WorldWideScience

Sample records for optimised dispersion management

  1. Optimised dispersion management and modulation formats for high speed optical communication systems

    DEFF Research Database (Denmark)

    Tokle, Torger

    2004-01-01

    This thesis studies dispersion management and modulation formats for optical communication systems using per channel bit rates at and above 10 Gbit/s. Novel modulation formats—including recently proposed multilevel phase modulation—are investigated and demonstrated at bit rates up to 80 Gbit/s. New...... system performance. Differential phase shift keying (DPSK) has recently been showed to be a promising modulation format for optical communication. We study DPSK with focus on differential quadrature phase shift keying (DQPSK). In a 12.5 Gbit/s WDM system, we demonstrate the suitability of DQPSK for ultra......-channel system, the optimum pulse width is very narrow. We find that a pulse width equal to 5% of the bit slot results in optimum performance for the system studied here. These narrow RZ pulses offer good receiver sensitivity and excellent tolerance to the nonlinear effect self phase modulation (SPM). However...

  2. Optimising resource management in neurorehabilitation.

    Science.gov (United States)

    Wood, Richard M; Griffiths, Jeff D; Williams, Janet E; Brouwers, Jakko

    2014-01-01

    To date, little research has been published regarding the effective and efficient management of resources (beds and staff) in neurorehabilitation, despite being an expensive service in limited supply. To demonstrate how mathematical modelling can be used to optimise service delivery, by way of a case study at a major 21 bed neurorehabilitation unit in the UK. An automated computer program for assigning weekly treatment sessions is developed. Queue modelling is used to construct a mathematical model of the hospital in terms of referral submissions to a waiting list, admission and treatment, and ultimately discharge. This is used to analyse the impact of hypothetical strategic decisions on a variety of performance measures and costs. The project culminates in a hybridised model of these two approaches, since a relationship is found between the number of therapy hours received each week (scheduling output) and length of stay (queuing model input). The introduction of the treatment scheduling program has substantially improved timetable quality (meaning a better and fairer service to patients) and has reduced employee time expended in its creation by approximately six hours each week (freeing up time for clinical work). The queuing model has been used to assess the effect of potential strategies, such as increasing the number of beds or employing more therapists. The use of mathematical modelling has not only optimised resources in the short term, but has allowed the optimality of longer term strategic decisions to be assessed.

  3. Optimisation of dispersion parameters of Gaussian plume model for CO₂ dispersion.

    Science.gov (United States)

    Liu, Xiong; Godbole, Ajit; Lu, Cheng; Michal, Guillaume; Venton, Philip

    2015-11-01

    The carbon capture and storage (CCS) and enhanced oil recovery (EOR) projects entail the possibility of accidental release of carbon dioxide (CO2) into the atmosphere. To quantify the spread of CO2 following such release, the 'Gaussian' dispersion model is often used to estimate the resulting CO2 concentration levels in the surroundings. The Gaussian model enables quick estimates of the concentration levels. However, the traditionally recommended values of the 'dispersion parameters' in the Gaussian model may not be directly applicable to CO2 dispersion. This paper presents an optimisation technique to obtain the dispersion parameters in order to achieve a quick estimation of CO2 concentration levels in the atmosphere following CO2 blowouts. The optimised dispersion parameters enable the Gaussian model to produce quick estimates of CO2 concentration levels, precluding the necessity to set up and run much more complicated models. Computational fluid dynamics (CFD) models were employed to produce reference CO2 dispersion profiles in various atmospheric stability classes (ASC), different 'source strengths' and degrees of ground roughness. The performance of the CFD models was validated against the 'Kit Fox' field measurements, involving dispersion over a flat horizontal terrain, both with low and high roughness regions. An optimisation model employing a genetic algorithm (GA) to determine the best dispersion parameters in the Gaussian plume model was set up. Optimum values of the dispersion parameters for different ASCs that can be used in the Gaussian plume model for predicting CO2 dispersion were obtained.

  4. Application of optimisation techniques in groundwater quantity and quality management

    Indian Academy of Sciences (India)

    Amlan Das; Bithin Datta

    2001-08-01

    This paper presents the state-of-the-art on application of optimisation techniques in groundwater quality and quantity management. In order to solve optimisation-based groundwater management models, researchers have used various mathematical programming techniques such as linear programming (LP), nonlinear programming (NLP), mixed-integer programming (MIP), optimal control theory-based mathematical programming, differential dynamic programming (DDP), stochastic programming (SP), combinatorial optimisation (CO), and multiple objective programming for multipurpose management. Studies reported in the literature on the application of these methods are reviewed in this paper.

  5. Optimisation as a process for understanding and managing river ecosystems

    OpenAIRE

    Barbour, EJ; Holz, L; G. Kuczera; Pollino, CA; Jakeman, AJ; Loucks, DP

    2016-01-01

    Optimisation can assist in the management of riverine ecosystems through the exploration of multiple alternative management strategies, and the evaluation of trade-offs between conflicting objectives. In addition, it can facilitate communication and learning about the system. However, the effectiveness of optimisation in aiding decision making for ecological management is currently limited by four major challenges: identification and quantification of ecosystem objectives; representation of e...

  6. Dispersion-Flattened Composite Highly Nonlinear Fibre Optimised for Broadband Pulsed Four-Wave Mixing

    DEFF Research Database (Denmark)

    Lillieholm, Mads; Galili, Michael; Oxenløwe, Leif Katsuo

    2016-01-01

    We present a segmented composite HNLF optimised for mitigation of dispersion-fluctuation impairments for broadband pulsed four-wave mixing. The HNLF-segmentation allows for pulsed FWMprocessing of a 13-nm wide input WDM-signal with -4.6-dB conversion efficiency...

  7. Dispersion management with metamaterials

    Energy Technology Data Exchange (ETDEWEB)

    Tassin, Philippe; Koschny, Thomas; Soukoulis, Costas M.

    2017-03-07

    An apparatus, system, and method to counteract group velocity dispersion in fibers, or any other propagation of electromagnetic signals at any wavelength (microwave, terahertz, optical, etc.) in any other medium. A dispersion compensation step or device based on dispersion-engineered metamaterials is included and avoids the need of a long section of specialty fiber or the need for Bragg gratings (which have insertion loss).

  8. Topology Optimisation for Energy Management in Underwater Sensor Networks

    Science.gov (United States)

    2015-01-01

    International Journal of Control, 2015 http://dx.doi.org/10.1080/00207179.2015.1017006 Topology optimisation for energy management in underwater...State University, University Park , PA 16802-1412, USA; bNaval Undersea Warfare Center, Newport, RI 02841-1708, USA and Department of Mechanical & Nuclear...Engineering, Pennsylvania State University, University Park , PA 16802-1412, USA; cUnited Technology Research Center, Cork, Ireland (Received 28

  9. Economic optimisation of flood risk management projects

    NARCIS (Netherlands)

    Tsimopoulou, V.

    2015-01-01

    The Netherlands has developed a flood risk management policy based on an economic rationale. After the flood disaster of 1953, when a large area of the south-western part of the country was flooded and more than 1800 people lost their lives, the so-called Delta Committee was installed, whose main pu

  10. Economic optimisation of flood risk management projects

    NARCIS (Netherlands)

    Tsimopoulou, V.

    2015-01-01

    The Netherlands has developed a flood risk management policy based on an economic rationale. After the flood disaster of 1953, when a large area of the south-western part of the country was flooded and more than 1800 people lost their lives, the so-called Delta Committee was installed, whose main

  11. Economic optimisation of flood risk management projects

    NARCIS (Netherlands)

    Tsimopoulou, V.

    2015-01-01

    The Netherlands has developed a flood risk management policy based on an economic rationale. After the flood disaster of 1953, when a large area of the south-western part of the country was flooded and more than 1800 people lost their lives, the so-called Delta Committee was installed, whose main pu

  12. Fractures in sport: Optimising their management and outcome.

    Science.gov (United States)

    Robertson, Greg Aj; Wood, Alexander M

    2015-12-18

    Fractures in sport are a specialised cohort of fracture injuries, occurring in a high functioning population, in which the goals are rapid restoration of function and return to play with the minimal symptom profile possible. While the general principles of fracture management, namely accurate fracture reduction, appropriate immobilisation and timely rehabilitation, guide the treatment of these injuries, management of fractures in athletic populations can differ significantly from those in the general population, due to the need to facilitate a rapid return to high demand activities. However, despite fractures comprising up to 10% of all of sporting injuries, dedicated research into the management and outcome of sport-related fractures is limited. In order to assess the optimal methods of treating such injuries, and so allow optimisation of their outcome, the evidence for the management of each specific sport-related fracture type requires assessment and analysis. We present and review the current evidence directing management of fractures in athletes with an aim to promote valid innovative methods and optimise the outcome of such injuries. From this, key recommendations are provided for the management of the common fracture types seen in the athlete. Six case reports are also presented to illustrate the management planning and application of sport-focussed fracture management in the clinical setting.

  13. Ganga a job management and optimising tool

    CERN Document Server

    Maier, A

    2008-01-01

    Ganga, the job-management system (http://cern.ch/ganga), developed as an ATLAS- LHCb common project, offers a simple, effcient and consistent user experience in a variety of heterogeneous environments: from local clusters to global Grid systems. Ganga helps end-users to organise their analysis activities on the Grid by providing automatic persistency of the job's metadata. A user has full access to the job history including their configuration and input/output. It is however important that users can see a single environment for developing and testing algorithms locally and for running on large data samples on the Grid. The tool allows for some basic monitoring and a steadily increasing number of users of more than 300 users have been confirmed, both in HEP, as well as in non-HEP applications. The paper will introduce the Ganga philosophy, the Ganga architecture and current and future strategy.

  14. Optimisation of key performance measures in air cargo demand management

    Directory of Open Access Journals (Sweden)

    Alexander May

    2014-03-01

    Full Text Available This article sought to facilitate the optimisation of key performance measures utilised for demand management in air cargo operations. The focus was on the Revenue Management team at Virgin Atlantic Cargo and a fuzzy group decision-making method was used. Utilising intelligent fuzzy multi-criteria methods, the authors generated a ranking order of ten key outcome-based performance indicators for Virgin Atlantic air cargo Revenue Management. The result of this industry-driven study showed that for Air Cargo Revenue Management, ‘Network Optimisation’ represents a critical outcome-based performance indicator. This collaborative study contributes to existing logistics management literature, especially in the area of Revenue Management, and it seeks to enhance Revenue Management practice. It also provides a platform for Air Cargo operators seeking to improve reliability values for their key performance indicators as a means of enhancing operational monitoring power.

  15. An optimisation approach for shallow lake restoration through macrophyte management

    Science.gov (United States)

    Xu, Z. H.; Yin, X. A.; Yang, Z. F.

    2014-06-01

    Lake eutrophication is a serious global environmental issue. Phytoremediation is a promising, cost-effective, and environmentally friendly technology for water quality restoration. However, besides nutrient removal, macrophytes also deeply affect the hydrologic cycle of a lake system through evapotranspiration. Changes in hydrologic cycle caused by macrophytes have a great influence on lake water quality restoration. As a result of the two opposite effects of macrophytes on water quality restoration (i.e. an increase in macrophytes can increase nutrient removal and improve water quality while also increasing evapotranspiration, reducing water volume and consequently decreasing water quality), rational macrophyte control through planting and harvest is very important. In this study, a new approach is proposed to optimise the initial planting area and monthly harvest scheme of macrophytes for water quality restoration. The month-by-month effects of macrophyte management on lake water quality are considered. Baiyangdian Lake serves as a case study, using the common reed. It was found that water quality was closest to Grade III on the Chinese water quality scale when the reed planting area was 123 km2 (40% of the lake surface area) and most reeds would be harvested at the end of June. The optimisation approach proposed in this study will be a useful reference for lake restoration.

  16. An optimisation approach for shallow lake restoration through macrophyte management

    Directory of Open Access Journals (Sweden)

    Z. H. Xu

    2014-01-01

    Full Text Available Lake eutrophication is a serious global environmental issue. Phytoremediation is a promising, cost-effective, and environmentally friendly technology for water quality restoration. However, besides nutrient removal, macrophytes also deeply affect the hydrologic cycle of lake system through evapotranspiration. Changes in hydrologic cycle caused by macrophytes have a great influence on lake water quality restoration. As a result of the two opposite effects of macrophytes on water quality restoration (i.e. an increase in macrophytes can increase nutrient removal and improve water quality while also increasing evapotranspiration, reducing water volume and consequently decreasing water quality, rational macrophyte control through planting and harvest is very important. In this study, a new approach is proposed to optimise the initial planting area and monthly harvest scheme of macrophytes for water quality restoration. The month-by-month effects of macrophyte management on lake water quality are considered. Baiyangdian Lake serves as a case study, using the common reed. It was found that water quality was closest to Grade III on the Chinese water quality scale when the reed planting area was 123 km2 (40% of the lake surface area and most reeds would be harvested at the end of June. The optimisation approach proposed in this study will be a useful reference for lake restoration.

  17. Dispersion Management with Higher Order Mode Fibers

    Institute of Scientific and Technical Information of China (English)

    Siddharth Ramachandran

    2003-01-01

    Dispersion compensation with few-mode fibers is emerging as a promising technique that can provide full dispersion and dispersion-slope compensation. The inherent modal path diversity of these fibers allows implementation of static as well as tunable dispersion management schemes. In addition, the low nonlinearityof this technology can improve system OSNR, leading to enhancements in transmission distances.

  18. Dispersion Management with Higher Order Mode Fibers

    Institute of Scientific and Technical Information of China (English)

    Siddharth; Ramachandran

    2003-01-01

    Dispersion compensation with few-mode fibers is emerging as a promising technique that can provide full dispersion and dispersion-slope compensation. The inherent modal path diversity of these fibers allows implementation of static as well as tunable dispersion management schemes. In addition, the low non-linearity of this technology can improve system OSNR, leading to enhancements in transmission distances.

  19. Topology optimisation for energy management in underwater sensor networks

    Science.gov (United States)

    Jha, Devesh K.; Wettergren, Thomas A.; Ray, Asok; Mukherjee, Kushal

    2015-09-01

    In general, battery-powered sensors in a sensor network are operable as long as they can communicate sensed data to a processing node. In this context, a sensor network has two competing objectives: (1) maximisation of the network performance with respect to the probability of successful search for a specified upper bound on the probability of false alarms, and (2) maximisation of the network's operable life. As both sensing and communication of data consume battery energy at the sensing nodes of the sensor network, judicious use of sensing power and communication power is needed to improve the lifetime of the sensor network. This paper presents an adaptive energy management policy that will optimally allocate the available energy between sensing and communication at each sensing node to maximise the network performance subject to specified constraints. Under the assumptions of fixed total energy allocation for a sensor network operating for a specified time period, the problem is reduced to synthesis of an optimal network topology that maximises the probability of successful search (of a target) over a surveillance region. In a two-stage optimisation, a genetic algorithm-based meta-heuristic search is first used to efficiently explore the global design space, and then a local pattern search algorithm is used for convergence to an optimal solution. The results of performance optimisation are generated on a simulation test bed to validate the proposed concept. Adaptation to energy variations across the network is shown to be manifested as a change in the optimal network topology by using sensing and communication models for underwater environment. The approximate Pareto-optimal surface is obtained as a trade-off between network lifetime and probability of successful search over the surveillance region.

  20. Sustainable management of a coupled groundwater-agriculture hydrosystem using multi-criteria simulation based optimisation.

    Science.gov (United States)

    Grundmann, Jens; Schütze, Niels; Lennartz, Franz

    2013-01-01

    In this paper we present a new simulation-based integrated water management tool for sustainable water resources management in arid coastal environments. This tool delivers optimised groundwater withdrawal scenarios considering saltwater intrusion as a result of agricultural and municipal water abstraction. It also yields a substantially improved water use efficiency of irrigated agriculture. To allow for a robust and fast operation we unified process modelling with artificial intelligence tools and evolutionary optimisation techniques. The aquifer behaviour is represented using an artificial neural network (ANN) which emulates a numerical density-dependent groundwater flow model. The impact of agriculture is represented by stochastic crop water production functions (SCWPF). Simulation-based optimisation techniques together with the SCWPF and ANN deliver optimal groundwater abstraction and cropping patterns. To address contradicting objectives, e.g. profit-oriented agriculture vs. sustainable abstraction scenarios, we performed multi-objective optimisations using a multi-criteria optimisation algorithm.

  1. L-band transmission over 1000 km using standard and dispersion compensating fibers in a pre-compensation scheme optimised at 1550 nm

    DEFF Research Database (Denmark)

    Peucheret, Christophe; Muñoz, Irene; Buxens, Alvaro A.;

    1999-01-01

    Transmission over 1000 km of a 10 Gbit/s signal at 1597 nm is demonstrated in a recirculating loop using standard fibre and wideband dispersion-compensating fibre in the pre-compensation configuration. It is shown that dispersion maps optimised for 1550 nm can be successfully used in the L...

  2. Intelligent Internet-based information system optimises diabetes mellitus management in communities.

    Science.gov (United States)

    Wei, Xuejuan; Wu, Hao; Cui, Shuqi; Ge, Caiying; Wang, Li; Jia, Hongyan; Liang, Wannian

    2017-01-01

    To evaluate the effect of an intelligent Internet-based information system upon optimising the management of patients diagnosed with type 2 diabetes mellitus (T2DM). In 2015, a T2DM information system was introduced to optimise the management of T2DM patients for 1 year in Fangzhuang community of Beijing, China. A total of 602 T2DM patients who were registered in the health service centre of Fangzhuang community were enrolled based on an isometric sampling technique. The data from 587 patients were used in the final analysis. The intervention effect was subsequently assessed by statistically comparing multiple parameters, such as the prevalence of glycaemic control, standard health management and annual outpatient consultation visits per person, before and after the implementation of the T2DM information system. In 2015, a total of 1668 T2DM patients were newly registered in Fangzhuang community. The glycaemic control rate was calculated as 37.65% in 2014 and significantly elevated up to 62.35% in 2015 ( p information system, the rate of standard health management was increased from 48.04% to 85.01% ( p information system optimised the management of T2DM patients in Fangzhuang community and decreased the outpatient numbers in both community and general hospitals, which played a positive role in assisting T2DM patients and their healthcare providers to better manage this chronic illness.

  3. Towards tailored and targeted adherence assessment to optimise asthma management

    NARCIS (Netherlands)

    van Boven, Job F. M.; Trappenburg, Jaap C. A.; van der Molen, Thys; Chavannes, Niels H.

    2015-01-01

    In this paper, we aim to emphasise the need for a more comprehensive and tailored approach to manage the broad nature of non-adherence, to personalise current asthma management. Although currently several methods are available to measure the extent of asthma patients' adherence, the vast majority do

  4. Towards tailored and targeted adherence assessment to optimise asthma management

    NARCIS (Netherlands)

    van Boven, Job F. M.; Trappenburg, Jaap C. A.; van der Molen, Thys; Chavannes, Niels H.

    2015-01-01

    In this paper, we aim to emphasise the need for a more comprehensive and tailored approach to manage the broad nature of non-adherence, to personalise current asthma management. Although currently several methods are available to measure the extent of asthma patients' adherence, the vast majority do

  5. Managing 'Generation Y' occupational therapists: optimising their potential.

    Science.gov (United States)

    Hills, Caroline; Ryan, Susan; Warren-Forward, Helen; Smith, Derek R

    2013-08-01

    'Generation Y' is a descriptor of those therapists born between 1982 and 2000. According to generational theory, each generation have unique characteristics due to the social and historical factors they have experienced during their formative years. Occupational therapy educators have reported on 'Generation Y' characteristics observed in occupational therapy students. This study aimed to investigate if managers considered there was a 'Generation Y' therapist and their observed characteristics in practice, as well as successful management strategies used to maximise their potential in the workplace. A hard copy survey based on the 'Generation Y' literature was sent to all managers listed on an Australian University database. Almost all respondents considered there was a 'Generation Y' therapist. Overall, managers reported characteristics of this staff group as being hard working, confident with technology, needing positive feedback and demanding professional development opportunities. Managers also reported that this group may be a challenge to retain in work positions. Managers also viewed 'Generation Y' staff as a positive energy and considered that in the future they will be of benefit to the profession. While there may be generational differences between therapists in the workplace, inclusive management styles may be the most appropriate management approach. Career guidance, facilitating creativity, increasing work responsibility and integrating new technologies like social networking into practice may be appropriate strategies for this staff group, to facilitate both their professional development and to retain them in the profession. © 2013 Occupational Therapy Australia.

  6. Cytomegalovirus quantification: where to next in optimising patient management?

    Science.gov (United States)

    Atkinson, Claire; Emery, Vincent C

    2011-08-01

    Over the years quantification of cytomegalovirus (HCMV) load in blood has become a mainstay of clinical management helping direct deployment of antiviral therapy, assess response to therapy and highlight cases of drug resistance. The review focuses on a brief historical perspective of HCMV quantification and the ways in which viral load is being used to improve patient management. A review of the published literature and also personal experience at the Royal Free Hospital. Quantification of HCMV is essential for efficient patient management. The ability to use real time quantitative PCR to drive pre-emptive therapy has improved patient management after transplantation although the threshold viral loads for deployment differ between laboratories. The field would benefit from access to a universal standard for quantification. We see that HCMV quantification will continue to be central to delivering individualised patient management and facilitating multicentre trials of new antiviral agents and vaccines in a variety of clinical settings. Copyright © 2011 Elsevier B.V. All rights reserved.

  7. Waste management system optimisation for Southern Italy with MARKAL model

    Energy Technology Data Exchange (ETDEWEB)

    Salvia, M.; Cosmi, C. [Istituto di Metodologie Avanzate di Analisi Ambientale, Consiglio Nazionale delle Ricerche, C. da S. Loja, 85050 (PZ) Tito Scalo (Italy); Macchiato, M. [Dipartimento di Scienze Fisiche, Universita Federico II, Via Cintia, 80126 Napoli (Italy); Mangiamele, L. [Dipartimento di Ingegneria e Fisica dell' Ambiente, Universita degli Studi della Basilicata, C. da Macchia Romana, 85100 Potenza (Italy)

    2002-01-01

    The MARKAL models generator was utilised to build up a comprehensive model of the anthropogenic activities system which points out the linkages between productive processes and waste disposal technologies. The aim of such a study is to determine the optimal configuration of the waste management system for the Basilicata region (Southern Italy), in order to support the definition of the regional waste management plan in compliance with the Italian laws. A sensitivity analysis was performed to evaluate the influence of landfilling fees on the choice of waste processing technologies, in order to foster waste management strategies which are environmentally sustainable, economically affordable and highly efficient. The results show the key role of separate collection and mechanical pre-treatments in the achievement of the legislative targets.

  8. OPTIMISING PROCESSES OF IT ORGANISATION THROUGH SOFTWARE PRODUCTS’ CONFIGURATION MANAGEMENT

    Directory of Open Access Journals (Sweden)

    Ion BULIGIU

    2009-01-01

    Full Text Available The present paper is focused on the efficiency of processes within IT firmswhich design software products, by finding optimum management solutionsfor these types of activities. In order to achieve this, we focus on softwareproducts configuration management, with specific objectives in documentingand ensuring visibility to the product’s configuration and of the stage ofachieving its physical and functional characteristics. Through configurationmanagement, technical and administrative rules are established and appliedfor designing, developing, producing and supporting the elements of theproduct’s configuration, in each stage of its lifecycle. The conclusions of thisresearch are focused on evaluating economic effects obtained byimplementing the quality management system, according to the ISO9001:2000 quality standard, while developing software products, at the levelof IT firm.

  9. Optimising Land-Sea Management for Inshore Coral Reefs

    Science.gov (United States)

    Gilby, Ben L.; Olds, Andrew D.; Connolly, Rod M.; Stevens, Tim; Henderson, Christopher J.; Maxwell, Paul S.; Tibbetts, Ian R.; Schoeman, David S.; Rissik, David; Schlacher, Thomas A.

    2016-01-01

    Management authorities seldom have the capacity to comprehensively address the full suite of anthropogenic stressors, particularly in the coastal zone where numerous threats can act simultaneously to impact reefs and other ecosystems. This situation requires tools to prioritise management interventions that result in optimum ecological outcomes under a set of constraints. Here we develop one such tool, introducing a Bayesian Belief Network to model the ecological condition of inshore coral reefs in Moreton Bay (Australia) under a range of management actions. Empirical field data was used to model a suite of possible ecological responses of coral reef assemblages to five key management actions both in the sea (e.g. expansion of reserves, mangrove & seagrass restoration, fishing restrictions) and on land (e.g. lower inputs of sediment and sewage from treatment plants). Models show that expanding marine reserves (a ‘marine action’) and reducing sediment inputs from the catchments (a ‘land action’) were the most effective investments to achieve a better status of reefs in the Bay, with both having been included in >58% of scenarios with positive outcomes, and >98% of the most effective (5th percentile) scenarios. Heightened fishing restrictions, restoring habitats, and reducing nutrient discharges from wastewater treatment plants have additional, albeit smaller effects. There was no evidence that combining individual management actions would consistently produce sizeable synergistic until after maximum investment on both marine reserves (i.e. increasing reserve extent from 31 to 62% of reefs) and sediments (i.e. rehabilitating 6350 km of waterways within catchments to reduce sediment loads by 50%) were implemented. The method presented here provides a useful tool to prioritize environmental actions in situations where multiple competing management interventions exist for coral reefs and in other systems subjected to multiple stressor from the land and the sea

  10. Optimised battery capacity utilisation within battery management systems

    NARCIS (Netherlands)

    Wilkins, S.; Rosca, B.; Jacob, J.; Hoedmaekers, E.

    2015-01-01

    Battery Management Systems (BMSs) play a key role in the performance of both hybrid and fully electric vehicles. Typically, the role of the BMS is to help maintain safety, performance, and overall efficiency of the battery pack. One important aspect of its operation is the estimation of the state of

  11. Optimised battery capacity utilisation within battery management systems

    NARCIS (Netherlands)

    Wilkins, S.; Rosca, B.; Jacob, J.; Hoedmaekers, E.

    2015-01-01

    Battery Management Systems (BMSs) play a key role in the performance of both hybrid and fully electric vehicles. Typically, the role of the BMS is to help maintain safety, performance, and overall efficiency of the battery pack. One important aspect of its operation is the estimation of the state of

  12. Make a CHANGE: optimising communication and pain management decisions.

    Science.gov (United States)

    Müller-Schwefe, Gerhard; Jaksch, Wolfgang; Morlion, Bart; Kalso, Eija; Schäfer, Michael; Coluzzi, Flaminia; Huygen, Frank; Kocot-Kepska, Magdalena; Mangas, Ana Cristina; Margarit, Cesar; Ahlbeck, Karsten; Mavrocordatos, Philippe; Alon, Eli; Collett, Beverly; Aldington, Dominic; Nicolaou, Andrew; Pergolizzi, Joseph; Varrassi, Giustino

    2011-02-01

    The major objectives of the CHANGE PAIN International Advisory Board are to enhance understanding of chronic pain and to develop strategies for improving pain management. At its second meeting, in November 2009, evidence was presented that around one person in five in Europe and the USA experiences chronic pain, and the delay before referral to a pain specialist is often several years. Moreover, physicians' pharmacological approach to chronic pain is inconsistent, as evidenced by the huge variation in treatment between different European countries. It was agreed that efficient communication between physician and patient is essential for effective pain management, and that efficacy/side-effect balance is a key factor in choosing an analgesic agent. The multifactorial nature of chronic pain produces various physical and psychological symptoms, so the management of chronic pain should be tailored to the individual. Pharmacological therapy must be matched to the causative mechanisms responsible, or it is likely to prove ineffective and risk the development of a 'vicious circle'; doses are increased because of inadequate pain relief, but this increases side-effects so doses are reduced, pain relief is then inadequate, so doses are increased, and so on. Pain management decisions should not therefore be based solely on the severity of pain. Based on the concept of individual treatment targets (ITT), the CHANGE PAIN Scale was adopted - a simple, user-friendly assessment tool to improve communication between physician and patient. The 11-point NRS enables the patient to rate the current pain intensity and to set a realistic individual target level. On the reverse are six key parameters affecting the patient's quality of life; clinicians simply need to agree with patients whether improvement is needed in each one. Regular use can establish the efficacy and tolerability of pain management, and the rate of progress towards individual treatment targets.

