Chain: A Dynamic Double Auction Framework for Matching Patient Agents

In this paper we present and evaluate a general framework for the design of truthful auctions for matching agents in a dynamic, two-sided market. A single commodity, such as a resource or a task, is bought and sold by multiple buyers and sellers that arrive and depart over time. Our algorithm, Chain, provides the first framework that allows a truthful dynamic double auction (DA) to be constructed from a truthful, single-period (i.e. static) double-auction rule. The pricing and matching method of the Chain construction is unique amongst dynamic-auction rules that adopt the same building block. We examine experimentally the allocative efficiency of Chain when instantiated on various single-period rules, including the canonical McAfee double-auction rule. For a baseline we also consider non-truthful double auctions populated with zero-intelligence plus"-style learning agents. Chain-based auctions perform well in comparison with other schemes, especially as arrival intensity falls and agent valuations become more volatile

Generalizing Boolean Satisfiability III: Implementation

This is the third of three papers describing ZAP, a satisfiability engine that substantially generalizes existing tools while retaining the performance characteristics of modern high-performance solvers. The fundamental idea underlying ZAP is that many problems passed to such engines contain rich internal structure that is obscured by the Boolean representation used; our goal has been to define a representation in which this structure is apparent and can be exploited to improve computational performance. The first paper surveyed existing work that (knowingly or not) exploited problem structure to improve the performance of satisfiability engines, and the second paper showed that this structure could be understood in terms of groups of permutations acting on individual clauses in any particular Boolean theory. We conclude the series by discussing the techniques needed to implement our ideas, and by reporting on their performance on a variety of problem instances

Marine Isotope Stage 11c in Europe: Recent advances in marine–terrestrial correlations and their implications for interglacial stratigraphy – a review

The interglacial known as MIS 11c (c. 426 000–396 000 years ago) receives intensive international interest because of its perceived role as an analogue for the current interglacial and its importance for understanding future climate change. Here we review the current understanding of the stratigraphy of this interglacial in Europe. This study considers (i) the evidence for the environmental history of this interglacial as reconstructed from the varved lake records from northern Europe, (ii) the climate history of MIS 11c as preserved in the long pollen records of southern Europe and (iii) a comparison of both of these with marine records from the North Atlantic. The result of this review is a discussion of the evidence for millennial and centennial scale climate change found in European records of MIS 11c, the patterns of warming that are seen across this interglacial and the discrepancy in aspects of the duration of this interglacial that seems to exist between the marine and terrestrial records of this warm period. A review of the recent advances in the study of MIS 11c in Europe confirms its importance for understanding both the past evolution of the Holocene and the future patterns of long-term climate change

Evaluating palliative care training in the oncology registrar programme in South Africa

Background. Following a World Health Assembly call in 2014 to strengthen palliative care, the South African (SA) Department of Health approved this strategy as part of the SA National Policy Framework and Strategy on Palliative Care. In 2016, the University of Cape Town, together with the College of Radiation Oncology of SA, identified the need to integrate palliative care (PC) into the oncology curriculum. In collaboration with the Cancer Association of SA, a research project was developed to introduce a 12-module curriculum at five teaching hospitals. The aim of this research was to evaluate the impact of a 1-year PC course within the training programme for specialist oncologists in SA. Objective. To determine the reaction of oncology registrars and their supervisors to the course to determine changes in knowledge and skills, and to determine the application in oncology practice. Methods. This study was a mixed-method prospective evaluation of an educational intervention. The educational programme used a blended learning method to train and support registrars (n=32) and facilitators (n=5) across five universities from August 2017 to September 2018. Evaluation feedback was electronically collected to determine the registrars’ reactions to the course materials. Pre and post multiple-choice questions (MCQs) were used to review their knowledge. Focus group discussions (FGDs) were used to explore reactions, change in knowledge and skills and how registrars integrated PC into their daily work. Results. There was an overwhelmingly positive reaction to the PC course by the oncology registrars and their supervisors. The training was found to be feasible, and the topics addressed appropriate. Concerns previously raised by the College of Radiation Oncology of SA regarding the feasibility and appropriateness of the course and material were found to be unsubstantiated. The poor MCQ results can be ascribed to poor sequencing of the execution of the question. However, the MCQs in modules 7 and 8 (symptom management) demonstrated the most significant change in knowledge and skills (symptom management). The FGDs demonstrated a perceived change in knowledge and skills, especially for communication skills and pain and symptom management. The FGDs also indicated that the registrars’ approach to PC changed in that they were able to integrate the principles of PC into practice, and now saw PC as an essential component of oncology. Lastly, registrars and their supervisors felt that the course addressed topics that formed part of their daily clinical work. Conclusion. This research supports the view that PC training is an essential component of oncology training in the SA setting. PC forms part of the daily practice of oncologists, and a structured curriculum prepares clinicians to be able to integrate evidence-based PC into the practice of oncology if they receive appropriate training. Supervisors of the oncology training programme and registrars are confident that the training of 12 modules across 1 year is feasible and appropriate

A selected ion flow tube study of the ion-molecule reactions of monochloroethene, trichloroethene and tetrachloroethene

