A File System Abstraction for Sense and Respond Systems

The heterogeneity and resource constraints of sense-and-respond systems pose significant challenges to system and application development. In this paper, we present a flexible, intuitive file system abstraction for organizing and managing sense-and-respond systems based on the Plan 9 design principles. A key feature of this abstraction is the ability to support multiple views of the system via filesystem namespaces. Constructed logical views present an application-specific representation of the network, thus enabling high-level programming of the network. Concurrently, structural views of the network enable resource-efficient planning and execution of tasks. We present and motivate the design using several examples, outline research challenges and our research plan to address them, and describe the current state of implementation.Comment: 6 pages, 3 figures Workshop on End-to-End, Sense-and-Respond Systems, Applications, and Services In conjunction with MobiSys '0

The system architecture of the Pocket Companion

In the Moby Dick project we design the architecture of a so-called Pocket Companion. It is a small personal portable computer with wireless communication facilities for every day use. The typical use of the Pocket Companion induces a number of requirements concerning security, performance, energy consumption, communication and size. We have shown that these requirements are interrelated and can only be met optimal with one single architecture. The Pocket Companion architecture consists of a central switch with a security module surrounded by several modules. The Pocket Companion is a personal machine. Communication, and particularly wireless communication, is essential for the system to support electronic transactions. Such a system requires a good security infrastructure not only for safeguarding personal data, but also to allow safe (financial) transactions. The integration of a security module in the Pocket Companion architecture provides the basis for a secure environment.\ud Because battery life is limited and battery weight is an important factor for the size and the weight of the Pocket Companion, energy consumption plays a crucial role in the architecture. An important theme of the architecture is: enough performance for minimal energy consumption

Octopus - an energy-efficient architecture for wireless multimedia systems

Multimedia computing and mobile computing are two trends that will lead to a new application domain in the near future. However, the technological challenges to establishing this paradigm of computing are non-trivial. Personal mobile computing offers a vision of the future with a much richer and more exciting set of architecture research challenges than extrapolations of the current desktop architectures. In particular, these devices will have limited battery resources, will handle diverse data types, and will operate in environments that are insecure, dynamic and which vary significantly in time and location. The approach we made to achieve such a system is to use autonomous, adaptable modules, interconnected by a switch rather than by a bus, and to offload as much as work as possible from the CPU to programmable modules that is placed in the data streams. A reconfigurable internal communication network switch called Octopus exploits locality of reference and eliminates wasteful data copies

A Technician's Dream? The Critical Reception of 3-D Films in Britain

Recent debates about the role of 3-D within cinema (and other media) have contained the traces of a largely anti-stereoscopic agenda that can be traced back to critical responses to 3-D in the 1950s. This article considers how British film reviews from the 1950s and 1980s established potent terms of discussion around the 3-D technology, its potential aesthetic development, and the role of stereoscopy within cinema. Exploring the parameters that the original reviewers set in place concerning the 3-D aesthetic, notably claims around realism, novelty, and gimmickry, the article argues that the language and terms of 1950s British film reviewers have worked to set an agenda that resonates through both the 1980s 3-D revival and modern day digital 3-D

Granadan reflections

This paper explores a practice of historical reflection grounded in the city of Granada’s aesthetic and architectural heritage. From the publication of Washington Irving’s Tales of Alhambra, in 1823, up through today, Granada has been a highly celebrated destination for travelers and tourists, drawn by the sublimity of its romantic oriental splendor. Yet, although the city is well known for the Orientalist fantasy it puts on display for touristic consumption, here I consider a form of reflection that cannot be encompassed within the protocols of discourse and experience mobilized by the tourist industry, and that indeed, may challenge those protocols and the assumptions about history and geography they entail. Specifically, drawing on the work of the late-nineteenth-century Spanish writer, Angel Ganivet, I trace a tradition of reflection that engages the city’s unique sensory and architectural configuration as the basis from which to reassess Spain’s relation to both Islam and Europe. I conclude with some general observations on the way the sensory and material infrastructure of Moorish Spain mediates and conditions the possibilities of finding a place for Islam in the country today

The stack resource protocol based on real time transactions

Current hard real time (HRT) kernels have their timely behaviour guaranteed at the cost of a rather restrictive use of the available resources. This makes current HRT scheduling techniques inadequate for use in a multimedia environment where one can profit by a better and more flexible use of the resources. It is shown that one can improve the flexibility and efficiency of real time kernels and a method is proposed for precise quality of service schedulability analysis of the stack resource protocol. This protocol is generalised by introducing real time transactions, which makes its use straightforward and efficient. Transactions can be refined to nested critical sections if the smallest estimation of blocking is desired. The method can be used for hard real time systems in general and for multimedia systems in particular