Search results for "imine"

The carbenoid-type reactivity of simplest nitrile imine from a molecular electron density theory perspective

2019

Abstract The [3 + 2] cycloaddition (32CA) reactions of the simplest nitrile imine with ethylene and electrophilic dicyanoethylene have been studied within the Molecular Electron Density Theory (MEDT) with the aim of characterising its reactivity. Topological analysis of the electron localisation function of NI shows that it has a carbenoid structure. The activation energy of the 32CA reaction of the simplest nitrile imine with dicyanoethylene is 5.6 kcal mol−1 lower than that involving ethylene, in agreement with the high polar character of the former reaction. Bonding Evolution Theory accounts for the cb-type reactivity of nitrile imine. Along the more favourable ortho regioisomeric path a…

L'enquête judiciaire en Europe au XIXe siècle : acteurs, imaginaires, pratiques

2007

The Youth Guarantee and lifelong guidance

2013

Towards Evidence-Based Academic Advising Using Learning Analytics

2018

Academic advising is a process between the advisee, adviser and the academic institution which provides the degree requirements and courses contained in it. Content-wise planning and management of the student’ study path, guidance on studies and academic career support is the main joint activity of advising. The purpose of this article is to propose the use of learning analytics methods, more precisely robust clustering, for creation of groups of actual study profiles of students. This allows academic advisers to provide evidence-based information on the study paths that have actually happened similarly to individual students. Moreover, academic institutions can focus on management and upda…

Variation in situation-specific engagement among lower secondary school students

2018

The majority of previous research has examined school engagement as an overall student characteristic. The present study contributes to the field by examining variation in students' situation-specific engagement from one lesson to another and by investigating situational determinants of such variation. An intensive one-week lesson-to-lesson data collection was conducted in four lower secondary school classrooms. Students rated their situation-specific engagement at the end of each lesson with a mobile-based InSitu instrument. Data comprising a total of 57 students and 1328 ratings were analyzed with two-level hierarchical multivariate model (between students, and within students between les…

Countering Adversarial Inference Evasion Attacks Towards ML-Based Smart Lock in Cyber-Physical System Context

2021

Machine Learning (ML) has been taking significant evolutionary steps and provided sophisticated means in developing novel and smart, up-to-date applications. However, the development has also brought new types of hazards into the daylight that can have even destructive consequences required to be addressed. Evasion attacks are among the most utilized attacks that can be generated in adversarial settings during the system operation. In assumption, ML environment is benign, but in reality, perpetrators may exploit vulnerabilities to conduct these gradient-free or gradient-based malicious adversarial inference attacks towards cyber-physical systems (CPS), such as smart buildings. Evasion attac…

Counter anion binding in the phenoxyimine, salan and metallocene olefin polymerization catalysts activated with perfluorophenylborate

2012

Abstract Ion pair separation is a process that may influence the activity of homogeneous catalysts of olefin polymerization. We have studied the energy of separation for selected titanium and zirconium metallocene and post-metallocene catalytic ion pairs by means of DFT, dispersion-corrected DFT and Paired Interacting Orbitals method (PIO). Unusually weak cation–anion interactions in the bis(phenoxyimine) systems were attributed to strong electron-donating properties of the phenoxyimine ligands. Energy decomposition analysis (EDA) revealed that almost 70% of the counter ion binding energy results from electrostatic interactions. The PIO method made it possible to analyze the nature of the c…

Automatic image-based identification and biomass estimation of invertebrates

2020

1. Understanding how biological communities respond to environmental changes is a key challenge in ecology and ecosystem management. The apparent decline of insect populations necessitates more biomonitoring but the time-consuming sorting and expert-based identification of taxa pose strong limitations on how many insect samples can be processed. In turn, this affects the scale of efforts to map and monitor invertebrate diversity altogether. Given recent advances in computer vision, we propose to enhance the standard human expert-based identification approach involving manual sorting and identification with an automatic image-based technology. 2. We describe a robot-enabled image-based ident…

One-Pixel Attack Deceives Computer-Assisted Diagnosis of Cancer

2020

Computer vision and machine learning can be used to automate various tasks in cancer diagnostic and detection. If an attacker can manipulate the automated processing, the results can be devastating and in the worst case lead to wrong diagnosis and treatment. In this research, the goal is to demonstrate the use of one-pixel attacks in a real-life scenario with a real pathology dataset, TUPAC16, which consists of digitized whole-slide images. We attack against the IBM CODAIT's MAX breast cancer detector using adversarial images. These adversarial examples are found using differential evolution to perform the one-pixel modification to the images in the dataset. The results indicate that a mino…

Mislabel Detection of Finnish Publication Ranks

2019

The paper proposes to analyze a data set of Finnish ranks of academic publication channels with Extreme Learning Machine (ELM). The purpose is to introduce and test recently proposed ELM-based mislabel detection approach with a rich set of features characterizing a publication channel. We will compare the architecture, accuracy, and, especially, the set of detected mislabels of the ELM-based approach to the corresponding reference results on the reference paper.