  13. Optimising the management of pulmonary arterial hypertension patients: emergency treatments

    Directory of Open Access Journals (Sweden)

    R. Naeije

    2010-09-01

    Full Text Available Pulmonary arterial hypertension (PAH is a rare and potentially fatal disease whose management is usually restricted to a few specialised centres. As patients do not necessarily live in the neighbourhood of these centres, daily care and emergencies have to be delegated to first and second lines. Treatment guidelines do not usually provide recommendations for acute emergency situations as evidence is scarce. This short review provides a description of our therapeutic protocols based on available data. A model of transmural organisation of care for PAH patients, currently applied in Belgium, is described. Thereafter, based on an analysis of the reasons of death in the PAH population, a review of the main emergencies is provided. Cardiac arrest and resuscitation, decompensated right heart failure, respiratory failure, arrhythmia, pericardial effusion, haemoptysis, surgery and drug-related adverse events will be discussed successively. Case reports showing the precariousness of PAH patients will enforce our thesis of the need for optimal patient management organisation.

  14. Optimisation models and solution methods for load management

    Energy Technology Data Exchange (ETDEWEB)

    Gustafsson, Stig-Inge [Linkoeping Univ. (Sweden). Div. of Wood Science and Technology; Roennqvist, Mikael; Claesson, Marcus [Linkoeping Univ. (Sweden). Div. of Optimisation

    2001-02-01

    The electricity market in Sweden has changed during recent years. Electricity for industrial use can nowadays be purchased from a number of competing electricity suppliers. Hence, the price for each kilowatt-hour is significantly lower than just two years ago and the interest for electricity conservation measures has declined. Part of the electricity tariff is, however, almost the same as before, i.e. the demand cost expressed in Swedish Kronor, SEK, for each kilowatt. This has put focus on load management measures in order to decrease this specific cost. Saving one kWh might lead to monetary savings between 0.22 to 914 SEK and this paper shows how to save only those kWh which really save money. A load management system has been installed in a small carpentry factory and the device can turn off equipment due to a certain priority and for a number of minutes each hour. The question is now, what level on the electricity load is optimal in a strict mathematical sense, i.e. how many kW should be set in the load management computer in order to get the best profitability? In this paper we develop a mathematical model which can be used both as a tool to find a best profitable subscription level and as a tool to control the turn of choices. Numerical results from a case study are presented.

  15. Optimising the management of fever and pain in children.

    Science.gov (United States)

    van den Anker, J N

    2013-01-01

    Fever and pain in children, especially associated with infections, such as otitis media, are very common. In paediatric populations, ibuprofen and paracetamol (acetaminophen) are both commonly used over-the-counter medicines for the management of fever or mild-to-moderate pain associated with sore throat, otitis media, toothache, earache and headache. Widespread use of ibuprofen and paracetamol has shown that they are both effective and generally well tolerated in the reduction in paediatric fever and pain. However, ibuprofen has the advantage of less frequent dosing (every 6-8 h vs. every 4 h for paracetamol) and its longer duration of action makes it a suitable alternative to paracetamol. In comparative trials, ibuprofen has been shown to be at least as effective as paracetamol as an analgesic and more effective as an antipyretic. The safety profile of ibuprofen is comparable to that of paracetamol if both drugs are used appropriately with the correct dosing regimens. However, in the overdose situation, the toxicity of paracetamol is not only reached much earlier, but is also more severe and more difficult to manage as compared with an overdose of ibuprofen. There is clearly a need for advanced studies to investigate the safety of these medications in paediatric populations of different ages and especially during prolonged use. Finally, the recently reported association between frequency and severity of asthma and paracetamol use needs urgent additional investigations.

  16. Removal of Disperse Red dye by bamboo-based activated carbon: optimisation, kinetics and equilibrium.

    Science.gov (United States)

    Wang, Lianggui

    2013-07-01

    This research involved the use of response surface methodology (RSM) to investigate the adsorption of Disperse Red 167 dye onto the bamboo-based activated carbon activated with H3PO4 (PBAC) in a batch process. F400, a commercially available activated carbon, was used in parallel for comparison. Analysis of variance showed that input variables such as the contact time, temperature, adsorbent dosage and the interaction between the temperature and the contact time had a significant effect on the dye removal for both adsorbents. RSM results show that the optimal contact time, temperature, initial dye concentration and adsorbent dosage for both adsorbents were found to be 15.4 h, 50 °C, 50.0 mg L(-1) and 12.0 g L(-1), respectively. Under these optimal conditions, the removal efficiencies reached 90.23% and 92.13% for PBAC and F400, respectively, with a desirability of 0.937. The validation of the experimental results confirmed the prediction of the models derived from RSM. The adsorption followed a nonlinear pseudo-first-order model and agreed well with the Freundlich and Temkin isotherm as judged by the levels of the AICc and the Akaike weight. Furthermore, the thermodynamics analysis indicated that, for both adsorbents, the adsorption was a physical process that was spontaneous, entropy-increasing and endothermic.

  17. Dispersion managed solitons in the presence of saturated nonlinearity

    Science.gov (United States)

    Hundertmark, Dirk; Lee, Young-Ran; Ried, Tobias; Zharnitsky, Vadim

    2017-10-01

    The averaged dispersion managed nonlinear Schrödinger equation with saturated nonlinearity is considered. It is shown that under rather general assumptions on the saturated nonlinearity, the ground state solution corresponding to the dispersion managed soliton can be found for both zero residual dispersion and positive residual dispersion. The same applies to diffraction management solitons, which are a discrete version describing certain waveguide arrays.

  18. Optimising Drug Solubilisation in Amorphous Polymer Dispersions: Rational Selection of Hot-melt Extrusion Processing Parameters.

    Science.gov (United States)

    Li, Shu; Tian, Yiwei; Jones, David S; Andrews, Gavin P

    2016-02-01

    The aim of this article was to construct a T-ϕ phase diagram for a model drug (FD) and amorphous polymer (Eudragit® EPO) and to use this information to understand the impact of how temperature-composition coordinates influenced the final properties of the extrudate. Defining process boundaries and understanding drug solubility in polymeric carriers is of utmost importance and will help in the successful manufacture of new delivery platforms for BCS class II drugs. Physically mixed felodipine (FD)-Eudragit(®) EPO (EPO) binary mixtures with pre-determined weight fractions were analysed using DSC to measure the endset of melting and glass transition temperature. Extrudates of 10 wt% FD-EPO were processed using temperatures (110°C, 126°C, 140°C and 150°C) selected from the temperature-composition (T-ϕ) phase diagrams and processing screw speed of 20, 100 and 200rpm. Extrudates were characterised using powder X-ray diffraction (PXRD), optical, polarised light and Raman microscopy. To ensure formation of a binary amorphous drug dispersion (ADD) at a specific composition, HME processing temperatures should at least be equal to, or exceed, the corresponding temperature value on the liquid-solid curve in a F-H T-ϕ phase diagram. If extruded between the spinodal and liquid-solid curve, the lack of thermodynamic forces to attain complete drug amorphisation may be compensated for through the use of an increased screw speed. Constructing F-H T-ϕ phase diagrams are valuable not only in the understanding drug-polymer miscibility behaviour but also in rationalising the selection of important processing parameters for HME to ensure miscibility of drug and polymer.

  19. Optimising postoperative pain management in the ambulatory patient.

    Science.gov (United States)

    Shang, Allan B; Gan, Tong J

    2003-01-01

    Over 60% of surgery is now performed in an ambulatory setting. Despite improved analgesics and sophisticated drug delivery systems, surveys indicate that over 80% of patients experience moderate to severe pain postoperatively. Inadequate postoperative pain relief can prolong recovery, precipitate or increase the duration of hospital stay, increase healthcare costs, and reduce patient satisfaction. Effective postoperative pain management involves a multimodal approach and the use of various drugs with different mechanisms of action. Local anaesthetics are widely administered in the ambulatory setting using techniques such as local injection, field block, regional nerve block or neuraxial block. Continuous wound infusion pumps may have great potential in an ambulatory setting. Regional anaesthesia (involving anaesthetising regional areas of the body, including single extremities, multiple extremities, the torso, and the face or jaw) allows surgery to be performed in a specific location, usually an extremity, without the use of general anaesthesia, and potentially with little or no sedation. Opioids remain an important component of any analgesic regimen in treating moderate to severe acute postoperative pain. However, the incorporation of non-opioids, local anaesthetics and regional techniques will enhance current postoperative analgesic regimens. The development of new modalities of treatment, such as patient controlled analgesia, and newer drugs, such as cyclo-oxygenase-2 inhibitors, provide additional choices for the practitioner. While there are different routes of administration for analgesics (e.g. oral, parenteral, intramuscular, transmucosal, transdermal and sublingual), oral delivery of medications has remained the mainstay for postoperative pain control. The oral route is effective, the simplest to use and typically the least expensive. The intravenous route has the advantages of a rapid onset of action and easier titratibility, and so is recommended for the

  20. Optimising the management of patients with difficult asthma.

    Science.gov (United States)

    Palmer, Evelyn; Higgins, Bernard

    2015-11-01

    Asthma affects 5.4 million people in the UK, around 1 in 12 of the population. Between 5 and 10% of asthma (depending on the definition used) is categorised as difficult asthma, a term which generally refers to patients who continue to experience symptoms and frequent exacerbations despite the prescription of high-dose asthma therapy. Difficult asthma is an indication for specialist review by an appropriate respiratory physician, but close liaison between primary, secondary and tertiary care is critical and it is therefore important that primary care health professionals should be aware of the principles of management. One of the most important questions to ask is whether the individual with difficult asthma is taking their treatment Identifying this, however, is not easy. GPs could assess prescription uptake, looking for low use of preventers and excess use of short-acting bronchodilators. Newer means of assessing adherence have been developed. Inhaler devices that can monitor completion and timing of actuations have been produced. Meters that measure FeNO are available. A recent UK study found that 12 out of 100 patients referred for difficult asthma did not have reversible airflow obstruction or a history suggestive of asthma. Diagnoses included COPD, cystic fibrosis, cardiomyopathy, respiratory muscle dysfunction and severe anxiety with vocal cord dysfunction.

  1. Distributed Optimisation Algorithm for Demand Side Management in a Grid-Connected Smart Microgrid

    Directory of Open Access Journals (Sweden)

    Omowunmi Mary Longe

    2017-06-01

    Full Text Available The contributions of Distributed Energy Generation (DEG and Distributed Energy Storage (DES for Demand Side Management (DSM purposes in a smart macrogrid or microgrid cannot be over-emphasised. However, standalone DEG and DES can lead to under-utilisation of energy generation by consumers and financial investments; in grid-connection mode, though, DEG and DES can offer arbitrage opportunities for consumers and utility provider(s. A grid-connected smart microgrid comprising heterogeneous (active and passive smart consumers, electric vehicles and a large-scale centralised energy storage is considered in this paper. Efficient energy management by each smart entity is carried out by the proposed Microgrid Energy Management Distributed Optimisation Algorithm (MEM-DOA installed distributively within the network according to consumer type. Each smart consumer optimises its energy consumption and trading for comfort (demand satisfaction and profit. The proposed model was observed to yield better consumer satisfaction, higher financial savings, and reduced Peak-to-Average-Ratio (PAR demand on the utility grid. Other associated benefits of the model include reduced investment on peaker plants, grid reliability and environmental benefits. The MEM-DOA also offered participating smart consumers energy and tariff incentives so that passive smart consumers do not benefit more than active smart consumers, as was the case with some previous energy management algorithms.

  2. Multi-objective optimisation of cost-benefit of urban flood management using a 1D2D coupled model.

    Science.gov (United States)

    Delelegn, S W; Pathirana, A; Gersonius, B; Adeogun, A G; Vairavamoorthy, K

    2011-01-01

    This paper presents a multi-objective optimisation (MOO) tool for urban drainage management that is based on a 1D2D coupled model of SWMM5 (1D sub-surface flow model) and BreZo (2D surface flow model). This coupled model is linked with NSGA-II, which is an Evolutionary Algorithm-based optimiser. Previously the combination of a surface/sub-surface flow model and evolutionary optimisation has been considered to be infeasible due to the computational demands. The 1D2D coupled model used here shows a computational efficiency that is acceptable for optimisation. This technological advance is the result of the application of a triangular irregular discretisation process and an explicit finite volume solver in the 2D surface flow model. Besides that, OpenMP based parallelisation was employed at optimiser level to further improve the computational speed of the MOO tool. The MOO tool has been applied to an existing sewer network in West Garforth, UK. This application demonstrates the advantages of using multi-objective optimisation by providing an easy-to-comprehend Pareto-optimal front (relating investment cost to expected flood damage) that could be used for decision making processes, without repeatedly going through the modelling-optimisation stage.

  3. Modelling airborne dispersion for disaster management

    Science.gov (United States)

    Musliman, I. A.; Yohnny, L.

    2017-05-01

    Industrial disasters, like any other disasters, can happen anytime, anywhere and in any form. Airborne industrial disaster is a kind of catastrophic event involving the release of particles such as chemicals and industrial wastes into environment in gaseous form, for instance gas leakages. Unlike solid and liquid materials, gases are often colourless and odourless, the particles are too tiny to be visible to the naked eyes; hence it is difficult to identify the presence of the gases and to tell the dispersion and location of the substance. This study is to develop an application prototype to perform simulation modelling on the gas particles to determine the dispersion of the gas particles and to identify the coverage of the affected area. The prototype adopted Lagrangian Particle Dispersion (LPD) model to calculate the position of the gas particles under the influence of wind and turbulent velocity components, which are the induced wind due to the rotation of the Earth, and Convex Hull algorithm to identify the convex points of the gas cloud to form the polygon of the coverage area. The application performs intersection and overlay analysis over a set of landuse data at Pasir Gudang, Johor industrial and residential area. Results from the analysis would be useful to tell the percentage and extent of the affected area, and are useful for the disaster management to evacuate people from the affected area. The developed application can significantly increase efficiency of emergency handling during a crisis. For example, by using a simulation model, the emergency handling can predict what is going to happen next, so people can be well informed and preparations works can be done earlier and better. Subsequently, this application helps a lot in the decision making process.

  4. The optimization of treatment and management of schizophrenia in Europe (OPTiMiSE) trial

    DEFF Research Database (Denmark)

    Leucht, Stefan; Winter-van Rossum, Inge; Heres, Stephan;

    2015-01-01

    gap leaves important questions unanswered. For example, when a first antipsychotic failed, is switching to another drug effective? And when should we use clozapine? The aim of this article is to review the efficacy of switching antipsychotics in case of nonresponse. We also present the European...... Commission sponsored "Optimization of Treatment and Management of Schizophrenia in Europe" (OPTiMiSE) trial which aims to provide a treatment algorithm for patients with a first episode of schizophrenia. METHODS: We searched Pubmed (October 29, 2014) for randomized controlled trials (RCTs) that examined...

  5. Optimisation of near-term PPCS power plant designs from the material managment stance

    Energy Technology Data Exchange (ETDEWEB)

    Pampin, R.; O' Brian, M.H. [Euratom/UKAEA Fusion Association, Culham Science Centre, Abingdon (United Kingdom)

    2007-07-01

    The effective management of active material arising from fusion power generation is of crucial importance to maximise the environmental benefits of fusion. In recent years, several EU and international activities have focused towards minimising fusion waste and its radiotoxicity. Reviews have been made of industry practices and international standards to support a comprehensive management strategy based on maximum clearance, recycling and refurbishment of materials. Following this effort, the next step is to optimise the power plant designs according to this strategy and following the 'low-activation-design' philosophy of earlier studies. In this paper, the design of two near-term PPCS plant models based on ITER-relevant technology, a helium-cooled pebble bed and lithium-lead blanket concepts, are re-visited to optimise the management of active materials and minimise wastes. Combined use of novel shielding materials, customised radial builds and impurity control achieve maximum clearance and recycling potential of the irradiated material, and minimise the radiotoxicity of any residual secondary wastes. Up to 17% of the material can achieve clearance before 100 years, representing the majority of the decommissioning stream. Of the remaining material, most can be recycled in conventional nuclear foundries. C-14 generation can be reduced by at least 95% with adequate control of nitrogen impurities. Results confirm the trends obtained in previous work pointing to over-conservatism of the original PPCS analyses based on out-of- date criteria and experience. (orig.)

  6. Characterisation of Reticon and Hamamatsu photodiode array and the subsequent development of high performance VME-based detector systems optimised for energy dispersive EXAFS

    Energy Technology Data Exchange (ETDEWEB)

    Bogg, D.; Dent, A.J.; Derbyshire, G.E.; Farrow, R.C.; Ramsdale, C.A.; Salvini, G. [Daresbury Lab., Warrington (United Kingdom). CCLRC

    1997-06-21

    Energy dispersive EXAFS is an established and successful technique employed at Daresbury Laboratory for the study of dynamic experiments. At the heart of this technique is an in house developed high-performance VME-based detector system using a photodiode array. This system originally used a Reticon RL1024S array but extensive investigation of three other photodiode arrays namely the Reticon 512T, 512SB and the Hamamatsu S3904 has enabled their characterisation and the subsequent development of optimised drive and signal processing electronics. This has provided two further systems which exhibit improved signal to noise, excellent linearity and increased operational speed. (orig.).

  7. Nonlinear Interactions of Dispersion-managed Soliton in OTDM Systems

    Institute of Scientific and Technical Information of China (English)

    CAI Ju; MAO Yu; LU Hui; ZHANG Li-na; YANG Xiang-lin

    2003-01-01

    The dispersion-managed soliton (DMS) transmission model of dispersion-managed systems is established,and the intrachannel DMS interactions equation is obtained.The impact of soliton interactions on DMS systems are numerically investigated.Finally,the relationships of the collision length changing with map strength are revealed.

  8. Instabilities of dispersion-managed solitons in the normal dispersion regime

    OpenAIRE

    Pelinovsky, Dmitry

    2000-01-01

    Dispersion-managed solitons are reviewed within a Gaussian variational approximation and an integral evolution model. In the normal regime of the dispersion map (when the averaged path dispersion is negative), there are two solitons of different pulse duration and energy at a fixed propagation constant. We show that the short soliton with a larger energy is linearly (exponentially) unstable. The other (long) soliton with a smaller energy is linearly stable but hits a resonance with excitation...

  9. Optimising stocking rate and grazing management to enhance environmental and production outcomes for native temperate grasslands

    Science.gov (United States)

    Badgery, Warwick; Zhang, Yingjun; Huang, Ding; Broadfoot, Kim; Kemp, David; Mitchell, David

    2015-04-01

    lamb/ha), because individual animal performance was greater for continuous grazing than higher intensity grazing systems (4-Paddock and 20-Paddock). Differences in SOC, CO2 flux and erosion were determined by landscape position rather than grazing treatment. To remove the confounding influences of stocking rate and grazing management, the Ausfarm biophysical model, calibrated to the experimental treatments, examined the interaction between grazing management and stocking rates. Ground cover and profitability were similar between grazing systems at lower stocking rates (3 ewes per ha), but continuous grazing had higher profitability and lower ground cover above the optimum stocking rate of 4 ewes per ha. The findings of these two studies suggest that optimising stocking rate is more important than grazing management for a sustainable and profitable grazing system. Grazing management can further enhance environmental outcomes for an optimal stocking rate, but the findings from the Chinese study particularly highlight the need to look at multiple ecosystem services, when optimising systems. The Australian study also suggests the optimum stocking rate is dependent on the intensity of grazing management. Further work is required to understand the influence of landscape on grassland production and how stocking rates and grazing management can be sustainably optimised for different landscape areas to utilise this variation more effectively.

  10. Management of winter weeds affects Frankliniella fusca (Thysanoptera: Thripidae) dispersal.

    Science.gov (United States)

    Beaudoin, A L P; Kennedy, G G

    2012-04-01

    Frankliniella fusca (Hinds) naturally disperses from winter weeds to crops in spring, causing direct and indirect damage. Field preparation before planting includes use of herbicides or cultivation to kill unwanted vegetation, which adversely affects F. fusca host plants and potentially influences F. fusca dispersal. Common chickweed, Stellaria media (L.), infested with F. fusca, was used as a model to study effects of timing and type of vegetation management on adult dispersal. Infested weeds were caged and F. fusca weekly dispersal was monitored using sticky traps. Weed management treatments performed at an early (14 April-11 May) or late (2 wk after early treatment) date consisted of glyphosate, paraquat, disking, hoeing, or untreated control. Late glyphosate and hoeing treatments resulted in cumulative dispersal statistically similar to or greater than from control plots. Compared with the control, significantly more F. fusca dispersed from the glyphosate and hoeing plots during the 3 wk after treatment. More thrips dispersed from the late paraquat treatment 1 wk post-application than from the control. Dispersal from the disked treatment and early paraquat treatment was similar to that of the control 1- to 3-wk post-treatment. Early treatments resulted in significantly smaller cumulative dispersal than the control in all but one instance. Late disking and paraquat treatments resulted in cumulative F. fusca captures that were statistically similar or less than that in the control. Winter weed management type and timing affect F. fusca dispersal magnitude and duration.

  11. Advanced data management for optimising the operation of a full-scale WWTP.

    Science.gov (United States)

    Beltrán, Sergio; Maiza, Mikel; de la Sota, Alejandro; Villanueva, José María; Ayesa, Eduardo

    2012-01-01

    The lack of appropriate data management tools is presently a limiting factor for a broader implementation and a more efficient use of sensors and analysers, monitoring systems and process controllers in wastewater treatment plants (WWTPs). This paper presents a technical solution for advanced data management of a full-scale WWTP. The solution is based on an efficient and intelligent use of the plant data by a standard centralisation of the heterogeneous data acquired from different sources, effective data processing to extract adequate information, and a straightforward connection to other emerging tools focused on the operational optimisation of the plant such as advanced monitoring and control or dynamic simulators. A pilot study of the advanced data manager tool was designed and implemented in the Galindo-Bilbao WWTP. The results of the pilot study showed its potential for agile and intelligent plant data management by generating new enriched information combining data from different plant sources, facilitating the connection of operational support systems, and developing automatic plots and trends of simulated results and actual data for plant performance and diagnosis.

  12. An optimised protocol to isolate high-quality genomic DNA from seed tissues streamlines the workflow to obtain direct estimates of seed dispersal distances in gymnosperms.

    Science.gov (United States)

    García, C; Escribano-Ávila, G

    2016-05-01

    Genotyping of maternally derived seed tissues from georefered seeds that moved away from their source tree yield direct estimates of seed dispersal distances when the location and the genotype of the fruiting tree are available. These estimates are instrumental in forecasting the response of plant communities to drivers of global change, such as fragmentation or the expansion of invasive species. Obtaining robust assessments of seed dispersal distances requires comparing reliable multilocus genotypes of maternally derived seed tissues and fruiting trees, as previously shown for angiosperm species. However, robust estimates of seed dispersal distances based on direct methods are rare in non-model gymnosperms due to the difficulty in isolating high quality DNA from inconspicuous maternally derived seed tissues. These tissues tend to yield low DNA quantities that increase the frequency of genotyping errors. Here, we deliver a step-by-step visual protocol used to identify and isolate different seed tissues of interest for dispersal studies: embryos (2n, bi-parentally derived), seed coats (2n, maternally derived), and megagametophytes (n, maternally derived). We also provide an optimised lab protocol used to obtain multilocus genotypes from the target seed tissue. These broadly applicable protocols proved successful both in avoiding contamination among different seed tissues and providing reliable multilocus genotypes.

  13. Optimisation of Oil Spill Dispersants on Weathered Oils. A New Approach Using Experimental Design and Multivariate Data Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Brandvik, Per Johan

    1997-12-31

    This thesis describes how laboratory experiments combined with numerical modelling were used to predict weathering of an oil slick at different environmental conditions (temperature, wind etc.). It also applies laboratory test methods to screen dispersant effectiveness under different temperatures and salinities. A new approach is developed for dispersant optimization based on statistical design and multivariate analysis; this resulted in a new dispersant with low toxicity and high effectiveness on a broad selection of oil types. The thesis illustrates the potential of dispersant used as an operational response method on oil spills by discussing three different oil spill scenarios and compares the effect of using dispersants to using mechanical recovery and to doing nothing. Some recommendations that may increase the effectiveness of the Norwegian oil spill contingency are also given. 172 refs., 65 figs., 9 tabs.

