512 research outputs found
Mobile Ad-Hoc Networks
Being infrastructure-less and without central administration control, wireless ad-hoc networking is playing a more and more important role in extending the coverage of traditional wireless infrastructure (cellular networks, wireless LAN, etc). This book includes state-of-the-art techniques and solutions for wireless ad-hoc networks. It focuses on the following topics in ad-hoc networks: quality-of-service and video communication, routing protocol and cross-layer design. A few interesting problems about security and delay-tolerant networks are also discussed. This book is targeted to provide network engineers and researchers with design guidelines for large scale wireless ad hoc networks
Designing Usable and Secure Authentication Mechanisms for Public Spaces
Usable and secure authentication is a research field that approaches different challenges related to authentication, including security, from a human-computer interaction perspective. That is, work in this field tries to overcome security, memorability and performance problems that are related to the interaction with an authentication mechanism. More and more services that require authentication, like ticket vending machines or automated teller machines (ATMs), take place in a public setting, in which security threats are more inherent than in other settings. In this work, we approach the problem of usable and secure authentication for public spaces.
The key result of the work reported here is a set of well-founded criteria for the systematic evaluation of authentication mechanisms. These criteria are justified by two different types of investigation, which are on the one hand prototypical examples of authentication mechanisms with improved usability and security, and on the other hand empirical studies of security-related behavior in public spaces. So this work can be structured in three steps:
Firstly, we present five authentication mechanisms that were designed to overcome the main weaknesses of related work which we identified using a newly created categorization of authentication mechanisms for public spaces. The systems were evaluated in detail and showed encouraging results for future use. This and the negative sides and problems that we encountered with these systems helped us to gain diverse insights on the design and evaluation process of such systems in general. It showed that the development process of authentication mechanisms for public spaces needs to be improved to create better results. Along with this, it provided insights on why related work is difficult to compare to each other. Keeping this in mind, first criteria were identified that can fill these holes and improve design and evaluation of authentication mechanisms, with a focus on the public setting.
Furthermore, a series of work was performed to gain insights on factors influencing the quality of authentication mechanisms and to define a catalog of criteria that can be used to support creating such systems. It includes a long-term study of different PIN-entry systems as well as two field studies and field interviews on real world ATM-use. With this, we could refine the previous criteria and define additional criteria, many of them related to human factors. For instance, we showed that social issues, like trust, can highly affect the security of an authentication mechanism.
We used these results to define a catalog of seven criteria. Besides their definition, we provide information on how applying them influences the design, implementation and evaluation of a the development process, and more specifically, how adherence improves authentication in general. A comparison of two authentication mechanisms for public spaces shows that a system that fulfills the criteria outperforms a system with less compliance. We could also show that compliance not only improves the authentication mechanisms themselves, it also allows for detailed comparisons between different systems
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Adaptive, reliable, and accurate positioning model for location-based services
This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.This thesis presents a new strategy in achieving highly reliable and accurate position solutions fulfilling the requirements of Location-Based Services (LBS) pedestriansâ applications. The new strategy is divided into two main parts. The first part integrates the available positioning technology within the surrounding LBS application context by introducing an adaptive LBS framework. The context can be described as a group of factors affecting the application behaviour; this includes environmental states, available resources and user preferences. The proposed adaptive framework consists of several stages, such as defining the contextual factors that have a direct effect on the positioning performance, identifying preliminary positioning performance requirements associated with different LBS application groups, and introducing an intelligent positioning services selection function. The second part of this work involves the design and development of a novel positioning model that is responsible for delivering highly reliable, accurate and precise position solutions to LBS users. This new model is based on the single frequency GPS Standard Positioning Service (SPS). Additionally, it is incorporated within the adaptive LBS framework while providing the position solutions, in which all identified contextual factors and application requirements are accounted. The positioning model operates over a client-server architecture including two main components, described as the Localisation Server (LS) and the Mobile Unit (MU). Hybrid functional approaches were developed at both components consisting of several processing procedures allowing the positioning model to operate in two position determination modes. Stand-alone mode is used if enough navigation information was available at the MU using its local positioning device (GPS/EGNOS receiver). Otherwise, server-based mode is utilised, in which the LS intervenes and starts providing the required position solutions. At the LS, multiple sources of GPS augmentation services were received using the Internet as the sole augmentation data transportation medium. The augmentation data was then processed and integrated for the purpose of guaranteeing the availability of valid and reliable information required for the provision of accurate and precise position solutions. Two main advanced position computation methods were developed at the LS, described as coordinate domain and raw domain.
