The Realist Tradition and the Limits of International Relations

Williams, Mike, Realist Tradition and the Limits of International Relations (Cambridge: Cambridge University Press, 2005), pp.ix+236 RAE2008

Through the Wire: Relations of Power and Relations of Violence

Edkins, J. and Pin-Fat, V. (2005). Through the Wire: Relations of Power and Relations of Violence. Millennium - Journal of International Studies. 34(1), pp.1-24 RAE2008

The English School of International Relations: A Contemporary Reassessment

Linklater, A. and Suganami, A. (2006). The English School of International Relations: A Contemporary Reassessment. Cambridge Studies in International Relations (No. 102). Cambridge: Cambridge University Press. RAE2008

'What Foes more dang'rous than too strong Allies?': Anglo-Welsh relations in eighteenth-century London

Prescott, Sarah, ''What Foes more dang'rous than too strong Allies?': Anglo-Welsh relations in eighteenth-century London', The Huntington Library Quarterly (2006) 69 (4) pp.535-554 RAE2008

Effects of a stay-green mutation on plant nitrogen relations in Lolium perenne during N starvation and after defoliation

Macduff, J. H., Humphreys, M. O., Thomas, Howard (2002). Effects of a stay-green mutation on plant nitrogen relations in Lolium perenne during N starvation and after defoliation. Annals of Botany, 89 (1), 11-21. Sponsorship: BBSRC RAE2008

Biblioteka Uniwersytecka w Poznaniu w Web 2.0 - rozwój przyjaznej komunikacji cyfrowej i wynikające z niej korzyści

Poster pokazuje metody komunikacji z czytelnikiem stosowane w Bibliotece Uniwersyteckiej w Poznaniu w technologii mediów cyfrowych. Cyfrowe narzędzia komunikacji stały się bardzo pomocne, niemal niezbędne w pozyskiwaniu nowych czytelników, podtrzymywaniu i rozwijaniu współpracy w społeczności w sieci Web.2.0, zarówno tej globalnej, jak i lokalnej akademickiej. Strona WWW jako statyczna komunikacyjnie jest wspierana przez fora dyskusyjne, chaty, wideokonferencje, warsztaty informacyjne, które są prowadzone w czasie rzeczywistym. Twórczą siłę relacji społecznych z biblioteką rozwinęły interaktywne serwisy społecznościowe (Facebook) oraz komunikatory internetowe integrowane na platformie Ask a Librarian. Biblioteka stała się Biblioteką 2.0 ukierunkowaną na komunikację z czytelnikiem. Aktywne uczestnictwo i udział czytelników przy tworzeniu zasobów naukowych wdrożyliśmy w projekcie instytucjonalnego repozytorium - Adam Mickiewicz Repository (AMUR). Biblioteka zmienia się dla czytelników i z czytelnikami. Wykorzystywane platformy i serwisy społecznościowe dostarczają unikatowych danych o nowych potrzebach informacyjnych i oczekiwaniach docelowego Patrona 2.0, co skutkuje doskonaleniu usług istniejących i tworzeniu nowych. Biblioteka monitoruje usługi i potrzeby czytelników przez prowadzone badania społeczne. Technologie cyfrowe stosowane w komunikacji sprawiają, iż biblioteka staje się bliższa, bardziej dostępna, aby stać się w rezultacie partnerem dla stałych i nowych czytelników. Biblioteka Uniwersytecka w Poznaniu bierze udział w programach europejskich w zakresie katalogowania i digitalizacji zasobu biblioteki cyfrowej WBC, w zakresie wdrożenia nowych technologii i rozwiązań podnoszących jakość usług bibliotecznych, działalności kulturotwórczej (Poznańska Dyskusyjna Akademia Kominksu, deBiUty) i edukacji informacyjnej. Biblioteka Uniwersytecka w Poznaniu jest członkiem organizacji międzynarodowych: LIBER (Liga Europejskich Bibliotek Naukowych), IAML (Stowarzyszenie Bibliotek Muzycznych, Archiwów i Ośrodków Dokumentacji), CERL - Europejskie Konsorcjum Bibliotek Naukowych.

