Search results for "Information Systems."
showing 10 items of 1545 documents
Using continuous user authentication to detect masqueraders
2003
Nowadays computer and network intrusions have become more common and more complicated, challenging the intrusion detection systems. Also, network traffic has been constantly increasing. As a consequence, the amount of data to be processed by an intrusion detection system has been growing, making it difficult to efficiently detect intrusions online. Proposes an approach for continuous user authentication based on the user’s behaviour, aiming at development of an efficient and portable anomaly intrusion detection system. A prototype of a host‐based intrusion detection system was built. It detects masqueraders by comparing the current user behaviour with his/her stored behavioural model. The m…
Probabilities of conditionals and previsions of iterated conditionals
2019
Abstract We analyze selected iterated conditionals in the framework of conditional random quantities. We point out that it is instructive to examine Lewis's triviality result, which shows the conditions a conditional must satisfy for its probability to be the conditional probability. In our approach, however, we avoid triviality because the import-export principle is invalid. We then analyze an example of reasoning under partial knowledge where, given a conditional if A then C as information, the probability of A should intuitively increase. We explain this intuition by making some implicit background information explicit. We consider several (generalized) iterated conditionals, which allow…
Five Challenges for Benefits Management in Complex Digitalisation Efforts – and a Research Agenda to Address Current Shortcomings
2019
Over the past decades a number of benefits realisation (BR) frameworks have been developed. The benefits management model (BMM) is considered to be the most widely adopted and is often seen as a reference for good practice in digitalisation efforts in single organisations. However, this literature provides little support for complex, inter‑organisational efforts. This is problematic, considering that digitalisation increasingly involves multiple organisations. To explore this gap, we studied the phenomenon in a Norwegian inter‑organisational eHealth effort. Based on a qualitative study involving 50 interviews, observations and document analyses, we identify five distinct challenges and sugg…
Intellectual capital reporting: A knowledge tool to coordinate a group of regional non-profit organisations
2017
Whilst many organizations worldwide have stopped disclosing Intellectual Capital (IC), to the best of our knowledge, the only longstanding NPO still measuring, managing and reporting its IC is a large Italian non-profit organization (NPO), ANPAS Piemonte. The main aim of the article is thus to investigate the reasons why ANPAS Piemonte continues to deal with IC, to examine the determinants of this choice, the costs and the benefits management gets from IC measurement, management and reporting. In other words, the paper aims to explore the intellectual capital (IC) reporting process from an internal, managerial point of view. The paper employ a case study methodology to address its aim, and …
On Modern Matrix Iteration Processes of Bernoulli and Graeffe Type
1958
Verso una dimensione narrativa delle mappe
2021
Tra il pensiero e la costruzione dell’architettura il disegno ha un ruolo baricentrico per connettere i diversi protagonisti di una realizzazione e per coinvolgere la collettività facendo percepire inedite prospettive. La scrittura si rivela utile per esplicitare ciò che nella grafica è sotteso e per stabilire un ordine nuovo nel ragionamento progettuale. I rapporti fra segni e significati si moltiplicano nei sistemi informativi recenti in cui si ha la sensazione di poter dire moltissimo (dati numerici e spaziali) ma a volte sfugge quella sintesi indispensabile per una interpretazione concreta, finalizzata alla costruzione di possibili esperienze fisiche. Per l’esplorazione dell’uso di dive…
A comparison of HDFS compact data formats: Avro versus Parquet
2017
In this paper, file formats like Avro and Parquet are compared with text formats to evaluate the performance of the data queries. Different data query patterns have been evaluated. Cloudera’s open-source Apache Hadoop distribution CDH 5.4 has been chosen for the experiments presented in this article. The results show that compact data formats (Avro and Parquet) take up less storage space when compared with plain text data formats because of binary data format and compression advantage. Furthermore, data queries from the column based data format Parquet are faster when compared with text data formats and Avro. Article in English. HDFS glaustųjų duomenų formatų palyginimas: Avro prieš Parquet…
Mining customer requirements from online reviews: A product improvement perspective
2016
We propose a filtering model to predict helpfulness of reviews for product design.We provide a way to use the KANO model based on online reviews.We explore how to obtain insights from Big Data through knowledge-based view. Big data commerce has become an e-commerce trend. Learning how to extract valuable and real time insights from big data to drive smarter and more profitable business decisions is a main task of big data commerce. Using online reviews as an example, manufacturers have come to value how to select helpful online reviews and what can be learned from online reviews for new product development. In this research, we first proposed an automatic filtering model to predict the help…
A new compact formulation for the discrete p-dispersion problem
2017
Abstract This paper addresses the discrete p -dispersion problem (PDP) which is about selecting p facilities from a given set of candidates in such a way that the minimum distance between selected facilities is maximized. We propose a new compact formulation for this problem. In addition, we discuss two simple enhancements of the new formulation: Simple bounds on the optimal distance can be exploited to reduce the size and to increase the tightness of the model at a relatively low cost of additional computation time. Moreover, the new formulation can be further strengthened by adding valid inequalities. We present a computational study carried out over a set of large-scale test instances i…
A distance metric on binary trees using lattice-theoretic measures
1990
A so called height function which is a strictly antitone supervaluation is defined on binary trees. Via lattice-theoretic results and using the height function, we can define a distance metric on binary trees of size n which can be computed in expected time O(n 3/2 )