Search results for "klusteri"

Two Overwatch Player Profiles

2022

AbstractWe pursue Overwatch player profiles via a statistical cluster analysis of survey data from the UK (N = 1089) and the USA (N = 417). The profiles are based on the players’ activity, challenge, and experiential preferences as well as motivations. Our analytical process produces six esports player clusters, two of which with Overwatch. The first (OW1) plays mainly Overwatch and Fortnite on a console, and they enjoy diverse types of non-competitive play elements more than other esports players. The second cluster (OW2) plays mainly Overwatch and League of Legends on a PC, and despite appearing more “competitive”, they did not report more competitive preferences. We suggest that the alle…

Selective Acrolein Hydrogenation over Ligand-Protected Gold Clusters : A Venus Flytrap Mechanism

2022

The catalytic partial hydrogenation of α,β-unsaturated aldehydes is an ideal reaction to understand the selectivity between two different functional groups Here the two functional groups are C═C and C═O, and the hydrogenation of C═O is preferentially desired due to the importance of the issuing products, unsaturated alcohols, in fine-chemical industries. Using density functional theory calculations, we investigate the catalytic competency toward this reaction of a Au nanocluster in the presence of protecting ligands that offer higher stability and the possibility for the uniform distribution of size-selected clusters in the catalytic system. meta-Mercaptobenzoic-acid-protected-protected Au …

Solubility-Driven Isolation of a Metastable Nonagold Cluster with Body-Centered Cubic Structure.

2020

The conventional synthetic methodology of atomically precise gold nanoclusters using reduction in solutions offers only thermodynamically most stable nanoclusters. We report herein a solubility‐driven isolation strategy to access the synthesis of a metastable gold cluster. The cluster, with the composition of [Au 9 (PPh 3 ) 8 ] + ( 1 ), displays an unusual, nearly perfect body‐centered‐cubic (bcc) structure. As revealed by ESI‐MS and UV/Vis measurement, the cluster is metastable in solution and converts to the well‐known [Au 11 (PPh 3 ) 8 Cl 2 ] + ( 2 ) within just 90 min. DFT calculations revealed that while both 1 and 2 are eight‐electron superatoms, there is a driving force to convert 1 …

Scalable robust clustering method for large and sparse data

2018

Datasets for unsupervised clustering can be large and sparse, with significant portion of missing values. We present here a scalable version of a robust clustering method with the available data strategy. Moreprecisely, a general algorithm is described and the accuracy and scalability of a distributed implementation of the algorithm is tested. The obtained results allow us to conclude the viability of the proposed approach. peerReviewed

Comparison of cluster validation indices with missing data

2018

Clustering is an unsupervised machine learning technique, which aims to divide a given set of data into subsets. The number of hidden groups in cluster analysis is not always obvious and, for this purpose, various cluster validation indices have been suggested. Recently some studies reviewing validation indices have been provided, but any experiments against missing data are not yet available. In this paper, performance of ten well-known indices on ten synthetic data sets with various ratios of missing values is measured using squared euclidean and city block distances based clustering. The original indices are modified for a city block distance in a novel way. Experiments illustrate the di…

Data-Driven Interactive Multiobjective Optimization Using a Cluster-Based Surrogate in a Discrete Decision Space

2019

In this paper, a clustering based surrogate is proposed to be used in offline data-driven multiobjective optimization to reduce the size of the optimization problem in the decision space. The surrogate is combined with an interactive multiobjective optimization approach and it is applied to forest management planning with promising results. peerReviewed

Anomaly-based online intrusion detection system as a sensor for cyber security situational awareness system

2016

Almost all the organisations and even individuals rely on complex structures of data networks and networked computer systems. That complex data ensemble, the cyber domain, provides great opportunities, but at the same time it offers many possible attack vectors that can be abused for cyber vandalism, cyber crime, cyber espionage or cyber terrorism. Those threats produce requirements for cyber security situational awareness and intrusion detection capability. This dissertation concentrates on research and development of anomaly-based network intrusion detection system as a sensor for a situational awareness system. In this dissertation, several models of intrusion detection systems are devel…

What Contributes to the Measured Chiral Optical Response of the Glutathione-Protected Au25 Nanocluster?

2023

The water-soluble glutathione-protected [Au25(GSH)18]−1 nanocluster was investigated by integrating several methodologies such as molecular dynamics simulations, essential dynamics analysis, and state-of-the-art time-dependent density functional theory calculations. Fundamental aspects such as conformational, weak interactions and solvent effects, especially hydrogen-bonds, were included and found to play a fundamental role in assessing the optical response of this system. Our analysis demonstrated not only that the electronic circular dichroism is extremely sensitive to the solvent presence but also that the solvent itself plays an active role in the optical activity of such system, formin…

On data mining applications in mobile networking and network security

2014

Taming big knowledge evolution

2016

Information and its derived knowledge are not static. Instead, information is changing over time and our understanding of it evolves with our ability and willingness to consume the information. When compared to humans, current computer systems seem very limited in their ability to really understand the meaning of things. On the other hand, they are very powerful when it comes down to performing exact computations. One aspect which sets humans apart from machines when trying to understand the world is that we will often make mistakes, forget information, or choose what to focus on. To put this in another perspective, it seems like humans can behave somehow more randomly and still outperform …