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Faculty of Informatics - Papers (Archive)

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Articles 841 - 870 of 2013

Full-Text Articles in Physical Sciences and Mathematics

How To Find The Sufficient Collision Conditions For Haval-128 Pass 3 By Backward Analysis, Pairat Thorncharoensri, Tianbing Xia, Yi Mu Jan 2007

How To Find The Sufficient Collision Conditions For Haval-128 Pass 3 By Backward Analysis, Pairat Thorncharoensri, Tianbing Xia, Yi Mu

Faculty of Informatics - Papers (Archive)

Wang et al. recently found several collisions in some hash functions, such as MD4, MD5, Haval-128 and RIPEMD. These findings have significantly changed our views about the security of existing hash functions. Unfortunately, al- though it is easy for us to verify the correctness of the collisions published by Wang et al., the sufficient condi- tions for collisions are not clear. In this paper, we present our methodology for constructing the sufficient conditions of collision tables by using Haval-128 Pass 3 as an ex- ample. We propose a backward analysis method of com- pression functions for constructing the sufficient condition …

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Enhanced Random Testing For Programs With High Dimensional Input Domains, Fei-Ching Kuo, K. Y. Sim, Chang-Ai Sun, S.-F. Tang, Zhiquan Zhou Jan 2007

Enhanced Random Testing For Programs With High Dimensional Input Domains, Fei-Ching Kuo, K. Y. Sim, Chang-Ai Sun, S.-F. Tang, Zhiquan Zhou

Faculty of Informatics - Papers (Archive)

Random Testing (RT) is a fundamental technique of software testing. Adaptive Random Testing (ART) has recently been developed as an enhancement of RT that has better fault detection effectiveness. Several methods (algorithms) have been developed to implement ART. In most ART algorithms, however, the above enhancement diminishes when the dimensionality of the input domain increases. In this paper, we investigate the nature of failure regions in high dimensional input domains and propose enhanced random testing algorithms that improve the fault detection effectiveness of RT in high dimensional input domains.

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The Impact Of Avatar Mobility On Distributed Server Assignment For Delivering Mobile Immersive Communication Environment, Ying Peng Que, Farzad Safaei, P. Boustead Jan 2007

The Impact Of Avatar Mobility On Distributed Server Assignment For Delivering Mobile Immersive Communication Environment, Ying Peng Que, Farzad Safaei, P. Boustead

Faculty of Informatics - Papers (Archive)

In our previous work, we proposed a distributed server architecture to deliver multi-party immersive voice communication service to mobile clients (e.g. Sony PSP) accessing a distributed virtual environment (DVE). We refer to such immersive voice communication service as mobile immersive communication environment (MICE). We also proposed solutions to assign server to create the auditory scene for each avatar. In this work, we ascertain the necessary update period of server reassignment in order to cope with avatar mobility in the virtual world. In our simulations, we measure the percentage differences in delay deviation and bandwidth cost between the case of no …

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An Immersive Voice Over Ip Service To Wireless Gaming: User Study And Impact Of Virtual World Mobility, Ying Peng Que, Farzad Safaei, P. Boustead Jan 2007

An Immersive Voice Over Ip Service To Wireless Gaming: User Study And Impact Of Virtual World Mobility, Ying Peng Que, Farzad Safaei, P. Boustead

Faculty of Informatics - Papers (Archive)

The current generation of VoIP services offer only single channel (mono) party-mix of voices. Thus when added to a network game engine, mono VoIP service can not really contribute to the gamers’ sense of virtual world immersion. As a future development, the Immersive VoIP service delivers to each gamer an Auditory Scene, mixing the live voices of surrounding gamers which are all directionally placed and distance attenuated according to the appropriate virtual world positions. In previous work, we have proposed the Wireless Immersive Communication Environment (WICE) which is special type of Immersive VoIP service tailored to the scarce resources of …

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Auto-Id And Location-Based Services In National Security: Social Implications, Holly Tootell Jan 2007

Auto-Id And Location-Based Services In National Security: Social Implications, Holly Tootell

Faculty of Informatics - Papers (Archive)

This paper provides an overview of auto-ID and location-based service technologies that are currently being used for the purposes of national security. The paper addresses the social dimensions of technology which have a bearing on their acceptance by individuals. This overview from both a technology and social perspective allows for an understanding to be created as increasingly decisions regarding adoption need to be made by different sectors in society.

