250 research outputs found

    Multi-level port resilience planning in the UK: how can information sharing be made easier?

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    Port resilience planning is a subset of the wider disaster resilience literature and it is concerned with how port stakeholders work together to make port systems more resilience. Port stakeholders include government departments, the port operator, ship operators, importers, agents and logistics firms. Ports are vital for the operation of cities and whole countries, especial island nations like the UK. Single port systems are multi-level systems with complex operational-level relationships and interdependencies. Additional levels to this include government and the policy-level. Preparing for the crises and disasters that might befall ports requires information sharing between stakeholders about key dependencies and alternative actions. The complexity of ports presents barriers to information sharing; as do commercial and political sensitivities. This paper uses a multi-level case study on the UK's system of ports to propose an approach to information sharing that uses the subjectivity of information from a supplier's perspective and from a user's perspective to reduce barriers of complexity, confidentiality and political sensitivity

    Combining machine learning with computational hydrodynamics for prediction of tidal surge inundation at estuarine ports

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    Accurate forecasts of extreme storm surge water levels are vital for operators of major ports. Existing regional tide-surge models perform well at the open coast but their low spatial resolution makes their forecasts less reliable for ports located in estuaries. In December 2013, a tidal surge in the North Sea with an estimated return period of 760 years partially flooded the Port of Immingham in the Humber estuary, on the UK east coast. Damage to critical infrastructure caused several weeks of disruption to vital supply chains and highlighted a need for additional forecasting tools to supplement national surge warnings. In this paper, we show that Artificial Neural Networks (ANNs) can generate better short-term forecasts of extreme water levels at estuarine ports. Using Immingham as a test case, an ANN is configured to simulate the tidal surge residual using an input vector that includes observations of surge at distant tide gauges in NW Scotland, wind and atmospheric pressure, and the predicted astronomical tide at Immingham. The forecast surge time-series, combined with the astronomical tide, provides a boundary condition for a local high-resolution 2D hydrodynamic model that predicts flood extent and damage potential across the port. Although the forecasting horizon of the ANN is limited, 6 to 24 hour forecasts at Immingham achieve an accuracy comparable to or better than the UK national tide-surge model and at far less computational cost. Use of a local rather than a larger regional hydrodynamic model means that potential inundation can be simulated very rapidly at high spatial resolution. Validation against the 2013 surge shows that the hybrid ANN-hydrodynamic model generates realistic flood extents that can inform port resilience planning

    PROBABILITY DENSITY FUNCTION OF M/G/1 QUEUES UNDER (0,K) CONTROL POLICIES: A SPECIAL CASE

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    In this paper we present probability density function of vacation period of M/G/1 queueing process that operates under (0,k) vacation policy, wherein the server goes on the vacation when the system becomes empty and re-opens for service immediately at the arrival of the kth customer. The number of lattice paths when last arrival is an arrival has also been derived. The transient analysis is based on approximating the general service time distribution by Coxian two-phase distribution and representing the corresponding queueing process as a lattice path. Finally the lattice path combinatorics is used to present the number of lattice paths

    A critical evaluation of the electronic surgical logbook

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    BACKGROUND: The Association of Surgeons of Great Britain and Ireland (ASGBI) devised the electronic surgical logbook (version 2.4) for higher trainees in General Surgery enabling trainees to compile a uniform data set of their operative and training experience. This is in use by higher surgical trainees (HST) in the United Kingdom. This logbook permits trainees to submit data centrally into a Regional Analysis Database (RAD). With the implementation of the European Working Time Directive (EWTD) there is need for reliable data to assess the effects of the directive on training. In order to draw meaningful conclusions from the database the quality of data needs to be validated. We critically analysed the RAD in the Yorkshire region for a one-year period. METHODS: The RAD from the ASGBI for the Yorkshire region was analysed. Data for the period 01/10/2002–30/09/2003 was identified and interrogated using Microsoft Excel (2000 version). The RAD was compared with information obtained from the Regional Surgical Advisor for Yorkshire with respect to hospitals, surgical consultants and HST's in the region during the study period. RESULTS: There were 13,755 operations entered for the study period. 579 corrections to the data had to be made (4.2%) and a further 1140 entries were deleted (8.2%). Following corrections and deletions 12,615 operative entries were available for analysis. Overall 12.5% of the data required either correction or exclusion from the database prior to analysis. CONCLUSION: The RAD has a large dataset useful to monitor and assess training. However, the quality of the data needs to be verified prior to use. Recommendations have been made to develop the ASGBI logbook, which would eventually translate to improved data reliability of the RAD