Data for the rate coefficients and product cations of the reactions of a large number of atomic and small molecular cations with monochloroethene, trichloroethene and tetrachloroethene in a selected ion flow tube at 298 K are reported. The recombination energy of the ions range from 6.27 eV (H$_3$O$^+$) through to 21.56 eV (Ne$^+$). Collisional rate coefficients are calculated by modified average dipole orientation theory and compared with experimental values. Thermochemistry and mass balance predict the most feasible neutral products. Together with previously reported results for the three isomers of dichloroethene (J. Phys. Chem. A., 2006, 110, 5760), the fragment ion branching ratios have been compared with those from threshold photoelectron photoion coincidence spectroscopy over the photon energy range 9-22 eV to determine the importance or otherwise of long-range charge transfer. For ions with recombination energy in excess of the ionisation energy of the chloroethene, charge transfer is energetically allowed. The similarity of the branching ratios from the two experiments suggest that long-range charge transfer is dominant. For ions with recombination energy less than the ionisation energy, charge transfer is not allowed; chemical reaction can only occur following formation of an ion-molecule complex, where steric effects are more significant. The products that are now formed and their percentage yield is a complex interplay between the number and position of the chlorine atoms with respect to the C=C bond, where inductive and conjugation effects can be important

Reducing inconsistencies in point observations of maximum flood inundation level

Flood simulation models and hazard maps are only as good as the underlying data against which they are calibrated and tested. However, extreme flood events are by definition rare, so the observational data of flood inundation extent are limited in both quality and quantity. The relative importance of these observational uncertainties has increased now that computing power and accurate lidar scans make it possible to run high-resolution 2D models to simulate floods in urban areas. However, the value of these simulations is limited by the uncertainty in the true extent of the flood. This paper addresses that challenge by analyzing a point dataset of maximum water extent from a flood event on the River Eden at Carlisle, United Kingdom, in January 2005. The observation dataset is based on a collection of wrack and water marks from two postevent surveys. A smoothing algorithm for identifying, quantifying, and reducing localized inconsistencies in the dataset is proposed and evaluated showing positive results. The proposed smoothing algorithm can be applied in order to improve flood inundation modeling assessment and the determination of risk zones on the floodplain

Investigation of shock waves in explosive blasts using fibre optic pressure sensors

The published version of this article may be accessed at the link below. Copyright @ IOP Publishing, 2006.We describe miniature all-optical pressure sensors, fabricated by wafer etching techniques, less than 1 mm(2) in overall cross-section with rise times in the mu s regime and pressure ranges typically 900 kPa (9 bar). Their performance is suitable for experimental studies of the pressure-time history for test models exposed to shocks initiated by an explosive charge. The small size and fast response of the sensors promises higher quality data than has been previously available from conventional electrical sensors, with potential improvements to numerical models of blast effects. Results from blast tests are presented in which up to six sensors were multiplexed, embedded within test models in a range of orientations relative to the shock front.Support from the UK Engineering&Physical Sciences Research Council and Dstl Fort Halstead through the MoD Joint Grants Scheme are acknowledged. WN MacPherson is supported by an EPSRC Advanced Research Fellowship

Numerical analysis of thermal stresses around fasteners in composite metal foils

The process of composite metal foil manufacturing (CMFM) has reduced a number of limitations associated with commercial additive manufacturing (AM) methods. The existing metal AM machines are restricted by their build envelope and there is a growing market for the manufacture of large parts using AM. These parts are subsequently manufactured in fragments and are fastened together. This paper analyses the thermal stresses around cylindrical fasteners for three layered metal composite parts consisting of aluminium foil, brazing paste and copper foil layers. The investigation aims to examine the mechanical integrity of the metallurgically bonded aluminium/copper foils of 100 micron thickness manufactured in a disc shape. A cylindrical fastener set at an elevated temperature of 100 °C is fitted in the middle of the disc which results in a steady-state thermal distribution. Radial and shear stresses are computed using finite element method which shows that non-zero shear stresses developed by the copper layer inhibit the axial slippage of the fastener and thereby establishing the suitability of rivet joints for CMFM parts

Statistical analysis plan for the TRANSLATE (TRANSrectal biopsy versus Local Anaesthetic Transperineal biopsy Evaluation of potentially clinically significant prostate cancer) multicentre randomised controlled trial

Background: The TRANSLATE (TRANSrectal biopsy versus Local Anaesthetic Transperineal biopsy Evaluation) trial assesses the clinical and cost-effectiveness of two biopsy procedures in terms of detection of clinically significant prostate cancer (PCa). This article describes the statistical analysis plan (SAP) for the TRANSLATE randomised controlled trial (RCT). Methods/design: TRANSLATE is a parallel, superiority, multicentre RCT. Biopsy-naïve men aged ≥ 18 years requiring a prostate biopsy for suspicion of possible PCa are randomised (computer-generated 1:1 allocation ratio) to one of two biopsy procedures: transrectal (TRUS) or local anaesthetic transperineal (LATP) biopsy. The primary outcome is the difference in detection rates of clinically significant PCa (defined as Gleason Grade Group ≥ 2, i.e. any Gleason pattern ≥ 4 disease) between the two biopsy procedures. Secondary outcome measures are th eProBE questionnaire (Perception Part and General Symptoms) and International Index of Erectile Function (IIEF, Domain A) scores, International Prostate Symptom Score (IPSS) values, EQ-5D-5L scores, resource use, infection rates, complications, and serious adverse events. We describe in detail the sample size calculation, statistical models used for the analysis, handling of missing data, and planned sensitivity and subgroup analyses. This SAP was pre-specified, written and submitted without prior knowledge of the trial results. Discussion: Publication of the TRANSLATE trial SAP aims to increase the transparency of the data analysis and reduce the risk of outcome reporting bias. Any deviations from the current SAP will be described and justified in the final study report and results publication. Trial registration: International Standard Randomised Controlled Trial Number ISRCTN98159689, registered on 28 January 2021 and registered on the ClinicalTrials.gov (NCT05179694) trials registry