The use of two relations in L-fuzzy contexts

In the analysis of relations among the elements of two sets it is usual to obtain different values depending on the point of view from which these relations are measured. The main goal of the paper is the modelization of these situations by means of a generalization of the L-fuzzy concept analysis called L-fuzzy bicontext. We study the L-fuzzy concepts of these L-fuzzy bicontexts obtaining some interesting results. Specifically, we will be able to classify the biconcepts of the L-fuzzy bicontext. Finally, a practical case is developed using this new tool.

Fixed Point vs. First-Order Logic on Finite Ordered Structures with Unary Relations

We prove that first order logic is strictly weaker than fixed point logic over every infinite classes of finite ordered structures with unary relations: Over these classes there is always an inductive unary relation which cannot be defined by a first-order formula, even when every inductive sentence (i.e., closed formula) can be expressed in first-order over this particular class. Our proof first establishes a property valid for every unary relation definable by first-order logic over these classes which is peculiar to classes of ordered structures with unary relations. In a second step we show that this property itself can be expressed in fixed point logic and can be used to construct a non-elementary unary relation.

User-Level Sandboxing: a Safe and Efficient Mechanism for Extensibility

Extensible systems allow services to be configured and deployed for the specific needs of individual applications. This paper describes a safe and efficient method for user-level extensibility that requires only minimal changes to the kernel. A sandboxing technique is described that supports multiple logical protection domains within the same address space at user-level. This approach allows applications to register sandboxed code with the system, that may be executed in the context of any process. Our approach differs from other implementations that require special hardware support, such as segmentation or tagged translation look-aside buffers (TLBs), to either implement multiple protection domains in a single address space, or to support fast switching between address spaces. Likewise, we do not require the entire system to be written in a type-safe language, to provide fine-grained protection domains. Instead, our user-level sandboxing technique requires only paged-based virtual memory support, and the requirement that extension code is written either in a type-safe language, or by a trusted source. Using a fast method of upcalls, we show how our sandboxing technique for implementing logical protection domains provides significant performance improvements over traditional methods of invoking user-level services. Experimental results show our approach to be an efficient method for extensibility, with inter-protection domain communication costs close to those of hardware-based solutions leveraging segmentation.

Efficient End-Host Architecture for High Performance Communication Using User-level Sandboxing

Current low-level networking abstractions on modern operating systems are commonly implemented in the kernel to provide sufficient performance for general purpose applications. However, it is desirable for high performance applications to have more control over the networking subsystem to support optimizations for their specific needs. One approach is to allow networking services to be implemented at user-level. Unfortunately, this typically incurs costs due to scheduling overheads and unnecessary data copying via the kernel. In this paper, we describe a method to implement efficient application-specific network service extensions at user-level, that removes the cost of scheduling and provides protected access to lower-level system abstractions. We present a networking implementation that, with minor modifications to the Linux kernel, passes data between "sandboxed" extensions and the Ethernet device without copying or processing in the kernel. Using this mechanism, we put a customizable networking stack into a user-level sandbox and show how it can be used to efficiently process and forward data via proxies, or intermediate hosts, in the communication path of high performance data streams. Unlike other user-level networking implementations, our method makes no special hardware requirements to avoid unnecessary data copies. Results show that we achieve a substantial increase in throughput over comparable user-space methods using our networking stack implementation.

Determining WWW User's Next Access and Its Application to Pre-fetching

World-Wide Web (WWW) services have grown to levels where significant delays are expected to happen. Techniques like pre-fetching are likely to help users to personalize their needs, reducing their waiting times. However, pre-fetching is only effective if the right documents are identified and if user's move is correctly predicted. Otherwise, pre-fetching will only waste bandwidth. Therefore, it is productive to determine whether a revisit will occur or not, before starting pre-fetching. In this paper we develop two user models that help determining user's next move. One model uses Random Walk approximation and the other is based on Digital Signal Processing techniques. We also give hints on how to use such models with a simple pre-fetching technique that we are developing.

