Potential applications of simulation modelling techniques in healthcare: lessons learned from aerospace and military

The Aerospace and Military areas are to do with complex missions and situations. Modelling and Simulation (M&S) has been applied in many areas of defence ranging from space sciences, satellite engineering to multi-warfare (air warfare, undersea warfare), air & missile defence, acquisition, tactical military trainings & exercises, national security analysis and strategic decision making & planning, etc. The application of simulation modelling techniques in healthcare would improve the provision of healthcare services; however, their application has been much relatively feeble in the healthcare sector as compared to the defence sector. This paper presents results from a systematic literature survey on applications of modelling simulation techniques in the Aerospace & Military. The knowledge gained or lessons learned from the survey were finally used to analyze the potential applications of the simulation modelling techniques to the healthcare sector. Results show that in the defence sector, Distributed Simulation has now become a widely adopted technique. However, System Dynamics (SD) and Discrete Event Simulation (DSE) have also gained relative attention. From this survey it becomes clear that various simulation modelling techniques are useful for specific purposes and have potential applications in the healthcare sector

Robust sliding mode control for discrete stochastic systems with mixed time delays, randomly occurring uncertainties, and randomly occurring nonlinearities

This is the post-print version of the paper. The official published version can be accessed from the link below - Copyright @ 2012 IEEEThis paper investigates the robust sliding mode control (SMC) problem for a class of uncertain nonlinear stochastic systems with mixed time delays. Both the sectorlike nonlinearities and the norm-bounded uncertainties enter into the system in random ways, and such randomly occurring uncertainties and randomly occurring nonlinearities obey certain mutually uncorrelated Bernoulli distributed white noise sequences. The mixed time delays consist of both the discrete and the distributed delays. The time-varying delays are allowed in state. By employing the idea of delay fractioning and constructing a new Lyapunov–Krasovskii functional, sufficient conditions are established to ensure the stability of the system dynamics in the specified sliding surface by solving a certain semidefinite programming problem. A full-state feedback SMC law is designed to guarantee the reaching condition. A simulation example is given to demonstrate the effectiveness of the proposed SMC scheme.This work was supported in part by the National Natural Science Foundation of China under Grants 61028008, 60825303 and 60834003, National 973 Project under Grant 2009CB320600, the Fok Ying Tung Education Fund under Grant 111064, the Special Fund for the Author of National Excellent Doctoral Dissertation of China under Grant 2007B4, the Key Laboratory of Integrated Automation for the Process Industry Northeastern University) from the Ministry of Education of China, the Engineering and Physical Sciences Research Council (EPSRC) of the U.K. under Grant GR/S27658/01, the Royal Society of the U.K., and the Alexander von Humboldt Foundation of Germany

H ∞ sliding mode observer design for a class of nonlinear discrete time-delay systems: A delay-fractioning approach

Copyright @ 2012 John Wiley & SonsIn this paper, the H ∞  sliding mode observer (SMO) design problem is investigated for a class of nonlinear discrete time-delay systems. The nonlinear descriptions quantify the maximum possible derivations from a linear model, and the system states are allowed to be immeasurable. Attention is focused on the design of a discrete-time SMO such that the asymptotic stability as well as the H ∞  performance requirement of the error dynamics can be guaranteed in the presence of nonlinearities, time delay and external disturbances. Firstly, a discrete-time discontinuous switched term is proposed to make sure that the reaching condition holds. Then, by constructing a new Lyapunov–Krasovskii functional based on the idea of ‘delay fractioning’ and by introducing some appropriate free-weighting matrices, a sufficient condition is established to guarantee the desired performance of the error dynamics in the specified sliding mode surface by solving a minimization problem. Finally, an illustrative example is given to show the effectiveness of the designed SMO design scheme

An investigation into modeling and simulation approaches for sustainable operations management

Modeling and simulation (M&S) studies have been widely used in industry to gain insights into existing or proposed systems of interest. The majority of these studies focus on productivity-related measures to evaluate systems' performance. This paradigm, however, needs to be shifted to cope with the advent of sustainability, as it is increasingly becoming an important issue in the managerial and the organizational agendas. The application of M&S to evaluate the often-competing metrics associated with sustainable operations management (SOM) is likely to be a challenge. The aim of this review is to investigate the underlying characteristics of SOM that lend towards modeling of production and service systems, and further to present an informed discussion on the suitability of specific modeling techniques in meeting the competing metrics for SOM. The triple bottom line, which is a widely used concept in sustainability and includes environmental, social, and economic aspects, is used as a benchmark for assessing this. Findings from our research suggest that a hybrid (combined) M&S approach could be an appropriate method for SOM analysis; however, it has its challenges.This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors

Use of creative tools, technologies, processes and practices in the sectors of Art, Media, and Architecture: State-of the-Art and desired future scenarios

The aim of the paper is to analyse and present the preliminary findings of the EU FP7 funded CRe-AM project for the Art, Media, and Architecture sectors. This project bridges communities of technology providers and innovators with the creative industries, with the aim to build sector-specific dynamic roadmaps for the future of the European creative industries by examining the current state-of-the-art tools, technologies, processes, and practices supporting the creative process against the future scenarios envisioned by stakeholders in these sectors.This work was carried out as part of CRe-AM project, which is supported by European Commission (grant agreement n°612451)

Modelling for sustainable development using the triple-bottom line: Methods, challenges and the need for hybrid M&S