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Reconfigurable Media Coding: A New Specification Model For Multimedia Coders, Christophe Lucarz, Marco Mattavelli, Joseph Thomas-Kerr, Jorn Janneck Jan 2007

Reconfigurable Media Coding: A New Specification Model For Multimedia Coders, Christophe Lucarz, Marco Mattavelli, Joseph Thomas-Kerr, Jorn Janneck

Faculty of Informatics - Papers (Archive)

Multimedia coding technology, after about 20 years of active research, has delivered a rich variety of different and complex coding algorithms. Selecting an appropriate subset of these algorithms would, in principle, enable a designer to produce the codec supporting any desired functionality as well as any desired trade-off between compression performance and implementation complexity. Currently, interoperability demands that this selection process be hard-wired into the normative descriptions of the codec, or at a lower level, into a predefined number of choices, known as profiles, codified within each standard specification. This paper presents an alternative paradigm for codec deployment that is …

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Subquadratic Binary Field Multiplier In Double Polynomial System, Pascal Giorgi, Christophe Negre, Thomas Plantard Jan 2007

Subquadratic Binary Field Multiplier In Double Polynomial System, Pascal Giorgi, Christophe Negre, Thomas Plantard

Faculty of Informatics - Papers (Archive)

We propose a new space efficient operator to multiply elements lying in a binary field F2k . Our approach is based on a novel system of representation called Double Polynomial System which set elements as a bivariate polynomials over F2. Thanks to this system of representation, we are able to use a Lagrange representation of the polynomials and then get a logarithmic time multiplier with a space complexity of O(k1:31) improving previous best known method.

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Business And It Alignment With Seam For Enterprise Architecture, Alain Wegmann, Gil Regev, Irina Rychkova, Lam-Son Le, Jose Diego De La Cruz, Philippe Julia Jan 2007

Business And It Alignment With Seam For Enterprise Architecture, Alain Wegmann, Gil Regev, Irina Rychkova, Lam-Son Le, Jose Diego De La Cruz, Philippe Julia

Faculty of Informatics - Papers (Archive)

To align an IT system with an organization's needs, it is necessary to understand the organization 's position within its environment as well as its internal configuration. In SEAM for enterprise architecture the organization is considered as a hierarchy of systems that span from business down to IT. The alignment process addresses the complete hierarchy. We illustrate the use of SEAM for enterprise architecture with an example in which a new hiring process and an IT system are developed. With this approach it is possible to train new engineers in the design of business and IT alignment. It is also …

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Spin-Polarized Transport In Dilute Magnetic Semiconductor Tunnel Junctions, J E. Bunder Jan 2007

Spin-Polarized Transport In Dilute Magnetic Semiconductor Tunnel Junctions, J E. Bunder

Faculty of Informatics - Papers (Archive)

No abstract provided.

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Adaptive Self-Organisation Of Wireless Ad-Hoc Control Networks, Fazel Naghdy, Nathan Simiana Jan 2007

Adaptive Self-Organisation Of Wireless Ad-Hoc Control Networks, Fazel Naghdy, Nathan Simiana

Faculty of Informatics - Papers (Archive)

A novel concept called Wireless ad-hoc Control Networks (WACNets), exploring an ad-hoc approach to networked distributed control, has been under study for the last five years in the research group. Such systems represent a new stage in the evolution of distributed control and monitoring. The work carried out in developing an adaptive self-organisation algorithm for WACNet is reported. The algorithm deploys a distance measure technique while satisfying the rules and assumptions developed for WACNet framework. The effectiveness of the algorithm is verified through computer simulation under a number of given scenarios. The results obtained show that the algorithm effectively drives …

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Empirical Modelling Of Human Gaits For Bipedal Robots, Matthew Field, David A. Stirling, Fazel Naghdy, Zengxi Pan Jan 2007

