16266061
Knowledge Management for a Large Service-Oriented Corporation
The design and maintenance of complex engineering systems such as a jet engine generates a significant amount of documentation. Increasingly, aerospace manufacturers are shifting their focus from selling products to providing services. As a result, when designing new products, engineers must increasingly consider the engine's complete life-cycle as part of the design process. To identify possible areas of concern, engineers must obtain knowledge gained from the entire life of similar engines. However, because of the size and distributed nature of the company's operation, engineers often do not have access to front-line maintenance data. In addition, the large number of documents accrued makes it impossible for them to be examined thoroughly. This paper presents a prototype knowledge-based document repository for such an application. It searches and analyzes distributed document resources, and provides engineers with a summary view of the underlying knowledge. The aim is to allow engineers to incorporate maintenance issues into the initial design. Unlike existing document repositories and digital libraries, our approach is knowledge-based, where users browse summary reports instead of following suggested links. To test the validity of our proposed architecture, we have developed and deployed a working prototype.
1615788
Provenance-based validation of e-science experiments
E-science experiments typically involve many distributed services maintained by different organisations. After an experiment has been executed, it is useful for a scientist to verify that the execution was performed correctly or is compatible with some existing experimental criteria or standards, not necessarily anticipated prior to execution. Scientists may also want to review and verify experiments performed by their colleagues. There are no existing frameworks for validating such experiments in today's e-science systems. Users therefore have to rely on error checking performed by the services, or adopt other ad hoc methods. This paper introduces a platform-independent framework for validating workflow executions. The validation relies on reasoning over the documented provenance of experiment results and semantic descriptions of services advertised in a registry. This validation process ensures experiments are performed correctly, and thus results generated are meaningful. The framework is tested in a bioinformatics application that performs protein compressibility analysis.
44354930
Cluster Computing and Grid 2005 Works in Progress
This is the second in a two-part series () of works-in-progress articles taken from a special session, which was part of the Cluster Computing and Grid 2005 conference (http://www.cs.cf.ac.uk/ccgrid2005), held in Cardiff, UK. The session was organized by Mark Baker (University of Portsmouth, UK) and Daniel S. Katz (Jet Propulsion Laboratory, US). For more information, you can contact the session organizers or the authors of the articles.
16395036
A Distributed Approach to Musical Composition
Current techniques for automated composition use a single algorithm, focusing on one aspect of musical generation. In our system we make use of several algorithms, distributed using an agent oriented middleware, with each specialising on a separate aspect of composition. This paper describes the architecture and algorithms behind this system, with a focus on the agent framework used for implementation. We show early results which encourage a future application of this framework in automated music composition and analysis.
8272641
Provenance-Based Validation of E-Science Experiments
E-Science experiments typically involve many distributed services maintained by different organisations. After an experiment has been executed, it is useful for a scientist to verify that the execution was performed correctly or is compatible with some existing experimental criteria or standards. Scientists may also want to review and verify experiments performed by their colleagues. There are no exsiting frameworks for validating such experiments in today's e-Science systems. Users therefore have to rely on error checking performed by the services, or adopt other ad hoc methods. This paper introduces a platform-independent framework for validating workflow executions. The validation relies on reasoning over the documented provenance of experiment results and semantic descriptions of services advertised in a registry. This validation process ensures experiments are performed correctly, and thus results generated are meaningful. The framework is tested in a bioinformatics application that performs protein compressibility analysis.
1798644
Complete Coverage by Mobile Robots Using Slice Decomposition Based on Natural Landmarks
In applications such as vacuum cleaning, painting, demining and foraging, a mobile robot must cover an unknown surface. The efficiency and completeness of coverage is improved by the construction of a map while the robot covers the surface. Existing methods generally use grid maps, which are susceptible to odometry error and may require considerable memory and computation. We propose a new "slice decomposition" ideally suited to coverage by a simple zigzag path. Cell boundaries are large, easily detectable natural landmarks. Therefore, the decomposition is robust against uncertainty in sensors. It can also handle a wider variety of environments. The proposed method has been evaluated using simulation and real robot experiments.
