Implementing unfamiliar functionalities in smartphone applications can be a difficult and a tedious task. Owing to the fact that the API do not have a formal way of representing the sequence of events may be one reason. This thesis describes the development process of various Arctis building blocks based on Android's API of Wi-Fi Direct. The objective of these blocks was to simplify the implementation of Wi-Fi Direct by confining a predictable sequence of events.An Android application was developed in order to test the functionalities, and to validate the prospects of portability for the various building blocks. The work resulted in a construction of three main building blocks, where each of them is responsible for a Wi-Fi Direct related function. Developers will be able to seamlessly utilize the Wi-Fi Direct functionality by combining and implementing these building blocks into their own applications.

Multibiometric Systems

This thesis investigates the permissions requested by Android applications, and the possibility of identifying suspicious applications based only on information presented to the user before an application is downloaded. During the course of this project, a large data set consisting of applications published on Google Play and three different third-party Android application markets was collected over a two-month period. These applications are analysed using manual pattern recognition and k-means clustering, focusing on the permissions they request. The pattern analysis is based on a smaller data set consisting of confirmed malicious applications. The method is evaluated based on its ability to recognise malicious potential in the analysed applications. The k-means clustering analysis takes the whole data set into consideration, in the attempt of uncovering suspicious patterns. This method is evaluated based on its ability to uncover distinct suspicious permission patterns and the findings acquired after further analysis of the clustering results.

The development of distributed, reactive and collaborative services is quite challenging. Rapidly composing services for collaborative learning activities require some development methods and tools. This thesis presents an extension of the City Guide application, a platform that supports situated collaborative services developed by Surya Bahudar Kathayat his PhD thesis: <i>On the Development of Situated Collaborative Services</i>. The application was developed using the engineering method SPACE and its development tool Arctis. In the extension made, two new services instant messaging and group chat have be composed and integrated into the application. The two services have been identified as basic support services that are required for a true collaborative learning experience. Using the architecture of the application, the instant messaging and group chat services were developed as components that could be incorporated with other components within the application. The results show the instant messaging and group chat service as standalone functionalities that handle their own message routing within the application and hence did not require the use of any other messaging protocols. The results also show that by using this architecture with the necessary Arctis modifications, the City Guide application opens up for unexplored possibilities where new services can be rapidly developed and integrated.

Access control of NUTS uplinkWe will focus in the authentication and integrity part in this thesis.

Vehicular ad-hoc networks (VANETs) have envisioned various applications that substantially improve traffic safety and efficiency along the roads and highways. There are on-going projects both in academia and industry to standardize VANETs and to start off their real-life deployment. Despite the huge benefits envisioned by VANETs, they cannot be readily deployed as they are subjects of serious security and privacy concerns. These security and privacy concerns should be addressed and thus VANETs require a sound Identity management architecture before their anticipated deployment. Current research efforts on Identity management (IdM) in VANETs focus on employing Public Key Infrastructure (PKI) schemes to offer the well-known security and privacy requirements for VANETs. However, identity management is a far broader concept than offering security and privacy requirements.This thesis proposed a novel Identity management (IdM) architecture for VANETs that makes distinction between identity of the driver and the identity of the vehicle. To the best of our knowledge, our architecture is the first one to make such a distinction. Smartphones are used for establishing the identity of the driver while the IP Multimedia Subsystem (IMS) is used as an identity provider by establishing an OpenID provider within IMS. To preserve anonymity of users and to avoid location tracking, we tweaked OpenID so that it assigns different pseudonym OpenID identifiers for each user. Finally, we showed how our architecture can be used to realize interoperability across different VANET domains even in the absence of trust relationship among them.

Networked control systems (NCSs) are a kind of distributed control systems in which the data between control components are exchanged via communication networks. Because of the attractive advantages of NCSs such as reduced system wiring, low weight, and ease of system diagnosis and maintenance, the research on NCSs has received much attention in recent years. The first part (Chapter 2 - Chapter 4) of the thesis is devoted to designing new controllers for NCSs by incorporating the network-induced delays. The thesis also conducts research on filtering of multirate systems and identification of Hammerstein systems in the second part (Chapter 5 - Chapter 6).<br /><br /> Network-induced delays exist in both sensor-to-controller (S-C) and controller-to-actuator (C-A) links. A novel two-mode-dependent control scheme is proposed, in which the to-be-designed controller depends on both S-C and C-A delays. The resulting closed-loop system is a special jump linear system. Then, the conditions for stochastic stability are obtained in terms of a set of linear matrix inequalities (LMIs) with nonconvex constraints, which can be efficiently solved by a sequential LMI optimization algorithm. Further, the control synthesis problem for the NCSs is considered. The definitions of <em>H₂</em> and <em>H_∞</em> norms for the special system are first proposed. Also, the plant uncertainties are considered in the design. Finally, the robust mixed <em>H₂/H_&infin;</em> control problem is solved under the framework of LMIs. <br /><br /> To compensate for both S-C and C-A delays modeled by Markov chains, the generalized predictive control method is modified to choose certain predicted future control signal as the current control effort on the actuator node, whenever the control signal is delayed. Further, stability criteria in terms of LMIs are provided to check the system stability. The proposed method is also tested on an experimental hydraulic position control system. <br /><br /> Multirate systems exist in many practical applications where different sampling rates co-exist in the same system. The <em>l₂-l_&infin;</em> filtering problem for multirate systems is considered in the thesis. By using the lifting technique, the system is first transformed to a linear time-invariant one, and then the filter design is formulated as an optimization problem which can be solved by using LMI techniques. <br /><br /> Hammerstein model consists of a static nonlinear block followed in series by a linear dynamic system, which can find many applications in different areas. New switching sequences to handle the two-segment nonlinearities are proposed in this thesis. This leads to less parameters to be estimated and thus reduces the computational cost. Further, a stochastic gradient algorithm based on the idea of replacing the unmeasurable terms with their estimates is developed to identify the Hammerstein model with two-segment nonlinearities. <br /><br /> Finally, several open problems are listed as the future research directions.

