Search results for "NETWORKS"
showing 10 items of 3260 documents
How to Improve the Reliability of Chord?
2008
In this paper we focus on Chord P2P protocol and we study the process of unexpected departures of nodes from this system. Each of such departures may effect in losing any information and in classical versions of this protocol the probability of losing some information is proportional to the quantity of information put into this system. This effect can be partially solved by gathering in the protocol multiple copies (replicas) of information. The replication mechanism was proposed by many authors. We present a detailed analysis of one variant of blind replication and show that this solution only partially solves the problem. Next we propose two less obvious modifications of the Chord protoco…
Violent Conflicts and the New Mediatization: The Impact of Social Media on the European Parliamentary Agenda Regarding the Syrian War
2018
As key institutions in Western democracies, parliaments have gained importance regarding foreign affairs issues in recent years. Their increasing role as moral tribunes and discussion forums on conflict prevention and resolution have led to the parliamentarization of international affairs. The examination of the parliamentary agenda and the actors who shape it constitutes a fundamental part of agenda-setting studies as applied to the media and political systems. Among these actors, mass media must be highlighted, taking into account the complex process of information gathering for members of Parliament, particularly in cases related to international violent conflicts. Moreover, in the speci…
Teaching Knowledge Management by Combining Wikis and Screen Capture Videos
2011
PurposeThis paper aims to report on the design and creation of a knowledge management course aimed at facilitating student creation and use of social interactive learning tools for enhanced learning.Design/methodology/approachThe era of social media and web 2.0 has enabled a bottom‐up collaborative approach and new ways to publish work on the web, promoted by tools such as YouTube video service. In this spirit a knowledge management course was designed aiming to facilitate university students to compose videos on different difficult concepts in the theory part of the course by searching for explanations on the web and by creating a Windows Media Player video focusing on the self‐defined pro…
Shared and personal learning spaces: Challenges for pedagogical design
2012
Abstract The development of new tools for collaboration, such as social software, plays a crucial role in leisure time and work activities. The aim of this article is to summarize the research in the field of computer-supported collaborative learning (CSCL). This is done particularly from the perspective of the blurred line between individual (personal) and group-level (shared) learning that the use of the new tools has forced us to re-think. First, individual and group-level perspectives to learning are discussed to make sense of the major notions of how learning is understood in CSCL research. Second, based on this theoretical grounding, it will be further elaborated what this means to th…
Two-phase routing in three-dimensional blocked optical tori
2014
The contribution of this paper is an all-optical 3D network architecture. We describe scheduled, two-phase routing for it. The three-dimensional blocked optical torus BOT of block size b consists of b2 × b2 × b2 nodes for the first phase routing. Processors are evenly deployed at the underlying torus so that every bth node consists of a processor. Additionally, a BOT consists of b3 blocks of b × b × b subnetworks for the second phase routing. Routing of each packet is done in two phases. Firstly, packets are routed from source processor to an intermediate target node at the target block. Secondly, packets are routed from the intermediate targets at the target block to the target processor (…
Anomaly Detection Algorithms for the Sleeping Cell Detection in LTE Networks
2015
The Sleeping Cell problem is a particular type of cell degradation in Long-Term Evolution (LTE) networks. In practice such cell outage leads to the lack of network service and sometimes it can be revealed only after multiple user complains by an operator. In this study a cell becomes sleeping because of a Random Access Channel (RACH) failure, which may happen due to software or hardware problems. For the detection of malfunctioning cells, we introduce a data mining based framework. In its core is the analysis of event sequences reported by a User Equipment (UE) to a serving Base Station (BS). The crucial element of the developed framework is an anomaly detection algorithm. We compare perfor…
A modelling framework for social media monitoring
2013
This paper describes a hierarchical, three-level modelling framework for monitoring social media. Immediate social reality is modelled through the first level of the models. They represent various virtual communities at social media sites and adhere to the social world models of the sites, i.e., the "site ontologies". The second-level model is a temporal multirelational graph that captures the static and dynamic properties of the first-level models from the perspective of the monitoring site. The third-level model consists of a temporal relational database scheme that models the temporal multirelational graph within the database. The models are specified and instantiated at the monitoring s…
Twister Tries
2015
Many commonly used data-mining techniques utilized across research fields perform poorly when used for large data sets. Sequential agglomerative hierarchical non-overlapping clustering is one technique for which the algorithms’ scaling properties prohibit clustering of a large amount of items. Besides the unfavorable time complexity of O(n 2 ), these algorithms have a space complexity of O(n 2 ), which can be reduced to O(n) if the time complexity is allowed to rise to O(n 2 log2 n). In this paper, we propose the use of locality-sensitive hashing combined with a novel data structure called twister tries to provide an approximate clustering for average linkage. Our approach requires only lin…
Consumer value of camera-based mobile interaction with the real world
2013
Camera-based mobile interaction with the real world allows consumers to connect digital information with the real-world environment, and furthermore, to interact with real-world objects and places. To explore and understand the types of consumer value in the context of such consumer-level applications, we applied the critical incident technique to reflect actual use experiences from 107 application users with a recognized consumer value framework by Holbrook. The findings of the study suggest that at the current state value is heavily based on utilitarian efficiency and excellence. Although the applications enable a diverse value, they have yet to fulfill their potential in providing hedoni…
Scalable Hierarchical Clustering: Twister Tries with a Posteriori Trie Elimination
2015
Exact methods for Agglomerative Hierarchical Clustering (AHC) with average linkage do not scale well when the number of items to be clustered is large. The best known algorithms are characterized by quadratic complexity. This is a generally accepted fact and cannot be improved without using specifics of certain metric spaces. Twister tries is an algorithm that produces a dendrogram (i.e., Outcome of a hierarchical clustering) which resembles the one produced by AHC, while only needing linear space and time. However, twister tries are sensitive to rare, but still possible, hash evaluations. These might have a disastrous effect on the final outcome. We propose the use of a metaheuristic algor…