37815796
An architectural infrastructure and topological optimization for end system multicast
Although IP-multicast has been proposed and investigated for the some time, there are major problems inherent in the IP-multicasting technique, for example, scalability problems, difficulty to allocate a globally unique multicast address, complexity to support higher level features such as reliable data transfer congestion/flow control and security, and more importantly, deployment problem due to architectural changes to core routers. Recently, end-system multicast (ESM) has been proposed as an alternative solution so that multicasting services can be quickly deployed. In this paper we consider the "architectural" and "optimization " issues on designing an ESM-tree. Specifically, we present a distributed algorithm on how to create and maintain an ESM-tree. We also propose a distributed algorithm to perform a tree optimization (TO) so that an ESM-tree can dynamically adapt to the changing network condition (e.g., drop in transfer bandwidth) so that nodes can receive the multicast data more efficiently. The propose distributed algorithm has the theoretical properties that at all times, a tree-topology can be maintained and that any node joining, leaving, as well as any tree optimization operation will not "partition" an ESM-tree. Therefore, our work can be used to provide an efficient architectural infrastructure for ESM services. We have implemented a prototype ESM system and carried out experiments to illustrate the effectiveness and performance of our ESM optimization protocol.
46438966
76-Space analysis of grey matter diffusivity: Methods and applications
Diffusion Weighted Imaging (DWI) and Diffusion Tensor Imaging (DTI) are widely used in the study and diagnosis of neurological diseases involving the White Matter (WM). However, many neurological and neurodegenerative diseases (e.g., Alzheimer's disease and Creutzfeldt-Jakob disease) are generally considered to involve the Grey Matter (GM). Investigation of GM diffusivity of normal aging and pathological brains has both scientific significance and clinical applications. Most of previous research reports on quantification of GM diffusivity were based on the manually labeled Region of Interests (ROI) analysis of specific neuroanatomic regions. The well-known drawbacks of ROI analysis include inter-rater variations, irreproducible results, tediousness, and requirement of a priori definition of interested regions. In this paper, we present a new framework of automated 76-space analysis of GM diffusivity using DWI/DTI. The framework will be evaluated using clinical data, and applied for study of normal brain, Creutzfeldt-Jakob disease and Schizophrenia.
2761285
Continuous Gesture Recognition using a Sparse Bayesian Classifier
An approach to recognise and segment 9 elementary gestures from a video input is proposed and it can be applied to continuous sign recognition. An isolated gesture is recognised by first converting a portion of video into a motion gradient orientation image and then classifying it into one of the 9 gestures by a sparse Bayesian classifier. The portion of video used is decided by using a sampling technique based on condensation framework. By doing so, gestures can be segmented from the video in a probabilistic manner. Experiments show that the proposed method can achieve accuracy around 90% in both isolated and continuous gesture recognition without using special equipment such as glove devices and the system can run in real-time
12209522
Workflow-enabled distributed component-based information architecture for digital medical imaging enterprises
Few information systems today offer a flexible means to define and manage the automated part of radiology processes, which provide clinical imaging services for the entire healthcare organization. Even fewer of them provide a coherent architecture that can easily cope with heterogeneity and inevitable local adaptation of applications and can integrate clinical and administrative information to aid better clinical, operational, and business decisions. We describe an innovative enterprise architecture of image information management systems to fill the needs. Such a system is based on the interplay of production workflow management, distributed object computing, Java and Web techniques, and in-depth domain knowledge in radiology operations. Our design adapts the approach of "4+1" architectural view. In this new architecture, PACS and RIS become one while the user interaction can be automated by customized workflow process. Clinical service applications are implemented as active components. They can be reasonably substituted by applications of local adaptations and can be multiplied for fault tolerance and load balancing. Furthermore, the workflow-enabled digital radiology system would provide powerful query and statistical functions for managing resources and improving productivity. This paper will potentially lead to a new direction of image information management. We illustrate the innovative design with examples taken from an implemented system.
7975007
Optimum design of very low distortion class E power amplifiers
In this paper, the optimum design of a class E power amplifier with resonant tank being symmetrically driven by two class E circuits is studied. The optimally designed symmetrical class E circuit has extremely low harmonic distortion, and the load matching network (if required) is non-critical and can be designed with ease. Practical steady-state design equations are derived and graphically presented. Experimental circuits are constructed for distortion evaluation.