Empirical Modelling Of Human Gaits For Bipedal Robots, Matthew Field, David A. Stirling, Fazel Naghdy, Zengxi Pan

Faculty of Informatics - Papers (Archive)

Modelling of human motion through a discrete sequence of motion primitives, retaining elements of skillful or unique motion of an individual is addressed. Using wireless inertial motion sensors, a skeletal model of the fluid human gait was gathered. The posture of the human model is described by nine sets of euler angles for each sample. An intrinsic classification algorithm known as Minimum Message Length encoding (MML) is deployed to segment the stream of data and subsequently formulate certain Gaussian Mixture Models (GMM) that contain a plausible range of motion primitives. The removal of certain less seemingly important modes has been …

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Dynamical Symmetry Enlargement In Metallic Zigzag Carbon Nanotubes, J E. Bunder, Hsiu-Hau Lin Jan 2007

Dynamical Symmetry Enlargement In Metallic Zigzag Carbon Nanotubes, J E. Bunder, Hsiu-Hau Lin

Faculty of Informatics - Papers (Archive)

No abstract provided.

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Oscillating Carbon Nanotori Along Carbon Nanotubes, Tamsyn A. Hilder, James M. Hill Jan 2007

Oscillating Carbon Nanotori Along Carbon Nanotubes, Tamsyn A. Hilder, James M. Hill

Faculty of Informatics - Papers (Archive)

The discovery of carbon nanostructures, such as nanotubes and C60 fullerenes, has given rise to a number of potential nanoscale devices. One such device is the gigahertz oscillator, comprising an inner shell sliding inside an outer shell of a multiwalled carbon nanotube, and which, at least theoretically, generates oscillatory frequencies in the gigahertz range. Following the concept of these gigahertz oscillators and the recent discovery of “fullerene crop circles,” here we propose the notion of a nanotorus-nanotube oscillator comprising a carbon nanotorus which is sucked by the van der Waals force onto the carbon nanotube, and subsequently oscillates along the …

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Continuum Modelling For Carbon And Boron Nitride Nanostructures, James M. Hill, Ngamta Thamwattana Jan 2007

Continuum Modelling For Carbon And Boron Nitride Nanostructures, James M. Hill, Ngamta Thamwattana

Faculty of Informatics - Papers (Archive)

Continmuum based models are presented here for certain boron nitride and carbon nanostructures.

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On The Characteristics Of Bgp Multiple Origin As Conflicts, Kwan-Wu Chin Jan 2007

On The Characteristics Of Bgp Multiple Origin As Conflicts, Kwan-Wu Chin

Faculty of Informatics - Papers (Archive)

The Internet has thousands of autonomous systems (ASs), each advertising one or more prefixes it owns. According to RFC 1930, each prefix should originate from a single AS. However, routing updates involving multiple ASs advertising reachability to a given prefix, so called multiple origin AS conflict (MOAS), are becoming prevalent. To this end, this paper analyzes and quantifies MOAS conflicts observed in routing updates collected over 21 days in January 2007, and presents ten reasons that explain why they occur.

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Real-Time Facial Feature Point Extraction, Ce Zhan, Wanqing Li, Philip Ogunbona, Farzad Safaei Jan 2007

Real-Time Facial Feature Point Extraction, Ce Zhan, Wanqing Li, Philip Ogunbona, Farzad Safaei

Faculty of Informatics - Papers (Archive)

Localization of facial feature points is an important step for many subsequent facial image analysis tasks. In this paper, we proposed a new coarse-to-fine method for extracting 20 facial feature points from image sequences. In particular, the Viola-Jones face detection method is extended to detect small-scale facial components with wide shape variations, and linear Kalman filters are used to smoothly track the feature points by handling detection errors and head rotations. The proposed method achieved higher than 90% detection rate when tested on the BioID face database and the FG-NET facial expression database. Moreover, our method shows robust performance against …

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Research On Bandwidth Reservation In Ieee 802.16 (Wimax) Networks, Yi Sun, Yilin Song, Jinglin Shi, Eryk Dutkiewicz Jan 2007

