Search results for "CLUSTER"

Dynamics of weak interactions in the ligand layer of meta-mercaptobenzoic acid protected gold nanoclusters Au68(m-MBA)32 and Au144(m-MBA)40

2020

Atomically precise metal nanoclusters, stabilized and functionalized by organic ligands, are emerging nanomaterials with potential applications in plasmonics, nano-electronics, bio-imaging, nanocatalysis, and as therapeutic agents or drug carriers in nanomedicine. The ligand layer has an important role in modifying the physico-chemical properties of the clusters and in defining the interactions between the clusters and the environment. While this role is well recognized from a great deal of experimental studies, there is very little theoretical information on dynamical processes within the layer itself. Here, we have performed extensive molecular dynamics simulations, with forces calculated…

ProcMiner: Advancing Process Analysis and Management

2007

This paper contributes both to research and practice on process mining. Previous research on process mining has focused on mining patterns from event log files to generate process models. The process mining approach adopted in this paper is focused on producing patterns about process models, not the models themselves. The approach is demonstrated by ProcMiner -an explorative research prototype for management, consolidating, publishing, retrieving, and analyzing process models. Content-based document clustering is applied to process models represented as XML database in order to find topical groups from models. In practice, organizations face numerous challenges in managing their process mod…

Unstable feature relevance in classification tasks

2011

Knowledge discovery using diffusion maps

2013

Parametrizētu algoritmu paātrinājumi kvantu datoram

2021

Darbā tiek aplūkots, kā uz kvantu datora iespējams paātrināt zināmus parametrizētus algoritmus problēmām “Closest string”, “Cluster vertex deletion”, “Cluster editing”, “Vertex cover” un “Longest path” problēmu risinājumiem, ka arī to uzlabošana kvantu datoram, izmantojot kvantu algoritmus meklēšanas koka apstaigāšanai un dinamiskai programmēšanai. Ir parādīts, kā izveidot kvantu algoritmus “Cluster vertex deletion” problēmas risinājumam ar laika sarežģītību 𝑂(1.7321^𝑘 * √𝑘 * 𝑛^3) un “Vertex cover” problēmai ar laiku 𝑂(1.175^𝑘 * 𝑘^𝑂(1) + 𝑛√𝑚), kas ir labāk, nekā labākajiem zināmajiem algoritmiem ar laiku 𝑂(1.9102^𝑘 * (𝑛 + 𝑚)) un 𝑂(1.2738^𝑘 + 𝑘𝑛), attiecīgi. Ka arī ir parād…

Les puits de l’oppidum de l’Ermitage (Agen, Lot-et-Garonne).

2007

Within the context of a “projet collectif de recherche”, the publication of works directed by Richard Boudet on the hillfort of the Ermitage in Agen, two wells have been studied. The analysis of structures and artefacts (pottery, metal, wood) suggests that they were probably used to draw water and not devoted to chthonian rituals. Comparisons with other wells un South West of Gaul suggest that in most cases, they may have been used in the same way, even though, in very few cases rituals relating to the domestic field cannot be excluded.

Radio frequency fingerprinting for outdoor user equipment localization

2017

The recent advancements in cellular mobile technology and smart phone usage have opened opportunities for researchers and commercial companies to develop ubiquitous low cost localization systems. Radio frequency (RF) fingerprinting is a popular positioning technique which uses radio signal strength (RSS) values from already existing infrastructures to provide satisfactory user positioning accuracy in indoor and densely built outdoor urban areas where Global Navigation Satellite System (GNSS) signal is poor and hard to reach. However a major requirement for the RF fingerprinting to maintain good localization accuracy is the collection and updating of large training database. The Minimization…

CHOOSING OF OPTIMAL REFERENCE SAMPLES FOR BOREAL LAKE CHLOROPHYLL A CONCENTRATION MODELING USING AERIAL HYPERSPECTRAL DATA

2018

Abstract. Optical remote sensing has potential to overcome the limitations of point estimations of lake water quality by providing spatial and temporal information. In open ocean waters the optical properties are dominated by phytoplankton density, while the relationship between color and the constituents is more complicated in inland waters varying regionally and seasonally. Concerning the difficulties relating to comprehensive modeling of complex inland and coastal waters, the alternative approach is considered in this paper: the raw digital numbers (DN) recorded using aerial remote hyperspectral sensing are used without corrections and derived by means of regression modeling to predict C…

CLUSTERING INCOMPLETE SPECTRAL DATA WITH ROBUST METHODS

2018

Abstract. Missing value imputation is a common approach for preprocessing incomplete data sets. In case of data clustering, imputation methods may cause unexpected bias because they may change the underlying structure of the data. In order to avoid prior imputation of missing values the computational operations must be projected on the available data values. In this paper, we apply a robust nan-K-spatmed algorithm to the clustering problem on hyperspectral image data. Robust statistics, such as multivariate medians, are more insensitive to outliers than classical statistics relying on the Gaussian assumptions. They are, however, computationally more intractable due to the lack of closed-for…

On the Location Attractiveness of Emerging Countries for Foreign Direct Investments

2016

Our paper investigates the FDI attracting potential of emerging markets by in terms of their location attributes. We use Statistical cluster analysis to study the dynamic evolution of emerging markets’ clusters, based on country attributes that are relevant for the MNEs location decision. We find that countries tend to be grouped at a geographical level or depending on the various resources they possess, except for China that clusters independently. Also, there are numerous countries’ transitions from one cluster to another over the years, which indicate a natural process of changing location attributes and market development for many emerging economies.