The positioning model was experimentally evaluated. According to the reported results, the LS through the developed position computation methods, was able to provide position samples with an accuracy of less than 2 meters, with high precision at 95% confidence level; this was achieved in urban, rural, and open space (clear satellite view) navigation environments. Additionally, the integrity of the position solutions was guaranteed in such environments during more than 90% of the navigation time, taking into consideration the identified integrity thresholds (Horizontal Alert Limits (HAL)=11 m). This positioning performance has outperformed the existing GPS/EGNOS service which was implemented at the MU in all scenarios and environments. In addition, utilising a simulation evaluation facility the developed positioning model performance was quantified with reference to a hybrid positioning service that will be offered by future Galileo Open Service (OS) along with GPS/EGNOS. Using the statistical t-test, it was concluded that there is no significant difference in terms of the position samplesâ accuracy achieved from the developed positioning model and the hybrid system at a particular navigation environment described as rural area. The p-value was 0.08 and the level of significance used was 0.05. However, a significant difference in terms of the service integrity for the advantage of the hybrid system was experienced in all remaining scenarios and environments more especially the urban areas due to surrounding obstacles and conditions
Recent Trends in Communication Networks
In recent years there has been many developments in communication technology. This has greatly enhanced the computing power of small handheld resource-constrained mobile devices. Different generations of communication technology have evolved. This had led to new research for communication of large volumes of data in different transmission media and the design of different communication protocols. Another direction of research concerns the secure and error-free communication between the sender and receiver despite the risk of the presence of an eavesdropper. For the communication requirement of a huge amount of multimedia streaming data, a lot of research has been carried out in the design of proper overlay networks. The book addresses new research techniques that have evolved to handle these challenges
Socio-Informatics
Contents
Editorial
Thematic Focus: Socio-Informatics
Introduction to the Thematic Focus âSocio-Informaticsâ / Claudia MĂźller
Digitalisation in Small German Metal-Working Companies. Appropriation of Technology in a âTraditionalâ Industrial Domain / Bernhard Nett, Jennifer BĂśnsch
Travelling by Taxi Brousse in Madagascar: An Investigation into Practices of Overland Transportation / Volker Wulf, Kaoru Misaki, Dave Randall, and Markus Rohde
Mobile and Interactive Media in the Store? Design Case Study on Bluetooth Beacon Concepts for Food Retail / Christian Reuter, Inken Leopold
Facebook and the Mass Media in Tunisia / Konstantin Aal, MarĂŠn Schorch, Esma Ben Hadj Elkilani, Volker Wulf
Book Review Symposium Charles Goodwin
Charles Goodwinâs Co-Operative Action: The Idea and the Argument / Erhard SchĂźttpelz, Christian Meyer
Multi-Modal Interaction and Tool-Making: Goodwinâs Intuition / Christian Meyer, Erhard SchĂźttpelz
Co-Operation is a Feature of Sociality, not an Attribute of People : âWe inhabit each otherâs actions.â (Goodwin, cover) / Jutta Wiesemann, Klaus Amann
The Making of the World in Co-Operative Action. From Sentence Construction to Cultural Evolution / JĂźrgen Streeck
On Goodwin and his Co-Operative Action / JĂśrg R. Bergman
Load balancing and context aware enhancements for RPL routed Internet of Things.
Internet of Things (IoT) has been paving the way for a plethora of potential applications, which becomes more spatial and demanding. The goal of this work is to optimise the performance within the IPv6 Routing Protocol for Low-Power and Lossy Networks (RPL) in the network layer.RPL still suffers from unbalanced load traffic among the candidate parents. Consequently, the overloaded parent node drains its energy much faster than other candidate parent nodes. This may lead to an early disconnection of a part of the network topology and affect the overall network reliability. To solve this problem, a new objective function (OF) has been proposed to usher better load balancing among the bottleneck candidate parents, and keep the overloaded nodes lifetime thriving to longer survival.Moreover, several IoT applications have antagonistic requirements but pertinent, which results in a greater risk of affecting the network reliability, especially within the emergency scenarios. With the presence of this challenging issue, the current standardised RPL OFs cannot sufficiently fulfil the antagonistic needs of Low-power and Lossy Networks (LLNs) applications. In response to the above issues, a context adaptive OF has been proposed to facilitate exchanging the synergy information between the application and network layers. Thus, the impact of the antagonistic requirements based on context parameters will be mitigated via rationalizing the selection decision of the routing path towards the root node.We implemented the proposed protocol and verified all our findings through excessive measurements via simulations and a realistic deployment using a real testbed of a multi-hop LLNs motes. The results proved the superiority of our solution over the existing ones with respect to end-to-end delay, packet delivery ratio and network lifetime. Our contribution has been accepted initially to be adopted within the standard body Internet Engineering Task Force (IETF)
Recent Developments in Smart Healthcare
Medicine is undergoing a sector-wide transformation thanks to the advances in computing and networking technologies. Healthcare is changing from reactive and hospital-centered to preventive and personalized, from disease focused to well-being centered. In essence, the healthcare systems, as well as fundamental medicine research, are becoming smarter. We anticipate significant improvements in areas ranging from molecular genomics and proteomics to decision support for healthcare professionals through big data analytics, to support behavior changes through technology-enabled self-management, and social and motivational support. Furthermore, with smart technologies, healthcare delivery could also be made more efficient, higher quality, and lower cost. In this special issue, we received a total 45 submissions and accepted 19 outstanding papers that roughly span across several interesting topics on smart healthcare, including public health, health information technology (Health IT), and smart medicine
Pro-collaborative mobile systems in next generation IP networks
Computing system designs of today take on either the interactive or the proactive
form. Motivated by the userâs desire to make his/her computing experience more
intelligent and personalised, the progression from interactive (human-centred) to
proactive (human-supervised) is evident. It can be observed that current research
mainly emphasises the user as the dominant focus of a user-system interaction.
