WSRF-based modeling of clinical trial information for collaborative cancer research

The CancerGrid consortium is developing open-standards cancer informatics to address the challenges posed by modern cancer clinical trials. This paper presents the service-oriented software paradigm implemented in CancerGrid to derive clinical trial information management systems for collaborative cancer research across multiple institutions. Our proposal is founded on a combination of a clinical trial (meta)model and WSRF (Web Services Resource Framework), and is currently being evaluated for use in early phase trials. Although primarily targeted at cancer research, our approach is readily applicable to other areas for which a similar information model is available.

High frequency sensing interrogation system using fiber Bragg grating based microwave photonic filtering

A high frequency sensing interrogation system by using fiber Bragg grating based microwave photonic filtering is proposed, in which the wavelength measurement sensitivity is proportional to the RF modulation frequency applied to the optical signal.

High-frequency fiber Bragg grating sensing interrogation system using Sagnac-loop-based microwave photonic filtering

A novel high-frequency fiber Bragg grating (FBG) sensing interrogation system by using fiber Sagnac-loop-based microwave photonic filtering is proposed and experimentally demonstrated. By adopting the microwave photonic filtering, the wavelength shift of sensing FBG can be converted into amplitude variation of the modulated electronic radio-frequency (RF) signal. In the experiment, the strain applied onto the sensing FBG has been demodulated by measuring the intensity of the recovered RF signal, and by modulating the RF signal with different frequencies, different interrogation sensitivities can be achieved.

An architecture for a collaborative authoring system

Collaborative working with the aid of computers is increasing rapidly due to the widespread use of computer networks, geographic mobility of people, and small powerful personal computers. For the past ten years research has been conducted into this use of computing technology from a wide variety of perspectives and for a wide range of uses. This thesis adds to that previous work by examining the area of collaborative writing amongst groups of people. The research brings together a number of disciplines, namely sociology for examining group dynamics, psychology for understanding individual writing and learning processes, and computer science for database, networking, and programming theory. The project initially looks at groups and how they form, communicate, and work together, progressing on to look at writing and the cognitive processes it entails for both composition and retrieval. The thesis then details a set of issues which need to be addressed in a collaborative writing system. These issues are then followed by developing a model for collaborative writing, detailing an iterative process of co-ordination, writing and annotation, consolidation, and negotiation, based on a structured but extensible document model. Implementation issues for a collaborative application are then described, along with various methods of overcoming them. Finally the design and implementation of a collaborative writing system, named Collaborwriter, is described in detail, which concludes with some preliminary results from initial user trials and testing.

Collaborative alliances and organisational innovation : a study of the innovation process

Despite the voluminous studies written about organisational innovation over the last 30-40 years our understanding of this phenomenon continues to be inconsistent and inconclusive (Wolfe, 1994). An assessment of the theoretical and methodological issues influencing the explanatory utility of many studies has led scholars (e.g. Slappendel, 1996) to re-evaluate the assumptions used to ground studies. Building on these criticisms the current study contributes to the development of an interactive perspective of organisational innovation. This work contributes empirically and theoretically to an improved understanding of the innovation process and the interaction between the realm of action and the mediating effects of pre-existing contingencies i.e. social control, economic exchange and the communicability of knowledge (Scarbrough, 1996). Building on recent advances in institutional theory (see Barley, 1986; 1990; Barley and Tolbert, 1997) and critical theory (Morrow, 1994, Sayer, 1992) the study aims to demonstrate, via longitudinal intensive research, the process through which ideas are translated into reality. This is significant because, despite a growing recognition of the implicit link between the strategic conduct of actors and the institutional realm in organisational analysis, there are few examples that theorise and empirically test these connections. By assessing an under researched example of technology transfer; the government's Teaching Company Scheme (TCS) this project provides a critique of the innovation process that contributes to theory and our appreciation of change in the UK government's premier technology transfer scheme (QR, 1996). Critical moments during the translation of ideas illustrate how elements that are linked to social control, economic exchange and communicability mediate the innovation process. Using analytical categories i.e. contradiction, slippage and dysfunctionality these are assessed in relation to the actions (coping strategies) of programme members over a two-year period. Drawing on Giddens' (1995) notion of the duality of structure this study explores the nature of the relationship between the task environment and institutional environment demonstrating how and why knowledge is both an enabler and barrier to organisational innovation.

Collaborative enterprise governance : sustainable management of inter-firm R&D relationships in the German car industry

This research reports on the appropriate governance, i.e. design and management, of inter-firm R&D relationships in order to achieve sustainable competitive success for the whole partnership as well as its individual members. An exploratory study in the German automotive industry using inductive Grounded Theory was conducted. This involved data collection via 28 semi-structured interviews with 16 companies in order to form a set of 35 tentative propositions that have been validated via a questionnaire survey receiving 110 responses from 52 companies. The research has resulted in the consolidation of the validated propositions into a novel concept termed Collaborative Enterprise Governance. The core of the concept is a competence based contingency framework that helps decision makers in selecting the most appropriate governance strategy (i.e. sourcing strategy) for an inter-firm R&D relationship between a buyer and its supplier. Thereby, the concept does not draw on whole company-to-company connectivity. It rather conceptualises an inter-firm relationship to be composed of autonomous cross-functional units of the individual partner companies that contribute value to a particular joint R&D project via the possession of task specific competencies. The novel concept and its elements have been evaluated in a focus group with industrial experts of the German automotive industry and revealed positive effects on the sustainable competitive success of the whole partnership and the individual partner companies. However, it also showed that current practice does not apply the right mechanisms for its implementation and hence guidelines for practitioners and decision makers involved in inter-firm R&D collaboration in the automotive industry are offered on how to facilitate the implementation and usage of the Collaborative Enterprise Governance philosophy.

