12,939 research outputs found

    Off-line computing for experimental high-energy physics

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    The needs of experimental high-energy physics for large-scale computing and data handling are explained in terms of the complexity of individual collisions and the need for high statistics to study quantum mechanical processes. The prevalence of university-dominated collaborations adds a requirement for high-performance wide-area networks. The data handling and computational needs of the different types of large experiment, now running or under construction, are evaluated. Software for experimental high-energy physics is reviewed briefly with particular attention to the success of packages written within the discipline. It is argued that workstations and graphics are important in ensuring that analysis codes are correct, and the worldwide networks which support the involvement of remote physicists are described. Computing and data handling are reviewed showing how workstations and RISC processors are rising in importance but have not supplanted traditional mainframe processing. Examples of computing systems constructed within high-energy physics are examined and evaluated

    Areas of outstanding natural beauty management plans - a guide

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    This is a summary of the guidance produced by the Countryside Agency to assist local authorities, AONB staff units, AONB partners and others concerned with the production and implementation of AONB Management Plans in England. A parallel text has been produced by the Countryside Council for Wales to cover Welsh AONBs. The aims of the guide are to: • assist local authorities and conservation boards to discharge their statutory functions with regard to the production of AONB Management Plans; • help ensure that Management Plans that are produced are appropriate to the needs of the AONB, have the commitment of all AONB partners1 and other stakeholders, are implemented, and their policy objectives achieved. The guide is has statutory force under the 2001 Countryside and Rights of Way Ac

    Analysis of approximate nearest neighbor searching with clustered point sets

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    We present an empirical analysis of data structures for approximate nearest neighbor searching. We compare the well-known optimized kd-tree splitting method against two alternative splitting methods. The first, called the sliding-midpoint method, which attempts to balance the goals of producing subdivision cells of bounded aspect ratio, while not producing any empty cells. The second, called the minimum-ambiguity method is a query-based approach. In addition to the data points, it is also given a training set of query points for preprocessing. It employs a simple greedy algorithm to select the splitting plane that minimizes the average amount of ambiguity in the choice of the nearest neighbor for the training points. We provide an empirical analysis comparing these two methods against the optimized kd-tree construction for a number of synthetically generated data and query sets. We demonstrate that for clustered data and query sets, these algorithms can provide significant improvements over the standard kd-tree construction for approximate nearest neighbor searching.Comment: 20 pages, 8 figures. Presented at ALENEX '99, Baltimore, MD, Jan 15-16, 199

    Surface finish control by electrochemical polishing in stainless steel 316 pipes

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    Electrochemical machining (ECM) is a non-conventional machining process which is based on the localised anodic dissolution of any conductive material. One of the main applications of ECM is the polishing of materials with enhanced characteristics, such as high strength, heat-resistance or corrosion-resistance, i.e. electrochemical polishing. The present work presents an evaluation of the parameters involved in the ECM of Stainless Steel 316 (SS316) with the objective of predicting the resulting surface finish on the sample. The interest of studying ECM on SS316 resides on the fact that a repeatable surface finish is not easily achieved. ECM experimental tests on SS316 pipes of 1.5" (0.0381 m) diameter were conducted by varying machining parameters such as voltage, interelectrode gap, electrolyte inlet temperature, and electrolyte flow rate. The surface finish of the samples was then evaluated in order to find the significance of each of these parameters on the surface quality of the end product. Results showed that overvoltage, which is dependent on the interelectrode gap and the electrolyte temperature, is one of the main parameters affecting the surface finish; additionally there is a strong relationship between the resulting surface finish and the electrolyte flow. The interelectrode gap and inlet electrolyte temperature also affect the resulting surface finish but their influence was not so evident in this work. Finally, the variation of the electrolyte temperature during the process was found to have a great impact on the uniformity of the surface finish along the sample. We believe that this contribution enables the tailoring of the surface finish to specific applications while reducing manufacturing costs and duration of the ECM process

    Techniques for using diazo materials in remote sensor data analysis

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    The use of data derived from LANDSAT is facilitated when special products or computer enhanced images can be analyzed. However, the facilities required to produce and analyze such products prevent many users from taking full advantages of the LANDSAT data. A simple, low-cost method is presented by which users can make their own specially enhanced composite images from the four band black and white LANDSAT images by using the diazo process. The diazo process is described and a detailed procedure for making various color composites, such as color infrared, false natural color, and false color, is provided. The advantages and limitations of the diazo process are discussed. A brief discussion interpretation of diazo composites for land use mapping with some typical examples is included

    The Change Process: Clients' Perspectives and Understanding of Change During Psychological Therapy

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    Background: Talking therapies, predominantly Cognitive Behaviour Therapy (CBT), represent a key approach to supporting mental health distress in the UK. CBT is beneficial for many individuals, yet it is common to ‘relapse’ and there are a significant number of individuals for whom it is unhelpful. Although research can evidence its effectiveness, decades of studies have yet to find clarity on the change mechanisms, the central tenet of therapy. Researchers propose that understanding how therapy works is a complex multifactorial process that has perhaps been skewed by a dominant quantitative approach. As the site of change and largest contributing variable of change, clients’ viewpoint is considered critical to the success of therapy. However, clients' perspective of how therapy works is limited and conflicting within the literature. Aims: To gain clients’ perspectives by exploring their understanding of how change occurs in therapy, as well as exploring how clients define change in therapy. Method: Drawing on a critical realist approach, this study utilised qualitative methods. Ten self-selecting participants who experienced positive change through CBT in NHS secondary care services partook in semi-structured interviews. Interview transcripts were analysed using Thematic Analysis. Results: Three main themes were identified from participants accounts: ‘Change as changeable’, ‘External help’ and ‘It’s not magic’. Conclusions: Findings highlighted the nonlinear, dynamic, complex and individualised process of change in therapy. A working definition of participants’ understanding of change has been offered, which can be utilised in research, policy and practice. Participants emphasised common factors of change. A Perceptual Control Theory framework was considered as one possible explanation of participants’ experiences as it was able to account for descriptions of change more than other theories. Implications of the study and further research ideas have been presented
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