Search results for "oftware"

On the chromatic number of disk graphs

1998

Colorings of disk graphs arise in the study of the frequency-assignment problem in broadcast networks. Motivated by the observations that the chromatic number of graphs modeling real networks hardly exceeds their clique number, we examine the related properties of the unit disk (UD) graphs and their different generalizations. For all these graphs including the most general class of the double disk (DD) graphs, it is shown that X(G) ≤ c.ω(G) for a constant c. Several coloring algorithms are analyzed for disk graphs, aiming to improve the bounds on X(G). We find that their worst-case performance expressed in the number of used colors is indeed reached in some instances.

Evaluating Bug-Fixing in Software Product Lines

2016

[Background] Bug-fixing could be complex in industrial practice since thousands of products share features in their configuration. Despite the importance and complexity of bug-fixing, there is still a lack of empirical data about the difficulties found in industrial Software Product Lines (SPLs). [Aims] This paper aims to evaluate engineers' performance fixing errors and propagating the fixes to other configured products in the context of an industrial SPL. [Method] We designed and conducted an empirical study to collect data with regard to bug-fixing tasks within the context of a Induction Hob SPL in the BSH group, the largest manufacturer of home appliances in Europe. [Results] We found t…

Comparative analysis of architectures for monitoring cloud computing infrastructures

2015

The lack of control over the cloud resources is one of the main disadvantages associated to cloud computing. The design of efficient architectures for monitoring such resources can help to overcome this problem. This contribution describes a complete set of architectures for monitoring cloud computing infrastructures, and provides a taxonomy of them. The architectures are described in detail, compared among them, and analysed in terms of performance, scalability, usage of resources, and security capabilities. The architectures have been implemented in real world settings and empirically validated against a real cloud computing infrastructure based on OpenStack. More than 1000 virtual machin…

An Investigation of Security and Privacy for Human Bond Communications

2017

FederatedCloudSim

2014

Recent developments show that the standardization of cloud service descriptions and exchange leads the way for the rise of cloud federations. In these federations CSPs (cloud service providers) can use resources of other CSPs in the case of a lack of local resources or they can add remote services to their catalogue. Cloud federations again demand for cloud brokers which offer the resources and services of different CSPs transparently to the users. Research of cloud federations in the real world is very complex and expensive as distributed hard- and software scenarios are needed. Therefore we present FederatedCloudSim, a very flexible cloud simulation framework that can be used to simulate …

Self-establishing a Service Level Agreement within Autonomic Cloud Networking Environment

2014

International audience; Today, cloud networking which is the ability to connect the user with his cloud services and to interconnect these services within an inter-cloud approach, is one of the recent research areas in the cloud computing research communities. The main drawback of cloud networking consists in the lack of Quality of Service (QoS) guarantee and management in conformance with a corresponding Service Level Agreement (SLA). Several research works have been proposed for the SLA establishing in cloud computing, but not in cloud networking. In this paper, we propose an architecture for self-establishing an end-to-end service level agreement between a Cloud Service User (CSU) and a …

Adding semantics to cloud computing to enhance service discovery and access

2012

Cloud computing is a technological paradigm that permits to offer computing services over the Internet. This new service model is closely related to previous, well-known distributed computing initiatives such as Web services and grid computing. In the current socio-economic climate, the affordability of cloud computing has gained it popularity among today's innovations. Under these circumstances, more and more cloud services become available. Consequently, it is becoming more and more difficult for service consumers to find and access those cloud services that fulfill their requirements. In this work, a cloud computing ontology is proposed that facilitates a semantic identification, discove…

SMART: Unique splitting-while-merging framework for gene clustering

2014

© 2014 Fa et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Successful clustering algorithms are highly dependent on parameter settings. The clustering performance degrades significantly unless parameters are properly set, and yet, it is difficult to set these parameters a priori. To address this issue, in this paper, we propose a unique splitting-while-merging clustering framework, named "splitting merging awareness tactics" (SMART), which does not require any a priori knowledge of either the number …

The on-line curvilinear component analysis (onCCA) for real-time data reduction

2015

Real time pattern recognition applications often deal with high dimensional data, which require a data reduction step which is only performed offline. However, this loses the possibility of adaption to a changing environment. This is also true for other applications different from pattern recognition, like data visualization for input inspection. Only linear projections, like the principal component analysis, can work in real time by using iterative algorithms while all known nonlinear techniques cannot be implemented in such a way and actually always work on the whole database at each epoch. Among these nonlinear tools, the Curvilinear Component Analysis (CCA), which is a non-convex techni…

Computation Cluster Validation in the Big Data Era

2017

Data-driven class discovery, i.e., the inference of cluster structure in a dataset, is a fundamental task in Data Analysis, in particular for the Life Sciences. We provide a tutorial on the most common approaches used for that task, focusing on methodologies for the prediction of the number of clusters in a dataset. Although the methods that we present are general in terms of the data for which they can be used, we offer a case study relevant for Microarray Data Analysis.