Broadband Wireless Access Systems (BWASs) such as High Speed Downlink Packet Access (HSDPA) and the Worldwide Interoperability for Microwave Access (WiMAX), pose a myriad of new opportunities for leveraging the support of a wide range of “content-rich” mobile multimedia services with diverse Quality of Service (QoS) requirements. This is due to the remarkably high bandwidth that is supported by these systems, which was previously only available to wireline connections. Despite the support for such high bandwidth, satisfying the diverse QoS of users while maximizing the revenues of network operators is still one of the major issues in these systems. Bandwidth management, therefore, will play a decisive role in the success of such wireless access systems. Without efficient bandwidth management, network operators may not be able to meet the growing demand of users for multimedia services, and may consequently suffer great revenue loss. Bandwidth management in BWASs is, however, a challenging problem due to many issues that need to be taken into consideration. Examples of such issues include the diverse QoS requirements of the services that BWASs support, the varying channel quality conditions of mobile users, and hence the varying amount of resources that are needed to guarantee certain QoS levels during the lifetime of user connections, the utilization of shared channels for data delivery instead of dedicated ones and network congestion. In this thesis, we address the problem of bandwidth management in BWASs and propose efficient economic-based solutions in order to deal with these issues at different bandwidth management levels, and hence enhance the QoS support in these systems. Specifically, we propose a bandwidth management framework for BWASs. The framework is designed to support multiple classes of traffic with different users having different QoS requirements, maximize the throughput of BWASs, support inter- and intra-class fairness, prevent network congestion and maximize the network operator’s revenues. The framework consists of three related components, namely packet scheduling, bandwidth provisioning and Call Admission Control-based dynamic pricing. By efficiently managing the wireless bandwidth prior to users’ admission (i.e.,pre-admission bandwidth management) and during the users’ connections (i.e., post-admission bandwidth management), these schemes are shown to achieve the design goals of our framework. / Thesis (Ph.D, Computing) -- Queen's University, 2009-04-01 15:35:36.213

In this thesis, we develop efficient algorithms for the jointly optimal power and channel resource allocation in different wireless cooperative multiple access systems. In addition, in some cases insight into the structure of the optimal allocation enables the development of modified cooperation schemes with better performance, and efficient algorithms are developed for jointly optimal power and channel resource allocation for these modified schemes too. The goal of the jointly optimal allocation algorithms developed in this thesis is to maximize the achievable rate regions of the schemes under consideration. Two cooperative channel models are considered; namely, the cooperative multiple access channel, and the multiple access relay channel. For the cooperative multiple access channel, two relaying strategies are considered; namely decode-and-forward (DF), and amplify-and-forward (AF). For the cooperative multiple access channel with DF relaying, systems with full-duplex nodes and systems with half-duplex nodes are considered. In the case of full-duplex nodes, it is shown that the non-convex formulation of the power allocation problem can be simplified and re-cast in a convex form. In fact, closed-form expressions for the optimal power allocation for each point on the boundary of an achievable rate region are obtained. In the case of half-duplex nodes, we propose a modified version of an existing cooperation scheme that, with jointly optimal power and channel resource allocation, can achieve a large fraction of the achievable rate region of the full-duplex case. An efficient algorithm for the jointly optimal power and channel resource allocation is also developed for that scheme. For the cooperative multiple access channel with AF relaying, we consider optimal power and channel resource allocation for a system of two half-duplex source nodes that transmit orthogonal signals, and an efficient algorithm for the optimal power and channel resource allocation is developed. This efficient algorithm is based on a closed-form solution for the optimal power allocation for a given channel resource allocation and on showing that the channel resource allocation problem is quasi-convex. The analysis of the optimal power allocation for a given channel resource allocation shows that the existing scheme that we consider does not use the channel resource efficiently. Therefore, we propose a modified cooperation scheme that maintains the orthogonality property of the original scheme, but provides larger achievable rate regions than those provided by the original scheme. For the multiple access relay channel, the optimal allocation of the relay power and the channel resource between different source nodes is considered in order to maximize the achievable rate region. Four relaying strategies are used; namely, regenerative decode-and-forward, non-regenerative decode-and-forward, amplify-and-forward, and compress-and-forward. For each of these strategies, an efficient algorithm is developed for the jointly optimal power and channel resource allocation. These algorithms are based on closed-form solutions for the optimal power allocation for a given resource allocation and on proving and exploiting the quasi-convexity of the joint allocation problem. The algorithms developed for the multiple access relay channel can be used for homogeneous (using the same relaying strategy for all users) or heterogeneous (using different relaying strategies with different users) relaying and for any number of users. / Thesis / Doctor of Philosophy (PhD)