  14. Optimising UK urban road verge contributions to biodiversity and ecosystem services with cost-effective management.

    Science.gov (United States)

    O'Sullivan, Odhran S; Holt, Alison R; Warren, Philip H; Evans, Karl L

    2017-04-15

    Urban road verges can contain significant biodiversity, contribute to structural connectivity between other urban greenspaces, and due to their proximity to road traffic are well placed to provide ecosystem services. Using the UK as a case study we review and critically evaluate a broad range of evidence to assess how this considerable potential can be enhanced despite financial, contractual and public opinion constraints. Reduced mowing frequency and other alterations would enhance biodiversity, aesthetics and pollination services, whilst delivering costs savings and potentially being publically acceptable. Retaining mature trees and planting additional ones is favourable to residents and would enhance biodiversity, pollution and climate regulation, carbon storage, and stormwater management. Optimising these services requires improved selection of tree species, and creating a more diverse tree stock. Due to establishment costs additional tree planting and maintenance could benefit from payment for ecosystem service schemes. Verges could also provide areas for cultivation of biofuels and possibly food production. Maximising the contribution of verges to urban biodiversity and ecosystem services is economical and becoming an increasingly urgent priority as the road network expands and other urban greenspace is lost, requiring enhancement of existing greenspace to facilitate sustainable urban development. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  15. Optimising the bio-piling of weathered hydrocarbons within a risk management framework

    Energy Technology Data Exchange (ETDEWEB)

    Hough, R.; Brassington, K.; Sinke, A.; Crossley, J.; Paton, G.; Semple, K.; Risdon, G.; Jacobson, Ch.; Daly, P.; Jackman, S.; Lethbridge, G.; Pollard, S. [Cranfield Univ. (United Kingdom)

    2005-07-01

    Thirty years of research into petroleum microbiology and bio-remediation have bypassed an important observation - that many hydrocarbon contaminated sites posing potential risks to human health harbour weathered, 'mid-distillate' or heavy oils rather than 'fresh product'. Ex-situ bio-piling is an important technology for treating soils contaminated with weathered hydrocarbons. However, its performance continues to be represented by reference to reductions in the hydrocarbon 'load' in the soils being treated, rather than reductions in the risks posed by the hydrocarbon contamination. The absence of 'risk' from the vocabulary of many operators and remediation projects reduces stakeholder (regulatory, investor, landowner, and public) confidence in remediation technologies, and subsequently limits the market potential of these technologies. Stakeholder confidence in the bio-piling of weathered hydrocarbons may be improved by demonstrating process optimisation within a validated risk management framework. To address these issues, a consortium led by Cranfield University's Integrated Waste Management Centre has secured funding from the UK Government's Bio-remediation LINK programme. Project PROMISE (involving BP, SecondSite Regeneration Ltd., Dew Remediation Ltd., TES Bretby (Mowlem Group), technology translators PERA, and academics from Aberdeen, Cranfield and Lancaster Universities) aims to improve market confidence in bio-piling by demonstrating how this treatment may be applied within a risk management context. For weathered hydrocarbons in particular, the underpinning scientific components of process control, waste diagnostics, environmental fate modelling, and risk assessment have yet to be fully integrated to allow bio-piling projects to be verified with improved confidence. The Joint Research Council Review of Bio-remediation recognised this in calling explicitly for the positioning of bio-remediation within a

  16. Optimising radioactive waste management channels: a key challenge for the future; L'optimisation des filieres de gestion des dechets radioactifs: un enjeu pour l'avenir

    Energy Technology Data Exchange (ETDEWEB)

    Boissier, F. [Agence Nationale pour la Gestion des Dechets Radioactifs - ANDRA, Dir. de la maitrise des risques, 92 - Chatenay Malabry (France)

    2011-02-15

    The objective set out in the 2010-2012 National Radioactive Materials and Waste Management Plan is to optimize the way in which waste is distributed across the different management channels. The aim of implementing such optimisation is intended to improve the technical and economic conditions under which waste is managed, at an equivalent level of safety, and even to improve safety performance. To achieve this, it is essential to take every stage in waste management into consideration: production, sorting, processing, packaging, storage and disposal. For each type of waste identified as a potential subject of optimised management, the possible alternatives at each stage are assessed. Next, by integrating the alternatives considered within an overall framework of radioactive waste management, it is possible to construct management scenarios that can be assessed in terms of safety, technical and economic performance, and social acceptability. This will then make it possible to decide, on a repeatable basis, on a waste management scenario considered to be optimised. ANDRA (French national agency for the management of radioactive waste) plans to deploy this approach mainly within the framework of the discussions it has been tasked with leading on industrial management scenarios for low-level, long-lived radioactive waste. (author)

  17. Volcanic hazard management in dispersed volcanism areas

    Science.gov (United States)

    Marrero, Jose Manuel; Garcia, Alicia; Ortiz, Ramon

    2014-05-01

    Traditional volcanic hazard methodologies were developed mainly to deal with the big stratovolcanoes. In such type of volcanoes, the hazard map is an important tool for decision-makers not only during a volcanic crisis but also for territorial planning. According to the past and recent eruptions of a volcano, all possible volcanic hazards are modelled and included in the hazard map. Combining the hazard map with the Event Tree the impact area can be zoned and defining the likely eruptive scenarios that will be used during a real volcanic crisis. But in areas of disperse volcanism is very complex to apply the same volcanic hazard methodologies. The event tree do not take into account unknown vents, because the spatial concepts included in it are only related with the distance reached by volcanic hazards. The volcanic hazard simulation is also difficult because the vent scatter modifies the results. The volcanic susceptibility try to solve this problem, calculating the most likely areas to have an eruption, but the differences between low and large values obtained are often very small. In these conditions the traditional hazard map effectiveness could be questioned, making necessary a change in the concept of hazard map. Instead to delimit the potential impact areas, the hazard map should show the expected behaviour of the volcanic activity and how the differences in the landscape and internal geo-structures could condition such behaviour. This approach has been carried out in La Palma (Canary Islands), combining the concept of long-term hazard map with the short-term volcanic scenario to show the expected volcanic activity behaviour. The objective is the decision-makers understand how a volcanic crisis could be and what kind of mitigation measurement and strategy could be used.

  18. Statistical characteristics and effects of polarization mode dispersion in dispersion managed soliton systems

    Institute of Scientific and Technical Information of China (English)

    XU Ming; JI Jian-hua

    2006-01-01

    Firstly,the JME(Jones matrix eigen) method is used to simulate the statistical characteristics of first- and second-order PMD in dispersion management system.Then,with help of the CNLSE (coupled nonlinear Schrdinger equations),the effects of PMD on DMS (dispersion managed soliton) transmission is studied with a variational method.The simplified relationships of the statistical parameters of second-order and first-order of PMD in dispersion management system have been gotten,from which the detailed information of second-order can be obtained,if the condition of DGD is given.The results have shown that the first and second-order PMD (polarization mode dispersion) vectors influence the evolution of energy and Mean square of time displacement of DMS in high-speed bit rates systems.When D1 stPMD>0.3 ps/km1/2,we must consider some means of control(for example the filter) to restrain the PMD.

  19. Impact of Polarization Mode Dispersion on Transmission Characteristics of Dispersion-Managed Solitons and Its Suppression

    Institute of Scientific and Technical Information of China (English)

    杨祥林; 徐铭; 蔡炬

    2003-01-01

    The coupled nonlinear Schrodinger equations for dispersion-managed soliton (DMS) with the impact of thepolarization mode dispersion (PMD) are constructed, and a PMD-suppression approach of DMS is proposed for the first time. Then, based on variational method, the analytical equations of the DMS transmission system within-line optical filter control are obtained. Finally, in order to investigate the validity of the equations, we presentan application sample for practical systems with in-line filter control. The results verify that the control is quiteeffective and valid.

  20. Multivariate optimisation of an ultrasound assisted-matrix solid-phase dispersion method combined with LC-fluorescence detection for simultaneous extraction and determination of aflatoxins in pistachio nut samples.

    Science.gov (United States)

    Manoochehri, Mahboobeh; Asgharinezhad, Ali Akbar; Safaei, Mahdi

    2013-01-01

    This paper describes the application of ultrasound-assisted matrix solid-phase dispersion as an extraction and clean-up procedure for aflatoxins (B1, B2, G1 and G2) and subsequent determination by LC-fluorescence detection. A Box-Behnken design was used to determine the parameters influencing the extraction procedure through response surface methodology and experimental design. The influence of different variables including type of dispersing phase, sample-to-dispersing phase ratio, type and quantity of clean-up phase, ultrasonication time, ultrasonication temperature, nature and volume of the elution solvent were investigated in the optimisation study. C18, graphitic carbon black and acetonitrile were selected as dispersing phase, clean-up phase and elution solvent, respectively. The optimised values were sample-to-dispersing phase ratio of 1:1, 50 mg of graphitic carbon black, 11 min ultrasonication time, 30°C ultrasonication temperature and 3 ml acetonitrile. Under the optimal conditions the limits of detection (LODs) were ranged from 0.04-0.11 µg kg(-1) and the relative standard deviations (RSDs) of the extraction method were less than 8.6%. The recoveries of the matrix solid-phase dispersion process ranged from 74% to 78% with relative standard deviation lower than 9% in all cases. Finally, the matrix solid-phase dispersion was successfully applied to extraction of trace amounts of aflatoxins in pistachio samples.

  1. Determination of volatile components of saffron by optimised ultrasound-assisted extraction in tandem with dispersive liquid-liquid microextraction followed by gas chromatography-mass spectrometry.

    Science.gov (United States)

    Sereshti, Hassan; Heidari, Reza; Samadi, Soheila

    2014-01-15

    In the present research, a combined extraction method of ultrasound-assisted extraction (UAE) in conjunction with dispersive liquid-liquid microextraction (DLLME) was applied to isolation and enrichment of saffron volatiles. The extracted components of the saffron were separated and determined by gas chromatography-mass spectrometry (GC-MS) technique. The mixture of methanol/acetonitrile was chosen for the extraction of the compounds and chloroform was used at the preconcentration stage. The important parameters, such as composition of extraction solvent, volume of preconcentration solvent, ultrasonic applying time, and salt concentration were optimised by using a half-fraction factorial central composite design (CCD). Under the optimal conditions, the linear dynamic ranges (LDRs) were 10-10,000mgL(-)(1). The determination coefficients (R(2)) were from 0.9990 to 0.9997. The limits of detection (LODs) and limits of quantification (LOQs) for the extracted compounds were 6-123mgL(-)(1) and 20-406mgL(-)(1), respectively. The relative standard deviations (RSDs) were 2.48-9.82% (n=3). The enhancement factors (EFs) were 3.6-41.3.

  2. Improved fiber nonlinearity mitigation in dispersion managed optical OFDM links

    Science.gov (United States)

    Tamilarasan, Ilavarasan; Saminathan, Brindha; Murugappan, Meenakshi

    2017-02-01

    Fiber nonlinearity is seen as a capacity limiting factor in OFDM based dispersion managed links since the Four Wave Mixing effects become enhanced due to the high PAPR. In this paper, the authors have compared the linear and nonlinear PAPR reduction techniques for fiber nonlinearity mitigation in OFDM based dispersion managed links. In the existing optical systems, linear transform techniques such as SLM and PTS have been implemented to reduce nonlinear effects. In the proposed study, superior performance of the L2-by-3 nonlinear transform technique is demonstrated for PAPR reduction to mitigate fiber nonlinearities. The performance evaluation is carried out by interfacing multiple simulators. The results of both linear and nonlinear transform techniques have been compared and the results show that nonlinear transform technique outperforms the linear transform in terms of nonlinearity mitigation and improved BER performance.

  3. Management and Control of Outsourcing in Dispersed Network Manufacturing Systems

    Institute of Scientific and Technical Information of China (English)

    Rob; Dekkers; Luping; Wang

    2002-01-01

    The trend of economic globalisation and advances in i nformation technology has led to the emergence of dispersed manufacturing system s as a form of the virtual organisation. New manufacturing strategy pays more at tention to the management of the total value chain and therefore puts emphasis o n outsourcing. In fact, outsourcing is an efficient way of utilizing available r esources and has become one key aspect of the manufacturing strategy. Improved d ecision and organization on outsourcing will result ...

  4. Multi-objective optimisation in carbon monoxide gas management at TRONOX KXN Sands

    Directory of Open Access Journals (Sweden)

    Stadler, Johan

    2014-08-01

    Full Text Available Carbon monoxide (CO is a by-product of the ilmenite smelting process from which titania slag and pig iron are produced. Prior to this project, the CO at Tronox KZN Sands in South Africa was burnt to get rid of it, producing carbon dioxide (CO2. At this plant, unprocessed materials are pre-heated using methane gas from an external supplier. The price of methane gas has increased significantly; and so this research considers the possibility of recycling CO gas and using it as an energy source to reduce methane gas demand. It is not possible to eliminate the methane gas consumption completely due to the energy demand fluctuation, and sub-plants have been assigned either CO gas or methane gas over time. Switching the gas supply between CO and methane gas involves production downtime to purge supply lines. Minimising the loss of production time while maximising the use of CO arose as a multi-objective optimisation problem (MOP with seven decision variables, and computer simulation was used to evaluate scenarios. We applied computer simulation and the multi-objective optimisation cross-entropy method (MOO CEM to find good solutions while evaluating the minimum number of scenarios. The proposals in this paper, which are in the process of being implemented, could save the company operational expenditure while reducing the carbon footprint of the smelter.

  5. Bi-Soliton Propagation in Dispersion-Managed Line under the Influence of Third-Order Dispersion

    Institute of Scientific and Technical Information of China (English)

    Xuesong Mao; Akihiro Maruta

    2003-01-01

    We show that bi-soliton which is a periodically stationary pulse consisting of two peaks can propagate in a dispersion-managed line under the influence of third-order dispersion. Numerical averaging method is used to extract bi-soliton from a couple of Gaussian pulses and its stability is studied by a free propagation for a long distance.

  6. Dispersal

    Science.gov (United States)

    Clobert, J.; Danchin, E.; Dhondt, A.A.; Nichols, J.D.

    2001-01-01

    The ability of species to migrate and disperse is a trait that has interested ecologists for many years. Now that so many species and ecosystems face major environmental threats from habitat fragmentation and global climate change, the ability of species to adapt to these changes by dispersing, migrating, or moving between patches of habitat can be crucial to ensuring their survival. This book provides a timely and wide-ranging overview of the study of dispersal and incorporates much of the latest research. The causes, mechanisms, and consequences of dispersal at the individual, population, species and community levels are considered. The potential of new techniques and models for studying dispersal, drawn from molecular biology and demography, is also explored. Perspectives and insights are offered from the fields of evolution, conservation biology and genetics. Throughout the book, theoretical approaches are combined with empirical data, and care has been taken to include examples from as wide a range of species as possible.

  7. Performance Optimization of Dispersion-Managed WDM Systems Based on Four-Wave Mixing

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    We systemically investigate the interchannel four-wave mixing (FWM) in dispersion-managed WDM systems with arbitrary launch position. We optimize the number of fiber sections, and the dispersion ratio for the system performance.

  8. Well-Posedness and averaging of NLS with time-periodic dispersion management

    CERN Document Server

    Antonelli, Paolo; Sparber, Christof

    2012-01-01

    We consider the Cauchy problem for dispersion managed nonlinear Schroedinger equations, where the dispersion map is assumed to be periodic and piecewise constant in time. We establish local and global well-posedness results and the possibility of finite time blow-up. In addition, we shall study the scaling limit of fast dispersion management and establish convergence to an effective model with averaged dispersion.

  9. [Efficient OP management. Suggestions for optimisation of organisation and administration as a basis for establishing statutes for operating theatres].

    Science.gov (United States)

    Geldner, G; Eberhart, L H J; Trunk, S; Dahmen, K G; Reissmann, T; Weiler, T; Bach, A

    2002-09-01

    Economic aspects have gained increasing importance in recent years. The operating room (OR) is the most cost-intensive sector and determines the turnover process of a surgical patient within the hospital. Thus, optimisation of workflow processes is of particular interest for health care providers. If the results of surgery are viewed as a product, everything associated with surgery can be evaluated analogously to a manufacturing process. All steps involved in producing the end-result can and should be analysed with the goal of producing an efficient, economical and quality product. The leadership that physicians can provide to manage this process is important and leads to the introduction of a specialised "OR manager". This position must have the authority to issue directives to all other members of the OR team. An OR management subordinates directly to the administration of the hospital. By integrating and improving management of various elements of the surgical process, health care institutions are able to rationally trim costs while maintaining high-quality services. This paper gives a short introduction into the difficulties of organising an OR. Some suggestions are made to overcome common shortcomings in the daily practise. A proposal for an "OR statute" is presented that should be a basis for discussion within the OR team. It must be modified according to individual needs and prerequisites in every hospital. The single best opportunity for dramatic improvement in effective resource use in surgical services lies in the perioperative process. The management strategy must focus on process measurement using information technology and feed-back implementing modern quality management tools.However, no short-term effects can be expected from these changes. Improvements take about a year and continuous feed-back of all measures must accompany the reorganisation process.

  10. Optimizing optical pre-dispersion using transmit DSP for mitigation of Kerr nonlinearities in dispersion managed cables

    Science.gov (United States)

    Hopkins, James; Gaudette, Jamie; Mehta, Priyanth

    2013-10-01

    With the advent of digital signal processing (DSP) in optical transmitters and receivers, the ability to finely tune the ratio of pre and post dispersion compensation can be exploited to best mitigate the nonlinear penalties caused by the Kerr effect. A portion of the nonlinear penalty in optical communication channels has been explained by an increase in peak to average power ratio (PAPR) inherent in highly dispersed signals. The standard approach for minimizing these impairments applies 50% pre dispersion compensation and 50% post dispersion compensation, thereby decreasing average PAPR along the length of the cable, as compared with either 100% pre or post dispersion compensation. In this paper we demonstrate that simply considering the net accumulated dispersion, and applying 50/50 pre/post dispersion is not necessarily the best way to minimize PAPR and subsequent Kerr nonlinearities. Instead, we consider the cumulative dispersion along the entire length of the cable, and, taking into account this additional information, derive an analytic formula for the minimization of PAPR. Alignment with simulation and experimental measurements is presented using a commercially available 100Gb/s dual-polarization binary phase-shift-keying (DP-BPSK) coherent modem, with transmitter and receiver DSP. Measurements are provided from two different 5000km dispersion managed Submarine test-beds, as well as a 3800km terrestrial test-bed with a mixture of SMF-28 and TWRS optical fiber. This method is shown to deviate significantly from the conventional 50/50 method described above, in dispersion managed communications systems, and more closely aligns with results obtained from simulation and data collected from laboratory test-beds.

  11. Optimising stock management in foundries to keep the economic size of orders

    OpenAIRE

    J. Szymszal; F. Binczyk; A. Smoliński; Kliś, J.

    2007-01-01

    Skillful stock management is one of the main conditions to raise the production output of an enterprise, foundry shop included. This article outlines modern methods of stock management using the generally available Excel calculation sheet to estimate the economic order quantity and minimum stock level required for selected auxiliary materials used in foundry production.

  12. A model for optimisation of water management in rice polders in Thailand

    NARCIS (Netherlands)

    Wandee, P.; Schultz, E.; Tingsanchali, T.

    2005-01-01

    This paper presents a mathematical model for the determination of optimal values for the main components of water management systems in rice polders in Thailand. The aim of the water management system in a rice area is to create good growing conditions for the crops. Under the hydrological

  13. Optimising invasive fish management in the context of invasive species legislation in South Africa

    Directory of Open Access Journals (Sweden)

    Darragh J. Woodford

    2017-03-01

    Full Text Available Background: South Africa hosts a large number of non-native freshwater fishes that were introduced for various industries. Many of these species are now listed under the National Environmental Management: Biodiversity Act (NEM:BA Alien and Invasive Species (A&IS lists and regulations, though the practical options available to conservation agencies to effectively manage these fishes vary greatly among species and regions. Objectives & methods: We assessed the history and status of national legislation pertaining to invasive freshwater fishes, and the practical implications of the legislation for managing different species with contrasting distributions, impacts and utilisation value. Results: The smallmouth bass, despite being a potential conflict-generating species, is fairly straightforward to manage based on current legislation. Two species of trout, which remain absent from the NEM:BA A&IS lists because of ongoing consultation with stakeholders, continue to be managed in regions like the Western Cape province using existing provincial legislation. To maximise the limited capacity for management within conservation agencies, we proposed a decision-support tool that prioritises invasive fish populations that represent high environmental risk and low potential for conflict with stakeholders. Using three case studies, we demonstrated how the tool can be used to set management goals of ‘eradicate’, ‘manage against impacts and further spread’ and ‘continue to monitor population’ as the most pragmatic solutions given the state of an invasion, its socio-economic impact and the capacity of the responsible agency to act. Conclusion: By choosing a pragmatic management strategy, conservation agencies can maximise the effective deployment of limited resources, while minimising avoidable conflicts with stakeholders.

  14. Optimising invasive fish management in the context of invasive species legislation in South Africa

    OpenAIRE

    Woodford, Darragh J.; Phillip Ivey; Jordaan, Martine S.; Peter K. Kimberg; Tsungai Zengeya; Olaf L.F. Weyl

    2017-01-01

    Background: South Africa hosts a large number of non-native freshwater fishes that were introduced for various industries. Many of these species are now listed under the National Environmental Management: Biodiversity Act (NEM:BA) Alien and Invasive Species (A&IS) lists and regulations, though the practical options available to conservation agencies to effectively manage these fishes vary greatly among species and regions. Objectives & methods: We assessed the history and status of na...

  15. Collision-induced timing jitter in dispersion-managed WDM soliton system with filtering

    Institute of Scientific and Technical Information of China (English)

    Jianxin Du(杜建新); Qihong Lou(楼祺洪)

    2004-01-01

    Taking into account the randomicity of collision positions and the arbitrary encoding of data in channel,the influences of different dispersion management on collision-induced timing jitter in a filtered wavelength division multiplexing (WDM) soliton system are obtained statistically and numerically by applying a set of coupled ordinary differential equations which are derived through variational procedure. The optimal dispersion managements which can greatly reduce the collision-induced timing jitter are found. The multi-channel collision-induced timing jitters in a filtered WDM soliton system are given with an optimal dispersion management and constant dispersion.

  16. Dispersion-managed dark solitons in erbium-doped fiber lasers

    OpenAIRE

    Zhang, Han; Tang, Dingyuan; Tlidi, Mustapha; Zhao, Luming; Wu,Xuan

    2010-01-01

    We report on the observation of dispersion-managed (DM) dark soliton emission in a net-normal dispersion erbium-doped fiber laser. We found experimentally that dispersion management could not only reduce the pump threshold for the dark soliton formation in a fiber laser, but also stabilize the single dark soliton evolution in the cavity. Numerical simulations have also confirmed the DM dark soliton formation in a fiber laser.

  17. Lower limb stress fractures in sport: Optimising their management and outcome

    Science.gov (United States)

    Robertson, Greg A J; Wood, Alexander M

    2017-01-01

    Stress fractures in sport are becoming increasing more common, comprising up to 10% of all of sporting injuries. Around 90% of such injuries are located in the lower limb. This articles aims to define the optimal management of lower limb stress fractures in the athlete, with a view to maximise return rates and minimise return times to sport. Treatment planning of this condition is specific to the location of the injury. However, there remains a clear division of stress fractures by “high” and “low” risk. “Low risk” stress fractures are those with a low probability of fracture propagation, delayed union, or non-union, and so can be managed reliably with rest and exercise limitation. These include stress fractures of the Postero-Medial Tibial Diaphysis, Metatarsal Shafts, Distal Fibula, Medial Femoral Neck, Femoral Shaft and Calcaneus. “High risk” stress fractures, in contrast, have increased rates of fracture propagation, displacement, delayed and non-union, and so require immediate cessation of activity, with orthopaedic referral, to assess the need for surgical intervention. These include stress fractures of the Anterior Tibial Diaphysis, Fifth Metatarsal Base, Medial Malleolus, Lateral Femoral Neck, Tarsal Navicular and Great Toe Sesamoids. In order to establish the optimal methods for managing these injuries, we present and review the current evidence which guides the treatment of stress fractures in athletes. From this, we note an increased role for surgical management of certain high risk stress fractures to improve return times and rates to sport. Following this, key recommendations are provided for the management of the common stress fracture types seen in the athlete. Five case reports are also presented to illustrate the application of sport-focussed lower limb stress fracture treatment in the clinical setting. PMID:28361017

  18. Dispersal and fallout simulations for urban consequences management (u)

    Energy Technology Data Exchange (ETDEWEB)

    Grinstein, Fernando F [Los Alamos National Laboratory; Wachtor, Adam J [Los Alamos National Laboratory; Nelson, Matt [Los Alamos National Laboratory; Brown, Michael [Los Alamos National Laboratory; Bos, Randy [Los Alamos National Laboratory; Patnik, Gopal [US NAVAL RESEARCH LAB.

    2010-01-01

    Hazardous chemical, biological, or radioactive releases from leaks, spills, fires, or blasts, may occur (intentionally or accidentally) in urban environments during warfare or as part of terrorist attacks on military bases or other facilities. The associated contaminant dispersion is complex and semi-chaotic. Urban predictive simulation capabilities can have direct impact in many threat-reduction areas of interest, including, urban sensor placement and threat analysis, contaminant transport (CT) effects on surrounding civilian population (dosages, evacuation, shelter-in-place), education and training of rescue teams and services. Detailed simulations for the various processes involved are in principle possible, but generally not fast. Predicting urban airflow accompanied by CT presents extremely challenging requirements. Crucial technical issues include, simulating turbulent fluid and particulate transport, initial and boundary condition modeling incorporating a consistent stratified urban boundary layer with realistic wind fluctuations, and post-processing of the simulation results for practical consequences management. Relevant fluid dynamic processes to be simulated include, detailed energetic and contaminant sources, complex building vortex shedding and flows in recirculation zones, and modeling of particle distributions, including particulate fallout, as well as deposition, re-suspension and evaporation. Other issues include, modeling building damage effects due to eventual blasts, addressing appropriate regional and atmospheric data reduction.

  19. Optimisation of the securities portfolio as a part of the risk management process

    Directory of Open Access Journals (Sweden)

    Srečko Devjak

    2004-01-01

    Full Text Available Securities of Slovene companies are listed at the Ljubljana Stock Exchange. Market capitalisation at the Ljubljana Stock Exchange has been growing since 1996 due to new listings of equities. On the basis of financial data time series for listed equities, the financial investor can calculate a risk for each individual security with a selected risk measure and can determine an optimal portfolio, subject to selected constraints. In this paper, we shall consequently determine an optimal portfolio of equities for the financial investor, investing his assets only in selected equities listed at the Ljubljana Stock Exchange. Selecting an appropriate risk measure is especially important for a commercial bank in a risk management process. Commercial banks can use internal models in the risk management process and for the purpose of capital charges as well. An optimal portfolio will be calculated, using a non-linear mathematical model.

  20. Optimisation of ultrasound-assisted reverse micelles dispersive liquid-liquid micro-extraction by Box-Behnken design for determination of acetoin in butter followed by high performance liquid chromatography.

    Science.gov (United States)

    Roosta, Mostafa; Ghaedi, Mehrorang; Daneshfar, Ali

    2014-10-15

    A novel approach, ultrasound-assisted reverse micelles dispersive liquid-liquid microextraction (USA-RM-DLLME) followed by high performance liquid chromatography (HPLC) was developed for selective determination of acetoin in butter. The melted butter sample was diluted and homogenised by n-hexane and Triton X-100, respectively. Subsequently, 400μL of distilled water was added and the microextraction was accelerated by 4min sonication. After 8.5min of centrifugation, sedimented phase (surfactant-rich phase) was withdrawn by microsyringe and injected into the HPLC system for analysis. The influence of effective variables was optimised using Box-Behnken design (BBD) combined with desirability function (DF). Under optimised experimental conditions, the calibration graph was linear over the range of 0.6-200mgL(-1). The detection limit of method was 0.2mgL(-1) and coefficient of determination was 0.9992. The relative standard deviations (RSDs) were less than 5% (n=5) while the recoveries were in the range of 93.9-107.8%.

  1. Optimising outpatient efficiency - development of an innovative 'Did Not Attend' management approach.

    Science.gov (United States)

    Boland, Billy; Burnett, Frances

    2014-08-01

    To examine non-attendance [or Did Not Attend (DNA)] rates in a community mental health follow-up outpatient clinic and evaluate a pragmatic initiative to reduce non-attendance. Clinical audit of attendance across two community psychiatry outpatient clinics was used to establish DNA rates at baseline. Both clinics sought to reduce the DNA rate and were made aware of the outcome of the first cycle of audit. Clinic A (intervention clinic) introduced an innovative new management approach aimed at reducing DNAs, whilst Clinic B (control clinic) introduced no further systematic measures. The clinics were then re-audited to establish the impact of the changes. We found that the introduction of the new management approach in Clinic A was associated with reduced numbers of service users failing to attend for a clinic appointment (n = 1134, relative risk 0.59, 95% Confidence Interval (C.I.) 0.44-0.77, NNT = 12). No such difference was identified in Clinic B. Intervention to reduce the DNA rate is realistically achievable with minimal effort and modest additional cost. The actions required of clinicians are practicable, and can have a direct impact without large-scale organisational change.

