118 research outputs found
Novel heuristic for low-batch manufacturing process scheduling optimisation with reference to process engineering
YesScheduling is an important element that has a major impact on the efficiency of all
manufacturing processes. It plays an important role in optimising the manufacturing times and
costs resulting in energy efficient processes. It has been estimated that more than 75% of
manufacturing processes occur in small batches. In such environments, processes must be able to
perform a variety of operations on a mix of different batches. Batch-job scheduling optimisation is
the response to such low batch manufacturing problems. The optimisation of batch-job process
scheduling problem is still a challenge to researchers and is far from being completely solved due
to its combinatorial nature. In this paper, a novel hybrid heuristic (HybH) solution approach for
batch-job scheduling problem is presented with the objective of optimising the overall Makespan
(Cmax). The proposed HybH is the combination of Index Based Heuristic (IBH) and the Finished
Batch-Job (FBJ) process schedule. The heuristic assigns the first operation to a batch-job using
IBH and the remaining operations on the basis FBJ process schedule. The FBJ process schedule
gives priority to the batch-job with early finished operations, without violating the constraints of
process order. The proposed HybH is explained with the help of a detailed example. Several
benchmark problems are solved from the literature to check the validity and effectiveness of the
proposed heuristic. The presented HybH has achieved batch-job process schedules which have
outperformed the traditional heuristics. The results are encouraging and show that the proposed
heuristic is a valid methodology for batch process scheduling optimisation
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A new paradigm for disc-pad interface models in friction brake system
In this paper a 2D coupled thermal-stress finite element model is established and used to predict thermal phenomena at the disc-pad interface of a disc brake system. The importance of certain critical settings and parameters for the 2D FE model has been identified (such as, a limited degree of freedom for a brake pad in place of accepted practice that considers uniform contact), here a non-uniform pressure distribution resulting from friction bending moment effects due to the introduction of a pivot point. These parameters affect the distributions of both interface temperature and pressure. The simulation results show that when the interface conductance h is 10^6 W/m^2K or higher, the interface temperature distribution is no longer sensitive to friction bending moment effects. However, when h is 30000 W/m^2K or lower, the interface temperature distribution and heat partition ratio are significantly affected by the setting used for the rotational degree of freedom of the pad. The simulation results provide a useful reference for a better design of a disc brake system for different applications
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Measured Water Temperature Characteristics in a Pipeline Distribution System
YesThis paper describes the design, development, deployment and performance assessment of a
prototype system for monitoring the 'health' of a water distribution network based on the
temperature distribution and time-dependent variations in temperature across the network. It
has been found that the water temperature can reveal unusual events in a water distribution
network, indicated by dynamic variations in spatial temperature differential. Based on this
indication it is shown how patterns of changes in the water temperature can be analysed using
AQUIS pipeline distribution software and used in conjunction with hydraulic (e.g. flow and
pressure) sensors to indicate the state of ÂżhealthÂż of the network during operation
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A finite element model of the electrofusion welding of thermoplastic pipes
An advanced finite element (FE) model of the electrofusion welding of thermoplastic
pipes has been developed using the ABAQUS FE package. The heat transfer analysis is coupled with
thermal deformation analysis to include the time-dependent closure of the initial gap between the
pipe and fitting. The effect of radial melt movement into the interface is modelled using a new `virtual
material movementÂż technique. The predicted results (temperature distribution in the weld region,
melt affected zones and gap closure time) are compared with experimental data and good agreement
is foun
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Artificial Neural Network Model for a Low Cost Failure Sensor: Performance Assessment in Pipeline Distribution
YesThis paper describes an automated event detection and
location system for water distribution pipelines which is based upon
low-cost sensor technology and signature analysis by an Artificial
Neural Network (ANN). The development of a low cost failure
sensor which measures the opacity or cloudiness of the local water
flow has been designed, developed and validated, and an ANN based
system is then described which uses time series data produced by
sensors to construct an empirical model for time series prediction and
classification of events. These two components have been installed,
tested and verified in an experimental site in a UK water distribution
system. Verification of the system has been achieved from a series of
simulated burst trials which have provided real data sets. It is
concluded that the system has potential in water distribution network
management
Bi-fuel SI Engine Model for Analysis and Optimization
YesThe natural gas as an alternative fuel has economical and environmental benefits. Bi-fuel engines powered by gasoline and compressed natural gas (CNG) are an intermediate and alternative step to dedicated CNG engines. The conversion to bi-fuel CNG engine could be a short-term solution to air pollution problem in many developing countries. In this paper a mathematical model of a bi-fuel four-stroke spark ignition (SI) engine is presented for comparative studies and analysis. It is based on the two-zone combustion model, and it has the ability to simulate turbulent combustion. The model is capable of predicting the cylinder temperature and pressure, heat transfer, brake work , brake thermal and volumetric efficiency, brake torque, brake specific fuel consumption (BSFC), brake mean effective pressure (BMEP), concentration of CO2, brake specific CO (BSCO) and brake specific NOx (BSNOx). The effect of engine speed, equivalence ratio and performance parameters using gasoline and CNG fuels are analysed. The model has been validated by experimental data using the results obtained from a bi-fuel engine. The results show the capability of the model in terms of engine performance optimization and minimization of the emissions. The engine used in this study is a typical example of a modified bi-fuel engine conversion, which could benefit the researchers in the field
A Patient-Centered Prescription Drug Label to Promote Appropriate Medication Use and Adherence
BACKGROUND: Patient misunderstanding of prescription drug label instructions is a common cause of unintentional misuse of medication and adverse health outcomes. Those with limited literacy and English proficiency are at greater risk.