This is the author accepted manuscript, the final version is available from IEEE via the DOI in this record.The concept of sustainable development (SDEV) is a topic of increasing significance in management decision making. SDEV is managed based on the triple-bottom line approach which stresses the importance of achieving a balance between economic, environmental and social impacts. In the context of management decision making, this implies that operational and strategic decisions in an organization must not be limited to the fulfillment of KPIs associated with productivity alone, but should also include metrics that are associated with the environment and society. Modeling & simulation (M&S) lends itself towards evaluation of the three, often competing, metrics. There are several M&S approaches like Discrete-event and System Dynamics; which of the existing techniques is the choice for modelling SDEV? Or, is a combined hybrid approach a better solution? The tutorial explores such questions related to the methodological aspects of M&S for SDEV analysis, and discusses the challenges for modeling such complex systems

A systematic review with procedural assessments and meta-analysis of Low Level Laser Therapy in lateral elbow tendinopathy (tennis elbow)

<p>Abstract</p> <p>Background</p> <p>Recent reviews have indicated that low level level laser therapy (LLLT) is ineffective in lateral elbow tendinopathy (LET) without assessing validity of treatment procedures and doses or the influence of prior steroid injections.</p> <p>Methods</p> <p>Systematic review with meta-analysis, with primary outcome measures of pain relief and/or global improvement and subgroup analyses of methodological quality, wavelengths and treatment procedures.</p> <p>Results</p> <p>18 randomised placebo-controlled trials (RCTs) were identified with 13 RCTs (730 patients) meeting the criteria for meta-analysis. 12 RCTs satisfied half or more of the methodological criteria. Publication bias was detected by Egger's graphical test, which showed a negative direction of bias. Ten of the trials included patients with poor prognosis caused by failed steroid injections or other treatment failures, or long symptom duration or severe baseline pain. The weighted mean difference (WMD) for pain relief was 10.2 mm [95% CI: 3.0 to 17.5] and the RR for global improvement was 1.36 [1.16 to 1.60]. Trials which targeted acupuncture points reported negative results, as did trials with wavelengths 820, 830 and 1064 nm. In a subgroup of five trials with 904 nm lasers and one trial with 632 nm wavelength where the lateral elbow tendon insertions were directly irradiated, WMD for pain relief was 17.2 mm [95% CI: 8.5 to 25.9] and 14.0 mm [95% CI: 7.4 to 20.6] respectively, while RR for global pain improvement was only reported for 904 nm at 1.53 [95% CI: 1.28 to 1.83]. LLLT doses in this subgroup ranged between 0.5 and 7.2 Joules. Secondary outcome measures of painfree grip strength, pain pressure threshold, sick leave and follow-up data from 3 to 8 weeks after the end of treatment, showed consistently significant results in favour of the same LLLT subgroup (p < 0.02). No serious side-effects were reported.</p> <p>Conclusion</p> <p>LLLT administered with optimal doses of 904 nm and possibly 632 nm wavelengths directly to the lateral elbow tendon insertions, seem to offer short-term pain relief and less disability in LET, both alone and in conjunction with an exercise regimen. This finding contradicts the conclusions of previous reviews which failed to assess treatment procedures, wavelengths and optimal doses.</p

Higher order nested wigner distributions: Properties and applications

The concept of Wigner distribution (WD) is extended to higher-order nested Wigner distributions. The nested ambiguity function (NAF) is also derived naturally by employing the known interrelation between the WD and the ambiguity function (AF). These distributions are obtained by nesting a function within itself a number of times. The definitions of these,new multidimensional distributions are given in analogy to the standard first-order 2-D distributions in both temporal/spatial and spectral forms and follow the definitions of quartic distributions presented in [21] and [22]. Some important properties are derived and discussed, including interrelationships between the various representations, marginals, correlations, and uncertainties, as well as their geometrical characteristics. The second-order nested Wigner distribution (NWD) is used to showcase the power of such distributions in potential application areas, such as signal estimation, signal separation, and radar signal analysis. For such signal processing tasks, it is demonstrated that the NWDs can be successful in situations where the standard 2-D distributions have proved to be inadequate. © 2006 IEEE

Combining web services and grid services: Practical approaches and implications to resource discovery

Web technologies have played a significant role in supporting the global sharing of Internet resources and thereby improving communications. On another front, Grids hold the promise to provide global interoperability and interconnectivity at a level considered impossible a few decades ago. In practice, there is not much difference between the existing Grid and Web infrastructures; in fact, a Grid infrastructure could be built by making minor modifications to a Web infrastructure. The implementation of Web-based Grids or a partially-Gridified Web is one of the potential solutions to Grid infrastructure problems. This can be done by sharing Grid services across the Grid infrastructure, effectively using the underlying Web services as vehicles or transporters of these services. The chapter discusses Grid services as another type of Grid resources, examines possible ways to integrate Grid services and Web services, and explores how this will support Grid resource discovery. It is argued that Grids should be developed using the underlying Web infrastructure and Grid services could be integrated with Web services using inheritance techniques to produce Grid-supported Web services. Furthermore, this approach seems to deal effectively with the problems of resource discovery in such partially-Gridified Web environments. An earlier version of this work has been presented in Naseer and Stergioulas (2006a). © 2008, IGI Global

Evaluating health information system interventions using analytical and modeling methods

In recent years the value of the use of evaluation methods in all aspects of economic sectors, including the field of health care, has been increasingly recognized. The thrust of this paper is to explore the potential use of a) Cost-Benefit Analysis and b) Simulation and Modeling methods in estimating the value of Health Information System (HIS) projects. These methods were chosen for consideration as the most appropriate, primarily because CBA can measure delivered value of HIS interventions by weighting cost and benefits and identifying what is more socially desirable, while Simulation and Modeling tools can be used to estimate the future value of health care changes concerning HIS. The paper discusses these two families of methods, their evaluation potential is analyzed, and arguments for and against the use of each method are presented. Finally, methodological considerations and limitations are discussed and areas for future research are suggested