  2. International management, political arena and dispersed entrepreneurship in the MNC

    NARCIS (Netherlands)

    Williams, C.; Lee, S.H.

    2009-01-01

    This paper presents a model of MNC dispersed entrepreneurship based on the concept of political arena. The model extends previous conceptualizations of MNC dispersed entrepreneurship by explaining how remote employees become stimulated to act as entrepreneurs through resolution of internal political

  3. Optimisation of industrial processes through modern maintenance management; Optimierung von Betriebsablaeufen durch modernes Instandhaltungsmanagement

    Energy Technology Data Exchange (ETDEWEB)

    Helmich, P.; Klocke, A.

    1997-12-31

    Maintenance is becoming an increasingly important issue for companies facing growing demands from the market with regard to quality, cost reduction, and security of supply. This gives rise to a multiplicity of tasks which have to be carried out in accordance with official licenses, legal regulations, guidelines, and ordinances. The present paper discusses requirements on maintenance planning and management tools (German: IPS). It deals with the technical features as well as with the cost/benefit aspects of the use of such tools. [Deutsch] Vor dem Hintergrund steigender Anforderungen des Marktes hinsichtlich Qualitaet, Kosteneinsparung und Lieferzuverlaessigkeit gewinnt die Instandhaltung in modernen Unternehmen zunehmend an Bedeutung. Die vielfaeltigen Aufgabenstellungen, die sich daraus ergeben, muessen unter Beruecksichtigung behoerdlicher Genehmigungen, einschlaegiger Gesetze, Richtlinien und Verordnungen durchgefuehrt werden. Im Beitrag werden die Anforderungen an Instandhaltungsplanungs und -steuerungswerkzeuge (IPS-Werkzeuge) diskutiert. Neben den technischen Merkmalen werden Kosten/Nutzen-Gesichtspunkte solcher Werkzeuge thematisiert. (orig./RHM)

  4. Model-based process management and process optimisation of industrial steam generators

    Energy Technology Data Exchange (ETDEWEB)

    Kaestner, Wolfgang; Hampel, Rainer; Foerster, Tom; Freund, Matthias [Univ. of Applied Sciences Zittau/Goerlitz, Zittau (Germany). IPM; Haake, Dietmar; Kanisch, Heiko [Vattenfall Europe Generation AG, Cottbus (Germany); Altmann, Ulrich-Steffen; Mueller, Frank [CombTec GmbH, Zittau (Germany)

    2010-07-01

    Within the framework of a joint project sponsored by BMBF the development of algorithms for the optimal process management of industrial steam generators was carried out. The research work was focussed on the reduction of high-temperature corrosion at the membrane walls of lignite-fired steam generators. In the result a system for demonstration of technology was installed successfully in a Vattenfall power plant in 2009. During the operation of the power plant the capability of the system to guarantee a stable and symmetric fire position was demonstrated. Current work is focussed on the further development and retrofitting of the system to apply it under real condition in a Vattenfall power plant. (orig.)

  5. Optimising the application of multiple-capture traps for invasive species management using spatial simulation.

    Science.gov (United States)

    Warburton, Bruce; Gormley, Andrew M

    2015-01-01

    Internationally, invasive vertebrate species pose a significant threat to biodiversity, agricultural production and human health. To manage these species a wide range of tools, including traps, are used. In New Zealand, brushtail possums (Trichosurus vulpecula), stoats (Mustela ermine), and ship rats (Rattus rattus) are invasive and there is an ongoing demand for cost-effective non-toxic methods for controlling these pests. Recently, traps with multiple-capture capability have been developed which, because they do not require regular operator-checking, are purported to be more cost-effective than traditional single-capture traps. However, when pest populations are being maintained at low densities (as is typical of orchestrated pest management programmes) it remains uncertain if it is more cost-effective to use fewer multiple-capture traps or more single-capture traps. To address this uncertainty, we used an individual-based spatially explicit modelling approach to determine the likely maximum animal-captures per trap, given stated pest densities and defined times traps are left between checks. In the simulation, single- or multiple-capture traps were spaced according to best practice pest-control guidelines. For possums with maintenance densities set at the lowest level (i.e. 0.5/ha), 98% of all simulated possums were captured with only a single capacity trap set at each site. When possum density was increased to moderate levels of 3/ha, having a capacity of three captures per trap caught 97% of all simulated possums. Results were similar for stoats, although only two potential captures per site were sufficient to capture 99% of simulated stoats. For rats, which were simulated at their typically higher densities, even a six-capture capacity per trap site only resulted in 80% kill. Depending on target species, prevailing density and extent of immigration, the most cost-effective strategy for pest control in New Zealand might be to deploy several single

  6. Optimising the application of multiple-capture traps for invasive species management using spatial simulation.

    Directory of Open Access Journals (Sweden)

    Bruce Warburton

    Full Text Available Internationally, invasive vertebrate species pose a significant threat to biodiversity, agricultural production and human health. To manage these species a wide range of tools, including traps, are used. In New Zealand, brushtail possums (Trichosurus vulpecula, stoats (Mustela ermine, and ship rats (Rattus rattus are invasive and there is an ongoing demand for cost-effective non-toxic methods for controlling these pests. Recently, traps with multiple-capture capability have been developed which, because they do not require regular operator-checking, are purported to be more cost-effective than traditional single-capture traps. However, when pest populations are being maintained at low densities (as is typical of orchestrated pest management programmes it remains uncertain if it is more cost-effective to use fewer multiple-capture traps or more single-capture traps. To address this uncertainty, we used an individual-based spatially explicit modelling approach to determine the likely maximum animal-captures per trap, given stated pest densities and defined times traps are left between checks. In the simulation, single- or multiple-capture traps were spaced according to best practice pest-control guidelines. For possums with maintenance densities set at the lowest level (i.e. 0.5/ha, 98% of all simulated possums were captured with only a single capacity trap set at each site. When possum density was increased to moderate levels of 3/ha, having a capacity of three captures per trap caught 97% of all simulated possums. Results were similar for stoats, although only two potential captures per site were sufficient to capture 99% of simulated stoats. For rats, which were simulated at their typically higher densities, even a six-capture capacity per trap site only resulted in 80% kill. Depending on target species, prevailing density and extent of immigration, the most cost-effective strategy for pest control in New Zealand might be to deploy several

  7. Optimisation of sludge line management to enhance phosphorus recovery in WWTP.

    Science.gov (United States)

    Marti, N; Ferrer, J; Seco, A; Bouzas, A

    2008-11-01

    The management of the sludge treatment line can be optimized to reduce uncontrolled phosphorus precipitation in the anaerobic digester and to enhance phosphorus recovery in WWTP. In this paper, four operational strategies, which are based on the handling of the prefermented primary sludge and the secondary sludge from an EBPR process, have been tested in a pilot plant. The separated or mixed sludge thickening, the use of a stirred contact tank and the elutriation of the thickened sludge are the main strategies studied. Both the reduction of phosphorus precipitation in the digester and the supernatant suitability for a struvite crystallization process were assessed in each configuration. The mixed sludge thickening combined with a high flowrate elutriation stream reduced the phosphorus precipitation in the digester by 46%, with respect to the separate sludge thickening configuration (common practice in WWTP). Moreover, in this configuration, 68% of the soluble phosphorus in the system is available for a possible phosphorus recovery process by crystallization (not studied in this work). However, a high Ca/P molar ratio was detected in the resultant supernatant which is pointed out as a problem for the efficiency of struvite crystallization.

  8. Guidelines for operator competence - Optimising facility management processes; Leitfaden Betreiberkompetenz. Schritt fuer Schritt Facility Management Prozesse optimieren

    Energy Technology Data Exchange (ETDEWEB)

    Moser, R.

    2005-06-15

    This brochure issued by IFMA (International Facility Management Association) Switzerland and the Swiss Federal Office of Energy (SFOE) presents interactive guidelines for energy management in the area of facility management. These guidelines are based on the results of a project carried out by the International Energy Agency's Annex 40 'Operator competence'. The guidelines provide a step-by-step guide from initial analysis through to successful project completion and answer many questions that may crop up during the process. The focus is placed on energy aspects. Tools and 14 sample process descriptions are provided along with practical examples. Theoretical aspects are also presented and discussed, including models for operator roles and the processes involved. Also, change, risk and knowledge management are examined. Notes and information on possibilities for further education are presented.

  9. Analytical Method for Designing Grating Compensated Dispersion-Managed Soliton Systems

    Institute of Scientific and Technical Information of China (English)

    Y.; H.; C.; Kwan; K.; Nakkeeran; P.; K.; A.; Wai

    2003-01-01

    We show a useful analytical method to design grating compensated dispersion-managed systems. Our method is in good agreement with the numerical results even in the presence of group delay ripples in the chirped fiber gratings.

  10. Dispersion management for two-level optically labeled signals in IP-over-WDM networks 4

    DEFF Research Database (Denmark)

    Chi, Nan; Carlsson, Birger; Holm-Nielsen, Pablo Villanueva;

    2002-01-01

    The transmission characteristics of a two-level optically labeled signal with ASK/DPSK modulation are investigated under varying dispersion management. A limitation of extinction ratio and the resilience of fiber span, compensation ratio, and power level are obtained...

  11. Dispersion-managed semiconductor mode-locked ring laser.

    Science.gov (United States)

    Resan, Bojan; Archundia, Luis; Delfyett, Peter J; Alphonse, Gerard

    2003-08-01

    A novel breathing-mode external sigma-ring-cavity semiconductor mode-locked laser is developed. Intracavity pulse compression and stretching produce linearly chirped pulses with an asymmetric exponential temporal profile. External dispersion compensation reduces the pulse duration to 274 fs (within 10% of the bandwidth limit).

  12. Waste flow analysis and life cycle assessment of integrated waste management systems as planning tools: Application to optimise the system of the City of Bologna.

    Science.gov (United States)

    Tunesi, Simonetta; Baroni, Sergio; Boarini, Sandro

    2016-09-01

    The results of this case study are used to argue that waste management planning should follow a detailed process, adequately confronting the complexity of the waste management problems and the specificity of each urban area and of regional/national situations. To support the development or completion of integrated waste management systems, this article proposes a planning method based on: (1) the detailed analysis of waste flows and (2) the application of a life cycle assessment to compare alternative scenarios and optimise solutions. The evolution of the City of Bologna waste management system is used to show how this approach can be applied to assess which elements improve environmental performance. The assessment of the contribution of each waste management phase in the Bologna integrated waste management system has proven that the changes applied from 2013 to 2017 result in a significant improvement of the environmental performance mainly as a consequence of the optimised integration between materials and energy recovery: Global Warming Potential at 100 years (GWP100) diminishes from 21,949 to -11,169 t CO2-eq y(-1) and abiotic resources depletion from -403 to -520 t antimony-eq. y(-1) This study analyses at great detail the collection phase. Outcomes provide specific operational recommendations to policy makers, showing the: (a) relevance of the choice of the materials forming the bags for 'door to door' collection (for non-recycled low-density polyethylene bags 22 kg CO2-eq (tonne of waste)(-1)); (b) relatively low environmental impacts associated with underground tanks (3.9 kg CO2-eq (tonne of waste)(-1)); (c) relatively low impact of big street containers with respect to plastic bags (2.6 kg CO2-eq. (tonne of waste)(-1)).

  13. Bright Chirp-free and Chirped Nonautonomous solitons under Dispersion and Nonlinearity Management

    CERN Document Server

    Yang, Zhan-Ying; Zhang, Tao; Yue, Rui-Hong

    2011-01-01

    We present a series of chirp-free and chirped analytical nonautonomous soliton solutions to the generalized nonlinear Schrodinger equation (NLSE) with distributed coefficients by Darboux transformation from a trivial seed. For chirpfree nonautonomous soliton, the dispersion management term can change the motion of nonautonomous soliton and do not affect its shape at all. Especially,the classical optical soliton can be presented with variable dispersion term and nonlinearity when there is no gain. For chirped nonautonomous soliton, dispersion management can affect the shape and motion of nonautonomous solitons meanwhile. The periodic dispersion term can be used to control its "breathing" shape, and it does not affect the trajectory of nonautonomous soliton center with a certain condition.

  14. Dispersion-managed soliton interactions in fibers with randomly varying birefringence

    Institute of Scientific and Technical Information of China (English)

    CAI; Ju; (蔡炬); YANG; Xianglin; (杨祥林)

    2003-01-01

    In this paper, a soliton transmission model in high-speed dispersion-managed systems is advanced, and the equation of intrachannel soliton interactions in randomly varying birefringent fibers is acquired. The soliton interactions with the impact of PMD in uniform dispersion systems and DMS systems are also investigated numerically. We reveal the change in the collision length with PMD and map strength, and verify the robustness of DMS to PMD in soliton interactions.

  15. Quality management of dispersion-strengthened beryllium-based composite alloy

    Directory of Open Access Journals (Sweden)

    Дмитро Миколайович Макаренко

    2016-05-01

    Full Text Available The article is devoted to investigation of the composition and properties of dispersion-strengthened beryllium-based composite alloy, used in various industries, including the aircraft manufacture aircraft. Analyzed the properties of these materials are analyzed to ensure their quality management. The mathematical relationship of dispersion strengthened beryllium-based composite alloy parameters from content of beryllium oxide and temperature are built

  16. Cytotoxic Drug Dispersal, Cytotoxic Safety, and Cytotoxic Waste Management: Practices and Proposed India-specific Guidelines.

    Science.gov (United States)

    Capoor, Malini R; Bhowmik, Kumar Tapas

    2017-01-01

    This article deals with practices related to cytotoxic drug dispersal, cytotoxic safety, and cytotoxic waste management and attempts at India-specific guidelines for their dispersal and disposal. The articles related to cytotoxic drug dispersal, cytotoxic safety, and cytotoxic waste management were reviewed from PubMed and their applicability in Indian health-care facilities (HCFs) was also reviewed. All HCFs dealing with cytotoxic drugs should consider cytotoxic policy, patient safety and health-care worker safety, and environmental monitoring program as per the available international guidelines customized as per Indian conditions. Utmost care in handling cytotoxic waste is quintessential. The formation of India-specific cytotoxic guidelines requires the inputs from all stakeholders. Cytotoxic waste, cytotoxic safety, and cytotoxic waste management should be the subject of a national strategy with an infrastructure, cradle-to-grave legislation, competent regulatory authority, and trained personnel.

  17. Concepts for design of an energy management system incorporating dispersed storage and generation

    Science.gov (United States)

    Kirkham, H.; Koerner, T.; Nightingale, D.

    1981-04-01

    New forms of generation based on renewable resources must be managed as part of existing power systems in order to be utilized with maximum effectiveness. Many of these generators are by their very nature dispersed or small, so that they will be connected to the distribution part of the power system. This situation poses new questions of control and protection, and the intermittent nature of some of the energy sources poses problems of scheduling and dispatch. Under the assumption that the general objectives of energy management will remain unchanged, the impact of dispersed storage and generation on some of the specific functions of power system control and its hardware are discussed.

  18. Concepts for design of an energy management system incorporating dispersed storage and generation

    Science.gov (United States)

    Kirkham, H.; Koerner, T.; Nightingale, D.

    1981-01-01

    New forms of generation based on renewable resources must be managed as part of existing power systems in order to be utilized with maximum effectiveness. Many of these generators are by their very nature dispersed or small, so that they will be connected to the distribution part of the power system. This situation poses new questions of control and protection, and the intermittent nature of some of the energy sources poses problems of scheduling and dispatch. Under the assumption that the general objectives of energy management will remain unchanged, the impact of dispersed storage and generation on some of the specific functions of power system control and its hardware are discussed.

  19. Generation of ultra broadband supercontinuum in dispersion managed silicon nanophotonic waveguides

    CERN Document Server

    Ciret, Charles

    2016-01-01

    Dispersion managed (DM) silicon nanophotonic waveguides are investigated for the generation of optimal ultra broadband supercontinuum (SC). DM waveguides are made of a longitudinally dependent group velocity dispersion resulting from the variation of the waveguide width with the propagation distance. For the generation of optimal SC, a genetic algorithm has been used to find the best dispersion map. This allows for the generation of a highly coherent supercontinuum spanning from 1100~nm to 2950~nm at -40~dB level for 2\\,$\\mu$m, 200 fs and 6.4 pJ input pulse. The comparison with optimal fixed width and tapered waveguides shows that the SC is 300\\,nm broader in the DM waveguide, while the high coherence is ensured by the varying dispersion.

  20. Optimised Design of Transparent Optical Domains

    DEFF Research Database (Denmark)

    Hanik, N.; Caspar, C.; Schmidt, F.;

    2000-01-01

    Three different design concepts for transparent, dispersion compensated, optical WDM transmission links are optimised numerically and experimentally for 10 Gbit/s data rate per channel. It is shown that robust transparent domains of 1,500 km in diameter can be realised using simple design rutes....

  1. Difficulties with assessment and management of an infant’s distress in the postoperative period: Optimising opportunities for interdisciplinary information-sharing

    Directory of Open Access Journals (Sweden)

    Carlye Weiner

    2016-12-01

    Full Text Available Objectives: The importance of accurate paediatric patient assessment is well established but under-utilised in managing postoperative medication regimens. Methods: Data for this case report were collected through observations of clinical practice, conduct of interviews, and retrieval of information from the medical record. This case report involving a hospitalised 1-year-old boy demonstrates the difficulties associated with assessing and managing postoperative distress, including pain and other clinical conditions related to the surgical procedure. Results: Postoperatively, there were difficulties in managing pain and an episode of over-sedation, occasioning opiate reversal with naloxone. In addition, he had decreasing oxygen saturation and increased work of breathing. X-ray showed changes consistent with either atelectasis or aspiration, and he was commenced on antibiotics. The patient experienced respiratory distress and required intervention from the medical emergency team. Conclusion: This case demonstrated the importance of comprehensive assessment and careful consideration of alternative causes of an infant’s distress using the results of assessment tools to aid decision-making. Communication moderates effective patient care, and more favourable outcomes could be achieved by optimising interdisciplinary information-sharing.

  2. Dispersion management for a sub-10-fs, 10 TW optical parametric chirped-pulse amplifier.

    Science.gov (United States)

    Tavella, Franz; Nomura, Yutaka; Veisz, Laszlo; Pervak, Vladimir; Marcinkevicius, Andrius; Krausz, Ferenc

    2007-08-01

    We report the amplification of three-cycle, 8.5 fs optical pulses in a near-infrared noncollinear optical parametric chirped-pulse amplifier (OPCPA) up to energies of 80 mJ. Improved dispersion management in the amplifier by means of a combination of reflection grisms and a chirped-mirror stretcher allowed us to recompress the amplified pulses to within 6% of their Fourier limit. The novel ultrabroad, ultraprecise dispersion control technology presented in this work opens the way to scaling multiterawatt technology to even shorter pulses by optimizing the OPCPA bandwidth.

  3. Using Data From Seed-Dispersal Modelling to Manage Invasive Tree Species: The Example of Fraxinus pennsylvanica Marshall in Europe

    Science.gov (United States)

    Schmiedel, Doreen; Huth, Franka; Wagner, Sven

    2013-10-01

    Management strategies to control invasive species need information about dispersal distances to predict establishment potential. Fraxinus pennsylvanica is a North American anemochorous tree species that is invasive in many Central European floodplain forests. To predict seed-dispersal potential, the stochastic model WaldStat was used, which enables different options for directionality (isotropic and anisotropic) to be simulated. In this article, we (1) show empirical results of fructification and seed dispersal for this tree species. The model predicts approximately 250,000 seeds for one F. pennsylvanica tree. These results were used to (2) calculate species-specific dispersal distances and effects of wind direction. To consider the influence of wind on dispersal potential of the tree species, long-distance dispersal (LDD [95th percentile dispersal distance]) was calculated. Mean dispersal distances varied between 47 and 66 m. LDD values modelled along the main wind direction ranged from 60 to 150 m. Seed production, dispersal distance, and direction data were (3) incorporated into theoretical management scenarios for forest ecosystems. Finally (4), we discuss management options and the practical relevance of model scenarios in relation to the accuracy of spatial dispersal predictions. Further analyses should be focused on possible, well-adapted management concepts at stand level that could restrict the potential spread of invasive species.

  4. Magneto-Optic Fiber Gratings Useful for Dynamic Dispersion Management and Tunable Comb Filtering

    Science.gov (United States)

    Wu, Bao-Jian; Lu, Xin; Qiu, Kun

    2010-06-01

    Intelligent control of dispersion management and tunable comb filtering in optical network applications can be performed by using magneto-optic fiber Bragg gratings (MFBGs). When a nonuniform magnetic field is applied to the MFBG with a constant grating period, the resulting grating response is equivalent to that of a conventional chirped grating. Under a linearly nonuniform magnetic field along the grating, a linear dispersion is achieved in the grating bandgap and the maximal dispersion slope can come to 1260 ps/nm2 for a 10-mm-long fiber grating at 1550 nm window. Similarly, a Gaussian-apodizing sampled MFBG is also useful for magnetically tunable comb filtering, with potential application to clock recovery from return-to-zero optical signals and optical carrier tracking.

  5. Dispersion management for nonlinearity mitigation in two-span 28 GBaud QPSK phase-sensitive amplifier links.

    Science.gov (United States)

    Astra, Egon; Olsson, Samuel L I; Eliasson, Henrik; Andrekson, Peter A

    2017-06-12

    We present an investigation of dispersion map optimization for two-span single-channel 28 GBaud QPSK transmission systems with phase-sensitive amplifiers (PSAs). In experiments, when the PSA link is operated in a highly nonlinear regime, a 1.4 dB error vector magnitude (EVM) improvement is achieved compared to a one-span optimized dispersion map link due to improved nonlinearity mitigation. The two-span optimized dispersion map of a PSA link differs from the optimized dispersion map of a dispersion managed phase-insensitive amplifier (PIA) link. Simulations show that the performance of the two-span dispersion map optimized PSA link does not improve by residual dispersion optimization. Further, by using the two-span optimized dispersion maps repeatedly in a long-haul PSA link instead of one-span optimized maps, the maximum transmission reach can be improved 1.5 times.

  6. Computer Based Optimisation Rutines

    DEFF Research Database (Denmark)

    Dragsted, Birgitte; Olsen, Flemmming Ove

    1996-01-01

    In this paper the need for optimisation methods for the laser cutting process has been identified as three different situations. Demands on the optimisation methods for these situations are presented, and one method for each situation is suggested. The adaptation and implementation of the methods...

  7. Computer Based Optimisation Rutines

    DEFF Research Database (Denmark)

    Dragsted, Birgitte; Olsen, Flemmming Ove

    1996-01-01

    In this paper the need for optimisation methods for the laser cutting process has been identified as three different situations. Demands on the optimisation methods for these situations are presented, and one method for each situation is suggested. The adaptation and implementation of the methods...

  8. Optimal optimisation in chemometrics

    NARCIS (Netherlands)

    Hageman, Joseph Albert

    2004-01-01

    The use of global optimisation methods is not straightforward, especially for the more difficult optimisation problems. Solutions have to be found for items such as the evaluation function, representation, step function and meta-parameters, before any useful results can be obtained. This thesis aims

  9. Population genetics of Ceratitis capitata in South Africa: implications for dispersal and pest management.

    Science.gov (United States)

    Karsten, Minette; van Vuuren, Bettine Jansen; Barnaud, Adeline; Terblanche, John S

    2013-01-01

    The invasive Mediterranean fruit fly (medfly), Ceratitis capitata, is one of the major agricultural and economical pests globally. Understanding invasion risk and mitigation of medfly in agricultural landscapes requires knowledge of its population structure and dispersal patterns. Here, estimates of dispersal ability are provided in medfly from South Africa at three spatial scales using molecular approaches. Individuals were genotyped at 11 polymorphic microsatellite loci and a subset of individuals were also sequenced for the mitochondrial cytochrome oxidase subunit I gene. Our results show that South African medfly populations are generally characterized by high levels of genetic diversity and limited population differentiation at all spatial scales. This suggests high levels of gene flow among sampling locations. However, natural dispersal in C. capitata has been shown to rarely exceed 10 km. Therefore, documented levels of high gene flow in the present study, even between distant populations (>1600 km), are likely the result of human-mediated dispersal or at least some form of long-distance jump dispersal. These findings may have broad applicability to other global fruit production areas and have significant implications for ongoing pest management practices, such as the sterile insect technique.

  10. Soliton-like pulse timing jitter in dispersion-managed systems

    Institute of Scientific and Technical Information of China (English)

    Li Qi-Liang; Li Qing-Shan; Lin Li-Bin

    2006-01-01

    In this paper, the timing jitter in dispersion-managed soliton-like systems with the Gaussian pulse is studied by using two methods. Firstly, the derivation of the dynamic equations for the evolution of soliton-like parameters and the timing jitter expressions for the dispersion-managed soliton-like systems are carried out by the perturbed variational method. By analysing and simulating these timing jitter expressions, one can find that the timing jitter is induced by the amplified spontaneous emission noise and the frequency shift, etc. Nonlinear gain can suppress the timing jitter.The chirp sign and the filters action have also effects on the total timing jitter. Secondly, the timing jitter is calculated and analysed by using the moment method. The results of the two methods prove to be consistent with each other.

  11. The effectiveness of a semi-tailored facilitator-based intervention to optimise chronic care management in general practice

    DEFF Research Database (Denmark)

    Due, Tina Drud; Thorsen, Thorkil; Kousgaard, Marius Brostrøm

    2014-01-01

    BACKGROUND: The Danish health care sector is reorganising based on disease management programmes designed to secure integrated and high quality chronic care across hospitals, general practitioners and municipalities. The disease management programmes assign a central role to general practice...... indicate that a semi-tailored facilitator-based intervention of relatively low intensity is unlikely to add substantially to the implementation of disease management programmes for DM2 and COPD in a context marked by important concurrent initiatives (including financial incentives and mandatory registry...

  12. The Use of ITIL for Process Optimisation in the IT Service Centre of Harz University, exemplified in the Release Management Process

    CERN Document Server

    Scheruhn, Hans-Juergen; Habel, Thomas

    2007-01-01

    This paper details the use of the IT Infrastructure Library Framework (ITIL) for optimising process workflows in the IT Service Centre of Harz University in Wernigerode, Germany, exemplified by the Release Management Process. It is described, how, during the course of a special ITIL project, the As-Is-Status of the various original processes was documented as part of the process life cycle and then transformed in the To-Be-Status, according to the ITIL Best Practice Framework. It is also shown, how the ITIL framework fits into the four-layered-process model, that could be derived from interviews with the universities IT support staff, and how the various modified processes interconnect with each other to form a value chain. The paper highlights the final results of the project and gives an outlook on the future use of ITIL as a business modelling tool in the IT Service Centre of Harz University. It is currently being considered, whether the process model developed during the project could be used as a referen...

  13. [Process optimisation: from theory to practical implementation].

    Science.gov (United States)

    Töpfer, Armin

    2010-01-01

    Today process optimisation is an indispensable approach to mastering the current challenges of modern health care management. The objective is to design business processes free of defects and free of waste as well as their monitoring and controlling with meaningful test statistics. Based on the identification of essential key performance indicators, key success factors and value cash generators two basic approaches to process optimisation, which are well-established and widely used in the industry, are now being implemented in the health care sector as well: Lean Management and Six Sigma.