The development of collaborative skills in young children

This thesis examines young children's early collaborative development when engaged in joint tasks with both a peer and a parent. It begins by examining how the term "collaborative" has been applied and researched in previous literature. As collaboration is found to usually require dialogue, and intersubjectivity is seen as an important component in the construction of both collaboration and dialogue, the ability to construct intersubjectivity is the subject of the rest of the chapter. The chapter concludes by introducing the research questions that underpin the experiments that follow. A number of experiments are then described. Experiments 1 and 2 investigate age differences in interaction styles and the communication strategies used by similar aged dyads. Experiments 3 and 4 investigate differences due to the age of the child and/or the status of the information giver (either parent or child) in the styles of interaction and the communication strategies used by parent and child dyads. Experiment 5 investigates the benefits of collaborating with a parent, and finally, Experiment 6 examines the collaborative ability of pre-schools. The thesis identifies a series of skills required for successful collaboration. These include recognition of a joint goal and the need to suppress individual desires, the ability to structure joint interaction, moving from role-based to a negotiating style, and communicative skills, for example, asking for clarification. Other reasons for children's failure in collaborative tasks involve task-related skills, such as the development of spatial terms, and failure to recognise the need for accuracy. The findings support Vygotsky's theory that when working with an adult, children perform at a higher level than when working with a peer. Evidence was also found of parents scaffolding the interaction for their children. However, further research is necessary to establish that such scaffolding skills affect the child's development of collaborative interactive skills.

The development of calibration and adaptive filtering procedures for neuromagnetic studies of human visual function

This thesis first considers the calibration and signal processing requirements of a neuromagnetometer for the measurement of human visual function. Gradiometer calibration using straight wire grids is examined and optimal grid configurations determined, given realistic constructional tolerances. Simulations show that for gradiometer balance of 1:104 and wire spacing error of 0.25mm the achievable calibration accuracy of gain is 0.3%, of position is 0.3mm and of orientation is 0.6°. Practical results with a 19-channel 2nd-order gradiometer based system exceed this performance. The real-time application of adaptive reference noise cancellation filtering to running-average evoked response data is examined. In the steady state, the filter can be assumed to be driven by a non-stationary step input arising at epoch boundaries. Based on empirical measures of this driving step an optimal progression for the filter time constant is proposed which improves upon fixed time constant filter performance. The incorporation of the time-derivatives of the reference channels was found to improve the performance of the adaptive filtering algorithm by 15-20% for unaveraged data, falling to 5% with averaging. The thesis concludes with a neuromagnetic investigation of evoked cortical responses to chromatic and luminance grating stimuli. The global magnetic field power of evoked responses to the onset of sinusoidal gratings was shown to have distinct chromatic and luminance sensitive components. Analysis of the results, using a single equivalent current dipole model, shows that these components arise from activity within two distinct cortical locations. Co-registration of the resulting current source localisations with MRI shows a chromatically responsive area lying along the midline within the calcarine fissure, possibly extending onto the lingual and cuneal gyri. It is postulated that this area is the human homologue of the primate cortical area V4.

Strong spectral filtering for a mode-locked similariton fiber laser

We propose a novel mode-locked fiber laser design that relies on attracting similariton solutions in fiber amplifiers with normal group-velocity dispersion and strong spectral filtering to compensate increased pulse duration and bandwidth. Stable high-energy, large-bandwidth pulses are obtained that can be linearly compressed, resulting in ultrashort pulses.

Projection and interpolation based techniques for structured and impulsive noise filtering

In this chapter we present the relevant mathematical background to address two well defined signal and image processing problems. Namely, the problem of structured noise filtering and the problem of interpolation of missing data. The former is addressed by recourse to oblique projection based techniques whilst the latter, which can be considered equivalent to impulsive noise filtering, is tackled by appropriate interpolation methods.

Repetition rate multiplication by phase-only filtering with multi-cavity optical structures

We propose several all-pass spectrally-periodic optical structures composed of simple optical cavities for the implementation of repetition rate multipliers of periodic pulse train with uniform output train envelope by phase-only filtering, and analyze them in terms of robustness and accuracy.

Adaptive congestion control of DSRC vehicle networks for collaborative road safety applications

Congestion control is critical for the provisioning of quality of services (QoS) over dedicated short range communications (DSRC) vehicle networks for road safety applications. In this paper we propose a congestion control method for DSRC vehicle networks at road intersection, with the aims of providing high availability and low latency channels for high priority emergency safety applications while maximizing channel utilization for low priority routine safety applications. In this method a offline simulation based approach is used to find out the best possible configurations of message rate and MAC layer backoff exponent (BE) for a given number of vehicles equipped with DSRC radios. The identified best configurations are then used online by an roadside access point (AP) for system operation. Simulation results demonstrated that this adaptive method significantly outperforms the fixed control method under varying number of vehicles. The impact of estimation error on the number of vehicles in the network on system level performance is also investigated.

Performance impact of asymmetric filtered 40Gb/s RZ DPSK system:tight optical filtering considerations

We present the impact of Asymmetric filtering of strong (e.g. 35 GHz) optical filters on the performance of 42.7 Gb/s 50% RZ-DPSK systems. The performance is evaluated when offsetting the filter by substantial amounts and it is found that with an offset of almost half the bit rate there is a significant improvement in the calculated Q.