Thermodynamic and spectroscopic measurements of the electron-hole drop binding energy in Ge: An old problem revisited

One can expect to get the electron-hole (EHD) binding energy φ either from spectroscopic or from threshold measurements. While the value obtained by the former is in excellent agreement with theory, the results given by the latter did not seem to lead to φ in a simple way. We present here new optical threshold studies in which we think that the right conditions to obtain a direct thermodynamic measurement of φ have been mastered. Besides, our results present novel features like a sharp jump of the EHD luminescence at threshold above 2.4 K and observation of hysteresis in the whole temperature range of our work.     

Shaping Minds Musically

Music is one of the most profound and enjoyable of human activities, yet much about it remains shrouded in mystery. Perhaps it is the combination of centrality and elusiveness that attracts an ever-growing number of psychologists, neuroscientists, neurologists, technologists, and musicians. This paper discusses two distinct but related areas — education and health — where we believe that new tools, concepts, and content can have a significant impact. Since 2001, our approach has been to bring together sophisticated and attractive new music, participatory musical activities that stimulate the creative imagination without requiring years of training, and innovative concepts about pedagogy and healing, to lay the foundations for a new field of 'active music'.     

Enterprise configuration management — controlling integration complexity

Greater use of flexible system architectures, and changes in product acquisition policy, are just two elements of delivery strategy that have led to a significant increase in systems integration scale and complexity. This has produced the need for a new approach to the way BT manages and controls system whole-life change. This paper describes a major BT initiative that will provide a configuration management environment capable of catering for many different viewpoints — from strategic planning through to operational deployment and eventual system withdrawal.     

Personal Virtual Humans — Inhabiting the TalkZone and beyond

One of the fundamental goals of graphics has always been to visually create a three-dimensional person that is indistinguishable from a real person. This target is only slightly short of being reached, as was demonstrated when Columbia Pictures released Final Fantasy in 2001, an animated science fiction film with high-definition emotive characters. Through what has been a cultural and technological convergence, we are now starting to see software tools and techniques that can generate life-like characters while not sacrificing the human judgement and artistic skills that are needed in character animation. Computer games, films, and the Internet are now starting to use virtual humans, which as our conclusion will show will become more realistic. However, a new challenge has been set — people now do not want to just play a computer game with a visually realistic character, or see a television programme with a vivid computer generated character — they want to see themselves in that computer game or film. The future is towards individuals having their own virtual clones, which they can utilise in computer-generated worlds an applications. This paper will discuss the advantages of having a personal computer-generated character, and also describe several systems that BTexact Technologies have successfully developed and deployed to generate them, as well as some of the applications for which they can be used. The paper will finish by glimpsing into the future of what we can expect to see in the next few years, with the advent of this new exciting technology.     

One-multiplier adaptive lattice algorithm for recursive filters

The formulation of one-multiplier lattice structures of the Gray-Markel type forinfinite impulse response filters is reviewed. Several special cases of this formulation — including the well-known Gray-Markel normalized lattice—are presented as scaled polynomial versions of the two-multiplier lattice. A new adaptive algorithm is presented for updating the parameters of one-multiplier lattice structured recursive filters. The LMS-based algorithm requires fewer computations than earlier reported algorithms [1]–[4].The research reported here was conducted with funds administered by the Naval Postgraduate School research council.     

The Socio-Economic Impact of Pervasive Computing — Intelligent Spaces and the Organisation of Business

Intelligent spaces (iSpaces) will change the way we live and work in the future. Although there are many visions of end-user applications, there has been much less attention on the impact of iSpaces on companies. Yet, iSpace technologies will have a profound effect, not only on the products and services offered, but also on the way companies are organised and managed. We look at three areas — the development of new organisational forms as a result of the emergence of complex services involving several companies working together, the need for successful companies to adopt management structures and systems that favour flexibility and adaptiveness in the face of a constantly changing market-place, and the impact of iSpaces on the way people work.iSpaces will break down the current boundaries that separate work, home and public spaces. A survey of attitudes toward the use of technology to mediate these boundaries was undertaken as part of the Eurescom project PROFIT. The results highlight concerns about non-independence, loss of control, security, privacy, and system failures that will need to be addressed if iSpaces are to experience wide-spread adoption.     

Extraction and evolution of Fowler-Nordheim tunneling parameters of thin gate oxides under EEPROM-like dynamic degradation

A new method is presented for the extraction of the Fowler-Nordheim (FN) tunneling parameters of thin gate oxides from experimental current-voltage characteristics of Metal-Oxide-Semiconductor (MOS) capacitors. In this technique, the classical low temperature FN current model is considered but an improved numerical procedure has been implemented for the calculation of the oxide electric field — gate voltage relationship. It is shown that this iterative method leads to an excellent fit of experimental data with theoretical curves for both p-type and n-type substrates, even in the case of high doping levels. The procedure allows the determination of both FN tunneling parameters and potential barrier heights at silicon and polysilicon interfaces with a systematic estimation of the statistical fitting errors on each parameter. It is applied here to the study of the variations of the FN tunneling parameters of thin oxides submitted to EEPROM-like dynamic degradation.     

