1,194 research outputs found
LPcomS: Towards a Low Power Wireless Smart-Shoe System for Gait Analysis in People with Disabilities
Gait analysis using smart sensor technology is an important medical diagnostic process and has many applications in rehabilitation, therapy and exercise training. In this thesis, we present a low power wireless smart-shoe system (LPcomS) to analyze different functional postures and characteristics of gait while walking. We have designed and implemented a smart-shoe with a Bluetooth communication module to unobtrusively collect data using smartphone in any environment. With the design of a shoe insole equipped with four pressure sensors, the foot pressure is been collected, and those data are used to obtain accurate gait pattern of a patient. With our proposed portable sensing system and effective low power communication algorithm, the smart-shoe system enables detailed gait analysis. Experimentation and verification is conducted on multiple subjects with different gait including free gait. The sensor outputs, with gait analysis acquired from the experiment, are presented in this thesis
A PROTOCOL SUITE FOR WIRELESS PERSONAL AREA NETWORKS
A Wireless Personal Area Network (WPAN) is an ad hoc network that consists of devices that surround an individual or an object. Bluetooth® technology is especially suitable for formation of WPANs due to the pervasiveness of devices with Bluetooth® chipsets, its operation in the unlicensed Industrial, Scientific, Medical (ISM) frequency band, and its interference resilience. Bluetooth® technology has great potential to become the de facto standard for communication between heterogeneous devices in WPANs.
The piconet, which is the basic Bluetooth® networking unit, utilizes a Master/Slave (MS) configuration that permits only a single master and up to seven active slave devices. This structure limitation prevents Bluetooth® devices from directly participating in larger Mobile Ad Hoc Networks (MANETs) and Wireless Personal Area Networks (WPANs). In order to build larger Bluetooth® topologies, called scatternets, individual piconets must be interconnected. Since each piconet has a unique frequency hopping sequence, piconet interconnections are done by allowing some nodes, called bridges, to participate in more than one piconet. These bridge nodes divide their time between piconets by switching between Frequency Hopping (FH) channels and synchronizing to the piconet\u27s master.
In this dissertation we address scatternet formation, routing, and security to make Bluetooth® scatternet communication feasible. We define criteria for efficient scatternet topologies, describe characteristics of different scatternet topology models as well as compare and contrast their properties, classify existing scatternet formation approaches based on the aforementioned models, and propose a distributed scatternet formation algorithm that efficiently forms a scatternet topology and is resilient to node failures.
We propose a hybrid routing algorithm, using a bridge link agnostic approach, that provides on-demand discovery of destination devices by their address or by the services that devices provide to their peers, by extending the Service Discovery Protocol (SDP) to scatternets.
We also propose a link level security scheme that provides secure communication between adjacent piconet masters, within what we call an Extended Scatternet Neighborhood (ESN)
A Mobile Secure Bluetooth-Enabled Cryptographic Provider
The use of digital X509v3 public key certificates, together with different standards
for secure digital signatures are commonly adopted to establish authentication proofs
between principals, applications and services. One of the robustness characteristics commonly
associated with such mechanisms is the need of hardware-sealed cryptographic
devices, such as Hardware-Security Modules (or HSMs), smart cards or hardware-enabled
tokens or dongles. These devices support internal functions for management and storage
of cryptographic keys, allowing the isolated execution of cryptographic operations, with
the keys or related sensitive parameters never exposed.
The portable devices most widely used are USB-tokens (or security dongles) and internal
ships of smart cards (as it is also the case of citizen cards, banking cards or ticketing
cards). More recently, a new generation of Bluetooth-enabled smart USB dongles appeared,
also suitable to protect cryptographic operations and digital signatures for secure
identity and payment applications. The common characteristic of such devices is to offer
the required support to be used as secure cryptographic providers. Among the advantages
of those portable cryptographic devices is also their portability and ubiquitous use, but,
in consequence, they are also frequently forgotten or even lost. USB-enabled devices imply
the need of readers, not always and not commonly available for generic smartphones
or users working with computing devices. Also, wireless-devices can be specialized or
require a development effort to be used as standard cryptographic providers.
An alternative to mitigate such problems is the possible adoption of conventional
Bluetooth-enabled smartphones, as ubiquitous cryptographic providers to be used, remotely,
by client-side applications running in users’ devices, such as desktop or laptop
computers. However, the use of smartphones for safe storage and management of private
keys and sensitive parameters requires a careful analysis on the adversary model assumptions.
