Search results for "Computer network"
showing 10 items of 1634 documents
“Your ride has arrived” – Exploring the nexus between subjective well-being, socio-cultural beliefs, COVID-19, and the sharing economy
2021
This study aimed to identify and explain different facets of the sharing economy and to differentiate between micro- and macro-mobility services. We also aimed to examine the correlation between the sharing economy and subjective well-being, cultural beliefs, and COVID-19. An exploratory research technique with face-to-face semi-structured interviews was used to collect data from a sample of 22 rideshare app users in a developing country between January and May 2020 and in July 2020. The data were analyzed using the NVivo 12 application. The major findings suggest that, considering their scope and use, sharing economy technology and services can be divided into four major domains: (1) hospi…
Mobility and Spatio-Temporal Exposure Control
2013
Modern risk assessment methods cover many issues and encompass both risk analysis and corresponding prevention/mitigation measures.However, there is still room for improvement and one aspect that may benefit from more work is “exposure control”.The “exposure” an asset experiences plays an important part in the risks facing the asset.Amongst the aspects that all too regularly get exposed is user identities and user location information,and in a context with mobile subscriber and mobility in the service hosting (VM migration/mobility) the problems associated with lost identity/location privacy becomes urgent.In this paper we look at “exposure control” as a way for analyzing and protecting use…
Attention Shaping and Software Risk—A Categorical Analysis of Four Classical Risk Management Approaches
1998
This paper examines software risk management in a novel way, emphasizing the ways in which managers address software risks through sequential attention shaping and intervention. Software risks are interpreted as incongruent states within a socio-technical model of organizational change that includes task, structure, technology, and actors. Such incongruence can lead to failures in developing or implementing the system and thus to major losses. Based on this model we synthesize a set of software risk factors and risk resolution techniques, which cover the socio-technical components and their interactions. We use the model to analyze how four classical risk management approaches—McFarlan's p…
Risk Analysis of a Fuel Storage Terminal Using HAZOP and FTA
2017
[EN] The size and complexity of industrial chemical plants, together with the nature of the products handled, means that an analysis and control of the risks involved is required. This paper presents a methodology for risk analysis in chemical and allied industries that is based on a combination of HAZard and OPerability analysis (HAZOP) and a quantitative analysis of the most relevant risks through the development of fault trees, fault tree analysis (FTA). Results from FTA allow prioritizing the preventive and corrective measures to minimize the probability of failure. An analysis of a case study is performed; it consists in the terminal for unloading chemical and petroleum products, and t…
Packet management techniques for measurement based end-to-end admission control in IP networks
2000
End-to-end Measurement Based connection Admission Control (EMBAC) mechanisms have been proposed to support real-time flows quality of service requirements over a Differentiated Services Internet architecture. The EMBAC basic idea is to decentralize the admission control decision, by requiring each individual user to probe the network path during flow setup, and by basing the accept/reject decision on the probing traffic statistics measured at the destination. In conformance with the differentiated services framework, routers are oblivious to individual flows and only need to serve data packets with a higher priority than probing traffic. In this paper, we build upon the observation that som…
A Novel Fault-Tolerant Routing Technique for Mesh-of-Tree based Network-on-Chip Design
2018
Due to the increase in the number of processing elements in System-on-Chips (SoCs), communication between the cores is becoming complex. A solution to this issue in SoCs gave rise to a new paradigm called Network-on-Chips (NoCs). In NoCs, communication between different cores is achieved using packet based switching techniques. In the deep sub-micron technology, NoCs are more susceptible to different kinds of faults which can be transient, intermittent and permanent. These faults can occur at any component of NoCs. This paper presents a novel Fault-Tolerant Routing (FTR) technique for Mesh-of-Tree (MoT) topology in the presence of router faults. The proposed technique is compared with routi…
Fault Tolerant Routing Methodology for Mesh-of-Tree based Network-on-Chips using Local Reconfiguration
2018
Increase in the processing elements in a System-on- Chip (SoC) has led to an increasing complexity between the cores in the entire network. This communication bottleneck led to rise in the new paradigm called Network-on-Chip (NoC). These NoC are very much susceptible to various types of faults which can be transient, intermittent or permanent. This paper presents a fault-tolerant routing technique which can route the packets from a source to a destination in presence of permanent faults in the leaf routers of Mesh-of-Tree topology where cores are connected. This is achieved by using reconfiguration in the local ports of the leaf routers by inserting multiplexers as a layer between the leaf …
Algorithmic Complexity Vulnerability Analysis of a Stateful Firewall
2016
Algorithmic complexity vulnerabilities are an opportunity for an ad-versary to conduct a sophisticated kind of attack i.e. on network infrastructure services. Such attacks take advantage of worst case time or space complexity of algorithms implemented on devices in their software. In this paper we address potential risks introduced by such algorithmic behavior in computer networks in particular on a stateful firewall. First we introduce the idea and theoretical background for the attack. We then describe in full detail a successfully con-ducted attack which takes advantage of the worst case computational complexi-ty of O(n2) of a hash table data structure used to store active sessions. The …
An API for Advanced Traffic Control in Diffserv Routers
2003
Distributed per-flow admission control is a promising solution for Differentiated Services networks. Its deployment in DiffSery domains requires the ability to suitably configure, in each network router, low-level packet forwarding mechanisms, such as packet dropping algorithms driven by traffic measurements. In this paper we first show that performance effectiveness is achieved by means of non traditional configuration of the forwarding mechanisms. Hence, we propose a modular Application Program Interface that allows to flexibly and adaptively configure the forwarding/dropping behavior associated to a router’s output queue, well beyond the traditional RED/RIO active queue management scheme…
About the stability of active queue management mechanisms
2004
In this paper, we discuss the influence of multiple bottlenecks on the stability of active queue management (AQM) controllers, usually configured on a single bottleneck basis. To see this, we consider a network scenario where RED is configured at each router according to previously developed control theoretic techniques. These configuration rules assure stability in a single bottleneck scenario. Yet, we show that instability may arise when two links become congested. We justify this result through a multiple bottleneck model.