A survey and performance evaluation of decentralized aggregation schemes for autonomic management

Over the last few years, autonomic network and service management has emerged as a serious alternative to traditional management approaches. In these systems, distributed entities, called autonomic managers, perform monitoring and control operations in an autonomous and decentralized way. The monitoring consists of providing indicators on the state of the system. Several monitoring solutions have been proposed to enable autonomic managers to obtain a partial or complete knowledge of an indicator through aggregation processes. Such a profusion of solutions raises important questions regarding the choice of an aggregation scheme in a particular operational context and for a particular management information because each class of solution presents different benefits and weaknesses. That is why, in this paper, we present the result of our study of decentralized aggregation schemes for autonomic network and service monitoring. The contribution is twofold: (i) a survey of decentralized aggregation schemes based on a refined taxonomy; and (ii) the results of an evaluation campaign we performed to compare typical aggregation schemes. These results highlight the context, in terms of the managed network behaviour as well as information dynamics, in which each aggregation scheme outperforms the others, thus helping autonomic management system designers in choosing the best scheme for their management purpose. Copyright © 2014 John Wiley & Sons, Ltd     

Desktop conversations — the future of multimedia conferencing

Both the recent explosion of interest in the Internet and the ongoing development of video-on-demand services have focused attention on the retrieval and delivery aspects of telecommunications networks. Yet the telephony network is fundamentally based on a much more basic human need — two-way communication. In fact, people normally communicate using conversation — interactive speech plus additional information in the form of non-verbal cues like body language.The underlying technologies and standards to enable the easy exchange of information in a conversational way are now converging — which brings together the fields of conferencing, multimedia, and telephony into a unified whole. This could well be the catalyst to turning data communications into the dominant conversational medium of the future.This paper looks at the ways that the desktop may soon rival the telephone as the natural route for carrying out a media-rich conversation with a remotely located person, and focuses on one example of a desktop conferencing application — Passepartout.     

Distributed objects and object databases

Due to the on-going shift from centralised to decentralised computing and a general trend towards the globalisation of commercial, economic and social activities, the information systems community has been faced with strong demands to develop distributed information systems (DISs) that span wide geographical areas. Three technologies have had significant impact on the new generation of DISs — distributed object technology, object database technology and Web technology. The paper examines two of these — DOT and ODBT. Each has advantages over the other, but more importantly they complement each other, and ways of using them together are explored.     

Advanced Multi-Objective Evolutionary Algorithms Applied to Two Problems in Telecommunications

Most research in optimisation is aimed at single objective problems, where the aim is to find a solution which maximises or minimises a single quality measure. However, as in nature, many problems in telecommunications are fundamentally multi-objective, particularly where the issues involved are related to quality of service, or cost/reliability trade-offs. There has been considerable research in multi-objective optimisation, but, until recently, the most prominently known multi-objective optimisation algorithms have tended to be rather slow, and there has been no universally accepted way to properly compare the performance of different methods. Here, we describe two evolutionary computation-based multi-objective optimisation methods which have recently been shown both to be considerably faster than the classical set of such methods, and to outperform existing methods on a wide range of test problems. We focus on two application areas in telecommunications — the adaptive distributed database management problem, and the offline-routeing problem. The speed and quality of these new methods suggest that their adoption in live applications of these and other telecommunications-related problems is feasible.     

Partial Key Recovery Attack Against RMAC

In this paper new “partial” key recovery attacks against the RMAC block cipher based Message Authentication Code scheme are described. That is we describe attacks that, in some cases, recover one of the two RMAC keys much more efficiently than previously described attacks. Although all attacks, but one, are of no major threat in practice, in some cases there is reason for concern. In particular, the recovery of the second RMAC key (of k bits) may only require around 2^k/2 block cipher operations (encryptions or decryptions). The RMAC implementation using triple DES proposed by NIST is shown to be very weak.     

The Stability, Scalability and Performance of Multi-agent Systems

Much has been published on the functional properties of multi-agent systems (MASs) including their co-ordination rationality and knowledge modelling. However, an important research area which has so far received only scant attention covers the non-functional properties of MASs which include performance, scalability and stability issues — clearly thes become increasingly important as the MAS field matures, and as more practical MASs become operational. An understanding of how to evaluate and assess such non-functional properties, and hence how to improve on them by altering the underlying MAS design, is gradually emerging as a pressing concern. This paper presents preliminary work to address such concerns; particularly, it investigates the performance and scalability of a multi-agent model we have developed.Firstly, this paper defines performance, scalability and stability within the context of multi-agent applications. Following, we describe a multi-agent model that we later use to illustrate our first attempts at evolving a procedure for analysing such non-functional properties of MASs. Next, we report on our initial attempts to investigate the performance and scalability of the multi-agent model. Finally, the significance of these results in particular and of such investigations in general is discussed.     