    Resilience orchestration and resilience facilitation: how government can orchestrate the whole UK ports market with limited resources: the case of UK ports resilience

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    Government departments have limited resources but they are responsible for the healthy functioning of whole markets. This tension is amplified by the opportunities to generate, share and use information from new data sources and digital technologies. Huge increases in volumes and types of data produced by sensors and firms' IT systems can potentially be shared between firms which can cause information overload. This paper uses government orchestration theory to investigate the problems and opportunities of the UK's maritime transport ministry as it supports resilience planning for the whole country's ports system. We build on the developing Lean Government (l-Government) literature by theorizing on the differences between government and other stakeholders. We use a case study to investigate how these differences hinder as well as support the role of a government department. And how the special perspective of an orchestrator can integrate and filter information, motivate diverse collaborators and support the use of orchestration platforms in l-Government

    4-Hydr­oxy-3-meth­oxy-5-nitro­aceto­phenone (5-nitro­apocynin)

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    The title mol­ecule, C9H9NO5, is close to planar (r.m.s. deviation from the mean plane of the non-H atoms = 0.058 Å). The OH group forms a bifurcated O—H⋯(O,O) hydrogen bond, with the intra­molecular component to a nitro O atom and the inter­molecular component to a keto O atom, the latter resulting in chains along [20]. A C—H⋯O inter­action reinforces the packing

    A retail category management model integrating shelf space and inventory levels

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    A retail category management model that considers the interplay of optimal product assortment decisions, space allocation and inventory quantities is presented in this paper. Specifically, the proposed model maximizes the total net profit in terms of decision variables expressing product assortment, shelf space allocation and common review period. The model takes into consideration several constraints such as the available shelf space, backroom inventory space, retailer's financial resources, and estimates of rate of demand for products based on shelf space allocation and competing products. The review period can take any values greater than zero. Results of the proposed model were compared withthe results of the current industry practice for randomly generated product assortments of size six, ten and fourteen. The model also outperformed the literature benchmark. The paper demonstrates that the optimal common review period is flexible enough to accommodate the administrative restrictions of delivery schedules for products, without significantly deviating from the optimal solution

    Anthraquinones- A probe to enhance the photovoltaic properties of DSSCs

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    Natural dye sensitized solar cells are a promising class of photovoltaic cells with the capacity of generating green energy at low production cost since no expensive equipment is required in their fabrication. Photovoltaics are a precious technology in the hasty world where energy prices are goes on increasing within seconds. Researchers are focusing to facilitate for producing eco-friendly, low cost and more efficient dye sensitized solar cells. In the present work we discuss the comparative photovoltaic studies of Lawsone, a natural dye from henna plant and Alizarin, a natural dye from the root of madder for fabricating the Dye sensitized solar cells (DSSCs). The absorption spectrum of Lawsone and Alizarin is found to be shifted to the longer wavelength region after the complex formation. As a result there is a significant increase in short circuit current density and conversion efficiency. This result compares with the standard dye i.e. N719 dye

    Use of Energy Consumption during Milling to Fill a Measurement Gap in Hybrid Additive Manufacturing

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    Coupling additive manufacturing (AM) with interlayer peening introduces bulk anisotropic properties within a build across several centimeters. Current methods to map high resolution anisotropy and heterogeneity are either destructive or have a limited penetration depth using a nondestructive method. An alternative pseudo-nondestructive method to map high-resolution anisotropy and heterogeneity is through energy consumption during milling. Previous research has shown energy consumption during milling correlates with surface integrity. Since surface milling of additively manufactured parts is often required for post-processing to improve dimensional accuracy, an opportunity is available to use surface milling as an alternative method to measure mechanical properties and build quality. The variation of energy consumption during the machining of additive parts, as well as hybrid AM parts, is poorly understood. In this study, the use of net cutting specific energy was proposed as a suitable metric for measuring mechanical properties after interlayer ultrasonic peening of 316 stainless steel. Energy consumption was mapped throughout half of a cuboidal build volume. Results indicated the variation of net cutting specific energy increased farther away from the surface and was higher for hybrid AM compared to as-printed and wrought. The average lateral and layer variation of the net cutting specific energy for printed samples was 81% higher than the control, which indicated a significantly higher degree of heterogeneity. Further, it was found that energy consumption was an effective process signature exhibiting strong correlations with microhardness. Anisotropy based on residual strains were measured using net cutting specific energy and validated by hole drilling. The proposed technique contributes to filling part of the measure gap in hybrid additive manufacturing and capitalizes on the preexisting need for machining of AM parts to achieve both goals of surface finish and quality assessment in one milling operation
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