In the last years hybrid optical networking is a topic of increasing interest for graceful migration to future high capacity integrated service networks.A new hybrid network architecture is proposed to harmonize different transport technologies and to support a suitable set of services: &apos;&apos;3-Level Integrated Hybrid Optical Network&apos;&apos; (3LIHON).The aim of this thesis is to study the performance of 3LIHON focusing on examining the Quality of Service (QoS) in the output part of the node.In particular we study the performance for Statistically Multiplexed (SM) traffic.In Chapter 1 we present the motivation of our study and the current work.We give the problem definition and define the goal of the thesis.Chapter 2 shows concepts and architecture of 3LIHON. Firstly we introduce the reference classes used and the Quality of Service (QoS) requirement.Furthermore we give a complete description of 3LIHON architecture describing transport services, architecture in detail, input and output part of the node.Finally we describe the advantages of 3LIHON network.To simulate the 3LIHON architecture we use a programming language called Simula and a context class for discrete event simulation called DEMOS.In Chapter 3 firstly we describe the simulation model implemented, moreover we give a code description.We show the sources characterization and the packets characterization for all type of traffic that 3LIHON is able to handle: Guaranteed Service Transport (GST) traffic, Statistically Multiplexed (SM) Real Time (RT) traffic and Statistically Multiplexed (SM) Best Effort (BE) traffic.The code used in this work is available in Appendix C.In Chapter 4 firstly we present the simulation scenario and then the obtained results.To evaluate the accuracy&apos;s level of our results we use a 95% confidence interval and more theoretical details about that are given in Appendix A.We consider three study cases and for each of them we analyze in details the Packet Loss Probability (PLP) of Statistically Multiplexed Real Time (SM/RT) packets, the Packet Loss Probability (PLP) of Statistically Multiplexed Best Effort (SM/BE) packets and the delay of Statistically Multiplexed Best Effort (SM/BE) packets in the Best Effort queue. Some additional results used to obtain the study case called Series Two in Chapter 2 are shown in Appendix B.In Chapter 5 are presented some conclusions of this work and in Chapter 6 we show some hints that can be the sparkle for further works.

Hybrid optical networks are considered as the most promising architectures for future optical networks, in order to achieve both better cost and performance. Dependability is a topic of increasing interest in order to provide the Quality of Service (QoS) expected for future optical networks. Recently, the 3-Level Integrated Hybrid Optical Network (3-LIHON) has been proposed as a new concept for future optical core networks, including different transport technologies to support a wide range of services. Due to the wide range of future telecommunication services foreseen for next generation optical backbone networks, the 3-LIHON architecture must be provided with differentiated dependability, in order to offer the availability demanded by the most critical services, as well as to utilize network resources efficiently. By focusing in a single 3-LIHON node, this thesis employs component redundancy to present a differentiated survivability model suitable for the 3-LIHON architecture. Several protection mechanisms for two of the three types of traffic supported by 3-LIHON are proposed in this research work. These mechanisms are analyzed by means of different dependability models, i.e. reliability block diagrams and Markov models; and a numerical evaluation of its unavailability is presented. In addition, simulation results measuring the impact on performance of some mechanisms are also presented. Then, the protection mechanisms are compared and evaluated, taking into account not only its unavailability and performance, but also other considerations such as cost and complexity. Finally, based on this evaluation, the best suited mechanisms are selected.

The Activity Coordination Tool (ACT) is a web application designed to automate theplanning and coordination of work packages. In the CMS experiment at CERN it isimportant that work packages in the underground facilities are properly planned inorder to not jeopardize time schedules, equipments, budgets and safety. The subjectof this thesis is the development of the database schema used by the ACT application.The schema has been developed from scratch in order to best fit the needs of CMS andto cover all aspects of the planning and coordination process not found in other CERNdatabases.Models and diagrams of the database schema are based on a step by step descriptionof the work package process. This step by step description was used to organize thedata, to make the data and data relationships consistency, and to make the databasestructure flexible for extensions in the future. These models would eventually be usedto implement the schema in the CMS online database.Another database at CERN has many similarities with the ACT database. These twodatabases will eventually merge due to common interest, and the ACT database schemaneeded therefore to resemble some tables in this database in order to facilitate themerging. Some problems with network traversal and security needs to be solved beforethese two databases can be merged.The architecture and usage of the database schema can affect the database performancebut it doesn’t contribute to the reliability of the databases system. The hardware andsoftware components making up the database system itself are usually the main contributorsto this. The CMS online network work hard to keep the performance and reliabilityof their database system as good as possible. Everything from disks to networkconnections is redundant. In addition to component redundancy are features providedby Oracle used to improve performance. The amount of server redundancy does howeverseem a bit exaggerated, and the performance could be slightly improved if otherOracle features were used.