Electrical characterization of thiols self-assembled layers on GaP (1 1 1) structures

The experimental studies on III–V semiconductor compounds surface passivation phenomena are mainly dedicated to solve some technological problems as those regarding the ways to keep the chemical stability of native oxides on surfaces. Self-assembled monolayers (SAMs) provide a simple way to produce relatively ordered structures at a molecular scale, which seems to be capable to protect the clean surface against the evolution of oxidation process. In this respect, thin films of SAMs of aliphatic thiol (dodencanthiol—CH₃(CH₂)₁₁SH) and aromatic thiol (4, 4′ tiobisbenzenthiol-S (C₆H₄SH)₂ have been deposited on the surface of GaP (1 1 1) samples. The electrical properties measurements of some structures based on GaP compound was performed. There were recorded current–voltage (I–V) characteristics for complex structures AuGeNi/R-SH/GaP and AuGeNi/Ar-SH/GaP in darkness and also exposed to a Xe lamp. In dark and in “reverse bias” way, the I–V characteristics present the feature of a Zenner diode for GaP/Ar-SH and a gradual increase of current for GaP/R-SH. In dark and “in forward bias” way, the current increases as for a normal diode for both GaP/Ar-SH and GaP/R-SH structures. The complex structures (e.g.: In/AuGeNi/R-SH/GaP/R-SH/AuGeNi/In) are less sensitive to light. The SEM analysis performed on a GaP/R-SH surface shows a continuous packed up layer while GaP/Ar-SH looks like an inhomogeneous deposition of layers with different thickness regions. The diodes’ ideality factors determined from I–V characteristics are unusually high (n2) as a possible result of inhomogeneous Schottky contacts or due to ageing effects, in the field of degradation.     

EDI — The Grand Daddy of Electronic Commerce

Electronic data interchange (EDI) has been around for more than a decade. It addresses a fundamental and enduring business problem — the exchange of data between the computer systems of organisations. It is currently the cornerstone of a number of successful global companies. However, its future lies with new 'trusted third parties' which combine data management with public key infrastructure, offering enhanced message switching and message translation in response to market trends.'eBusiness' has a number of forms — business to consumer, now growing fast as 'Web-shopping', consumer to consumer, and business to business, the longest established. In the last category there is a major sub-area of 'upply-chain-driven' trading. This was the first area of automation and was initiated by the process-driven industries such as retail distribution, automotive manufacture and international logistics. Indeed, whole industries are today totally dependent on EDI-driven processes.     

Primitive Polynomials Over GF(2) of Degree up to 660 with Uniformly Distributed Coefficients

New tables of primitive polynomials of degree up to 660 over the Galois field of 2 elements are provided. These polynomials have been obtained for ring generators—a new class of linear feedback shift registers featuring enhanced properties over conventional shift registers. For each degree polynomials with five, seven and nine nonzero coefficients are presented. The coefficients are uniformly separated from each other so that the resulting implementations are highly modular.     

The Future of Work — Understanding the Role of Technology

The twentieth century has seen many major changes in the nature of work and its role in people's lives. Organisational change has been driven by dramatic changes in the economic and social climate during this period. This is happening at an increasingly rapid rate as we enter the new century. This paper reviews current trends in the world of work. It will focus on the increasing dispersal of the workforce and how communications technology makes possible working arrangements which were previously unthinkable. BT aims to design future products and services which address the real needs of people working in the future. This is being tackled by building up a fundamental understanding of the issues affecting relationships between individuals and organisations, and the potential impact of computer-mediated communications technology on these relationships. This paper focuses on the work that has been done to understand the issue of trust, a key element of the way that people relate to each other at work. This research has culminated in the definition of a theoretical model of trust which has been used to analyse two particular practical studies — a long-term flexible working trial and a series of trials with innovative desktop conferencing tools.     

Media Fabric — A Process-Oriented Approach to Media Creation and Exchange

This paper explores the emergence of a new paradigm we call the 'media fabric' — a semi-intelligent organism consisting of a vast and evolving collection of media artefacts, structures and programs that support our engagement in meaningful real-time dialogues, art making, and social interaction. Situated in and around modern communications networks, the media fabric beckons us into an evolving landscape of creative story potential that is synergistic with our imagination, integral to our everyday life, mindful of itself and our intentions, improvisationally shaped, and provides us with interactions and remaindered artefacts that are evocative and self-reflective.