  14. Isogeometric design optimisation

    NARCIS (Netherlands)

    Nagy, A.P.

    2011-01-01

    Design optimisation is of paramount importance in most engineering, e.g. aeronautical, automotive, or naval, disciplines. Its interdisciplinary character is manifested in the synthesis of geometric modelling, numerical analysis, mathematical programming, and computer sciences. The evolution of the f

  15. Sub-picosecond chirped return-to-zero nonlinear optical pulse propagating in dense dispersion-managed fibre

    Science.gov (United States)

    Guo, Shuqin; Le, Zichun; Quan, Bisheng

    2006-01-01

    By numerical simulation, we show that the fourth-order dispersion (FOD) makes sub-picosecond optical pulse broaden as second-order dispersion (SOD), makes optical pulse oscillate simultaneously as third-order dispersion (TOD). Based on above two reasons, sub-picosecond optical pulse will be widely broaden and lead to emission of continuum radiation during propagation. Here, resemble to two- and third-order dispersion compensation, fourth-order dispersion compensation is also suggested in a dispersion-managed optical fiber link, which is realized by arranging two kinds of fiber with opposite dispersion sign in each compensation cell. For sake of avoiding excessively broadening, ultra short scale dispersion compensation cell is required in ultra high speed optical communication system. In a full dispersion compensation optical fiber system which path average dispersion is zero about SOD, TOD, and FOD, even suffering from affection of high order nonlinear like self-steep effect and self-frequency shift, 200 fs gauss optical pulse can stable propagate over 1000 km with an optimal initial chirp. When space between neighboring optical pulse is only 2 picoseconds corresponding to 500 Gbit/s transmitting capacity, eye diagram is very clarity after 1000 km. The results demonstrate that ultra short scale dispersion compensation including FOD is need and effective in ultra-high speed optical communication.

  16. Real-time optimisation of the Hoa Binh reservoir, Vietnam

    DEFF Research Database (Denmark)

    Richaud, Bertrand; Madsen, Henrik; Rosbjerg, Dan

    2011-01-01

    -time optimisation. First, the simulation-optimisation framework is applied for optimising reservoir operating rules. Secondly, real-time and forecast information is used for on-line optimisation that focuses on short-term goals, such as flood control or hydropower generation, without compromising the deviation......Multi-purpose reservoirs often have to be managed according to conflicting objectives, which requires efficient tools for trading-off the objectives. This paper proposes a multi-objective simulation-optimisation approach that couples off-line rule curve optimisation with on-line real...... of the forecast is addressed. The results illustrate the importance of a sufficient forecast lead time to start pre-releasing water in flood situations....

  17. Performance Analysis of High-speed Optical Pulse Transmission in Dispersion-managed Nonlinear Birefringent Fiber Using Quantum Well Laser Diode Sources

    Institute of Scientific and Technical Information of China (English)

    YAN Minhui; CHEN Jianping

    2002-01-01

    This paper analyzes the high bit-rate optical pulse trasmission in single mode optical fiber with chromatic dispersion, polarization mode dispersion (small random birefringence) and nonlinearity. Numerical method employed can precisely describe their interactive effect on transmission performance. Different dispersion maps and the related performance are analysed. Various simulation results and discussion are given. The results show that chromatic dispersion compensation should be carefully designed. Appropriate dispersion management can also alleviate the effect of polarization mode dispersion.

  18. Intracranial Pressure Monitoring as a Part of Multimodal Monitoring Management of Patients with Critical Polytrauma: Correlation between Optimised Intensive Therapy According to Intracranial Pressure Parameters and Clinical Picture

    Science.gov (United States)

    Luca, Loredana; Rogobete, Alexandru Florin; Bedreag, Ovidiu Horea; Sarandan, Mirela; Cradigati, Carmen Alina; Papurica, Marius; Gruneantu, Anelore; Patrut, Raluca; Vernic, Corina; Dumbuleu, Corina Maria; Sandesc, Dorel

    2015-01-01

    Objective Trauma patient requires a complex therapeutic management because of multiple severe injuries or secondary complications. The most significant injury found in patients with trauma is head injury, which has the greatest impact on mortality. Intracranial pressure (ICP) monitoring is required in severe traumatic head injury because it optimises treatment based on ICP values and cerebral perfusion pressure (CPP). Methods From a total of 64 patients admitted in the intensive care unit (ICU) ‘Casa Austria’, from the Polytraumatology Clinic of the Emergency County Hospital “Pius Brinzeu” Timisoara, Romania, between January 2014 and December 2014; only patients who underwent ICP monitoring (n=10) were analysed. The study population was divided into several categories depending on the time passed since trauma to the time of installation of ICP monitoring (24 h). Comparisons were made in terms of the number of days admitted in the ICU and mortality between patients with head injury who benefited and those who did not benefit from ICP monitoring. Results The results show the positive influence of ICP monitoring on the number of admission days in ICU because of the possibility that the number of admission days to augment therapeutic effects in patients who benefited from ICP monitoring reduces by 1.93 days compared with those who did not undergo ICP monitoring. Conclusion ICP monitoring and optimizing therapy according to the ICP and CPP has significant influence on the rate of survival. ICP monitoring is necessary in all patients with head trauma injury according to recent guidelines. The main therapeutic goal in the management of the trauma patient with head injury is to minimize the destructive effects of the associated side effects. PMID:27366538

  19. Dispersion management for controlling image plane in Fourier-domain spectrally encoded endoscopy.

    Science.gov (United States)

    Merman, Michal; Yelin, Dvir

    2011-02-28

    Spectrally encoded endoscopy (SEE) uses single optical fiber and miniature diffractive optics to allow imaging through a miniature probe. Utilizing Fourier-domain interferometry, SEE was shown capable of video-rate three-dimensional imaging, albeit at limited depth of field due to the limited spectral resolution of the detection spectrometer. We show that by using dispersion management at the reference arm of the interferometer, the tilt and curvature of the field of view could be adjusted without modifying the endoscopic probe itself. By controlling the group velocity dispersion, this technique is demonstrated useful for imaging specimen regions which reside outside the system's depth of field. This approach could be used to improve usability, functionality and image quality of SEE without affecting probe size and flexibility.

  20. Intrachannel cross-phase modulation-induced phase shift in high-speed dispersion-managed optical fiber transmission system

    Science.gov (United States)

    Syed, Nitu; Faisal, Mohammad

    2013-12-01

    We investigate the intrachannel cross-phase modulation (IXPM)-induced phase shift in optical return-to-zero pulse propagating in a periodically dispersion-managed long-haul optical fiber transmission line. Necessary dynamical equations for various pulse parameters have been derived using variational analysis to estimate the phase shift. These equations are solved by the Runge-Kutta method. The analytical result is verified by numerical simulation based on split-step Fourier method. We therefore explore the effects of various parameters, such as transmission distance, input power, duty cycle, dispersion map strength, and residual dispersion, on phase shift for a 40 Gb/s single-channel transmission system. We also check the impact of variation of bit rate on phase shift. We find that IXPM-induced phase shift can be mitigated by proper adjustment of dispersion management and different pulse parameters like duty cycle, dispersion map strength, and peak power.

  1. The magnitude of reciprocity in chronic pain management: experiences of dispersed ethnic populations of Muslim women.

    Science.gov (United States)

    Müllersdorf, Maria; Zander, Viktoria; Eriksson, Henrik

    2011-12-01

    Dispersed ethnic populations believe their health to be worse than the ethnic majority group in Sweden. Most studies in rehabilitation exclude dispersed ethnic populations who can not read or speak the national language although this group seems to be in need of rehabilitation to a larger extent than privileged majority groups. The aim of the study was to examine the experience of living with musculoskeletal pain and experience of health care among dispersed ethnic populations of Muslim women. The method used was inspired by Grounded Theory in this study. Interviews were made with five first-generation Muslim immigrant women who had come to Sweden via Iraq as refugees. Two interviews were performed with interpreters. A preliminary core category 'The magnitude of reciprocity' based on three categories emerged from the analysis: (1) Impact of pain, (2) Managing pain and (3) Facing health care. Chronic pain limited the informants physically and emotionally, as well as impacting on their everyday life. Informants managed their pain primarily through medicine and physical activity, which gave at least temporary relief. Health care providers were perceived as doing their best but experiences of bad meetings were also witnessed. The factors important in achieving a good meeting in this study appeared to be; time, dialogue, honesty and understanding. Communication skills, feelings of being taken seriously and a sense of security were additional factors. Not being properly examined, or offered optimal treatment, not being believed or understood, were all seen as signs of dismissal within health care. The limitations of this study are primarily concerned with language difficulties resulting in various shortcomings. Reciprocal recognition and support connected to the specific life experiences of women that come with forced resettlement from the Muslim world to the European diaspora is a vital part of a holistic approach to pain management.

  2. Problems and tendencies in management optimisation of hospital sector within health care system of Republic of Bulgaria

    Directory of Open Access Journals (Sweden)

    M.G. Stoycheva

    2013-03-01

    Full Text Available The aim of the article. The purpose of this article is to analyze the specifics, priorities and tendencies of the reforms in hospital sector management within the health care system of Republic of Bulgaria, the hospital care organization practices in relation to the National discussions on issues of hospital sector of the health care system.The results of the analysis. The accession of Republic of Bulgaria to the EU has created new conditions in defining the priorities in the area of public health care, including hospital medical aid. Summarizing, accumulation and transfer of experience in reforming of health care systems of the European Union member states, development of unified requirements, harmonization of legislation, financing, structure of functioning and management of hospital care within the health care system, lead to the need of deep analysis of situation, strategic priorities renewal, management optimization of whole health care system, and in particular the hospital care system in Republic of Bulgaria.In the article the author analyses the research and publications of some major materials, regulations and documents, which provided the basis for the reforms in the health care management system in Republic of Bulgaria in its continuing integration into the pan-European system. Illustrating current situation analysis, the author shares the opinion that the most important part in the organization of common management system in health care is the sector responsible for the development of hospital financing.The author pays special attention to the issues of economic activity of health care institutions.The author cites a number of documents of the National Centre for Medical Information (NCMI noting that leading specialists of the Centre: .Dikov, R.Kolarova, T.Hundurzhievhave prepared detailed reports on economics 2001-2008 and comparative analysis of the medical institutions operation as well as those for outpatient care in Republic of

  3. Distributed demand-side management optimisation for multi-residential users with energy production and storage strategies

    Directory of Open Access Journals (Sweden)

    Emmanuel Chifuel Manasseh

    2014-12-01

    Full Text Available This study considers load control in a multi-residential setup where energy scheduler (ES devices installed in smart meters are employed for demand-side management (DSM. Several residential end-users share the same energy source and each residential user has non-adjustable loads and adjustable loads. In addition, residential users may have storage devices and renewable energy sources such as wind turbines or solar as well as dispatchable generators. The ES devices exchange information automatically by executing an iterative distributed algorithm to locate the optimal energy schedule for each end-user. This will reduce the total energy cost and the peak-to-average ratio (PAR in energy demand in the electric power distribution. Users possessing storage devices and dispatchable generators strategically utilise their resources to minimise the total energy cost together with the PAR. Simulation results are provided to evaluate the performance of the proposed game theoretic-based distributed DSM technique.

  4. MoS2-clad microfibre laser delivering conventional, dispersion-managed and dissipative solitons

    Science.gov (United States)

    Cui, Yudong; Lu, Feifei; Liu, Xueming

    2016-07-01

    Molybdenum disulfide (MoS2), whose monolayer possesses a direct band gap, displays promising applications in optoelectronics, photonics, and lasers. Recent researches have demonstrated that MoS2 has not only a significant broadband saturable absorption performance, but also a higher optical nonlinear response than graphene. However, MoS2 shows much lower optical damage threshold owing to the poorer thermal conductivity and mechanical property. Here, we exploit a MoS2-clad microfibre (MCM) as the saturable absorber (SA) for the generation of ultrashort pulses under different dispersion conditions. The improved evanescent field interaction scheme can overcome the laser-induced thermal damage, as well as take full advantage of the strong nonlinear effect of MoS2. With the MCM SA, conventional, dispersion-managed, and dissipative solitons are generated around 1600 nm in Er-doped fibre lasers with anomalous, near-zero, and normal cavity dispersions, respectively. Our work paves the way for applications of 2D layered materials in photonics, especially in laser sources.

  5. MoS2-clad microfibre laser delivering conventional, dispersion-managed and dissipative solitons

    Science.gov (United States)

    Cui, Yudong; Lu, Feifei; Liu, Xueming

    2016-01-01

    Molybdenum disulfide (MoS2), whose monolayer possesses a direct band gap, displays promising applications in optoelectronics, photonics, and lasers. Recent researches have demonstrated that MoS2 has not only a significant broadband saturable absorption performance, but also a higher optical nonlinear response than graphene. However, MoS2 shows much lower optical damage threshold owing to the poorer thermal conductivity and mechanical property. Here, we exploit a MoS2-clad microfibre (MCM) as the saturable absorber (SA) for the generation of ultrashort pulses under different dispersion conditions. The improved evanescent field interaction scheme can overcome the laser-induced thermal damage, as well as take full advantage of the strong nonlinear effect of MoS2. With the MCM SA, conventional, dispersion-managed, and dissipative solitons are generated around 1600 nm in Er-doped fibre lasers with anomalous, near-zero, and normal cavity dispersions, respectively. Our work paves the way for applications of 2D layered materials in photonics, especially in laser sources. PMID:27456468

  6. Action on AMD. Optimising patient management: act now to ensure current and continual delivery of best possible patient care.

    Science.gov (United States)

    Amoaku, W; Blakeney, S; Freeman, M; Gale, R; Johnston, R; Kelly, S P; McLaughlan, B; Sahu, D; Varma, D

    2012-02-01

    In recent years, there have been significant advances in the clinical management of patients with wet age-related macular degeneration (wet AMD)--a rapidly progressing and potentially blinding degenerative eye disease. Wet AMD is responsible for more than half of registered severe sight impairment (blindness) in the United Kingdom, and patients who are being treated for wet AMD require frequent and long-term follow-up for treatment to be most effective. The clinical workload associated with the frequent follow-up required is substantial. Furthermore, as more new patients are diagnosed and the population continues to age, the patient population will continue to increase. It is thus vital that clinical services continue to adapt so that they can provide a fast and efficient service for patients with wet AMD. This Action on AMD document has been developed by eye health-care professionals and patient representatives, the Action on AMD group. It is intended to highlight the urgent and continuing need for change within wet AMD services. This document also serves as a guide for eye health-care professionals, NHS commissioners, and providers to present possible solutions for improving NHS retinal and macular services. Examples of good practice and service development are considered and can be drawn upon to help services meet the recommended quality of care and achieve best possible outcomes.

  7. Incorporating cache management behavior into seed dispersal: the effect of pericarp removal on acorn germination.

    Directory of Open Access Journals (Sweden)

    Xianfeng Yi

    Full Text Available Selecting seeds for long-term storage is a key factor for food hoarding animals. Siberian chipmunks (Tamias sibiricus remove the pericarp and scatter hoard sound acorns of Quercus mongolica over those that are insect-infested to maximize returns from caches. We have no knowledge of whether these chipmunks remove the pericarp from acorns of other species of oaks and if this behavior benefits seedling establishment. In this study, we tested whether Siberian chipmunks engage in this behavior with acorns of three other Chinese oak species, Q. variabilis, Q. aliena and Q. serrata var. brevipetiolata, and how the dispersal and germination of these acorns are affected. Our results show that when chipmunks were provided with sound and infested acorns of Quercus variabilis, Q. aliena and Q. serrata var. brevipetiolata, the two types were equally harvested and dispersed. This preference suggests that Siberian chipmunks are incapable of distinguishing between sound and insect-infested acorns. However, Siberian chipmunks removed the pericarp from acorns of these three oak species prior to dispersing and caching them. Consequently, significantly more sound acorns were scatter hoarded and more infested acorns were immediately consumed. Additionally, indoor germination experiments showed that pericarp removal by chipmunks promoted acorn germination while artificial removal showed no significant effect. Our results show that pericarp removal allows Siberian chipmunks to effectively discriminate against insect-infested acorns and may represent an adaptive behavior for cache management. Because of the germination patterns of pericarp-removed acorns, we argue that the foraging behavior of Siberian chipmunks could have potential impacts on the dispersal and germination of acorns from various oak species.

  8. Particle Swarm Optimisation with Spatial Particle Extension

    DEFF Research Database (Denmark)

    Krink, Thiemo; Vesterstrøm, Jakob Svaneborg; Riget, Jacques

    2002-01-01

    In this paper, we introduce spatial extension to particles in the PSO model in order to overcome premature convergence in iterative optimisation. The standard PSO and the new model (SEPSO) are compared w.r.t. performance on well-studied benchmark problems. We show that the SEPSO indeed managed...

  9. Optimisation of Investment Resources at Small Enterprises

    Directory of Open Access Journals (Sweden)

    Shvets Iryna B.

    2014-03-01

    Full Text Available The goal of the article lies in the study of the process of optimisation of the structure of investment resources, development of criteria and stages of optimisation of volumes of investment resources for small enterprises by types of economic activity. The article characterises the process of transformation of investment resources into assets and liabilities of the balances of small enterprises and conducts calculation of the structure of sources of formation of investment resources in Ukraine at small enterprises by types of economic activity in 2011. On the basis of the conducted analysis of the structure of investment resources of small enterprises the article forms main groups of criteria of optimisation in the context of individual small enterprises by types of economic activity. The article offers an algorithm and step-by-step scheme of optimisation of investment resources at small enterprises in the form of a multi-stage process of management of investment resources in the context of increase of their mobility and rate of transformation of existing resources into investments. The prospect of further studies in this direction is development of a structural and logic scheme of optimisation of volumes of investment resources at small enterprises.

  10. Simulation versus Optimisation

    DEFF Research Database (Denmark)

    Lund, Henrik; Arler, Finn; Østergaard, Poul Alberg

    2017-01-01

    investment optimisation or optimal solutions approach. On the other hand the analytical simulation or alternatives assessment approach. Awareness of the dissimilar theoretical assumption behind the models clarifies differences between the models, explains dissimilarities in results, and provides...... a theoretical and methodological foundation for understanding and interpreting results from the two archetypes. Keywords: energy system analysis; investment optimisation models; simulations models; modelling theory;renewable energy......In recent years, several tools and models have been developed and used for the design and analysis of future national energy systems. Many of these models focus on the integration of various renewable energy resources and the transformation of existing fossil-based energy systems into future...

  11. Optimising AspectJ

    DEFF Research Database (Denmark)

    Avgustinov, Pavel; Christensen, Aske Simon; Hendren, Laurie

    2005-01-01

    AspectJ, an aspect-oriented extension of Java, is becoming increasingly popular. However, not much work has been directed at optimising compilers for AspectJ. Optimising AOP languages provides many new and interesting challenges for compiler writers, and this paper identifies and addresses three...... all of the techniques in this paper in abc, our AspectBench Compiler for AspectJ, and we demonstrate significant speedups with empirical results. Some of our techniques have already been integrated into the production AspectJ compiler, ajc 1.2.1....

  12. Optimising Magnetostatic Assemblies

    DEFF Research Database (Denmark)

    Insinga, Andrea Roberto; Smith, Anders

    the optimal remanence distribution with respect to a linear objective functional. Additionally, it is shown here that the same formalism can be applied to the optimisation of the geometry of magnetic systems. Specifically, the border separating the permanent magnet from regions occupied by air or soft...

  13. Optimising pain management- An update

    African Journals Online (AJOL)

    nociceptive (somatic or visceral pain), namely pain caused by surgery, medical ... This is pain in one or more anatomic regions of the body that persists for ... data pointed out that it may be more efficacious and safe when used alone as a ...

  14. Optimisation of Receivables Management in a Mine, Using Linear Programming / Optymalizacja zarządzania należnościami w kopalni z wykorzystaniem programowania liniowego

    Science.gov (United States)

    Czopek, Kazimierz; Trzaskuś-Żak, Beata

    2013-06-01

    The paper presents an example of a theoretical linear programming model in the management of mine receivables. To this end, an economic production model of linear programming was applied to optimising the revenue of the mine. The amount of product sold by the mine to individual customers was assumed as the decisive variable, and the product price was the parameter of the objective function. As for boundaries, upper receivable limits were assumed for each of the adopted receivable collection cycles. The sequence of collection cycles, and the receivable values assigned to them, were adopted according to the growing probability of overdue and uncollectible receivables. Two receivables-management optimisation cases were analysed, in which the objective function was to maximise the sales value (revenue) of the Mine. The first case studied in the model involves application of a discount to reduce the product price, in a mine whose production output is not being used to capacity. To improve cash flow, the mine offers its customers a reduced price and increased purchasing up to the mine's capacity in exchange for shortened receivable collection times. Fixed and variable-cost accounting is applied to determine the relevant price reduction. In the other case analysed, the mine sells as much as its current output allows, but despite that is still forced to reduce the price of its products. Application of a discount in this case (reducing the product price) inevitably involves shortened receivable collection times and reduced costs of financing trade credit. Artykuł przedstawia przykład teoretycznego modelu programowania liniowego w zarządzaniu należnościami kopalni. Wykorzystano w tym celu model produkcyjno-gospodarczy programowania liniowego do optymalizacji wartości przychodu kopalni. Jako zmienną decyzyjną modelu przyjęto ilość sprzedaży produktu kopalni do poszczególnych odbiorców, natomiast parametrem funkcji celu jest cena sprzedaży produktu. W

  15. Optimisation by hierarchical search

    Science.gov (United States)

    Zintchenko, Ilia; Hastings, Matthew; Troyer, Matthias

    2015-03-01

    Finding optimal values for a set of variables relative to a cost function gives rise to some of the hardest problems in physics, computer science and applied mathematics. Although often very simple in their formulation, these problems have a complex cost function landscape which prevents currently known algorithms from efficiently finding the global optimum. Countless techniques have been proposed to partially circumvent this problem, but an efficient method is yet to be found. We present a heuristic, general purpose approach to potentially improve the performance of conventional algorithms or special purpose hardware devices by optimising groups of variables in a hierarchical way. We apply this approach to problems in combinatorial optimisation, machine learning and other fields.

  16. Optimising costs in WLCG operations

    CERN Document Server

    Pradillo, Mar; Flix, Josep; Forti, Alessandra; Sciabà, Andrea

    2015-01-01

    The Worldwide LHC Computing Grid project (WLCG) provides the computing and storage resources required by the LHC collaborations to store, process and analyse the 50 Petabytes of data annually generated by the LHC. The WLCG operations are coordinated by a distributed team of managers and experts and performed by people at all participating sites and from all the experiments. Several improvements in the WLCG infrastructure have been implemented during the first long LHC shutdown to prepare for the increasing needs of the experiments during Run2 and beyond. However, constraints in funding will affect not only the computing resources but also the available effort for operations. This paper presents the results of a detailed investigation on the allocation of the effort in the different areas of WLCG operations, identifies the most important sources of inefficiency and proposes viable strategies for optimising the operational cost, taking into account the current trends in the evolution of the computing infrastruc...

  17. Maturity dispersion, stock auto-correlation, and management strategy in exploited populations.

    Science.gov (United States)

    Gurney, William S C; McKenzie, Eddie; Bacon, Philip J

    2010-07-01

    Fishery management policies need to be based on historical summaries of stock status which are well correlated with the size of the group of individuals who will be affected by any harvest. This paper is motivated by the problem of managing stocks of Atlantic salmon, which can be accurately monitored during the riverine stages of their life-history, but which spend a lengthy period at sea before returning to spawn. We begin by formulating a minimal stochastic model of stock-recruitment driven population dynamics, which linearises to a standard ARMA form. We investigate the relation between maturity dispersion and the auto-covariance of stock fluctuations driven by process noise in the recruitment process and/or random variability in survival from recruitment to spawning. We demonstrate that significant reductions in fluctuation intensity and/or increases in long-run average yield can be achieved by controlling harvesting in response to the value of a historical summary focussed on lags at which the uncontrolled population dynamics produce strong correlations. We apply our minimal model to two well-characterised Atlantic salmon populations, and find poor agreement between predicted and observed stock fluctuation ACF. Re-examination of the ancilliary data available for one of our two exemplary systems leads us to propose an extended model which also linearises to ARMA form, and which predicts a fluctuation ACF more closely in agreement with that observed, and could thus form a satisfactory vehicle for policy discussion.

  18. Improving recruitment to a study of telehealth management for long-term conditions in primary care: two embedded, randomised controlled trials of optimised patient information materials.