Research On Bandwidth Reservation In Ieee 802.16 (Wimax) Networks, Yi Sun, Yilin Song, Jinglin Shi, Eryk Dutkiewicz

Faculty of Informatics - Papers (Archive)

According to the characteristics and QoS requirements of different types of service flows, this paper proposes a dynamic, prediction-based, multi-class, adaptive bandwidth reservation scheme for IEEE 802.16 (WiMAX) networks. The scheme adopts different bandwidth reservation and admission control policies to different types of service flows and therefore guarantees that the real-time sessions have higher priorities than non real-time sessions and that handover sessions have higher priorities than new sessions. In addition, a bandwidth reservation adaptation algorithm is also proposed. The algorithm adjusts the amount of bandwidth reserved for handover sessions according to the current network conditions thus creating a balance …

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Modeling And Solving Semiring Constraint Satisfaction Problems By Transformation To Weighted Semiring Max-Sat, Louise Leenen, Anbulagan Anbulagan, Thomas Meyer, Aditya K. Ghose Jan 2007

Modeling And Solving Semiring Constraint Satisfaction Problems By Transformation To Weighted Semiring Max-Sat, Louise Leenen, Anbulagan Anbulagan, Thomas Meyer, Aditya K. Ghose

Faculty of Informatics - Papers (Archive)

We present a variant of the Weighted Maximum Satisfiability Problem(Weighted Max-SAT), which is a modeling of the Semiring Con- straint Satisfaction framework. We show how to encode a Semiring Con- straint Satisfaction Problem (SCSP) into an instance of a propositional Weighted Max-SAT, and call the encoding Weighted Semiring Max-SAT (WS-Max-SAT). The clauses in our encoding are highly structured and we exploit this feature to develop two algorithms for solving WS-Max- SAT: an incomplete algorithm based on the well-known GSAT algorithm for Max-SAT, and a branch-and-bound algorithm which is complete. Our preliminary experiments show that the translation of SCSP into WS- …

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Analyzing The Key Variables In The Adoption Process Of Hl7, Alejandro E. Flores Zuniga, Khin Than Win Jan 2007

Analyzing The Key Variables In The Adoption Process Of Hl7, Alejandro E. Flores Zuniga, Khin Than Win

Faculty of Informatics - Papers (Archive)

The intention of this paper is to provide an analysis of variables that could affect the adoption of HL7 message standard. Based on the review of 33 cases where HL7 was successfully implemented the authors present relevant evidence related to inherent limitation of HL7. The result from this study indicates that it is necessary to enhance the standard to overcome particular limitations and facilitate the implementation of inter-institutional software interfaces based on HL7.

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A Wireless Sensor Node Architecture Using Remote Power Charging, For Interaction Applications, Matthew D'Souza, Konstanty Bialkowski, Adam Postula, Montserrat B. Ros Jan 2007

A Wireless Sensor Node Architecture Using Remote Power Charging, For Interaction Applications, Matthew D'Souza, Konstanty Bialkowski, Adam Postula, Montserrat B. Ros

Faculty of Informatics - Papers (Archive)

The wireless sensor node architecture proposed inthis paper is optimized for use in a wireless interactivepoint, listen and see system. In particular, we focus ondeveloping a wireless sensor node that can beremotely charged by harvesting microwave energy.The current system implementation allows a user toaccess information from a remote sensor via theirmobile computing device. These sensors are limited incomplexity due to the limited power available, and arecumbersome since manual intervention is required toreplace its batteries. We propose a system wherebattery powered wireless sensor nodes can berecharged by harvesting energy from a microwaveRadio Frequency (RF) signal source. The remotepower charging module of …

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The Benefits & Concerns Of Public Data Availability In Australia: A Survey Of Security Experts, Roba Abbas Jan 2007

The Benefits & Concerns Of Public Data Availability In Australia: A Survey Of Security Experts, Roba Abbas

Faculty of Informatics - Papers (Archive)