<p>The recent increase in performance of embedded processors has enabled the use of computationally heavy asymmetric cryptography in small and power efficient embedded systems. The goal of this thesis is to analyze whether it is possible to use this type of cryptography to enhance the security in access systems.</p><p>This report contains a literature study of the complications related to access systems and their functionality. Also a basic introduction to cryptography is included.</p><p>Several cryptographic algorithms were implemented using the public library LibTomCrypt and benchmarked on an ARM7-processor platform. The asymmetric coding schemes were ECC and RSA. The tested symmetric algorithms included AES, 3DES and Twofish among others. The benchmark considered both codesize and speed of the algorithms.</p><p>The two asymmetric algorithms, ECC and RSA, are possible to be used in an ARM7 based access system. Although, both technologies can be configured to finish the calculations within a reasonable time-frame of 10 Sec, ECC archives a higher security level for the same execution time. Therefore, an implementation of ECC would be preferable since it is faster and requires less resources. Some further suggestions of improvements to the implementation is discussed in the final chapters.</p>

The recent increase in performance of embedded processors has enabled the use of computationally heavy asymmetric cryptography in small and power efficient embedded systems. The goal of this thesis is to analyze whether it is possible to use this type of cryptography to enhance the security in access systems. This report contains a literature study of the complications related to access systems and their functionality. Also a basic introduction to cryptography is included. Several cryptographic algorithms were implemented using the public library LibTomCrypt and benchmarked on an ARM7-processor platform. The asymmetric coding schemes were ECC and RSA. The tested symmetric algorithms included AES, 3DES and Twofish among others. The benchmark considered both codesize and speed of the algorithms. The two asymmetric algorithms, ECC and RSA, are possible to be used in an ARM7 based access system. Although, both technologies can be configured to finish the calculations within a reasonable time-frame of 10 Sec, ECC archives a higher security level for the same execution time. Therefore, an implementation of ECC would be preferable since it is faster and requires less resources. Some further suggestions of improvements to the implementation is discussed in the final chapters.

Die derzeitigen Probleme bei der Planung, Durchführung und Überwachung des seilunterstützten Rettens und Bergens entstehen durch die hohen Anforderungen an die Rettungsteams und die erforderlichen kurzen Ablaufzeiten. Einerseits sind die • Güte der Qualifikation der Rettungsteams und der Ausbilder, • Angemessenheit der Ausrüstung der Rettungsteams, • tatsächliche Arbeitssicherheit der Prozesse für alle beteiligten Personen, • tatsächliche Prozesssicherheit unterteilt nach technischer und menschlicher Zuverlässigkeit derzeit nicht ausreichend bewertbar, und andererseits sind die technologischen Abläufe mit ihren Gefährdungs- und Gestaltungspotentialen nur einem kleinen Kreis von Fachleuten bekannt. Dieses Erfahrungswissen gilt es, für alle Anwender zu erschließen. Betrachtet man nun die große Methodenvielfalt der seilunterstützten Rettungs- und Bergeverfahren, die auftretenden Fehler bei Übungen und die Unsicherheit der Planer und überwachenden Personen dieser Verfahren bezüglich der Gefährdungen der Rettungsteams und der zu rettenden bzw. zu bergenden Personen, so zeigen sich Probleme in der Prozessgestaltung. In dieser Arbeit wird, aufbauend auf die Standardisierung der Fertigungsverfahren, ein Baukasten-System mit standardisierten Prozessbausteinen und einem Ablaufalgorithmus zur Anwendung entwickelt, mit der die Aufbau- und Ablauforganisation der Rettungsprozesse beschrieben werden kann. Für die derzeit typischen Rettungs- und Bergeprozesse wurden Standardprozesse entwickelt und in ihren Gültigkeitsbereichen definiert. Der Baustein-Katalog, bestehend aus 127 Prozessbausteinen, ist an der Professur Arbeitswissenschaft der TU Chemnitz erhältlich.

This thesis deals with automation of buildings, provides the possibility of automation in today's intelligent buildings. The issue of building automation for security and access systems is solved in details. This thesis contains the basic rules of the systems and procedure in the implementation of access and security systems. The target of this thesis is the proposal of the access and security system for buildings. Part of the thesis is also creating a model, on which will be presented the access and security system. This model will be used by the company ELMONT GROUP as a basis for dealing with contracts.

