Fracture clinic redesign reduces the cost of outpatient orthopaedic trauma care

Objectives: “Virtual fracture clinics” have been reported as a safe and effective alternative to the traditional fracture clinic. Robust protocols are used to identify cases that do not require further review, with the remainder triaged to the most appropriate subspecialist at the optimum time for review. The objective of this study was to perform a “top-down” analysis of the cost effectiveness of this virtual fracture clinic pathway. Methods: National Health Service financial returns relating to our institution were examined for the time period 2009 to 2014 which spanned the service redesign. Results: The total staffing costs rose by 4% over the time period (from £1 744 933 to £1 811 301) compared with a national increase of 16%. The total outpatient department rate of attendance fell by 15% compared with a national fall of 5%. Had our local costs increased in line with the national average, an excess expenditure of £212 705 would have been required for staffing costs. Conclusions: The virtual fracture clinic system was associated with less overall use of staff resources in comparison to national cost data. Adoption of this system nationally may have the potential to achieve significant cost savings

An approach to open virtual commissioning for component-based automation

Increasing market demands for highly customised products with shorter time-to-market and at lower prices are forcing manufacturing systems to be built and operated in a more efficient ways. In order to overcome some of the limitations in traditional methods of automation system engineering, this thesis focuses on the creation of a new approach to Virtual Commissioning (VC). In current VC approaches, virtual models are driven by pre-programmed PLC control software. These approaches are still time-consuming and heavily control expertise-reliant as the required programming and debugging activities are mainly performed by control engineers. Another current limitation is that virtual models validated during VC are difficult to reuse due to a lack of tool-independent data models. Therefore, in order to maximise the potential of VC, there is a need for new VC approaches and tools to address these limitations. The main contributions of this research are: (1) to develop a new approach and the related engineering tool functionality for directly deploying PLC control software based on component-based VC models and reusable components; and (2) to build tool-independent common data models for describing component-based virtual automation systems in order to enable data reusability. [Continues.

Determination of measurement uncertainty by Monte Carlo simulation

Modern coordinate measurement machines (CMM) are universal tools to measure geometric features of complex three-dimensional workpieces. To use them as reliable means of quality control, the suitability of the device for the specific measurement task has to be proven. Therefore, the ISO 14253 standard requires, knowledge of the measurement uncertainty and, that it is in reasonable relation with the specified tolerances. Hence, the determination of the measurement uncertainty, which is a complex and also costly task, is of utmost importance. The measurement uncertainty is usually influenced by several contributions of various sources. Among those of the machine itself, e.g., guideway errors and the influence of the probe and styli play an important role. Furthermore, several properties of the workpiece, such as its form deviations and surface roughness, have to be considered. Also the environmental conditions, i.e., temperature and its gradients, pressure, relative humidity and others contribute to the overall measurement uncertainty. Currently, there are different approaches to determine task-specific measurement uncertainties. This work reports on recent advancements extending the well-established method of PTB's Virtual Coordinate Measuring Machine (VCMM) to suit present-day needs in industrial applications. The VCMM utilizes numerical simulations to determine the task-specific measurement uncertainty incorporating broad knowledge about the contributions of, e.g., the used CMM, the environment and the workpiece

Integrated Real-Virtuality System and Environments for Advanced Control System Developers and Machines Builders

The pace of technological change is increasing and sophisticated customer driven markets are forcing rapid machine evolution, increasing complexity and quality, and faster response. To survive and thrive in these markets, machine builders/suppliers require absolute customer and market orientation, focusing on .. rapid provision of solutions rather than products. Their production systems will need to accommodate unpredictable changes while maintaining financial and operational efficiency with short lead and delivery times. Real-Virtuality (R-V) systems are an innovative environment to address these requirements by facilitating enhanced support in machine system design utilising integrated real-virtual environments centred on concurrent machine system development and realization. This environment supports not only machine system design but also the development of the' control system at the same time. Utilising the Real-Virtual Mapping Environment (RVMI;:), 3-D simulation machine models can perform actual machine operations in real-time when coupled with the real machine controller. This provides a more understandable, reliable and transparent machine function and performance. The research study explores different types of controller verification methods and proposes a new method which employs the use of a control signal emulator. The research study has fomulated a novel technique for emulating quadrature encoder signals to provide virtual closed loop control of servomotors. The deployment of a control signal emulator technique makes the system unique and removes its dependency on specific hardware. Enabling the real-time data from the signal emulation environment eases the task of realising a real-time machine simulator. To evaluate the proposed architecture, three case studies were performed. The results have shown that it is possible to create verified and validated machine control programs with no modification needed when applied to the real machine. The migration from the virtual to the real world is totally seamless. The result from the ????study show that the virtual machine is able to operate and respond as a real machine in real-time. This opens up the unexplored potential of integrated 3-D virtual technology. The real-time 3-D simulation virtual machine will enable commissioning and training to be conducted '!-t an earlier stage in the design process (without having to wait for the real machine to be built). Furthermore, various test scenarios can also be developed and tested on the system which helps to provide a better lofriderstanding of the machine behaviours and responses. This research study has made an original contribution in the field of machine system development. It has contributed a novel approach of using emulated control signals to provide machine control programmers with a platform to test their application programs at machine level which involves both discrete digital signals and continuous signals. The real-time virtual environment extends the application domain for the use of simulation. The architecture proposed is generic; to be exact it is not constrained to a specific industrial control system or to a specific simulation vendor

