonlinear state-space models. Good initialvalues for the model parameters are obtained by identifyingseparately the linear dynamics and the nonlinear terms inthe model. In particular, the nonlinear dynamic problem istransformed into an approximate static formulation, and simpleregression methods are applied to obtain the solution in a fast andefficient way. The proposed method is validated by means of twomeasurement examples: the Wiener-Hammerstein benchmarkproblem, and the identification of a crystal detector.
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| 3. |
- Marconato, A., et al.
(författare)
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Separate initialization of dynamics and nonlinearities in nonlinear state-space models
- 2012
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Ingår i: 2012 IEEE I2MTC - International Instrumentation and Measurement Technology Conference, Proceedings. - 9781457717710 ; , s. 2104-2108
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Konferensbidrag (refereegranskat)abstract
- This work focuses on the identification of nonlinear dynamic systems. In particular the problem of obtaining good starting values for the identification of nonlinear state-space models is addressed. A fast and efficient initialization algorithm is proposed, combining the use of methods from the statistical learning community to model the nonlinearities and classic system identification tools to capture system dynamics. The performance of the method is evaluated on simulation examples.
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| 4. |
- Priest, Sally J., et al.
(författare)
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The European union approach to flood risk management and improving societal resilience : Lessons from the implementation of the Floods Directive in six European countries
- 2016
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Ingår i: Ecology and Society. - 1708-3087. ; 21:4
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Tidskriftsartikel (refereegranskat)abstract
- Diversity in flood risk management approaches is often considered to be a strength. However, in some national settings, and especially for transboundary rivers, variability and incompatibility of approaches can reduce the effectiveness of flood risk management. Placed in the context of increasing flood risks, as well as the potential for flooding to undermine the European Union’s sustainable development goals, a desire to increase societal resilience to flooding has prompted the introduction of a common European Framework. We provide a legal and policy analysis of the implementation of the Floods Directive (2007/60/EC) in six countries: Belgium (Flemish region), England, France, the Netherlands, Poland, and Sweden. Evaluation criteria from existing legal and policy literature frame the study of the Directive and its effect on enhancing or constraining societal resilience by using an adaptive governance approach. These criteria are initially used to analyze the key components of the EU approach, before providing insight of the implementation of the Directive at a national level. Similarities and differences in the legal translation of European goals into existing flood risk management are analyzed alongside their relative influence on policy and practice. The research highlights that the effect of the Floods Directive on increasing societal resilience has been nationally variable, in part because of its focus on procedural obligations, rather than on more substantive requirements. Analysis shows that despite a focus on transboundary river basin management, existing traditions of flood risk management have overridden objectives to harmonize flood risk management in some cases. The Directive could be strengthened by requiring more stringent cooperation and providing the competent authorities in international river basin districts with more power. Despite some shortcomings in directly affecting flood risk outcomes, the Directive has positively stimulated discussion and flood risk management planning in countries that were perhaps lagging behind
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| 5. |
- van Doorn-Hoekveld, Willemijn J., et al.
(författare)
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Distributional effects of flood risk management : a cross-country comparison of preflood compensation
- 2016
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Ingår i: Ecology and Society. - 1708-3087. ; 21:4
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Tidskriftsartikel (refereegranskat)abstract
- We seek to examine the manner in which either the EU member states of France, the Netherlands, Poland, and Sweden or parts of them, such as the country of England in the UK or the Flemish Region in Belgium, deal with the distributional effects of the flood risk management strategies prevention, defense, and mitigation. Measures carried out in each of these strategies can cause preflood harm, as in the devaluation of property or loss of income. However, different member states and authorities address this harm in different ways. A descriptive overview of the different compensation regimes in the field of flood risk management is followed by an analysis of these differences and an explanation of what may cause them, such as the geographical differences that lead to differences in the way that they interfere with private rights and the dominant legal principles that underlie compensation regimes. An elaborated compensation regime could lead to more equitable and legitimate flood risk management because the burdens are fairly spread and all interests—including those of injured parties—are considered in the decision-making process. Our aim is to stimulate the hardly existent discussion on the financial harm that is caused by measures to prevent floods (preflood), in addition to the already existing discussion on the ex post flood distributional effects.
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| 6. |
- Driessen, Peter P. J., et al.
(författare)
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Governance Strategies for Improving Flood Resilience in the Face of Climate Change
- 2018
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Ingår i: Water. - : MDPI. - 2073-4441. ; 10:11
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Tidskriftsartikel (refereegranskat)abstract
- Flooding is the most common of all natural disasters and accounts for large numbers of casualties and a high amount of economic damage worldwide. To be ‘flood resilient’, countries should have sufficient capacity to resist, the capacity to absorb and recover, and the capacity to transform and adapt. Based on international comparative research, we conclude that six key governance strategies will enhance ‘flood resilience’ and will secure the necessary capacities. These strategies pertain to: (i) the diversification of flood risk management approaches; (ii) the alignment of flood risk management approaches to overcome fragmentation; (iii) the involvement, cooperation, and alignment of both public and private actors in flood risk management; (iv) the presence of adequate formal rules that balance legal certainty and flexibility; (v) the assurance of sufficient financial and other types of resources; (vi) the adoption of normative principles that adequately deal with distributional effects. These governance strategies appear to be relevant across different physical and institutional contexts. The findings may also hold valuable lessons for the governance of climate adaptation more generally.
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| 7. |
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| 8. |
- Van Calster, B., et al.
(författare)
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Preoperative diagnosis of ovarian tumors using Bayesian kernel-based methods
- 2007
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Ingår i: Ultrasound in Obstetrics & Gynecology. - : Wiley. - 1469-0705 .- 0960-7692. ; 29:5, s. 496-504
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Tidskriftsartikel (refereegranskat)abstract
- Objectives To develop flexible classifiers that predict malignancy in adnexal masses using a large database from nine centers. Methods The database consisted of 1066 patients with at least one persistent adnexal mass for which a large amount of clinical and ultrasound data were recorded. The outcome of interest was the histological classification of the adnexal mass as benign or malignant. The outcome was predicted using Bayesian least squares support vector machines in comparison with relevance vector machines. The models were developed on a training set (n = 754) and tested on a test set (n = 312). Results Twenty-five percent of the patients (n = 266) bad a malignant tumor. Variable selection resulted in a set of 12 variables for the models: age, maximal diameter of the ovary, maximal diameter of the solid component, personal history of ovarian cancer, hormonal therapy, very strong intratumoral blood flow (i.e. color score 4), ascites, presumed ovarian origin of tumor, multilocular-solid tumor, blood flow within papillary projections, irregular internal cyst wall and acoustic shadows. Test set area under the receiver-operating characteristics curve (AUC) for all models exceeded 0.940, with a sensitivity above 90% and a specificity above 80% for all models. The least squares support vector machine model with linear kernel performed very well, with an AUC of 0.946, 91% sensitivity and 84% specificity. The models performed well in the test sets of all the centers. Conclusions Bayesian kernel-based methods can accurately separate malignant from benign masses. The robustness of the models will be investigated in future studies. Copyright (c) 2007 ISUOG. Published by John Wiley & Sons, Ltd.
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