This paper gauges the attitudes of security experts in Australia with regards to public data availability on critical infrastructure protection (CIP). A qualitative survey was distributed to a individuals considered experts in CIP-related research in Australia, in order to address the censorship versus open access debate concerning public data. The intention of the study was to gain an insight into the perceived benefits and threats of public data availability by security experts, and to provide the basis for a security solution to be utilised by the Australian Government sector (at all levels). The findings however can also be applied to …

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Ber-Delay Characteristics Analysis Of Ieee 802.15.4 Wireless Sensor Networks With Cooperative Mimo, Mohd Riduan Bin Ahmad, Eryk Dutkiewicz, Xiaojing Huang Jan 2007

Ber-Delay Characteristics Analysis Of Ieee 802.15.4 Wireless Sensor Networks With Cooperative Mimo, Mohd Riduan Bin Ahmad, Eryk Dutkiewicz, Xiaojing Huang

Faculty of Informatics - Papers (Archive)

This paper presents a study of the impact of transmission delay differences between co-operating nodes on bit error rate performance and energy consumption of wireless sensor networks. We consider a wireless sensor network using an Alamouti virtual MIMO (multiple-input multiple-output) configuration between collaborating nodes operating in quasi-static Rayleigh flat-fading channels. Our results show that above certain delay difference (in the range above 0.75Tb), the traditional non-cooperative approach is more energy-efficient than the cooperative strategy and that the transmission delay difference has the most significant on the transmission energy consumption in the delay range of below 0.75Tb.

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Performance Improvement And Dynamical Behaviour Analysis Of A Cascade Of Two Cstrs, Harvinder S. Sidhu, Simon D. Watt, Mark I. Nelson, Ajay K. Ray Jan 2007

Performance Improvement And Dynamical Behaviour Analysis Of A Cascade Of Two Cstrs, Harvinder S. Sidhu, Simon D. Watt, Mark I. Nelson, Ajay K. Ray

Faculty of Informatics - Papers (Archive)

We revisit the analysis of a reactor network consisting of two coupled continuous stirred tank reactors (CSTRs) arranged in series (Chem. Eng. J. 59 (1995) 169). The main idea proposed in this earlier work is to improve process conversion by generating periodic behaviour in the first reactor (by appropriate choice of design and operational parameters) which then ‘forces’ the second reactor. The performance of this cascade system was shown to be greatly enhanced using the above strategy. In this paper we show some conceptual errors in the analysis in the original paper. We also show that by employing a systematic …

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Becoming Multiliterate: Digital Video News Construction Within A Technology-Supported Learning Environment, Lori Lockyer, Ian M. Brown, David Blackall, Barry M. Harper, Phillip J. Mckerrow Jan 2007

Becoming Multiliterate: Digital Video News Construction Within A Technology-Supported Learning Environment, Lori Lockyer, Ian M. Brown, David Blackall, Barry M. Harper, Phillip J. Mckerrow

Faculty of Informatics - Papers (Archive)

Twenty-first century literacies imply multiliteracies – going beyond language literacy and numeracy to, among others, information, visual, media and technological literacies. An education that develops capabilities across a range of literacies equips young people with the skills necessary to participate in a complex, globalized workplace and community. A key step toward realizing such national and state education agendas is specific curriculum interventions that are translated to the classroom level. This paper reports on a case study that explored both the process and outcomes of the implementation of an education program which was designed to incorporate multiliteracies.

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System Architecture And Mobility Management For Mobile Immersive Communications, Mehran Dowlatshahi, Farzad Safaei Jan 2007

System Architecture And Mobility Management For Mobile Immersive Communications, Mehran Dowlatshahi, Farzad Safaei

Faculty of Informatics - Papers (Archive)

We propose a system design for delivery of immersive communications to mobile wireless devices based on a distributed proxy model. It is demonstrated that this architecture addresses key technical challenges for the delivery of these services, that is, constraints on link capacity and power consumption in mobile devices. However, additional complexity is introduced with respect to application layer mobility management. The paper proposes three possible methods for updating proxy assignments in response to mobility management and compares the performance of these methods.