    Science.gov (United States)

    Man, Mei-See; Rick, Jo; Bower, Peter

    2015-07-19

    Patient understanding of study information is fundamental to gaining informed consent to take part in a randomised controlled trial. In order to meet the requirements of research ethics committees, patient information materials can be long and need to communicate complex messages. There is concern that standard approaches to providing patient information may deter potential participants from taking part in trials. The Systematic Techniques for Assisting Recruitment to Trials (MRC-START) research programme aims to test interventions to improve trial recruitment. The aim of this study was to investigate the effect on recruitment of optimised patient information materials (with improved readability and ease of comprehension) compared with standard materials. The study was embedded within two primary care trials involving patients with long-term conditions. The Healthlines Study involves two linked trials evaluating a telehealth intervention in patients with depression (Healthlines Depression) or raised cardiovascular disease risk (Healthlines CVD). We conducted two trials of a recruitment intervention, embedded within the Healthlines host trials. Patients identified as potentially eligible in each of the Healthlines trials were randomised to receive either the original patient information materials or optimised versions of these materials. Primary outcomes were the proportion of participants randomised (Healthlines Depression) and the proportion expressing interest in taking part (Healthlines CVD). In Healthlines Depression (n = 1364), 6.3% of patients receiving the optimised patient information materials were randomised into the study compared to 4.0% in those receiving standard materials (OR = 1.63, 95% CI = 1.00 to 2.67). In Healthlines CVD (n = 671) 24.0% of those receiving optimised patient information materials responded positively to the invitation to participate, compared to 21.9% in those receiving standard materials (OR = 1.12, 95% CI = 0.78 to 1

  19. Management of dispersion, nonlinearity and polarization-dependent effects in high-speed reconfigurable WDM fiber optic communication systems

    Science.gov (United States)

    Luo, Ting

    As optical communications approach more data bandwidth, longer transmission distance, and more reconfigurability, dispersion, nonlinearity and polarization-dependent effects are becoming key issues for future all-optical fiber optic systems and networks. For ≥10 Gbit/s optical fiber transmission systems, it is critical that chromatic dispersion and polarization-mode-dispersion be well monitored and compensated using some type of dispersion monitoring and compensation. On the other hand, dispersive and nonlinear effects in optical fiber systems can also be beneficial and have applications on pulse management, all-optical signal processing and network function, which will be essential for high bite-rate optical networks and replacing the expensive optical-electrical-optical (O/E/O) conversion. In this Ph.D. dissertation, we present a detailed research on dispersion, nonlinearity, and polarization-dependent effects in high-speed optical communication systems. We have demonstrated: (i) A dynamic channel-spacing tunable multi-wavelength Erbium-doped fiber laser; (ii) Chromatic-dispersion-insensitive PMD monitoring by tracking the radio-frequency extracted from the vestigial-sideband; (iii) A method for simultaneous chromatic and polarization-mode dispersions monitoring by adding a frequency-shifted carrier; (iv) Polarization-insensitive optical parametric amplification by depolarizing the pump; (v) All optical chromatic dispersion monitoring potential for ultra-high speed (>40 Gbit/s) optical systems using cross-phase modulation in a highly nonlinear fiber; (vi) A novel fiber-based autocorrelator using polarimetric four-wave mixing effect and a tunable differential-group-delay element; (vii) A simple all-fiber-based autocorrelator by measuring the degree-of-polarization; and (viii) Reduction of pattern dependent data distortion in a stimulated Brillouin scattering based slow light element. These techniques will play key roles in future high-speed dynamic WDM optical

  20. Earth Observation and Life Cycle Assessment in Support of a Sustainable and Innovative Water Sector. RESEWAM-O, Remote Sensing for Water Management Optimisation

    Science.gov (United States)

    Lopez-Baeza, Ernesto

    2016-07-01

    RESEWAM-O, Remote Sensing for Water Management Optimisation, a European Innovation Partnership on Water (EIP-Water) Action Group is an innovation opportunity service, par excellence envisaging the provision of a versatile methodology -in principle applicable in all sensitive areas in the world- that integrates the knowledge, diagnostic and monitoring capacity of remote sensing with optimum engineering solutions and efficient financial tools. For the first time, the problem (water scarcity) and the solution (water resources connections, treatment plants, preserving freshwater supplies for urban uses that will be connected through a feasibility plan) are approached together within the same vision, also with a life cycle thinking perspective. The use of reclaimed water has been noted as one possible alternative water source in water scarce regions that may be appropriate to consider within water scarcity planning. There certainly exist solutions related to the use of reclaimed water to develop smart agriculture initiatives, but RESEWAM-O's premise is to create a new methodology that combines remote sensing knowledge and technology to identify, classify and diagnose potential sensitive areas, financial tools including feasibility analyses to know the real cost and the benefit from the project, and engineering studies to restore or create water infrastructures, naturally taking into account all water resources that are available in the area or in neighbouring areas. Similarly, we know about initiatives to recover or recharge aquifer storage with reclaimed wastewater but, as another step forward, RESEWAM-O will use reclaimed water from small wastewater treatment facilities in the rural areas to offer agricultural farmers/cooperatives the possibility of actually reusing this water, thus preserving their freshwater for urban uses. The final objective is to put together agricultural farmers/cooperatives, companies suppliers of water services and the administration to

  1. Dynamics of a Dispersion-Managed Passively Mode-Locked Er-Doped Fiber Laser Using Single Wall Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Norihiko Nishizawa

    2015-07-01

    Full Text Available We investigated the dynamics of a dispersion-managed, passively mode-locked, ultrashort-pulse, Er-doped fiber laser using a single-wall carbon nanotube (SWNT device. A numerical model was constructed for analysis of the SWNT fiber laser. The initial process of passive mode-locking, the characteristics of the output pulse, and the dynamics inside the cavity were investigated numerically for soliton, dissipative-soliton, and stretched-pulse mode-locking conditions. The dependencies on the total dispersion and recovery time of the SWNTs were also examined. Numerical results showed similar behavior to experimental results.

  2. Optimisation of Microstrip Antenna

    Directory of Open Access Journals (Sweden)

    H. El Hamchary

    1996-04-01

    Full Text Available When choosing the most appropriate microstrip antenna configuration for particular applications, the kind of excitation of the radiating element is an essential factor that requires careful considerations. For controlling the distribution of energy of the linear or planar array of elements and for coupling energy to the individual elements, a wide variety of feed mechanisms are available. In this paper, the coaxial antenna feeding is assumed and the best (optimised feeding is found. Then, antenna characteristics such as radiation pattern, return loss, input impedance, and VSWR are obtained.

  3. A Global Optimisation Toolbox for Massively Parallel Engineering Optimisation

    CERN Document Server

    Biscani, Francesco; Yam, Chit Hong

    2010-01-01

    A software platform for global optimisation, called PaGMO, has been developed within the Advanced Concepts Team (ACT) at the European Space Agency, and was recently released as an open-source project. PaGMO is built to tackle high-dimensional global optimisation problems, and it has been successfully used to find solutions to real-life engineering problems among which the preliminary design of interplanetary spacecraft trajectories - both chemical (including multiple flybys and deep-space maneuvers) and low-thrust (limited, at the moment, to single phase trajectories), the inverse design of nano-structured radiators and the design of non-reactive controllers for planetary rovers. Featuring an arsenal of global and local optimisation algorithms (including genetic algorithms, differential evolution, simulated annealing, particle swarm optimisation, compass search, improved harmony search, and various interfaces to libraries for local optimisation such as SNOPT, IPOPT, GSL and NLopt), PaGMO is at its core a C++ ...

  4. OptiPhy, a technical-economic optimisation model for improving the management of plant protection practices in agriculture: a decision-support tool for controlling the toxicity risks related to pesticides.

    Science.gov (United States)

    Mghirbi, Oussama; LE Grusse, Philippe; Fabre, Jacques; Mandart, Elisabeth; Bord, Jean-Paul

    2017-03-01

    The health, environmental and socio-economic issues related to the massive use of plant protection products are a concern for all the stakeholders involved in the agricultural sector. These stakeholders, including farmers and territorial actors, have expressed a need for decision-support tools for the management of diffuse pollution related to plant protection practices and their impacts. To meet the needs expressed by the public authorities and the territorial actors for such decision-support tools, we have developed a technical-economic model "OptiPhy" for risk mitigation based on indicators of pesticide toxicity risk to applicator health (IRSA) and to the environment (IRTE), under the constraint of suitable economic outcomes. This technical-economic optimisation model is based on linear programming techniques and offers various scenarios to help the different actors in choosing plant protection products, depending on their different levels of constraints and aspirations. The health and environmental risk indicators can be broken down into sub-indicators so that management can be tailored to the context. This model for technical-economic optimisation and management of plant protection practices can analyse scenarios for the reduction of pesticide-related risks by proposing combinations of substitution PPPs, according to criteria of efficiency, economic performance and vulnerability of the natural environment. The results of the scenarios obtained on real ITKs in different cropping systems show that it is possible to reduce the PPP pressure (TFI) and reduce toxicity risks to applicator health (IRSA) and to the environment (IRTE) by up to approximately 50 %.

  5. Simple Combinatorial Optimisation Cost Games

    NARCIS (Netherlands)

    van Velzen, S.

    2005-01-01

    In this paper we introduce the class of simple combinatorial optimisation cost games, which are games associated to {0, 1}-matrices.A coalitional value of a combinatorial optimisation game is determined by solving an integer program associated with this matrix and the characteristic vector of the

  6. Development of oral dispersible tablets containing prednisolone nanoparticles for the management of pediatric asthma

    Directory of Open Access Journals (Sweden)

    Chen YD

    2015-11-01

    Full Text Available Yi-Dan Chen,1 Zhong-Yuan Liang,1 Yan-Yan Cen,1 He Zhang,2 Mei-Gui Han,2 Yun-Qiao Tian,2 Jie Zhang,2 Shu-Jun Li,2 Da-Sheng Yang2 1College of Pharmacy, The Third Military Medical University, Chongqing, 2Department of Pediatrics, The First Affiliated Hospital of Xinxiang Medical University, Xinxiang, People’s Republic of ChinaAbstract: The purpose of the present study was to develop oral dispersible tablets containing prednisolone (PDS-loaded chitosan nanoparticles using microcrystalline cellulose (MCC 101, lactose, and croscarmellose sodium (CCS. The PDS-loaded chitosan nanoparticles were formulated by ionotropic external gelation technique in order to enhance the solubility of PDS in salivary pH. Prepared nanoparticles were used for the development of oral fast disintegrating tablets by direct compression method. The prepared tablets were evaluated for disintegration time (DT, in vitro drug release (DR, thickness, weight variation, drug content uniformity, friability, and hardness. The effect of concentrations of the dependent variables (MCC, lactose, CCS on DT and in vitro DR was studied. Fast disintegrating tablets of PDS can be prepared by using MCC, CCS, and lactose with enhanced solubility of PDS. The minimum DT was found to be 15 seconds, and the maximum DR within 30 minutes was 98.50%. All independent variables selected for the study were statistically significant. Oral fast disintegrating tablets containing PDS nanoparticles could be the better choice for the pediatric patients that would result in better patient compliance. From this study, it can be concluded that fast disintegrating tablets could be a potential drug delivery technology for the management of asthma in pediatrics. Keywords: asthma, superdisintegrant, prednisolone, oral tablets, MCC, CCS, factorial design, ANOVA

  7. 1700 nm dispersion managed mode-locked bismuth fiber laser

    OpenAIRE

    Teppo Noronen; Sergei Firstov; Evgeny Dianov; Okhotnikov, Oleg G.

    2016-01-01

    We demonstrate the first 1.7 μm bismuth-doped fiber laser generating ultrashort pulses via passive mode-locking. Pulse operation has been achieved for both anomalous and normal dispersion of the laser cavity owing to broadband characteristics of carbon nanotube saturable absorber. The laser delivered 1.65 ps pulses in net anomalous dispersion regime. In normal dispersion regime, the laser delivered 14 ps pulses which could be compressed to 1.2 ps using external fiber compressor.

  8. 1700 nm dispersion managed mode-locked bismuth fiber laser

    Science.gov (United States)

    Noronen, Teppo; Firstov, Sergei; Dianov, Evgeny; Okhotnikov, Oleg G.

    2016-04-01

    We demonstrate the first 1.7 μm bismuth-doped fiber laser generating ultrashort pulses via passive mode-locking. Pulse operation has been achieved for both anomalous and normal dispersion of the laser cavity owing to broadband characteristics of carbon nanotube saturable absorber. The laser delivered 1.65 ps pulses in net anomalous dispersion regime. In normal dispersion regime, the laser delivered 14 ps pulses which could be compressed to 1.2 ps using external fiber compressor.

  9. Topology optimised wavelength dependent splitters

    DEFF Research Database (Denmark)

    Hede, K. K.; Burgos Leon, J.; Frandsen, Lars Hagedorn

    A photonic crystal wavelength dependent splitter has been constructed by utilising topology optimisation1. The splitter has been fabricated in a silicon-on-insulator material (Fig. 1). The topology optimised wavelength dependent splitter demonstrates promising 3D FDTD simulation results....... This complex photonic crystal structure is very sensitive against small fabrication variations from the expected topology optimised design. A wavelength dependent splitter is an important basic building block for high-performance nanophotonic circuits. 1J. S. Jensen and O. Sigmund, App. Phys. Lett. 84, 2022...

  10. Engineering Optimisation by Cuckoo Search

    CERN Document Server

    Yang, Xin-She

    2010-01-01

    A new metaheuristic optimisation algorithm, called Cuckoo Search (CS), was developed recently by Yang and Deb (2009). This paper presents a more extensive comparison study using some standard test functions and newly designed stochastic test functions. We then apply the CS algorithm to solve engineering design optimisation problems, including the design of springs and welded beam structures. The optimal solutions obtained by CS are far better than the best solutions obtained by an efficient particle swarm optimiser. We will discuss the unique search features used in CS and the implications for further research.

  11. Topology optimised wavelength dependent splitters

    DEFF Research Database (Denmark)

    Hede, K. K.; Burgos Leon, J.; Frandsen, Lars Hagedorn;

    A photonic crystal wavelength dependent splitter has been constructed by utilising topology optimisation1. The splitter has been fabricated in a silicon-on-insulator material (Fig. 1). The topology optimised wavelength dependent splitter demonstrates promising 3D FDTD simulation results....... This complex photonic crystal structure is very sensitive against small fabrication variations from the expected topology optimised design. A wavelength dependent splitter is an important basic building block for high-performance nanophotonic circuits. 1J. S. Jensen and O. Sigmund, App. Phys. Lett. 84, 2022...

  12. Optimisation of the Laser Cutting Process

    DEFF Research Database (Denmark)

    Dragsted, Birgitte; Olsen, Flemmming Ove

    1996-01-01

    The problem in optimising the laser cutting process is outlined. Basic optimisation criteria and principles for adapting an optimisation method, the simplex method, are presented. The results of implementing a response function in the optimisation are discussed with respect to the quality as well...

  13. Optimising costs in WLCG operations

    Science.gov (United States)

    Alandes Pradillo, María; Dimou, Maria; Flix, Josep; Forti, Alessandra; Sciabà, Andrea

    2015-12-01

    The Worldwide LHC Computing Grid project (WLCG) provides the computing and storage resources required by the LHC collaborations to store, process and analyse the 50 Petabytes of data annually generated by the LHC. The WLCG operations are coordinated by a distributed team of managers and experts and performed by people at all participating sites and from all the experiments. Several improvements in the WLCG infrastructure have been implemented during the first long LHC shutdown to prepare for the increasing needs of the experiments during Run2 and beyond. However, constraints in funding will affect not only the computing resources but also the available effort for operations. This paper presents the results of a detailed investigation on the allocation of the effort in the different areas of WLCG operations, identifies the most important sources of inefficiency and proposes viable strategies for optimising the operational cost, taking into account the current trends in the evolution of the computing infrastructure and the computing models of the experiments.

  14. ATLAS software configuration and build tool optimisation

    Science.gov (United States)

    Rybkin, Grigory; Atlas Collaboration

    2014-06-01

    ATLAS software code base is over 6 million lines organised in about 2000 packages. It makes use of some 100 external software packages, is developed by more than 400 developers and used by more than 2500 physicists from over 200 universities and laboratories in 6 continents. To meet the challenge of configuration and building of this software, the Configuration Management Tool (CMT) is used. CMT expects each package to describe its build targets, build and environment setup parameters, dependencies on other packages in a text file called requirements, and each project (group of packages) to describe its policies and dependencies on other projects in a text project file. Based on the effective set of configuration parameters read from the requirements files of dependent packages and project files, CMT commands build the packages, generate the environment for their use, or query the packages. The main focus was on build time performance that was optimised within several approaches: reduction of the number of reads of requirements files that are now read once per package by a CMT build command that generates cached requirements files for subsequent CMT build commands; introduction of more fine-grained build parallelism at package task level, i.e., dependent applications and libraries are compiled in parallel; code optimisation of CMT commands used for build; introduction of package level build parallelism, i. e., parallelise the build of independent packages. By default, CMT launches NUMBER-OF-PROCESSORS build commands in parallel. The other focus was on CMT commands optimisation in general that made them approximately 2 times faster. CMT can generate a cached requirements file for the environment setup command, which is especially useful for deployment on distributed file systems like AFS or CERN VMFS. The use of parallelism, caching and code optimisation significantly-by several times-reduced software build time, environment setup time, increased the efficiency of

  15. Isogeometric Analysis and Shape Optimisation

    DEFF Research Database (Denmark)

    Gravesen, Jens; Evgrafov, Anton; Gersborg, Allan Roulund

    obtained and also some of the problems we have encountered. One of these problems is that the geometry of the shape is given by the boundary alone. And, it is the parametrisation of the boundary which is changed by the optimisation procedure. But isogeometric analysis requires a parametrisation......One of the attractive features of isogeometric analysis is the exact representation of the geometry. The geometry is furthermore given by a relative low number of control points and this makes isogeometric analysis an ideal basis for shape optimisation. I will describe some of the results we have...... of the whole domain. So in every optimisation cycle we need to extend a parametrisation of the boundary of a domain to the whole domain. It has to be fast in order not to slow the optimisation down but it also has to be robust and give a parametrisation of high quality. These are conflicting requirements so we...

  16. Turbulence optimisation in stellarator experiments

    Energy Technology Data Exchange (ETDEWEB)

    Proll, Josefine H.E. [Max-Planck/Princeton Center for Plasma Physics (Germany); Max-Planck-Institut fuer Plasmaphysik, Wendelsteinstr. 1, 17491 Greifswald (Germany); Faber, Benjamin J. [HSX Plasma Laboratory, University of Wisconsin-Madison, Madison, WI 53706 (United States); Helander, Per; Xanthopoulos, Pavlos [Max-Planck/Princeton Center for Plasma Physics (Germany); Lazerson, Samuel A.; Mynick, Harry E. [Plasma Physics Laboratory, Princeton University, P.O. Box 451 Princeton, New Jersey 08543-0451 (United States)

    2015-05-01

    Stellarators, the twisted siblings of the axisymmetric fusion experiments called tokamaks, have historically suffered from confining the heat of the plasma insufficiently compared with tokamaks and were therefore considered to be less promising candidates for a fusion reactor. This has changed, however, with the advent of stellarators in which the laminar transport is reduced to levels below that of tokamaks by shaping the magnetic field accordingly. As in tokamaks, the turbulent transport remains as the now dominant transport channel. Recent analytical theory suggests that the large configuration space of stellarators allows for an additional optimisation of the magnetic field to also reduce the turbulent transport. In this talk, the idea behind the turbulence optimisation is explained. We also present how an optimised equilibrium is obtained and how it might differ from the equilibrium field of an already existing device, and we compare experimental turbulence measurements in different configurations of the HSX stellarator in order to test the optimisation procedure.

  17. ERP Systems Created to Support Academic Management in Contexts of Geographic Dispersion: A Case Study in Regional Higher Education

    Directory of Open Access Journals (Sweden)

    Gabriel Moreno

    2017-01-01

    Full Text Available In response to extension of coverage goals in higher education, academic programs offering has been growing in regions geographically dispersed which management requires solid information systems able to adapt to the context needs and particularities. This paper presents a descriptive case study conducted in one of the head offices of Corporación Universitaria Minuto de Dios operating in 34 municipalities of cundinamarca department in colombia, highlighting challenges evidenced in the process of design and implementation of a custom ERP system. The case of study provides wide contextual details about selection and design of components, customization, integration and evaluation of the ERP system. Through this analysis are documented (a the challenges in integration, escalability and interoperability of ERP systems in higher education that are evidenced in a context of regionalization with geographic dispersion variables; and (b the differential features provided by a custom ERP system respect to the currently used systems in higher education.

  18. Optimisation of load control

    Energy Technology Data Exchange (ETDEWEB)

    Koponen, P. [VTT Energy, Espoo (Finland)

    1998-08-01

    Electricity cannot be stored in large quantities. That is why the electricity supply and consumption are always almost equal in large power supply systems. If this balance were disturbed beyond stability, the system or a part of it would collapse until a new stable equilibrium is reached. The balance between supply and consumption is mainly maintained by controlling the power production, but also the electricity consumption or, in other words, the load is controlled. Controlling the load of the power supply system is important, if easily controllable power production capacity is limited. Temporary shortage of capacity causes high peaks in the energy price in the electricity market. Load control either reduces the electricity consumption during peak consumption and peak price or moves electricity consumption to some other time. The project Optimisation of Load Control is a part of the EDISON research program for distribution automation. The following areas were studied: Optimization of space heating and ventilation, when electricity price is time variable, load control model in power purchase optimization, optimization of direct load control sequences, interaction between load control optimization and power purchase optimization, literature on load control, optimization methods and field tests and response models of direct load control and the effects of the electricity market deregulation on load control. An overview of the main results is given in this chapter

  19. Efficacy of water dispersible formulations of biocontrol strains of Aspergillus flavus for aflatoxin management in corn

    Science.gov (United States)

    Field experiments were conducted in 2011 and 2012 to evaluate the efficacy of water dispersible granule (WDG) formulations of biocontrol strains of Aspergillus flavus in controlling aflatoxin contamination of corn. In 2011, when aflatoxin was present at very high levels, no WDG treatment provided s...

  20. Evolution of dark-dark soliton pairs in a dispersion managed erbium-doped fiber ring laser

    Science.gov (United States)

    Yue, B. H.; Yang, L. Z.; Wang, J. F.; Yang, L.

    2013-07-01

    The evolution of dark-dark soliton pairs is numerically investigated in a dispersion managed erbium-doped fiber ring laser. It is found that the fluctuation of the background, the sideband intensity of the optical spectrum, the distance and the width of dark-dark soliton pairs are related to the orientation of the polarization controllers and the pump power of the fiber ring laser. The evolution of dark-dark soliton pairs is caused by the modulation instability and the balance between gain and loss in the fiber ring laser.

  1. Solitary waves for a coupled nonlinear Schrodinger system with dispersion management

    Directory of Open Access Journals (Sweden)

    Panayotis Panayotaros

    2010-08-01

    Full Text Available We consider a system of coupled nonlinear Schrodinger equations with periodically varying dispersion coefficient that arises in the context of fiber-optics communication. We use Lions's Concentration Compactness principle to show the existence of standing waves with prescribed L^2 norm in an averaged equation that approximates the coupled system. We also use the Mountain Pass Lemma to prove the existence of standing waves with prescribed frequencies.

  2. Using Satellite Classes to Optimise Access to and Participation in First-Year Business Management: A Case at an Open and Distance-Learning University in South Africa

    Science.gov (United States)

    Swanepoel, Elana; De Beer, Andreas; Muller, Helene

    2009-01-01

    We investigated the effect of satellite classes as a component of blended learning, to enhance student performance of the Business Management I and Management I students at an open and distance-learning university. We discuss the evolution of distance education, the interactivities promoted by open and distance learning and the concept of blended…

  3. A comparative study of marriage in honey bees optimisation (MBO ...

    African Journals Online (AJOL)

    2012-02-15

    Feb 15, 2012 ... complicate water management decision-making. ... evolutionary algorithms, such as the genetic algorithm (GA), ant colony optimisation for continuous ... biological properties. ... and proposed a new algorithm,called the 'artificial bee colony' ... as a set of transitions in a state–space (the environment), where.

  4. TEM turbulence optimisation in stellarators

    CERN Document Server

    Proll, J H E; Xanthopoulos, P; Lazerson, S A; Faber, B J

    2015-01-01

    With the advent of neoclassically optimised stellarators, optimising stellarators for turbulent transport is an important next step. The reduction of ion-temperature-gradient-driven turbulence has been achieved via shaping of the magnetic field, and the reduction of trapped-electron mode (TEM) turbulence is adressed in the present paper. Recent analytical and numerical findings suggest TEMs are stabilised when a large fraction of trapped particles experiences favourable bounce-averaged curvature. This is the case for example in Wendelstein 7-X [C.D. Beidler $\\textit{et al}$ Fusion Technology $\\bf{17}$, 148 (1990)] and other Helias-type stellarators. Using this knowledge, a proxy function was designed to estimate the TEM dynamics, allowing optimal configurations for TEM stability to be determined with the STELLOPT [D.A. Spong $\\textit{et al}$ Nucl. Fusion $\\bf{41}$, 711 (2001)] code without extensive turbulence simulations. A first proof-of-principle optimised equilibrium stemming from the TEM-dominated stella...

  5. Optimising growth in phenylketonuria

    DEFF Research Database (Denmark)

    Dokoupil, Katharina; Gokmen-Ozel, Hulya; Lammardo, Anna Maria

    2012-01-01

    . Protein requirements in dietary management of PKU are met mostly from Phe-free protein substitutes with the intake of natural protein restricted to patient tolerance. Several reports have suggested that growth in early childhood in PKU is sub-optimal, relative to non-PKU control groups or reference...... populations. We reviewed the literature searching for evidence regarding PKU and growth as well as possible links between dietary management of PKU and growth. The search retrieved only limited evidence on the effect of PKU and its dietary management on growth. Physical development in PKU remains an under...

  6. Road transport management system: a self regulation initiative to promote load optimisation, vehicle maintenance and driver wellness in heavy vehicle transport in South Africa

    CSIR Research Space (South Africa)

    Nordengen, Paul A

    2008-04-01

    Full Text Available vehicle transport industry through a Road Transport Management System (RTMS) with the aim of contributing to the road authorities’ efforts to address the above problems. During 2003 a heavy vehicle accreditation scheme was developed and implemented...

  7. Optimising fisheries management in relation to tuna catches in the western central Pacific Ocean : a review of research priorities and opportunities

    OpenAIRE

    Evans, K.; Young, J. W.; Nicol, S.; Kolody, D.; Allain, V.; Bell, J.; Brown, J. N.; Ganachaud, Alexandre; Hobday, A.J.; Hunt, B.; Innes, J; Sen Gupta, A.; van Sebille, E.; Kloser, R; Patterson, T.

    2015-01-01

    Some of the most important development goals for the countries and territories of the Western and Central Pacific Ocean (WCPO) involve the sustainable management of their fisheries in light of environmental, economic and social uncertainties. The responses of fish populations to variability in the marine environment have implications for decision making processes associated with resource management. There is still considerable uncertainty in estimating the responses of tuna populations to sho...

  8. 赋权增能:残疾人体育健身指导员培养管理的优化路径%Empowerment:The Optimised Modes for Training and Managing Fitness Instructors for People with Disability

    Institute of Scientific and Technical Information of China (English)

    吴燕丹; 王聪颖; 张韬磊

    2016-01-01

    Including research methodologies such literature review ,interview ,empirical study , this paper aims to provide an insight to the problems that exists in the training and managing of fitness instructors for PWD .This paper also argues that insufficient structural empower‐ment ,administrative empowerment and the weak environment empowerment jointly contribute to the underdeveloped interior and exterior empowerment for fitness instructors for PWD .O‐verall ,the study attempts to offer available plans to optimise the empowerment system ,intend‐ing to improve the sports participants for PWD in general .%采用文献调研、调查访谈、实证研究等方法,深度审视残疾人体育健身指导员在培养管理过程中存在的问题,指出由于制度赋权不足、管理赋权脱节和环境赋权薄弱,造成残疾人体育健身指导员内在增能与外在增能的匮乏。从为残疾人体育健身指导员赋权增能的视角提出完善制度建设,促进资源整合,强化专业能力等改善策略,为残疾人参与体育活动提供有力的支持。

  9. Cogeneration technologies, optimisation and implementation

    CERN Document Server

    Frangopoulos, Christos A

    2017-01-01

    Cogeneration refers to the use of a power station to deliver two or more useful forms of energy, for example, to generate electricity and heat at the same time. This book provides an integrated treatment of cogeneration, including a tour of the available technologies and their features, and how these systems can be analysed and optimised.

  10. Optimisation of solar synoptic observations

    Science.gov (United States)

    Klvaña, Miroslav; Sobotka, Michal; Švanda, Michal

    2012-09-01

    The development of instrumental and computer technologies is connected with steadily increasing needs for archiving of large data volumes. The current trend to meet this requirement includes the data compression and growth of storage capacities. This approach, however, has technical and practical limits. A further reduction of the archived data volume can be achieved by means of an optimisation of the archiving that consists in data selection without losing the useful information. We describe a method of optimised archiving of solar images, based on the selection of images that contain a new information. The new information content is evaluated by means of the analysis of changes detected in the images. We present characteristics of different kinds of image changes and divide them into fictitious changes with a disturbing effect and real changes that provide a new information. In block diagrams describing the selection and archiving, we demonstrate the influence of clouds, the recording of images during an active event on the Sun, including a period before the event onset, and the archiving of long-term history of solar activity. The described optimisation technique is not suitable for helioseismology, because it does not conserve the uniform time step in the archived sequence and removes the information about solar oscillations. In case of long-term synoptic observations, the optimised archiving can save a large amount of storage capacities. The actual capacity saving will depend on the setting of the change-detection sensitivity and on the capability to exclude the fictitious changes.

  11. For Time-Continuous Optimisation

    DEFF Research Database (Denmark)

    Heinrich, Mary Katherine; Ayres, Phil

    2016-01-01

    Strategies for optimisation in design normatively assume an artefact end-point, disallowing continuous architecture that engages living systems, dynamic behaviour, and complex systems. In our Flora Robotica investigations of symbiotic plant-robot bio-hybrids, we re- quire computational tools...

