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Numerous studies of human user behaviours in cybersecurity tasks have used traditional research methods, such as self-reported surveys or empirical experiments, to identify relationships between various factors of interest and user security performance. This work takes a different approach, applying computational cognitive modelling to research the decision-making of cybersecurity users. The model described here relies on cognitive memory chunk activation to analytically simulate the decision-making process of a user classifying legitimate and phishing emails. Suspicious-seeming cues in each email are processed by examining similar, past classifications in long-term memory. We manipulate five parameters (Suspicion Threshold, Maximum Cues Processed, Weight of Similarity, Flawed Perception Level, Legitimate-to-Phishing Email Ratio in long-term memory) to examine their effects on accuracy, email processing time and decision confidence. Furthermore, we have conducted an empirical, unattended study of US participants performing the same task. Analyses on the empirical study data and simulation output, especially clustering analysis, show that these two research approaches complement each other for more insightful understanding of this phishing detection task. The analyses also demonstrate several limitations of this computational model that cannot easily capture certain user types and phishing detection strategies, calling for a more dynamic and sophisticated model construction.

 

We report the synthesis, characterization and reactivity of an air-stable, well-defined acenaphthoimidazolylidene palladium–BIAN–NHC chloro dimer complex, [Pd(BIAN–IPr)(μ-Cl)Cl] 2 . This rapidly activating catalyst merges the reactive properties of palladium chloro dimers, [Pd(NHC)(μ-Cl)Cl] 2 , with the attractive structural features of the BIAN framework. [Pd(BIAN–IPr)(μ-Cl)Cl] 2 is the most reactive Pd( ii )–NHC precatalyst discovered to date undergoing fast activation under both an inert atmosphere and aerobic conditions. The catalyst features bulky-yet-flexible sterics that render the C–H substituents closer to the metal center in combination with rapid dissociation to monomers and strong σ-donor properties. [Pd(BIAN–IPr)(μ-Cl)Cl] 2 should be considered as a catalyst for reactions using well-defined Pd( ii )–NHCs. 

Over the last 20 years, N-heterocyclic carbenes (NHCs) have emerged as a dominant direction in ligand development in transition metal catalysis. In particular, strong σ-donation in combination with tunable steric environment make NHCs to be among the most common ligands used for C–C and C–heteroatom bond formation. Herein, we report the study on steric and electronic properties of thiazol-2-ylidenes. We demonstrate that the thiazole heterocycle and enhanced π-electrophilicity result in a class of highly active carbene ligands for electrophilic cyclization reactions to form valuable oxazoline heterocycles. The evaluation of steric, electron-donating and π-accepting properties as well as structural characterization and coordination chemistry is presented. This mode of catalysis can be applied to late-stage drug functionalization to furnish attractive building blocks for medicinal chemistry. Considering the key role of N-heterocyclic ligands, we anticipate thatN-aryl thiazol-2-ylidenes will be of broad interest as ligands in modern chemical synthesis.