The design options to implement a practical and secure smartphone-enabled
cryptographic solution as a product, also requires the approach and the better use of
the more interesting facilities provided by frameworks, programming environments and
mobile operating systems services.
In this dissertation we addressed the design, development and experimental evaluation
of a secure mobile cryptographic provider, designed as a mobile service provided in a smartphone. The proposed solution is designed for Android-Based smartphones and
supports on-demand Bluetooth-enabled cryptographic operations, including standard
digital signatures. The addressed mobile cryptographic provider can be used by applications
running on Windows-enabled computing devices, requesting digital signatures.
The solution relies on the secure storage of private keys related to X509v3 public certificates
and Android-based secure elements (SEs). With the materialized solution, an
application running in a Windows computing device can request standard digital signatures
of documents, transparently executed remotely by the smartphone regarded as a
standard cryptographic provider
Context Aware Computing for The Internet of Things: A Survey
As we are moving towards the Internet of Things (IoT), the number of sensors
deployed around the world is growing at a rapid pace. Market research has shown
a significant growth of sensor deployments over the past decade and has
predicted a significant increment of the growth rate in the future. These
sensors continuously generate enormous amounts of data. However, in order to
add value to raw sensor data we need to understand it. Collection, modelling,
reasoning, and distribution of context in relation to sensor data plays
critical role in this challenge. Context-aware computing has proven to be
successful in understanding sensor data. In this paper, we survey context
awareness from an IoT perspective. We present the necessary background by
introducing the IoT paradigm and context-aware fundamentals at the beginning.
Then we provide an in-depth analysis of context life cycle. We evaluate a
subset of projects (50) which represent the majority of research and commercial
solutions proposed in the field of context-aware computing conducted over the
last decade (2001-2011) based on our own taxonomy. Finally, based on our
evaluation, we highlight the lessons to be learnt from the past and some
possible directions for future research. The survey addresses a broad range of
techniques, methods, models, functionalities, systems, applications, and
middleware solutions related to context awareness and IoT. Our goal is not only
to analyse, compare and consolidate past research work but also to appreciate
their findings and discuss their applicability towards the IoT.Comment: IEEE Communications Surveys & Tutorials Journal, 201
Choice and chance:model-based testing of stochastic behaviour
Probability plays an important role in many computer applications. A vast number of algorithms, protocols and computation methods uses randomisation to achieve their goals. A crucial question then becomes whether such probabilistic systems work as intended. To investigate this, such systems are often subjected to a large number of well-designed test cases, that compare a observed behaviour to a requirements specification. Model-based testing is an innovative testing technique rooted in formal methods, that aims at automating this labour intense and often error-prone manual task. By providing faster and more thorough testing at lower cost, it has gained rapid popularity in industry and academia alike. However, classic model-based testing methods are insufficient when dealing with inherently stochastic systems. This thesis introduces a rigorous model-based testing framework, that is capable to automatically test such systems. The presented methods are capable of judging functional correctness, discrete probability choices, and hard and soft-real time constraints. The framework is constructed in a clear step-by-step approach. First, the model-based testing landscape is laid out, and related work is discussed. Next, we instantiate a model-based testing framework to highlight the purpose of individual theoretical components like, e.g., a conformance relation, test cases, and practical test generation algorithms. This framework is then conservatively extended by introducing discrete probability choices to the specification language. A last step further extends this probabilistic framework by adding hard and soft real time constraints. Classical functional correctness verdicts are thus extended with goodness of fit methods known from statistics. Proofs of the framework’s correctness are presented before its capabilities are exemplified by studying smaller scale case studies known from the literature. The framework reconciles non-deterministic and probabilistic choices in a fully-fledged way via the use of schedulers. Schedulers then become a subject worthy to study in their own rights. This is done in the second part of this thesis; we introduce a most natural equivalence relation based on schedulers for Markov automata, and compare its distinguishing power to notions of trace distributions and bisimulation relations. Lastly, the power of different scheduler classes of stochastic automata is investigated. We compare reachability probabilities of different schedulers by altering the information available to them. A hierarchy of scheduler classes is established, with the intent to reduce complexity of related problems by gaining near optimal results for smaller scheduler classes
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