  12. For Time-Continuous Optimisation

    DEFF Research Database (Denmark)

    Heinrich, Mary Katherine; Ayres, Phil

    2016-01-01

    Strategies for optimisation in design normatively assume an artefact end-point, disallowing continuous architecture that engages living systems, dynamic behaviour, and complex systems. In our Flora Robotica investigations of symbiotic plant-robot bio-hybrids, we re- quire computational tools...

  13. Optimising boiler performance.

    Science.gov (United States)

    Mayoh, Paul

    2009-01-01

    Soaring fuel costs continue to put the squeeze on already tight health service budgets. Yet it is estimated that combining established good practice with improved technologies could save between 10% and 30% of fuel costs for boilers. Paul Mayoh, UK technical manager at Spirax Sarco, examines some of the practical measures that healthcare organisations can take to gain their share of these potential savings.

  14. Simple models of district heating systems for load and demand side management and operational optimisation; Simple modeller for fjernvarmesystemer med henblik pae belastningsudjaevning og driftsoptimering

    Energy Technology Data Exchange (ETDEWEB)

    Boehm, B. [Technical Univ. of Denmark, Dept. of Mechanical Engineering, Kgs. Lyngby (Denmark); Larsen, H.V. [Risoe National Lab., System Analysis Dept., Roskilde (DK)

    2004-12-01

    The purpose of this research project has been to further develop and test simple (aggregated) models of district heating (DH) systems for simulation and operational optimization, and to investigate the influence of Load Management and Demand Side Management (DMS) on the total operational costs. The work is based on physical-mathematical modelling and simulation of DH systems, and is a continuation of previous EFP-96 work. In the present EFP-2001 project the goals have been to improve the Danish method of aggregation by addressing the problem of aggregation of pressure losses, and to test the methods on a much larger data set than in the EFP-1996 project. In order to verify the models it is crucial to have good data at disposal. Full information on the heat loads and temperatures not only at the DH plant but also at every consumer (building) is needed, and therefore only a few DH systems in Denmark can supply such data. (BA)

  15. Digital compensation of cross-phase modulation distortions using perturbation technique for dispersion-managed fiber-optic systems.

    Science.gov (United States)

    Liang, Xiaojun; Kumar, Shiva; Shao, Jing; Malekiha, Mahdi; Plant, David V

    2014-08-25

    A digital compensation scheme based on a perturbation theory for mitigation of cross-phase modulation (XPM) distortions is developed for dispersion-managed fiber-optic communication systems. It is a receiver-side scheme that uses a hard-decision unit to estimate data for the calculation of XPM fields using the perturbation technique. The intra-channel nonlinear distortions are removed by intra-channel digital backward propagation (DBP) based on split-step Fourier scheme before the hard-decision unit. The perturbation technique is shown to be effective in mitigating XPM distortions. However, wrong estimations in the hard-decision unit result in performance degradation. A hard-decision correction method is proposed to correct the wrong estimations. Numerical simulations show that the hybrid compensation scheme with DBP for dispersion and intra-channel nonlinear impairments compensation and the perturbation technique for XPM compensation brings up to 3.7 dBQ and 1.7 dBQ improvements as compared with the schemes of linear compensation only and intra-channel DBP, respectively. The perturbation technique for XPM compensation requires only one-stage (or two-stage when hard-decision correction is applied) compensation and symbol-rate signal processing.

  16. Demonstration of Raman-based, dispersion-managed VCSEL technology for fibre-to-the-hut application

    Science.gov (United States)

    Rotich Kipnoo, E. K.; Kiboi Boiyo, D.; Isoe, G. M.; Chabata, T. V.; Gamatham, R. R. G.; Leitch, A. W. R.; Gibbon, T. B.

    2017-03-01

    For the first time, we experimentally investigate the use of vertical cavity surface emitting lasers (VCSELs) in the fibre-to-the-home (FTTH) flavour for Africa, known as fibre-to-the-hut. Fibre-to-the-hut is a VCSEL based passive optical network technology designed and optimized for African continent. VCSELs have attracted attention in optical communication due to its vast advantages; low power consumption, relatively cheap costs among others. A 4.25 Gb/s uncooled VCSEL is used in a dispersion managed, Raman assisted network achieving beyond 100 km of error free transmission suited for FTTHut scenario. Energy-efficient high performance VCSEL is modulated using a 27-1 PRBS pattern and the signal transmitted on a G.655 fibre utilizing the minimum attenuation window.

  17. The mosquito ultra-low volume dispersion model for estimating environmental concentrations of insecticides used for adult mosquito management.

    Science.gov (United States)

    Schleier, Jerome J; Peterson, Robert K D

    2014-09-01

    Computer models for pesticide drift are widely used tools by regulatory agencies to estimate the deposition of pesticides beyond the intended target area. Currently, there is no model in use that has been validated or verified as an accurate means of estimating concentrations of insecticides after ground-based ultra-low volume (ULV) applications used for adult mosquito management. To address the need for a validated model we created a spreadsheet-based model called Mosquito Ultra-Low Volume Dispersion (MULV-Disp) to aid in the adoption and to provide easier use of a validated model. We explain the origin, use, and utility of MULV-Disp, which can be used by regulatory agencies and other interested parties to estimate deposition of ULV insecticides.

  18. Perceptions and experiences of the implementation, management, use and optimisation of electronic prescribing systems in hospital settings: protocol for a systematic review of qualitative studies

    Science.gov (United States)

    Farre, Albert; Bem, Danai; Heath, Gemma; Shaw, Karen; Cummins, Carole

    2016-01-01

    Introduction There is increasing evidence that electronic prescribing (ePrescribing) or computerised provider/physician order entry (CPOE) systems can improve the quality and safety of healthcare services. However, it has also become clear that their implementation is not straightforward and may create unintended or undesired consequences once in use. In this context, qualitative approaches have been particularly useful and their interpretative synthesis could make an important and timely contribution to the field. This review will aim to identify, appraise and synthesise qualitative studies on ePrescribing/CPOE in hospital settings, with or without clinical decision support. Methods and analysis Data sources will include the following bibliographic databases: MEDLINE, MEDLINE In Process, EMBASE, PsycINFO, Social Policy and Practice via Ovid, CINAHL via EBSCO, The Cochrane Library (CDSR, DARE and CENTRAL databases), Nursing and Allied Health Sources, Applied Social Sciences Index and Abstracts via ProQuest and SCOPUS. In addition, other sources will be searched for ongoing studies (ClinicalTrials.gov) and grey literature: Healthcare Management Information Consortium, Conference Proceedings Citation Index (Web of Science) and Sociological abstracts. Studies will be independently screened for eligibility by 2 reviewers. Qualitative studies, either standalone or in the context of mixed-methods designs, reporting the perspectives of any actors involved in the implementation, management and use of ePrescribing/CPOE systems in hospital-based care settings will be included. Data extraction will be conducted by 2 reviewers using a piloted form. Quality appraisal will be based on criteria from the Critical Appraisal Skills Programme checklist and Standards for Reporting Qualitative Research. Studies will not be excluded based on quality assessment. A postsynthesis sensitivity analysis will be undertaken. Data analysis will follow the thematic synthesis method. Ethics and

  19. A study to assess COPD Symptom-based Management and to Optimise treatment Strategy in Japan (COSMOS-J based on GOLD 2011

    Directory of Open Access Journals (Sweden)

    Betsuyaku T

    2013-10-01

    Full Text Available Tomoko Betsuyaku,1 Motokazu Kato,2 Keisaku Fujimoto,3 Gerry Hagan,4 Akihiro Kobayashi,5 Hideki Hitosugi,5 Mark James,5 Paul W Jones61Division of Pulmonary Medicine, Department of Medicine, Keio University, Tokyo, Japan; 2Department of Respiratory Disease, Kishiwada City Hospital, Osaka, Japan; 3Department of Clinical Laboratory Sciences, Shinshu University, Nagano, Japan; 4Private Practice, Marbella, Spain; 5GlaxoSmithKline KK, Tokyo, Japan; 6Division of Clinical Science, St George’s, University of London, London, UKBackground and objective: The Global initiative for chronic Obstructive Lung Disease (GOLD Committee has proposed a COPD assessment framework focused on symptoms and on exacerbation risk. This study will evaluate a symptom and exacerbation risk-based treatment strategy based on GOLD in a real-world setting in Japan. Optimal management of COPD will be determined by assessing symptoms using the COPD Assessment Test (CAT and by assessing the frequency of exacerbations.Methods: This study (ClinicalTrials.gov identifier: NCT01762800 is a 24-week, multicenter, randomized, double-blind, double-dummy, parallel-group study. It aims to recruit 400 patients with moderate-to-severe COPD. Patients will be randomized to receive treatment with either salmeterol/fluticasone propionate (SFC 50/250 µg twice daily or with tiotropium bromide 18 µg once daily. Optimal management of patients will be assessed at four-weekly intervals and, if patients remain symptomatic, as measured using the CAT, or experience an exacerbation, they have the option to step up to treatment with both drugs, ie, SFC twice daily and tiotropium once daily (TRIPLE therapy. The primary endpoint of the study will be the proportion of patients who are able to remain on the randomized therapy.Results: No data are available. This paper summarizes the methodology of the study in advance of the study starting.Conclusion: The results of this study will help physicians to understand

  20. Optimising Code Generation with haggies

    OpenAIRE

    Reiter, Thomas

    2009-01-01

    This article describes haggies, a program for the generation of optimised programs for the efficient numerical evaluation of mathematical expressions. It uses a multivariate Horner-scheme and Common Subexpression Elimination to reduce the overall number of operations. The package can serve as a back-end for virtually any general purpose computer algebra program. Built-in type inference that allows to deal with non-standard data types in strongly typed languages and a very flexible, pattern-ba...

  1. ATLAS software configuration and build tool optimisation

    CERN Document Server

    Rybkin, G; The ATLAS collaboration

    2014-01-01

    ATLAS software code base is over 6 million lines organised in about 2000 packages. It makes use of some 100 external software packages, is developed by more than 400 developers and used by more than 2500 physicists from over 200 universities and laboratories in 6 continents. To meet the challenge of configuration and building of this software, the Configuration Management Tool (CMT) is used. CMT expects each package to describe its build targets, build and environment setup parameters, dependencies on other packages in a text file called requirements, and each project (group of packages) to describe its policies and dependencies on other projects in a text project file. Based on the effective set of configuration parameters read from the requirements files of dependent packages and project files, CMT commands build the packages, generate the environment for their use, or query the packages. The main focus was on build time performance that was optimised within several approaches: reduction of the number of re...

  2. ATLAS software configuration and build tool optimisation

    CERN Document Server

    Rybkin, G; The ATLAS collaboration

    2013-01-01

    ATLAS software code base is over 6 million lines organised in about 2000 packages. It makes use of some 100 external software packages, is developed by more than 400 developers and used by more than 2500 physicists from over 200 universities and laboratories in 6 continents. To meet the challenge of configuration and building of this software, the Configuration Management Tool (CMT) is used. CMT expects each package to describe its build targets, build and environment setup parameters, dependencies on other packages in a text file called requirements, and each project (group of packages) to describe its policies and dependencies on other projects in a text project file. Based on the effective set of configuration parameters read from the requirements files of dependent packages and project files, CMT commands build the packages, generate the environment for their use, or query the packages. The main focus was on build time performance that was optimised within several approaches: reduction of the number of re...

  3. Contribution to energy optimization, management and processing; Contribution a l'optimisation, la gestion et le traitement de l'energie

    Energy Technology Data Exchange (ETDEWEB)

    Alonso, C.

    2003-12-15

    Nowadays, renewable energies become an alternative solution to the classical energies obtained from fossil resources. Renewable energies have reached a high level of development, mainly in terms of cost and production facilities. However, the electrical conversion systems are often not optimized in terms of reliability, electrical efficiency and cost production. For that, there is a lot of reticence to install these systems in home sites or in big centrals for mass energy production. Since 1997 LAAS-CNRS has focused his research in the optimization of the power conversion chains from a system point of view. Indeed, due to the inexistence of optimal solutions for these electrical systems and the absence of research groups in France interested in this problem, the research goals were finally centered on the electrical conversion and thermal management of photovoltaic energy systems. First works were focused in the optimization of conversion efficiency. For that, LAAS-CNRS has developed and installed a complete outdoor photovoltaic system. The PV demonstration site has 1 kW of peak power and an automatic measurement system capable of characterize the electrical efficiency of different power conversion structures with high level of precision. Novel power conversion structures devoted for photovoltaic systems have been developed in collaboration of foreign research groups like the GAEI from University Rovira i Virgili (Tarragona) and the EPIC from the Polytechnic University of Catalonia (Barcelona). Meteorological dependence of the renewable energy sources produces a low level of predictability of the energy production. In order to produce energy without strong variations we have coupled different energy sources like PV generators and small wind generators by means of batteries. Additional studies have been made regarding to the optimal battery management. Maturity in the studies of the photovoltaic systems shows news trends and new possible applications of this systems

  4. Evaluation of a dual-room sliding gantry CT concept for workflow optimisation in polytrauma and regular in- and outpatient management

    Energy Technology Data Exchange (ETDEWEB)

    Frellesen, Claudia; Boettcher, Marie; Wichmann, Julian L.; Drieske, Martina; Kerl, J. Matthias; Lehnert, Thomas [Department of Diagnostic and Interventional Radiology, Clinic of the Goethe University, Frankfurt (Germany); Nau, Christoph; Geiger, Emmanuel; Wutzler, Sebastian [Department of Trauma, Reconstructive and Hand Surgery, Clinic of the Goethe University, Frankfurt (Germany); Ackermann, Hanns [Department of Biostatistics and Mathematical Modelling, Clinic of the Goethe University, Theodor-Stern-Kai 7, 60590 Frankfurt (Germany); Vogl, Thomas J. [Department of Diagnostic and Interventional Radiology, Clinic of the Goethe University, Frankfurt (Germany); Bauer, Ralf W., E-mail: ralfwbauer@aol.com [Department of Diagnostic and Interventional Radiology, Clinic of the Goethe University, Frankfurt (Germany)

    2015-01-15

    Highlights: • A sliding gantry trauma room CT solution facilitates significantly faster polytrauma management. • Faster and more efficient resumption of regularly scheduled patients due to a two room solution is supported. • Sliding gantry CT achieves the same patient throughput as two separate conventional CT devices. - Abstract: Objectives: To reveal the impact on workflow from introducing a dual-room sliding gantry CT to the trauma room for polytrauma and regularly scheduled in- outpatients with regard to efficiency and degree of capacity utilisation. Materials and methods: Time analysis was performed for 30 polytrauma patients each in 2 different trauma room settings, the new trauma room comprising a sliding gantry CT, the old one a stationary single-room CT. Complete trauma room and diagnostic workup times were manually measured and compared for both groups. In a third scenario, the number of CT scans performed with one single sliding gantry CT and the two-room concept was compared to the number of CT scans performed on two separate regular CT units in a 5 days clinical routine sample. Results: Patients demographics and type of CT examinations were comparable for all patient groups. The median time from patient arrival in the trauma room until beginning of CT scanning was 6 min shorter for the sliding gantry CT group (21 vs.15 min). Sliding gantry CT embedded in a two-room solution achieved 252 CT scans in 5 working days, compared to 250 CT scans on two separate regular CT units with the same man power. Conclusions: Sliding gantry CT in the trauma room allows for significant time saving in the diagnostic workup of polytrauma patients and faster resumption of the regular in- outpatient's CT schedule is possible. With the same man power, the dual-room solution is able to generate the same throughput as two separate CT units.

  5. Managing New Product Development Teams in a Globally Dispersed NPD Program

    DEFF Research Database (Denmark)

    Salomo, Søren; Keinschmidt, Elko J.; de Brentani, Ulrike

    2010-01-01

    product development (NPD) a major concern. To ensure success in this complex and competitive endeavor, companies must rely on global NPD teams that make use of the talents and knowledge available in different parts of the global organization. Thus, cohesive and well-functioning global NPD teams become...... be nested in a corporate environment in which there is a commitment of sufficient resources and where senior management plays an active role in leading, championing, and coordinating the global NPD effort. This need for commitment and global team integration becomes even more important for success...... a critical capability by which firms can effectively leverage this much more diverse set of perspectives, experiences, and cultural sensitivities for the global NPD effort. The present research addresses the global NPD team and its impact on performance from both an antecedent and a contingency perspective...

  6. Optimal Energy Management in Hybrid Electric Trucks Using Route Information Optimisation de la gestion de l’énergie dans des véhicules poids lourds électriques hybrides utilisant le guidage d’itinéraire

    Directory of Open Access Journals (Sweden)

    van Keulen T.

    2009-08-01

    Full Text Available To benchmark a hybrid vehicle’s Energy Management Strategy (EMS usually a given, often certified, velocity trajectory is exploited. In this paper it is reasoned that it is also beneficial to optimize the velocity trajectory. Especially optimizing the vehicle braking trajectories, through maximization of energy recuperation, results in considerable fuel savings on the same traveled distance. Given future route (target velocities as function of traveled distance/location, traffic, and possibly weather information, together with the vehicle’s road load parameters, the future power request trajectory can be estimated. Dynamic Programming (DP techniques can then be used to predict the optimal power split trajectory for the upcoming route, such that a desired state-of-charge at the end of the route is reached. The DP solution is re-calculated at a certain rate in order to adapt to changing conditions, e.g., traffic conditions, and used in a lower level real-time EMS to guarantee both battery state-of-charge as well as minimal fuel consumption. Pour évaluer la Stratégie de Gestion de l’Énergie (SGE d’un véhicule hybride, on exploite généralement un cycle de conduite donné, souvent certifié. Dans cet article, l’optimisation de l’itinéraire apparaît aussi comme nécessaire. L’optimisation, en particulier, des conditions de freinage du véhicule, par la maximisation de la récupération d’énergie, permet des économies considérables de combustible sur une même distance parcourue. Pour un itinéraire donné (vitesses cibles en fonction de la distance parcourue et de la position, compte tenu des conditions de circulation, des éventuelles données météorologiques et des paramètres de perte du véhicule, on peut estimer les besoins en puissance nécessaire pour le parcourir. Des techniques de Programmation Dynamique (PD peuvent alors être employées pour prévoir la répartition de puissance optimale pour un parcours donn

  7. Robust optimisation of railway crossing geometry

    Science.gov (United States)

    Wan, Chang; Markine, Valeri; Dollevoet, Rolf

    2016-05-01

    This paper presents a methodology for improving the crossing (frog) geometry through the robust optimisation approach, wherein the variability of the design parameters within a prescribed tolerance is included in the optimisation problem. Here, the crossing geometry is defined by parameterising the B-spline represented cross-sectional shape and the longitudinal height profile of the nose rail. The dynamic performance of the crossing is evaluated considering the variation of wheel profiles and track alignment. A multipoint approximation method (MAM) is applied in solving the optimisation problem of minimising the contact pressure during the wheel-rail contact and constraining the location of wheel transition at the crossing. To clarify the difference between the robust optimisation and the normal deterministic optimisation approaches, the optimisation problems are solved in both approaches. The results show that the deterministic optimum fails under slight change of the design variables; the robust optimum, however, has improved and robust performance.

  8. An Optimisation Approach for Room Acoustics Design

    DEFF Research Database (Denmark)

    Holm-Jørgensen, Kristian; Kirkegaard, Poul Henning; Andersen, Lars

    2005-01-01

    This paper discuss on a conceptual level the value of optimisation techniques in architectural acoustics room design from a practical point of view. It is chosen to optimise one objective room acoustics design criterium estimated from the sound field inside the room. The sound field is modeled...... using the boundary element method where absorption is incorporated. An example is given where the geometry of a room is defined by four design modes. The room geometry is optimised to get a uniform sound pressure....

  9. GIS-based tools to identify tradeoffs between waste management and remediation strategies from radiological dispersal device incidents

    Energy Technology Data Exchange (ETDEWEB)

    Lemieux, P.; Wood, J.; Snyder, E. [U.S. Environmental Protection Agency, Research Triangle Park, NC (United States); Boe, T. [Oak Ridge Inst. for Science and Education, Research Triangle Park, NC (United States); Schulthiesz, D.; Peake, T.; Ierardi, M. [U.S. Environmental Protection Agency, Washington, DC (United States); Hayes, C.; Rodgers, M. [Eastern Research Group, Inc., Morrisville, NC (United States)

    2011-07-01

    Management of waste and debris from the detonation of a Radiological Dispersal Device (RDD) will likely comprise a significant portion of the overall remediation effort and possibly contribute to a significant portion of the overall remediation costs. As part of the recent National Level Exercise, Liberty RadEx, that occurred in Philadelphia in April 2010, a methodology was developed by EPA to generate a first-order estimate of a waste inventory for the hypothetical RDD from the exercise scenario. Determination of waste characteristics and whether the generated waste is construction and demolition (C&D) debris, municipal solid waste (MSW), hazardous waste, mixed waste, or low level radioactive waste (LLRW), and characterization of the wastewater that is generated from the incident or subsequent cleanup activities will all influence the cleanup costs and timelines. Decontamination techniques, whether they involve chemical treatment, abrasive removal, or aqueous washing, will also influence the waste generated and associated cleanup costs and timelines. This paper describes the ongoing effort to develop a tool to support RDD planning and response activities by assessing waste quantities and characteristics as a function of potential mitigation strategies and targeted cleanup levels. (author)

  10. Mode-locked semiconductor laser system with intracavity spatial light modulator for linear and nonlinear dispersion management.

    Science.gov (United States)

    Balzer, Jan C; Döpke, Benjamin; Brenner, Carsten; Klehr, Andreas; Erbert, Götz; Tränkle, Günther; Hofmann, Martin R

    2014-07-28

    We analyze the influence of second and third order intracavity dispersion on a passively mode-locked diode laser by introducing a spatial light modulator (SLM) into the external cavity. The dispersion is optimized for chirped pulses with highest possible spectral bandwidth that can be externally compressed to the sub picosecond range. We demonstrate that the highest spectral bandwidth is achieved for a combination of second and third order dispersion. With subsequent external compression pulses with a duration of 437 fs are generated.

  11. Optimisation combinatoire Theorie et algorithmes

    CERN Document Server

    Korte, Bernhard; Fonlupt, Jean

    2010-01-01

    Ce livre est la traduction fran aise de la quatri me et derni re dition de Combinatorial Optimization: Theory and Algorithms crit par deux minents sp cialistes du domaine: Bernhard Korte et Jens Vygen de l'universit de Bonn en Allemagne. Il met l accent sur les aspects th oriques de l'optimisation combinatoire ainsi que sur les algorithmes efficaces et exacts de r solution de probl mes. Il se distingue en cela des approches heuristiques plus simples et souvent d crites par ailleurs. L ouvrage contient de nombreuses d monstrations, concises et l gantes, de r sultats difficiles. Destin aux tudia

  12. Optimisation of the LHCb detector

    CERN Document Server

    Hierck, R

    2003-01-01

    This thesis describes a comparison of the LHCb classic and LHCb light concept from a tracking perspective. The comparison includes the detector occupancies, the various pattern recognition algorithms and the reconstruction performance. The final optimised LHCb setup is used to study the physics performance of LHCb for the Bs->DsK and Bs->DsPi decay channels. This includes both the event selection and a study of the sensitivity for the Bs oscillation frequency, delta m_s, the Bs lifetime difference, DGamma_s, and the CP parameter gamma-2delta gamma.

  13. Optimisation of the LHCb detector

    CERN Document Server

    Hierck, R H

    2003-01-01

    This thesis describes a comparison of the LHCb classic and LHCb light concept from a tracking perspective. The comparison includes the detector occupancies, the various pattern recognition algorithms and the reconstruction performance. The final optimised LHCb setup is used to study the physics performance of LHCb for the Bs->DsK and Bs->DsPi decay channels. This includes both the event selection and a study of the sensitivity for the Bs oscillation frequency, delta m_s, the Bs lifetime difference, DGamma_s, and the CP parameter gamma-2delta gamma.

  14. Calculating NMR parameters in aluminophosphates: evaluation of dispersion correction schemes.

    Science.gov (United States)

    Sneddon, Scott; Dawson, Daniel M; Pickard, Chris J; Ashbrook, Sharon E

    2014-02-14

    Periodic density functional theory (DFT) calculations have recently emerged as a popular tool for assigning solid-state nuclear magnetic resonance (NMR) spectra. However, in order for the calculations to yield accurate results, accurate structural models are also required. In many cases the structural model (often derived from crystallographic diffraction) must be optimised (i.e., to an energy minimum) using DFT prior to the calculation of NMR parameters. However, DFT does not reproduce weak long-range "dispersion" interactions well, and optimisation using some functionals can expand the crystallographic unit cell, particularly when dispersion interactions are important in defining the structure. Recently, dispersion-corrected DFT (DFT-D) has been extended to periodic calculations, to compensate for these missing interactions. Here, we investigate whether dispersion corrections are important for aluminophosphate zeolites (AlPOs) by comparing the structures optimised by DFT and DFT-D (using the PBE functional). For as-made AlPOs (containing cationic structure-directing agents (SDAs) and framework-bound anions) dispersion interactions appear to be important, with significant changes between the DFT and DFT-D unit cells. However, for calcined AlPOs, where the SDA-anion pairs are removed, dispersion interactions appear much less important, and the DFT and DFT-D unit cells are similar. We show that, while the different optimisation strategies yield similar calculated NMR parameters (providing that the atomic positions are optimised), the DFT-D optimisations provide structures in better agreement with the experimental diffraction measurements. Therefore, it appears that DFT-D calculations can, and should, be used for the optimisation of calcined and as-made AlPOs, in order to provide the closest agreement with all experimental measurements.

  15. Dose optimisation in single plane interstitial brachytherapy

    DEFF Research Database (Denmark)

    Tanderup, Kari; Hellebust, Taran Paulsen; Honoré, Henriette Benedicte;

    2006-01-01

    BACKGROUND AND PURPOSE: Brachytherapy dose distributions can be optimised       by modulation of source dwell times. In this study dose optimisation in       single planar interstitial implants was evaluated in order to quantify the       potential benefit in patients. MATERIAL AND METHODS: In 14...

  16. Self-optimising control of sewer systems

    DEFF Research Database (Denmark)

    Mauricio Iglesias, Miguel; Montero-Castro, Ignacio; Mollerup, Ane Loft;

    The design of sewer system control is a complex task given the large size of the sewer networks, the transient dynamics of the water flows and the stochastic nature of rainfall. This contribution presents a generic methodology for the design of a self-optimising controller in sewer systems...... to design an optimising control strategy for a subcathcment area in Copenhagen....

  17. An Optimisation Approach for Room Acoustics Design

    DEFF Research Database (Denmark)

    Holm-Jørgensen, Kristian; Kirkegaard, Poul Henning; Andersen, Lars

    2005-01-01

    This paper discuss on a conceptual level the value of optimisation techniques in architectural acoustics room design from a practical point of view. It is chosen to optimise one objective room acoustics design criterium estimated from the sound field inside the room. The sound field is modeled...