OBJECTIVE: To test the effectiveness of a patient-centered drug label strategy, including a Universal Medication Schedule (UMS), to improve proper regimen use and adherence compared to a current standard.
DESIGN: Two-arm, multi-site patient-randomized pragmatic trial.
PARTICIPANTS: English- and Spanish-speaking patients from eight community health centers in northern Virginia who received prescriptions from a central-fill pharmacy and who were 1) â„30Â years of age, 2) diagnosed with type 2 diabetes and/or hypertension, and 3) taking â„2 oral medications.
INTERVENTION: A patient-centered label (PCL) strategy that incorporated evidence-based practices for format and content, including prioritized information, larger font size, and increased white space. Most notably, instructions were conveyed with the UMS, which uses standard intervals for expressing when to take medicine (morning, noon, evening, bedtime).
MAIN MEASURES: Demonstrated proper use of a multi-drug regimen; medication adherence measured by self-report and pill count at 3 and 9Â months.
KEY RESULTS: A total of 845 patients participated in the study (85.6Â % cooperation rate). Patients receiving the PCL demonstrated slightly better proper use of their drug regimens at first exposure (76.9Â % vs. 70.1Â %, pâ=â0.06) and at 9Â months (85.9Â % vs. 77.4Â %, pâ=â0.03). The effect of the PCL was significant for English-speaking patients (OR 2.21, 95Â % CI 1.13-4.31) but not for Spanish speakers (OR 1.19, 95Â % CI 0.63-2.24). Overall, the intervention did not improve medication adherence. However, significant benefits from the PCL were found among patients with limited literacy (OR 5.08, 95Â % CI 1.15-22.37) and for those with medications to be taken â„2 times a day (OR 2.77, 95Â % CI 1.17-6.53).
CONCLUSIONS: A simple modification to pharmacy-generated labeling, with minimal investment required, can offer modest improvements to regimen use and adherence, mostly among patients with limited literacy and more complex regimens. Trial Registration (ClinicalTrials.gov): NCT00973180, NCT01200849
Otto coupling to a transverse-electric-polarized mode on a metamaterial surface
publication-status: Publishedtypes: ArticleAlastair P. Hibbins, Matthew J. Lockyear and J. Roy Sambles, Physical Review B, Vol. 84, article 115130 (2011). Copyright © 2011 by the American Physical Society.Using the Otto geometry, prism coupling of microwave radiation to a metamaterial surface that supports a bound transverse-electric-polarized surface mode is demonstrated. The dispersion of this surface mode is characterised experimentally for incident radiation beyond the critical angle of the prism, and its resonant fields are explored using a numerical model
Surface plasmons on zig-zag gratings
publication-status: Publishedtypes: ArticleThis paper was published in Optics Express and is made available as an electronic reprint with the permission of OSA. The paper can be found at the following URL on the OSA website: http://dx.doi.org/10.1364/OE.20.023921
Systematic or multiple reproduction or distribution to multiple locations via electronic or other means is prohibited and is subject to penalties under law.© Copyright 2012 Optical Society of Americ
Ethnicity data resource in population-wide health records:completeness, coverage and granularity of diversity
Intersectional social determinants including ethnicity are vital in health research. We curated a population-wide data resource of self-identified ethnicity data from over 60 million individuals in England primary care, linking it to hospital records. We assessed ethnicity data in terms of completeness, consistency, and granularity and found one in ten individuals do not have ethnicity information recorded in primary care. By linking to hospital records, ethnicity data were completed for 94% of individuals. By reconciling SNOMED-CT concepts and census-level categories into a consistent hierarchy, we organised more than 250 ethnicity sub-groups including and beyond âWhiteâ, âBlackâ, âAsianâ, âMixedâ and âOther, and found them to be distributed in proportions similar to the general population. This large observational dataset presents an algorithmic hierarchy to represent self-identified ethnicity data collected across heterogeneous healthcare settings. Accurate and easily accessible ethnicity data can lead to a better understanding of population diversity, which is important to address disparities and influence policy recommendations that can translate into better, fairer health for all.<br/
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