Mixed partitions of sets of triples into small planes

We continue our study of partitions of the set of all ((v)(3)) triples chosen from a v-set into pairwise disjoint planes with three points per line. We develop further necessary conditions for the existence of partitions of such sets into copies of PG(2, 2) and copies of AG(2, 3), and deal with the cases v = 13, 14, 15 and 17. These partitions, together with those already known for v = 12, 16 and 18, then become starters for recursive constructions of further infinite families of partitions. (C) 2004 Elsevier B.V. All rights reserved.

The utility and limitations of chloroplast DNA analysis for identifying native British oak stands and for guiding replanting strategy

We report a method using variation in the chloroplast genome (cpDNA) to test whether oak stands of unknown provenance are of native and/or local origin. As an example, a sample of test oaks, of mostly unknown status in relation to nativeness and localness, were surveyed for cpDNA type. The sample comprised 126 selected trees, derived from 16 British seed stands, and 75 trees, selected for their superior phenotype (201 tree samples in total). To establish whether these two test groups are native and local, their cpDNA type was compared with that of material from known autochthonous origin (results of a previous study which examined variation in 1076 trees from 224 populations distributed across Great Britain). In the previous survey of autochthonous material, four cpDNA types were identified as native; thus if a test sample possessed a new haplotype then it could be classed as non-native. Every one of the 201 test samples possessed one of the four cpDNA types found within the autochthonous sample. Therefore none could be proven to be introduced and, on this basis, was considered likely to be native. The previous study of autochthonous material also found that cpDNA variation was highly structured geographically and, therefore, if the cpDNA type of the test sample did not match that of neighbouring autochthonous trees then it could be considered to be non-local. A high proportion of the seed stand group (44.2 per cent) and the phenotypically superior trees (58.7 per cent) possessed a cpDNA haplotype which matched that of the neighbouring autochthonous trees and, therefore, can be considered as local, or at least cannot be proven to be introduced. The remainder of the test sample could be divided into those which did not grow in an area of overall dominance (18.7 per cent of seed stand trees and 28 per cent of phenotypically superior) and those which failed to match the neighbouring autochthonous haplotype (37.1 per cent and 13.3 per cent, respectively). Most of the non-matching test samples were located within 50 km of an area dominated by a matching autochthonous haplotype (96.0 per cent and 93.5 per cent, respectively), and potentially indicates only local transfer. Whilst such genetic fingerprinting tests have proven useful for assessing the origin of stands of unknown provenance, there are potential limitations to using a marker from the chloroplast genome (mostly adaptively neutral) for classifying seed material into categories which have adaptive implications. These limitations are discussed, particularly within the context of selecting adaptively superior material for restocking native forests.

A framework of lessons learned from community-based marine reserves and its effectiveness in guiding a new coastal management initiative in the Philippines

Community-based coastal resource management has been widely applied within the Philippines. However, small-scale community-based reserves are often inefficient owing to management inadequacies arising because of a lack of local support or enforcement or poor design. Because there are many potential pitfalls during the establishment of even small community-based reserves, it is important for coastal managers, communities, and facilitating institutions to have access to a summary of the key factors for success. Reviewing relevant literature, we present a framework of lessons learned during the establishment of protected areas, mainly in the Philippines. The framework contains summary guidance on the importance of (1) an island location, (2) small community population size, (3) minimal effect of land-based development, (4) application of a bottom-up approach, (5) an external facilitating institution, (6) acquisition of title, (7) use of a scientific information database, (8) stakeholder involvement, (9) the establishment of legislation, (10) community empowerment, (11) alternative livelihood schemes, (12) surveillance, (13) tangible management results, (14) continued involvement of external groups after reserve establishment, and (15) small-scale project expansion. These framework components guided the establishment of a community-based protected area at Danjugan Island, Negros Occidental, Philippines. This case study showed that the framework was a useful guide that led to establishing and implementing a community-based marine reserve. Evaluation of the reserve using standard criteria developed for the Philippines shows that the Danjugan Island protected area can be considered successful and sustainable. At Danjugan Island, all of the lessons synthesized in the framework were important and should be considered elsewhere, even for relatively small projects. As shown in previous projects in the Philippines, local involvement and stewardship of the protected area appeared particularly important for its successful implementation. The involvement of external organizations also seemed to have a key role in the success of the Danjugan Island project by guiding local decision-makers in the sociobiological principles of establishing protected areas. However, the relative importance of each component of the framework will vary between coastal management initiatives both within the Philippines and across the wider Asian region.