Die derzeitigen Probleme bei der Planung, Durchführung und Überwachung des seilunterstützten Rettens und Bergens entstehen durch die hohen Anforderungen an die Rettungsteams und die erforderlichen kurzen Ablaufzeiten. Einerseits sind die • Güte der Qualifikation der Rettungsteams und der Ausbilder, • Angemessenheit der Ausrüstung der Rettungsteams, • tatsächliche Arbeitssicherheit der Prozesse für alle beteiligten Personen, • tatsächliche Prozesssicherheit unterteilt nach technischer und menschlicher Zuverlässigkeit derzeit nicht ausreichend bewertbar, und andererseits sind die technologischen Abläufe mit ihren Gefährdungs- und Gestaltungspotentialen nur einem kleinen Kreis von Fachleuten bekannt. Dieses Erfahrungswissen gilt es, für alle Anwender zu erschließen. Betrachtet man nun die große Methodenvielfalt der seilunterstützten Rettungs- und Bergeverfahren, die auftretenden Fehler bei Übungen und die Unsicherheit der Planer und überwachenden Personen dieser Verfahren bezüglich der Gefährdungen der Rettungsteams und der zu rettenden bzw. zu bergenden Personen, so zeigen sich Probleme in der Prozessgestaltung. In dieser Arbeit wird, aufbauend auf die Standardisierung der Fertigungsverfahren, ein Baukasten-System mit standardisierten Prozessbausteinen und einem Ablaufalgorithmus zur Anwendung entwickelt, mit der die Aufbau- und Ablauforganisation der Rettungsprozesse beschrieben werden kann. Für die derzeit typischen Rettungs- und Bergeprozesse wurden Standardprozesse entwickelt und in ihren Gültigkeitsbereichen definiert. Der Baustein-Katalog, bestehend aus 127 Prozessbausteinen, ist an der Professur Arbeitswissenschaft der TU Chemnitz erhältlich.

Computer haben fast jeden Lebensbereich durchdrungen, was viele Vorteile - aber auch Herausforderungen - für ihre Nutzer mit sich bringt. Dies wird vor allem bei der Benutzung von Fahrkartenautomaten (FKA) oder anderer Technik im öffentlichen Raum deutlich, denn diese sollten spontan benutzbar sein, stellen gerade ältere Benutzer aber oft vor Probleme. Sind sie zu alt, um Technik zu benutzen? Diese Dissertation verfolgt zwei Ziele: Zum einen soll die Gebrauchstauglichkeit eines Fahrkartenautomaten (FKA) verbessert werden, indem zwei einander ergänzende Ansätze angewandt werden und die daraus entstehenden drei FKA-Varianten (Original, Video, Wizard) hinsichtlich der Kriterien der Gebrauchstauglichkeit Effektivität, Effizienz und Zufriedenstellung verglichen werden. Zum anderen wird der Einfluß des Alters und alterskorrelierter Benutzermerkmale auf die erfolgreiche Benutzung dieser funktional equivalenten FKA-Gestaltungsvarianten unter besonderer Berücksichtigung des Merkmals Computerwissen geschätzt. In einem zweifaktoriellen quasi-experimentellen Versuchsplan mit zwei (Alter: jung, alt) mal drei (experimentelle Bedingung: Kontrolle, Video, Wizard) Faktorstufen lösten 62 ältere (M=68 Jahre) und 62 jüngere (M=25 Jahre) Versuchsteilnehmer die selben elf Aufgaben: Die Kontrollgruppe nutzte einen simulierten FKA der BVG (Berliner Verkehrsbetriebe), die Videogruppe sah ein kurzes Instruktionsvideo bevor sie den selben FKA nutzte und die Wizardgruppe nutzte statt dessen eine umgestaltete graphische Benutzungsschnittstelle. Die Ergebnisse legen nahe, daß Technik im öffentlichen Raum durch die Integration einer minimalen Videoinstruktion oder eines aufgabenorientierten Wizards mit angemessenem Aufwand universell nutzbar gestaltet werden kann und daß nicht das chronologische Alter die erfolgreiche Nutzung des FKA beeinflußt, sondern altersbezogene Nutzermerkmale, welche gemessen werden können und sollten, um eine nutzungsgerechte Gestaltung zu ermöglichen. / Computer technology has permeated almost every sphere of daily living, bringing about many advantages - and challenges - for its users. This becomes particularly apparent for older people’s use of public access systems like ticket vending machines (TVM), which should be „walk-up and use systems“ but often pose challenging problems for them. Are they too old to use IT? This thesis aims to (a) improve the usability of a ticket vending machine (TVM) following two different approaches (teach or design) and to compare the resulting three TVM designs (original, video, wizard) regarding the usability criteria effectiveness, efficiency and satisfaction, and to (b) estimate the impact of age and age-correlated user characteristics on the successful use of these functionally equivalent TVM designs with a special focus on computer literacy. In a two (young, old) by three (control, video, wizard) factorial quasi experimental research design, 62 older (M=68 years) and 62 younger (M=25 years) participants solved the same eleven tasks: The control group used a simulated TVM of the BVG (public transportation in Berlin, Germany), the video group watched a brief instructional video integrated into the same TVM before using it and the wizard group used a redesigned wizard interface instead. MANOVA indicates that video and wizard substantially improved TVM usability, increasing effectiveness for the older groups from 52% to 80% and 88% respectively. Hierarchical regression analysis revealed that user characteristics had a strong effect on effectiveness of BVG-TVM use, but a weaker effect in the video (36%) and wizard (5%) conditions (universal usability). Results suggest that integration of minimal video instruction or a task oriented wizard design can make public access systems truly universally usable with reasonable effort and that not chronological age itself predicts successful TVM use, but age related user characteristics, which can - and should - be measured and designed for.