Comparison of DC and SRF Photoemission Guns For High Brightness High Average Current Beam Production

A comparison of the two most prominent electron sources of high average current high brightness electron beams, DC and superconducting RF photoemission guns, is carried out using a large-scale multivariate genetic optimizer interfaced with space charge simulation codes. The gun geometry for each case is varied concurrently with laser pulse shape and parameters of the downstream beamline elements of the photoinjector to obtain minimum emittance as a function of bunch charge. Realistic constraints are imposed on maximum field values for the two gun types. The SRF and DC gun emittances and beam envelopes are compared for various values of photocathode thermal emittance. The performance of the two systems is found to be largely comparable provided low intrinsic emittance photocathodes can be employed

Jäähdytystornien mallintaminen ja lämmön talteenotto

The European Organization for Nuclear Research (CERN) has agreed on a commitment to minimize the environmental impact of the wide range of activities the Laboratory carries out. A key measure is waste heat recovery (WHR), as approximately 75 % of the power consumed in the electricity intensive particle accelerator complex, is dissipated to the sky as waste heat by cooling towers. A project for installing waste heat recovery to the cooling system of the Large Hadron Collider (LHC) at LHC point 8 has started and is expected to be operational in the beginning of 2020, after the second LHC long shutdown in 2018-2019. The operation of WHR causes a risk of temperature transients in case of unexpected WHR shutdowns. A dynamic simulation model of the cooling towers is needed to verify robustness against these temperature transients. In this Thesis, a thorough literature review of existing evaporative cooling tower modeling methods is performed, and the hybrid modeling method presented by Jin & al. (2007), is implemented to simulate the cooling towers at LHC point 8. The developed model is validated against real operational data. To the authors knowledge, this study is the first published use case of this evaporative cooling tower modeling method. A selection of anticipated sudden WHR shutdown scenarios are simulated in virtual commissioning environment with real programmable logic controller (PLC) to verify robustness of the cooling system against sudden temperature transients. A conclusion is that the cooling towers and their current control scheme is sufficient in dampening the anticipated temperature transients. This knowledge allows the WHR installation project to proceed.Euroopan hiukkasfysiikan tutktimuskeskuksella CERN:illä on tavoitteenaan minimoida laboration aktiviteettien ympäristövaikutukset. Tämän tavoitteen saavuttamisessa lämmön talteenotto (LTO) on tärkeässä roolissa, sillä energiaintensiivisessä hiukkaskiihdytinkompleksissa noin 75 prosenttia käytetystä sähkötehosta haihdutetaan taivaalle jäähdytystornien kautta hukkalämpönä. Toisen pitkän käyttökaton aikana vuosina 2019 - 2020 suuren hadronitörmäyttimen (LHC) pisteelle 8 asennetaan lämmön talteenottojärjestelmä. Lämmön talteenoton käyttö aiheuttaa riskin lämpötilavaihteluiden syntymiselle, jos hukkalämmön vastaanotto katkeaa äkillisesti. Dynaaminen jäähdytystornien simulaointimalli tarvitaan suuren hadronitörmäyttimen toiminnan kannalta kriittisen jäähdytysjärjestelmän luotettavuuden varmistamiseksi. Tässä diplomityössä esitellään kattava kirjallisuuskatsaus jäähdytystornien mallinusmenetelmistä ja implementoidaan Jin & al. (2007) julkaisema hybridi-menetelmä LHC pisteen 8 jäähdytystornien simuloimiseksi. Malli validoidaan järjestelmästä mitattua dataa vasten. Tehdyn kirjallisuusselvityksen perusteella tämä diplomityö on ensimmäinen julkaisu, jossa tätä jäähdystornien mallinusmenetelmää sovelletaan käytössä olevan järjestelmän simuloimiseen. Järjestelmän lämpötilatransienttien vaimmenuskyvyn tutkimiseksi jäähdytystornimallilla simuloidaan eri vuodenaikoina odetettavissa olevia lämmön talteenoton pysähtymisiä virtual commissioning -ympäristössä, jossa todellinen ohjelmoitava logiikka (Programmable Logic Controller PLC) ohjaa mallia. Simulointien tulokset osoittavat, että nykyinen jäähdytyskapasiteetti ja ohjauslogiikka vaimentavat odotettavissa olevia transientteja tehokkaasti. Tämän tiedon perusteella lämmön talteenottoprojekti voi edetä