Edge-to-edge matching model for predicting orientation relationships and habit planes-the improvements

The edge-to-edge matching model has been further developed along with the Cu/Cr system as an example. The conditions for zigzag atom rows to be matching directions are included and the critical value of interatomic spacing misfit along matching directions and the critical value of d-value mismatch between matching planes are proposed in the new version of the model. (c) 2005 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Guiding local regression using visualisation

Solving many scientific problems requires effective regression and/or classification models for large high-dimensional datasets. Experts from these problem domains (e.g. biologists, chemists, financial analysts) have insights into the domain which can be helpful in developing powerful models but they need a modelling framework that helps them to use these insights. Data visualisation is an effective technique for presenting data and requiring feedback from the experts. A single global regression model can rarely capture the full behavioural variability of a huge multi-dimensional dataset. Instead, local regression models, each focused on a separate area of input space, often work better since the behaviour of different areas may vary. Classical local models such as Mixture of Experts segment the input space automatically, which is not always effective and it also lacks involvement of the domain experts to guide a meaningful segmentation of the input space. In this paper we addresses this issue by allowing domain experts to interactively segment the input space using data visualisation. The segmentation output obtained is then further used to develop effective local regression models.

Using DEA and simulation in guiding operating units to improved performance

The potential for the use of DEA and simulation in a mutually supporting role in guiding operating units to improved performance is presented. An analysis following a three-stage process is suggested. Stage one involves obtaining the data for the DEA analysis. This can be sourced from historical data, simulated data or a combination of the two. Stage two involves the DEA analysis that identifies benchmark operating units. In the third stage simulation can now be used in order to offer practical guidance to operating units towards improved performance. This can be achieved by the use of sensitivity analysis of the benchmark unit using a simulation model to offer direct support as to the feasibility and efficiency of any variations in operating practices to be tested. Alternatively, the simulation can be used as a mechanism to transmit the practices of the benchmark unit to weaker performing units by building a simulation model of the weaker unit to the process design of the benchmark unit. The model can then compare performance of the current and benchmark process designs. Quantifying improvement in this way provides a useful driver to any process change initiative that is required to bring the performance of weaker units up to the best in class. © 2005 Operational Research Society Ltd. All rights reserved.

The Audit Commission:guiding, steering and regulating local government

How does the non-executant state ensure that its agents are fulfilling their obligations to deliver nationally determined policies? In the case of elected local government in England and Wales, this function is carried out by the Audit Commission (AC) for Local Authorities and the Health Service for England and Wales. Since being established in 1983, it is the means by which local authorities are held to account by central government, both for its own purposes and on behalf of other interested stakeholders. Although the primary function of the AC is to ensure that local authorities are fulfilling their obligations, it does so by using different methods. By acting as a regulator, an independent expert, an opinion former and a mediator, the AC steers local authorities to ensure that they are compliant with the regulatory regime and are implementing legislation properly.

Simulation of guiding-centre soliton transmission system stability in the presence of polarisation mode dispersion

Results of full numerical simulations of a guiding-centre soliton system with randomly birefringent SMF fibre are shown and analysed. It emerges that the soliton system becomes unstable even for small amounts of PMD.

Method for characterisation of weakly guiding waveguides by measuring mode field diameter

In this paper, we described an efficient theoretical approach to determine the integral characteristics such as Mode Field Diameter (MFD) and V-parameter of the Weakly guiding waveguides. To test the described method we measured MFD for the commercially available step index single mode fibre with known parameters. The results of these measurements are presented for two different wavelengths. It is worth noting that the developed approach implies infinite cladding, thus care should be taken to avoid influence of finiteness of cladding when MFD compares to cladding diamete.

Gravity field recovery using two low satellites in different orbital planes

This study is concerned with gravity field recovery from low-low satellite to satellite range rate data. An improvement over a coplanar mission is predicted in the errors associated with certain parts of the geopotential by the separation of the orbital planes of the two satellites. Using Hill's equations an analytical scheme to model the range rate residuals is developed. It is flexible enough to model equally well the residuals between pairs of satellites in the same orbital plane or whose planes are separated in right ascension. The possible benefits of such an orientation to gravity field recovery from range rate data can therefore be analysed, and this is done by means of an extensive error analysis. The results of this analysis show that for an optimal planar mission improvements can be made by separating the satellites in right ascension. Gravity field recoveries are performed in order to verify and gauge the limitations of the analytical model, and to support the results of the error analysis. Finally the possible problem of the differential decay rates of two satellites due to the diurnal bulge are evaluated.