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Modelling Mas-Specific Security Features, Ghassan Beydoun, Graham C. Low, Haralambos Mouratidis, Brian Henderson-Sellers Jan 2007

Modelling Mas-Specific Security Features, Ghassan Beydoun, Graham C. Low, Haralambos Mouratidis, Brian Henderson-Sellers

Faculty of Informatics - Papers (Archive)

In this paper, we pursue a modelling approach to address security requirements for multi-agent systems (MAS). This will allow developers to account for both the system and agent-specific security requirements of a MAS during the requirements phase and throughout the whole Software Development Lifecycle of the system. We focus on autonomy, mobility and cooperation of individual agents and how these create additional security vulnerabilities to the system. In proposing a set of generic modelling primitives for these engendered requirements in the analysis of the MAS, we extend our recently proposed MAS metamodel.

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Scalability Of Manet Routing Protocols For Heterogeneous And Homogenous Networks, Huda Mubarak Al Amri, Mehran Abolhasan, Tadeusz A. Wysocki Jan 2007

Scalability Of Manet Routing Protocols For Heterogeneous And Homogenous Networks, Huda Mubarak Al Amri, Mehran Abolhasan, Tadeusz A. Wysocki

Faculty of Informatics - Papers (Archive)

In Mobile Ad hoc Network (MANET), mobility, traffic and node density are main network conditions that significantly affect the performance of routing protocols. Much of the previous researches in MANET routing have focused on developing strategies, which suit one specific networking scenario. Therefore, there is no existing protocol that can work well in all different networking scenarios. This paper reviews characteristics of each different classes of routing protocols. Moreover, most of current routing protocols assume homogeneous networking conditions where all nodes have the same capabilities and resources. Although homogenous networks are easy to model and analysis, they exhibits poor scalability …

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Do Suppliers Of Third Party Logistics Understand Their Customers?, Tim Coltman, Byron W. Keating, Anton Kriz Jan 2007

Do Suppliers Of Third Party Logistics Understand Their Customers?, Tim Coltman, Byron W. Keating, Anton Kriz

Faculty of Informatics - Papers (Archive)

Supply chain management (SCM) research has tended to focus on the planning and management of a broad range of activities involved in sourcing and procurement, conversion, and management of logistics. However, the domain is increasingly recognising the importance of coordination and collaboration between channel partners. As such, there is a need to better understand how channel partners make decisions; and in particular, whether there is an alignment in the expectations of these partners. In this study we use a form of discrete choice analyses to explore the relative importance of various supply chain components for buyers of a third party …

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Group Extensions And The Primitive Ideal Spaces Of Toeplitz Algebras, Sriwulan Adji, Iain F. Raeburn, Rizky Rosjanuardi Jan 2007

Group Extensions And The Primitive Ideal Spaces Of Toeplitz Algebras, Sriwulan Adji, Iain F. Raeburn, Rizky Rosjanuardi

Faculty of Informatics - Papers (Archive)

Let Γ be a totally ordered abelian group and I an order ideal in Γ. We prove a theorem which relates the structure of the Toeplitz algebra T(Γ) to the structure of the Toeplitz algebras T(I) and T(Γ/I). We then describe the primitive ideal space of the Toeplitz algebra T(Γ) when the set Σ(Γ) of order ideals in Γ is well-ordered, and use this together with our structure theorem to deduce information about the ideal structure of T(Γ) when 0→ I→ Γ→ Γ/I→ 0 is a non-trivial group …

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Something Smart Going On: The Apocalyptic Aesthetics Of Surveillance, Marcus O'Donnell Jan 2007

Something Smart Going On: The Apocalyptic Aesthetics Of Surveillance, Marcus O'Donnell

Faculty of Informatics - Papers (Archive)

This paper analyses surveillance as an integral element in contemporary discourses of the apocalyptic. It outlines a model of the apocalyptic that has its roots in the western religious tradition particularly the last book of the Christian bible: The Book of Revelation. It explores the intersecting narratives of surveillance, the apocalyptic and the forensic as a way of contextualising contemporary political, pop cultural and technological events. Each of these narratives play themselves out through a dialectical logic: surveillance is seen as bringing both intrusion and protection; the apocalypse is harbinger of both destruction and a new world; while the forensic …

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