Large-scale unit commitment under uncertainty: an updated literature survey

The Unit Commitment problem in energy management aims at finding the optimal production schedule of a set of generation units, while meeting various system-wide constraints. It has always been a large-scale, non-convex, difficult problem, especially in view of the fact that, due to operational requirements, it has to be solved in an unreasonably small time for its size. Recently, growing renewable energy shares have strongly increased the level of uncertainty in the system, making the (ideal) Unit Commitment model a large-scale, non-convex and uncertain (stochastic, robust, chance-constrained) program. We provide a survey of the literature on methods for the Uncertain Unit Commitment problem, in all its variants. We start with a review of the main contributions on solution methods for the deterministic versions of the problem, focussing on those based on mathematical programming techniques that are more relevant for the uncertain versions of the problem. We then present and categorize the approaches to the latter, while providing entry points to the relevant literature on optimization under uncertainty. This is an updated version of the paper "Large-scale Unit Commitment under uncertainty: a literature survey" that appeared in 4OR 13(2), 115--171 (2015); this version has over 170 more citations, most of which appeared in the last three years, proving how fast the literature on uncertain Unit Commitment evolves, and therefore the interest in this subject

1 LICIA-INSA de Strasbourg

Abstract. This paper presents how Self-Organizing Maps and especially Kohonen maps can be applied to digital images of ancient collections in the perspective of valorization and diffusion. As an illustration, a scheme of transparency reduction of the digitized Gutenberg Bible is presented. In this two steps method, the Kohonen map is trained to generate a set of test vectors that will train in a supervised manner a classical feed-forward network. The testing step consists then in classifying each pixel into one class out of four by feeding directly the feed forward network. The pixels belonging to the transparency class are then removed. 1

Treatment times, functional outcome, and hemorrhage rates after switching to tenecteplase for stroke thrombolysis: Insights from the TETRIS registry

International audienceIntroduction: The encouraging efficacy and safety data on intravenous thrombolysis with tenecteplase in ischemic stroke and its practical advantages motivated our centers to switch from alteplase to tenecteplase. We report its impact on treatment times and clinical outcomes. Methods: We retrospectively analyzed clinical and procedural data of patients treated with alteplase or tenecteplase in a comprehensive (CSC) and a primary stroke center (PSC), which transitioned respectively in 2019 and 2018. Tenecteplase enabled in-imaging thrombolysis in the CSC. The main outcomes were the imaging-to-thrombolysis and thrombolysis-to-puncture times. We assessed the association of tenecteplase with 3-month functional independence and parenchymal hemorrhage (PH) with multivariable logistic models. Results: We included 795 patients, 387 (48.7%) received alteplase and 408 (51.3%) tenecteplase. Both groups (tenecteplase vs alteplase) were similar in terms of age (75 vs 76 years), baseline NIHSS score (7 vs 7.5) and proportion of patients treated with mechanical thrombectomy (24.1% vs 27.5%). Tenecteplase patients had shorter imaging-to-thrombolysis times (27 vs 36 min, p < 0.0001) mainly driven by patients treated in the CSC (22 vs 38 min, p < 0.001). In the PSC, tenecteplase patients had shorter thrombolysis-to-puncture times (84 vs 95 min, p = 0.02), reflecting faster interhospital transfer for MT. 3-month functional independence rate was higher in the tenecteplase group (62.8% vs 53.4%, p < 0.01). In the multivariable analysis, tenecteplase was significantly associated with functional independence (OR a 1.68, 95% CI 1.15–2.48, p < 0.01), but not with PH (OR a 0.68, 95% CI 0.41–1.12, p = 0.13). Conclusion: Switch from alteplase to tenecteplase reduced process times and may improve functional outcome, with similar safety profile