Consider a model that we called the opponent-process model. It contains two
processes, one representing the user and the other the system, where both processes
are capable of dominating each other, though working collaboratively towards a
predefined task. We argue the necessity to design computing systems which are
balanced in this model, such that the system process, at times, becomes the dominant
process. We refer to this as the pro-collaborative design form.
We dissect mobility into the notion of a nomadic user and the notion of a
nomadic system. The examination into the nomadic user problem space reveals the
potential for applying the pro-collaborative approach in optimising handoff
management. Significant performance advantages can be obtained with our proposed
S-MIP framework, based on the pro-collaborative design, when compared with
established handoff latency optimisation schemes. The key differentiator lies in its
indicative approach in addressing handoff ambiguity. Instead of passively
anticipating through prediction as to when a mobile user might cross network
boundaries (user-dominant), the system actively indicates to the user when, where
and how to handoff (system-dominant). This eliminates the handoff ambiguity.
Regarding the notion of a nomadic system, that is, the ability to move services
offered by computing systems to arbitrary points in the Internet, we explore the idea
of the dynamic extension of network services to a mobile user on-demand. Based on
the pro-collaborative form, we develop the METAMORPHOSE architecture which
facilitates such a dynamic service extension. By assuming the proliferation of
programmable network switches and computational resources within the Internet, we
re-examine how âlooseâ service agreements between network services providers can
be, to achieve such borderless moving-service offerings.
The viability of the pro-collaborative form is reflected through our design and
implementation of protocols and architectures which address the notion of nomadic
user and nomadic system
The integrity of digital technologies in the evolving characteristics of real-time enterprise architecture
Advancements in interactive and responsive enterprises involve real-time access to the information and capabilities of emerging technologies. Digital technologies (DTs) are emerging technologies that provide end-to-end business processes (BPs), engage a diversified set of real-time enterprise (RTE) participants, and institutes interactive DT services. This thesis offers a selection of the authorâs work over the last decade that addresses the real-time access to changing characteristics of information and integration of DTs. They are critical for RTEs to run a competitive business and respond to a dynamic marketplace. The primary contributions of this work are listed below.
⢠Performed an intense investigation to illustrate the challenges of the RTE during the advancement of DTs and corresponding business operations.
⢠Constituted a practical approach to continuously evolve the RTEs and measure the impact of DTs by developing, instrumenting, and inferring the standardized RTE architecture and DTs.
⢠Established the RTE operational governance framework and instituted it to provide structure, oversight responsibilities, features, and interdependencies of business operations.
⢠Formulated the incremental risk (IR) modeling framework to identify and correlate the evolving risks of the RTEs during the deployment of DT services.
⢠DT service classifications scheme is derived based on BPs, BP activities, DTâs paradigms, RTE processes, and RTE policies.
⢠Identified and assessed the evaluation paradigms of the RTEs to measure the progress of the RTE architecture based on the DT service classifications.
The starting point was the authorâs experience with evolving aspects of DTs that are disrupting industries and consequently impacting the sustainability of the RTE. The initial publications emphasized innovative characteristics of DTs and lack of standardization, indicating the impact and adaptation of DTs are questionable for the RTEs. The publications are focused on developing different elements of RTE architecture. Each published work concerns the creation of an RTE architecture framework fit to the purpose of business operations in association with the DT services and associated capabilities. The RTE operational governance framework and incremental risk methodology presented in subsequent publications ensure the continuous evolution of RTE in advancements of DTs. Eventually, each publication presents the evaluation paradigms based on the identified scheme of DT service classification to measure the success of RTE architecture or corresponding elements of the RTE architecture
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