Ensenada Center for Scientific Research and Higher Education

About: Ensenada Center for Scientific Research and Higher Education is a facility organization based out in Ensenada, Mexico. It is known for research contribution in the topics: Population & Nonlinear system. The organization has 1934 authors who have published 3733 publications receiving 63115 citations.

Semi-supervised anomaly detection algorithms: A comparative summary and future research directions

Abstract: While anomaly detection is relatively well-studied, it remains a topic of ongoing interest and challenge, as our society becomes increasingly interconnected and digitalized. In this paper, we focus on existing anomaly detection approaches, by empirically studying the performance of 29 semi-supervised anomaly detection algorithms on 95 benchmark imbalanced databases from the KEEL repository. These include well-established and commonly used classifiers (e.g., One-Class Support Vector Machine (ocSVM) and Isolation Forest) and recent proposals (e.g., BRM and XGBOD). Findings from our in-depth empirical study show that BRM is a robust classifier, in terms of achieving better classification results than the other 28 state-of-the-art techniques on diverse anomaly detection problems. We also observe that OCKRA, Isolation Forest, and ocSVM achieve good performance overall AUC, but poor classification results on databases where the number of objects is equal or greater than 1,460, all features are nominal, or the imbalance ratio is equal or greater than 39.14.

One-pot myrtenol amination over Au nanoparticles supported on different metal oxides

Abstract: The one-pot amination of natural terpene alcohol (myrtenol, with a primary hydroxyl group) was studied over gold catalysts supported on different metal oxides such as ZrO2, MgO, Al2O3, CeO2, La2O3 using the equimolar amounts of substrates under nitrogen pressure. The synthesized catalysts were characterized by TEM, N2 adsorption techniques and XPS. The correlation between acid–base properties of support and catalytic performance was established. A nearly complete myrtenol conversion as well as the highest selectivity to secondary amine of about 52% were reached after 16 h over Au/ZrO2 with both acidic and basic surface sites.