Reliability, Availability, Dependability and Performability: A User-centered View

Reliability and availability have long been considered twin system properties that could be enhanced by distribution. Paradoxically, the traditional definitions of these properties do not recognize the positive impact of recovery as distinct from simple repair and restart on reliability, nor the negative effect of recovery, and of internetworking of clients and servers, on availability. As a result of employing the standard definitions, reliability would tend to be underestimated, and availability overestimated. We offer revised definitions of these two critical metrics, which we call service reliability and service availability, that improve the match between their formal expression, and intuitive meaning. A fortuitous advantage of our approach is that the product of our two metrics yields a highly meaningful figure of merit for the overall dependability of a system. But techniques that enhance system dependability exact a performance cost, so we conclude with a cohesive definition of performability that rewards the system for performance that is delivered to its client applications, after discounting the following consequences of failure: service denial and interruption, lost work, and recovery cost.

BRITE: Universal Topology Generation from a User's Perspective

Effective engineering of the Internet is predicated upon a detailed understanding of issues such as the large-scale structure of its underlying physical topology, the manner in which it evolves over time, and the way in which its constituent components contribute to its overall function. Unfortunately, developing a deep understanding of these issues has proven to be a challenging task, since it in turn involves solving difficult problems such as mapping the actual topology, characterizing it, and developing models that capture its emergent behavior. Consequently, even though there are a number of topology models, it is an open question as to how representative the topologies they generate are of the actual Internet. Our goal is to produce a topology generation framework which improves the state of the art and is based on design principles which include representativeness, inclusiveness, and interoperability. Representativeness leads to synthetic topologies that accurately reflect many aspects of the actual Internet topology (e.g. hierarchical structure, degree distribution, etc.). Inclusiveness combines the strengths of as many generation models as possible in a single generation tool. Interoperability provides interfaces to widely-used simulation and visualization applications such as ns and SSF. We call such a tool a universal topology generator. In this paper we discuss the design, implementation and usage of the BRITE universal topology generation tool that we have built. We also describe the BRITE Analysis Engine, BRIANA, which is an independent piece of software designed and built upon BRITE design goals of flexibility and extensibility. The purpose of BRIANA is to act as a repository of analysis routines along with a user–friendly interface that allows its use on different topology formats.

An Efficient User-Level Shared Memory Mechanism for Application-Specific Extensions

This paper focuses on an efficient user-level method for the deployment of application-specific extensions, using commodity operating systems and hardware. A sandboxing technique is described that supports multiple extensions within a shared virtual address space. Applications can register sandboxed code with the system, so that it may be executed in the context of any process. Such code may be used to implement generic routines and handlers for a class of applications, or system service extensions that complement the functionality of the core kernel. Using our approach, application-specific extensions can be written like conventional user-level code, utilizing libraries and system calls, with the advantage that they may be executed without the traditional costs of scheduling and context-switching between process-level protection domains. No special hardware support such as segmentation or tagged translation look-aside buffers (TLBs) is required. Instead, our ``user-level sandboxing'' mechanism requires only paged-based virtual memory support, given that sandboxed extensions are either written by a trusted source or are guaranteed to be memory-safe (e.g., using type-safe languages). Using a fast method of upcalls, we show how our mechanism provides significant performance improvements over traditional methods of invoking user-level services. As an application of our approach, we have implemented a user-level network subsystem that avoids data copying via the kernel and, in many cases, yields far greater network throughput than kernel-level approaches.

SymbolDesign: A User-centered Method to Design Pen-based Interfaces and Extend the Functionality of Pointer Input Devices

A method called "SymbolDesign" is proposed that can be used to design user-centered interfaces for pen-based input devices. It can also extend the functionality of pointer input devices such as the traditional computer mouse or the Camera Mouse, a camera-based computer interface. Users can create their own interfaces by choosing single-stroke movement patterns that are convenient to draw with the selected input device and by mapping them to a desired set of commands. A pattern could be the trace of a moving finger detected with the Camera Mouse or a symbol drawn with an optical pen. The core of the SymbolDesign system is a dynamically created classifier, in the current implementation an artificial neural network. The architecture of the neural network automatically adjusts according to the complexity of the classification task. In experiments, subjects used the SymbolDesign method to design and test the interfaces they created, for example, to browse the web. The experiments demonstrated good recognition accuracy and responsiveness of the user interfaces. The method provided an easily-designed and easily-used computer input mechanism for people without physical limitations, and, with some modifications, has the potential to become a computer access tool for people with severe paralysis.