  18. Haemodynamic optimisation in lower limb arterial surgery

    DEFF Research Database (Denmark)

    Bisgaard, J; Gilsaa, T; Rønholm, E;

    2012-01-01

    index was optimised by administering 250 ml aliquots of colloid intraoperatively and during the first 6 h post-operatively. Following surgery, fluid optimisation was supplemented with dobutamine, if necessary, targeting an oxygen delivery index level ≥ 600 ml/min(/) m(2) in the intervention group...

  19. Development of a Dispersal Model for Balsam Woolly Adelgid, Adelges piceae Ratzeburg (Hemiptera: Adelgidae, to Facilitate Landscape-Level Management Planning

    Directory of Open Access Journals (Sweden)

    L. W. Lass

    2014-01-01

    Full Text Available The balsam woolly adelgid (Adelges piceae Ratzeburg attacks subalpine fir (Abies lasiocarpa (Hook. Nutt. in eastern Washington, Oregon, and northern Idaho. Historical balsam woolly adelgid distributions present an opportunity to understand climatic factors that influence the species’ distribution at a landscape scale. The distribution data allows for creation of predictive models that detail the likelihood of occurrence and associated geographic data allow modeling of species dispersal. Predictive variables linked to the distribution of the hosts and to abiotic environmental conditions were utilized to create a spatial probability model of occurrence. Balsam woolly adelgid predominantly disperses by wind, and hence, both wind speed and wind direction were used to create a dispersal probability model. Results from wind dispersal modeling suggested that two-thirds of the new infestations were due to July and August wind direction and speed. Average July winds ranged from 0.5 to 3.27 m/s, flowing south westerly, and August winds ranged from 0.43 to 1.55 m/s, flowing north easterly. Land managers can use the results of the predictive model to better understand where current infestations are likely to expand. Prediction of where the balsam woolly adelgid might move allows managers to adjust actions to respond to future insect movement and establishment.

  20. Evolutionary programming for neutron instrument optimisation

    Science.gov (United States)

    Bentley, Phillip M.; Pappas, Catherine; Habicht, Klaus; Lelièvre-Berna, Eddy

    2006-11-01

    Virtual instruments based on Monte-Carlo techniques are now integral part of novel instrumentation development and the existing codes (McSTAS and Vitess) are extensively used to define and optimise novel instrumental concepts. Neutron spectrometers, however, involve a large number of parameters and their optimisation is often a complex and tedious procedure. Artificial intelligence algorithms are proving increasingly useful in such situations. Here, we present an automatic, reliable and scalable numerical optimisation concept based on the canonical genetic algorithm (GA). The algorithm was used to optimise the 3D magnetic field profile of the NSE spectrometer SPAN, at the HMI. We discuss the potential of the GA which combined with the existing Monte-Carlo codes (Vitess, McSTAS, etc.) leads to a very powerful tool for automated global optimisation of a general neutron scattering instrument, avoiding local optimum configurations.

  1. Evolutionary programming for neutron instrument optimisation

    Energy Technology Data Exchange (ETDEWEB)

    Bentley, Phillip M. [Hahn-Meitner Institut, Glienicker Strasse 100, D-14109 Berlin (Germany)]. E-mail: phillip.bentley@hmi.de; Pappas, Catherine [Hahn-Meitner Institut, Glienicker Strasse 100, D-14109 Berlin (Germany); Habicht, Klaus [Hahn-Meitner Institut, Glienicker Strasse 100, D-14109 Berlin (Germany); Lelievre-Berna, Eddy [Institut Laue-Langevin, 6 rue Jules Horowitz, BP 156, 38042 Grenoble Cedex 9 (France)

    2006-11-15

    Virtual instruments based on Monte-Carlo techniques are now integral part of novel instrumentation development and the existing codes (McSTAS and Vitess) are extensively used to define and optimise novel instrumental concepts. Neutron spectrometers, however, involve a large number of parameters and their optimisation is often a complex and tedious procedure. Artificial intelligence algorithms are proving increasingly useful in such situations. Here, we present an automatic, reliable and scalable numerical optimisation concept based on the canonical genetic algorithm (GA). The algorithm was used to optimise the 3D magnetic field profile of the NSE spectrometer SPAN, at the HMI. We discuss the potential of the GA which combined with the existing Monte-Carlo codes (Vitess, McSTAS, etc.) leads to a very powerful tool for automated global optimisation of a general neutron scattering instrument, avoiding local optimum configurations.

  2. Optimising preterm nutrition: present and future

    LENUS (Irish Health Repository)

    Brennan, Ann-Marie

    2016-04-01

    The goal of preterm nutrition in achieving growth and body composition approximating that of the fetus of the same postmenstrual age is difficult to achieve. Current nutrition recommendations depend largely on expert opinion, due to lack of evidence, and are primarily birth weight based, with no consideration given to gestational age and\\/or need for catch-up growth. Assessment of growth is based predominately on anthropometry, which gives insufficient attention to the quality of growth. The present paper provides a review of the current literature on the nutritional management and assessment of growth in preterm infants. It explores several approaches that may be required to optimise nutrient intakes in preterm infants, such as personalising nutritional support, collection of nutrient intake data in real-time, and measurement of body composition. In clinical practice, the response to inappropriate nutrient intakes is delayed as the effects of under- or overnutrition are not immediate, and there is limited nutritional feedback at the cot-side. The accurate and non-invasive measurement of infant body composition, assessed by means of air displacement plethysmography, has been shown to be useful in assessing quality of growth. The development and implementation of personalised, responsive nutritional management of preterm infants, utilising real-time nutrient intake data collection, with ongoing nutritional assessments that include measurement of body composition is required to help meet the individual needs of preterm infants.

  3. La location-gérance, mode d’exploitation du fonds de commerce ou instrument d’optimisation fiscale ?

    National Research Council Canada - National Science Library

    Mohamed EL GDAIHI

    2014-01-01

    ...; fiscal optimisation is done more or less in transparency. The result will be reversed when the group of companies has neither legal personality nor processes and arrangements to allow tax savings, the lease under management is a case in point...

  4. LA LOCATION-GÉRANCE, MODE D'EXPLOITATION DU FONDS DE COMMERCE OU INSTRUMENT D'OPTIMISATION FISCALE ?

    National Research Council Canada - National Science Library

    Mohamed El Gdaihi

    2014-01-01

    ...; fiscal optimisation is done more or less in transparency. The result will be reversed when the group of companies has neither legal personality nor processes and arrangements to allow tax savings, the lease under management is a case in point...

  5. Optimising Comprehensibility in Interlingual Translation

    DEFF Research Database (Denmark)

    Nisbeth Jensen, Matilde

    2015-01-01

    . It is argued that Plain Language writing is a type of intralingual translation as it involves rewriting or translating a complex monolingual text into comprehensible language. Based on Plain Language literature, a comprehensibility framework is elaborated, which is subsequently exemplified through...... the functional text type of Patient Information Leaflet. Finally, the usefulness of applying the principles of Plain Language and intralingual translation for optimising comprehensibility in interlingual translation is discussed....... information on medication and tax information. Such texts are often written by experts and received by lay people, and, in today’s globalised world, they are often translated as well. In these functional texts, the receiver is not a mere recipient of information, but s/he needs to be able to act upon it...

  6. Honeybee economics: optimisation of foraging in a variable world.

    Science.gov (United States)

    Stabentheiner, Anton; Kovac, Helmut

    2016-06-20

    In honeybees fast and efficient exploitation of nectar and pollen sources is achieved by persistent endothermy throughout the foraging cycle, which means extremely high energy costs. The need for food promotes maximisation of the intake rate, and the high costs call for energetic optimisation. Experiments on how honeybees resolve this conflict have to consider that foraging takes place in a variable environment concerning microclimate and food quality and availability. Here we report, in simultaneous measurements of energy costs, gains, and intake rate and efficiency, how honeybee foragers manage this challenge in their highly variable environment. If possible, during unlimited sucrose flow, they follow an 'investment-guided' ('time is honey') economic strategy promising increased returns. They maximise net intake rate by investing both own heat production and solar heat to increase body temperature to a level which guarantees a high suction velocity. They switch to an 'economizing' ('save the honey') optimisation of energetic efficiency if the intake rate is restricted by the food source when an increased body temperature would not guarantee a high intake rate. With this flexible and graded change between economic strategies honeybees can do both maximise colony intake rate and optimise foraging efficiency in reaction to environmental variation.

  7. Semantic Query Optimisation with Ontology Simulation

    CERN Document Server

    Gupta, Siddharth

    2010-01-01

    Semantic Web is, without a doubt, gaining momentum in both industry and academia. The word "Semantic" refers to "meaning" - a semantic web is a web of meaning. In this fast changing and result oriented practical world, gone are the days where an individual had to struggle for finding information on the Internet where knowledge management was the major issue. The semantic web has a vision of linking, integrating and analysing data from various data sources and forming a new information stream, hence a web of databases connected with each other and machines interacting with other machines to yield results which are user oriented and accurate. With the emergence of Semantic Web framework the na\\"ive approach of searching information on the syntactic web is clich\\'e. This paper proposes an optimised semantic searching of keywords exemplified by simulation an ontology of Indian universities with a proposed algorithm which ramifies the effective semantic retrieval of information which is easy to access and time sav...

  8. Alginate microencapsulated hepatocytes optimised for transplantation in acute liver failure.

    Directory of Open Access Journals (Sweden)

    Suttiruk Jitraruch

    Full Text Available BACKGROUND AND AIM: Intraperitoneal transplantation of alginate-microencapsulated human hepatocytes is an attractive option for the management of acute liver failure (ALF providing short-term support to allow native liver regeneration. The main aim of this study was to establish an optimised protocol for production of alginate-encapsulated human hepatocytes and evaluate their suitability for clinical use. METHODS: Human hepatocyte microbeads (HMBs were prepared using sterile GMP grade materials. We determined physical stability, cell viability, and hepatocyte metabolic function of HMBs using different polymerisation times and cell densities. The immune activation of peripheral blood mononuclear cells (PBMCs after co-culture with HMBs was studied. Rats with ALF induced by galactosamine were transplanted intraperitoneally with rat hepatocyte microbeads (RMBs produced using a similar optimised protocol. Survival rate and biochemical profiles were determined. Retrieved microbeads were evaluated for morphology and functionality. RESULTS: The optimised HMBs were of uniform size (583.5±3.3 µm and mechanically stable using 15 min polymerisation time compared to 10 min and 20 min (p<0.001. 3D confocal microscopy images demonstrated that hepatocytes with similar cell viability were evenly distributed within HMBs. Cell density of 3.5×10(6 cells/ml provided the highest viability. HMBs incubated in human ascitic fluid showed better cell viability and function than controls. There was no significant activation of PBMCs co-cultured with empty or hepatocyte microbeads, compared to PBMCs alone. Intraperitoneal transplantation of RMBs was safe and significantly improved the severity of liver damage compared to control groups (empty microbeads and medium alone; p<0.01. Retrieved RMBs were intact and free of immune cell adherence and contained viable hepatocytes with preserved function. CONCLUSION: An optimised protocol to produce GMP grade alginate

  9. Using Lean principles to optimise inpatient phlebotomy services.

    Science.gov (United States)

    Le, Rachel D; Melanson, Stacy E F; Santos, Katherine S; Paredes, Jose D; Baum, Jonathan M; Goonan, Ellen M; Torrence-Hill, Joi N; Gustafson, Michael L; Tanasijevic, Milenko J

    2014-08-01

    In the USA, inpatient phlebotomy services are under constant operational pressure to optimise workflow, improve timeliness of blood draws, and decrease error in the context of increasing patient volume and complexity of work. To date, the principles of Lean continuous process improvement have been rarely applied to inpatient phlebotomy. To optimise supply replenishment and cart standardisation, communication and workload management, blood draw process standardisation, and rounding schedules and assignments using Lean principles in inpatient phlebotomy services. We conducted four Lean process improvement events and implemented a number of interventions in inpatient phlebotomy over a 9-month period. We then assessed their impact using three primary metrics: (1) percentage of phlebotomists drawing their first patient by 05:30 for 05:00 rounds, (2) percentage of phlebotomists completing 08:00 rounds by 09:30, and (3) number of errors per 1000 draws. We saw marked increases in the percentage of phlebotomists drawing their first patient by 05:30, and the percentage of phlebotomists completing rounds by 09:30 postprocess improvement. A decrease in the number of errors per 1000 draws was also observed. This study illustrates how continuous process improvement through Lean can optimise workflow, improve timeliness, and decrease error in inpatient phlebotomy. We believe this manuscript adds to the field of clinical pathology as it can be used as a guide for other laboratories with similar goals of optimising workflow, improving timeliness, and decreasing error, providing examples of interventions and metrics that can be tailored to specific laboratories with particular services and resources. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  10. Systematic delay-driven power optimisation and power-driven delay optimisation of combinational circuits

    OpenAIRE

    Mehrotra, Rashmi

    2013-01-01

    With the proliferation of mobile wireless communication and embedded systems, the energy efficiency becomes a major design constraint. The dissipated energy is often referred as the product of power dissipation and the input-output delay. Most of electronic design automation techniques focus on optimising only one of these parameters either power or delay. Industry standard design flows integrate systematic methods of optimising either area or timing while for power consumption optimisation o...

  11. A STUDY ON OPTIMISATION OF RESOURCES FOR MULTIPLE PROJECTS BY USING PRIMAVERA

    OpenAIRE

    B. S. K. REDDY; SK. NAGARAJU; MD. SALMAN

    2015-01-01

    Resources play vital role in construction projects. The performance of construction industry depends chiefly on how best the resources are managed. Optimisation play pivotal role in resource management, but task is highly haphazard and chaotic under the influence of complexities and vastness. Management always looks for optimum utility of resources available with them. Hence, the project management has got important place especially in resource allocation and smooth functioning with alloca...

  12. Design optimisation of a flywheel hybrid vehicle

    Energy Technology Data Exchange (ETDEWEB)

    Kok, D.B.

    1999-11-04

    during the engine start-up and shutdown periods. Correct throttle valve control ensures that hydrocarbon emissions are not critical for legislative emission limits, but the engine's standard lambda control cannot prevent an increase of nitric oxides. In order to improve tailpipe emissions, the thermo-chemical behaviour of the catalytic converter is investigated and adapted for hybrid vehicle application. In cold-start situations, the fuel consumption and exhaust gas emissions of a mechanical driveline with internal combustion engine increase. A detailed numerical investigation of the thermal behaviour of the hybrid driveline showed that the energy-efficient operation of the engine decreases thermal waste energy that is available to warm up driveline components. Therefore, a redesign of the cooling circuitry and thermal management of the driveline was required to improve system warm-up. A computer model has been developed that combines the functional description of the flywheel hybrid vehicle with the calculation of energy losses. Apart from standardised European drive cycles, velocity profiles that represent more realistic vehicle utilisation are used to assess and optimise the hybrid vehicle's fuel economy, exhaust gas emission and acceleration performance. Subdivision of energy consumption enabled the classification of those systems and components that have a major effect on fuel consumption. Of these, the optimised flywheel system, the hydraulic system, and the transmission consume energy of comparable magnitude in city driving. It is shown that the system's fuel economy is mainly a result of the improved engine operation. Regenerative braking has only limited effect on vehicle fuel consumption. Experiments with an early prototype of the hybrid driveline yielded no gains in fuel consumption when compared to a conventional CVT reference vehicle due to high storage losses in the flywheel system. However, the improved prototype of the flywheel hybrid

  13. Benchmarks for dynamic multi-objective optimisation

    CSIR Research Space (South Africa)

    Helbig, M

    2013-06-01

    Full Text Available When algorithms solve dynamic multi-objective optimisation problems (DMOOPs), benchmark functions should be used to determine whether the algorithm can overcome specific difficulties that can occur in real-world problems. However, for dynamic multi...

  14. Topology optimisation for natural convection problems

    CERN Document Server

    Alexandersen, Joe; Andreasen, Casper Schousboe; Sigmund, Ole

    2014-01-01

    This paper demonstrates the application of the density-based topology optimisation approach for the design of heat sinks and micropumps based on natural convection effects. The problems are modelled under the assumptions of steady-state laminar flow using the incompressible Navier-Stokes equations coupled to the convection-diffusion equation through the Boussinesq approximation. In order to facilitate topology optimisation, the Brinkman approach is taken to penalise velocities inside the solid domain and the effective thermal conductivity is interpolated in order to accommodate differences in thermal conductivity of the solid and fluid phases. The governing equations are discretised using stabilised finite elements and topology optimisation is performed for two different problems using discrete adjoint sensitivity analysis. The study shows that topology optimisation is a viable approach for designing heat sink geometries cooled by natural convection and micropumps powered by natural convection.

  15. Topology Optimisation for Coupled Convection Problems

    DEFF Research Database (Denmark)

    Alexandersen, Joe

    This thesis deals with topology optimisation for coupled convection problems. The aim is to extend and apply topology optimisation to steady-state conjugate heat transfer problems, where the heat conduction equation governs the heat transfer in a solid and is coupled to thermal transport...... in a surrounding uid, governed by a convection-diffusion equation, where the convective velocity field is found from solving the isothermal incompressible steady-state Navier-Stokes equations. Topology optimisation is also applied to steady-state natural convection problems. The modelling is done using stabilised...... finite elements, the formulation and implementation of which was done partly during a special course as prepatory work for this thesis. The formulation is extended with a Brinkman friction term in order to facilitate the topology optimisation of fluid flow and convective cooling problems. The derived...

  16. An optimisation method for complex product design

    Science.gov (United States)

    Li, Ni; Yi, Wenqing; Bi, Zhuming; Kong, Haipeng; Gong, Guanghong

    2013-11-01

    Designing a complex product such as an aircraft usually requires both qualitative and quantitative data and reasoning. To assist the design process, a critical issue is how to represent qualitative data and utilise it in the optimisation. In this study, a new method is proposed for the optimal design of complex products: to make the full use of available data, information and knowledge, qualitative reasoning is integrated into the optimisation process. The transformation and fusion of qualitative and qualitative data are achieved via the fuzzy sets theory and a cloud model. To shorten the design process, parallel computing is implemented to solve the formulated optimisation problems. A parallel adaptive hybrid algorithm (PAHA) has been proposed. The performance of the new algorithm has been verified by a comparison with the results from PAHA and two other existing algorithms. Further, PAHA has been applied to determine the shape parameters of an aircraft model for aerodynamic optimisation purpose.

  17. User perspectives in public transport timetable optimisation

    DEFF Research Database (Denmark)

    Jensen, Jens Parbo; Nielsen, Otto Anker; Prato, Carlo Giacomo

    2014-01-01

    The present paper deals with timetable optimisation from the perspective of minimising the waiting time experienced by passengers when transferring either to or from a bus. Due to its inherent complexity, this bi-level minimisation problem is extremely difficult to solve mathematically, since...... on the large-scale public transport network in Denmark. The timetable optimisation approach yielded a yearly reduction in weighted waiting time equivalent to approximately 45 million Danish kroner (9 million USD)....

  18. Analysing bone regeneration using topological optimisation

    Directory of Open Access Journals (Sweden)

    Diego Alexander Garzón Alvarado

    2010-04-01

    Full Text Available The present article's object is to present the mathematical foundations of topological optimisation aimed at carrying out a study of bone regeneration. Bone structure can be economically adopted to different mechanical demands responding to topological optimisation models (having "minimum" mass and "high" resistance. Such analysis is essential for formulating physical therapy in patients needing partial or total strengthening of a particular bone's tissue structure. A mathematical model is formulated, as are the methods for resolving it.

  19. Feeding and dispersal behavior of the cotton leafworm, Alabama argillacea (Hübner) (Lepidoptera: Noctuidae), on Bt and non-Bt cotton: implications for evolution and resistance management.

    Science.gov (United States)

    Ramalho, Francisco S; Pachú, Jéssica K S; Lira, Aline C S; Malaquias, José B; Zanuncio, José C; Fernandes, Francisco S

    2014-01-01

    The host acceptance of neonate Alabama argillacea (Hübner) (Lepidoptera: Noctuidae) larvae to Bt cotton plants exerts a strong influence on the potential risk that this pest will develop resistance to Bt cotton. This will also determine the efficiency of management strategies to prevent its resistance such as the "refuge-in-the-bag" strategy. In this study, we assessed the acceptance of neonate A. argillacea larvae to Bt and non-Bt cotton plants at different temperatures during the first 24 h after hatching. Two cotton cultivars were used in the study, one a Bt DP 404 BG (Bollgard) cultivar, and the other, an untransformed isoline, DP 4049 cultivar. There was a greater acceptance by live neonate A. argillacea larvae for the non-Bt cotton plants compared with the Bt cotton plants, especially in the time interval between 18 and 24 h. The percentages of neonate A. argillacea larvae found on Bt or non-Bt plants were lower when exposed to temperatures of 31 and 34 °C. The low acceptance of A. argillacea larvae for Bt cotton plants at high temperatures stimulated the dispersion of A. argillacea larvae. Our results support the hypothesis that the dispersion and/or feeding behavior of neonate A. argillacea larvae is different between Bt and non-Bt cotton. The presence of the Cry1Ac toxin in Bt cotton plants, and its probable detection by the A. argillacea larvae tasting or eating it, increases the probability of dispersion from the plant where the larvae began. These findings may help to understand how the A. argillacea larvae detect the Cry1Ac toxin in Bt cotton and how the toxin affects the dispersion behavior of the larvae over time. Therefore, our results are extremely important for the management of resistance in populations of A. argillacea on Bt cotton.

  20. Optimisation is at the heart of the operation.

    Science.gov (United States)

    Jones, Darren

    2013-11-01

    In our other article based around operating theatres in this issue of HEJ (see pages 64-72), we examine how some of the latest technology is benefiting users, but in this article--with all areas of the NHS charged with reducing energy consumption and cutting carbon emissions--Darren Jones, MD at carbon and energy management specialist, Low Carbon Europe, takes a detailed look, with the help of a 'real-life' case study based on recent experience at London's Heart Hospital, at operating theatre optimisation and HTM 03-01 audits.

  1. Identifying appropriate spatial scales for marine conservation and management using a larval dispersal model: The case of Concholepas concholepas (loco) in Chile

    Science.gov (United States)

    Garavelli, Lysel; Kaplan, David Michael; Colas, François; Stotz, Wolfgang; Yannicelli, Beatriz; Lett, Christophe

    2014-05-01

    Along the coast of Chile, fisheries targeting the marine gastropod Concholepas concholepas, commonly named “loco”, were highly valuable until the end of the 80s when catches declined significantly. Since the late 90s, a management plan based on territorial-user-rights areas has been implemented, with limited effect on stock recovery. More effective loco conservation and management is impeded by lack of information regarding connectivity via larval dispersal between these individually-managed areas. To develop a regional view of loco connectivity, we integrate loco life history information into a biophysical, individual-based larval dispersal model. This model is used to evaluate scales of loco connectivity and seasonality in connectivity patterns, as well as to partition the coast into largely disconnected subpopulations using a recently developed connectivity-matrix clustering algorithm. We find mean dispersal distances ranging from 170 to 220 km depending on release depth of larvae and planktonic larval duration. Settlement success levels depend quantitatively on the physical and biological processes included in the model, but connectivity patterns remain qualitatively similar. Model estimates of settlement success peak for larval release dates in late austral autumn, consistent with field results and with favorable conditions for larval coastal retention due to weak upwelling during austral autumn. Despite the relatively homogeneous Chilean coastline, distinct subpopulations with minimal connectivity between them are readily identifiable. Barriers to connectivity that are robust to changes in model configuration exist at 23°S and 29°S latitudes. These zones are all associated with important headlands and embayments of the Chilean coast.

  2. Nuclear power plant maintenance optimisation SENUF network activity

    Energy Technology Data Exchange (ETDEWEB)

    Ahlstrand, R.; Bieth, M.; Pla, P.; Rieg, C.; Trampus, P. [Inst. for Energy, EC DG Joint Research Centre, Petten (Netherlands)

    2004-07-01

    During providing scientific and technical support to TACIS and PHARE nuclear safety programs a large amount of knowledge related to Russian design reactor systems has accumulated and led to creation of a new Network concerning Nuclear Safety in Central and Eastern Europe called ''Safety of Eastern European type Nuclear Facilities'' (SENUF). SENUF contributes to bring together all stakeholders of TACIS and PHARE: beneficiaries, end users, Eastern und Western nuclear industries, and thus, to favour fruitful technical exchanges and feedback of experience. At present the main focus of SENUF is the nuclear power plant maintenance as substantial element of plant operational safety as well as life management. A Working Group has been established on plant maintenance. One of its major tasks in 2004 is to prepare a status report on advanced strategies to optimise maintenance. Optimisation projects have an interface with the plant's overall life management program. Today, almost all plants involved in SENUF network have an explicit policy to extend their service life, thus, component ageing management, modernization and refurbishment actions became much more important. A database is also under development, which intends to help sharing the available knowledge and specific equipment and tools. (orig.)

  3. The first “lost year” of Mediterranean sea turtles: dispersal patterns indicate subregional management units for conservation

    DEFF Research Database (Denmark)

    Casale, Paolo; Mariani, Patrizio

    2014-01-01

    mainly disperse to the Ionian, Adriatic and south-central Mediterranean areas. Combining hatchling dispersal with existing empirical information on juveniles and adults, a general distribution model among nesting sites, oceanic and neritic foraging grounds for Mediterranean sea turtles is proposed......Identifying highly frequented areas is a priority for sea turtle conservation, and the distribution of young individuals in open waters represents a major knowledge gap due to methodological biases. The drift of hatchlings from 38 loggerhead and 10 green turtle nesting sites in the Mediterranean...... were simulated for the first six months of life, with the simulations being repeated for five different years (2001 – 2005). The results indicate that hatchlings from the Levantine and south-central Mediterranean sites are mainly retained in the same areas of origin, while those from the Ionian area...

  4. Optimisation Modelling of Efficiency of Enterprise Restructuring

    Directory of Open Access Journals (Sweden)

    Yefimova Hanna V.

    2014-03-01

    Full Text Available The article considers issues of optimisation of the use of resources directed at restructuring of a shipbuilding enterprise, which is the main prerequisite of its efficiency. Restructuring is considered as a process of complex and interconnected change in the structure of assets, liabilities, enterprise functions, initiated by dynamic environment, which is based on the strategic concept of its development and directed at increase of efficiency of its activity, which is expressed in the growth of cost. The task of making a decision to restructure a shipbuilding enterprise and selection of a specific restructuring project refers to optimisation tasks of prospective planning. Enterprise resources that are allocated for restructuring serve as constraints of the mathematical model. Main criteria of optimisation are maximisation of pure discounted income or minimisation of expenditures on restructuring measures. The formed optimisation model is designed for assessment of volumes of attraction of own and borrowed funds for restructuring. Imitation model ensures development of cash flows. The task solution is achieved on the basis of the complex of interrelated optimisation and imitation models and procedures on formation, selection and co-ordination of managerial decisions.

  5. Organisational design elements and competencies for optimising the expertise of knowledge workers in a shared services centre

    Directory of Open Access Journals (Sweden)

    Mark Ramsey

    2011-02-01

    Full Text Available Orientation: Organisations are still structured according to the Industrial Age control model that restricts optimising the expertise of knowledge workers.Research purpose: The general aim of the research was to explore the organisation design elements and competencies that contribute to optimising the expertise of knowledge workers in a shared services centre.Motivation for the study: Current organisational design methodologies do not emphasise optimising the expertise of knowledge workers. This research addresses the challenge of how an organisation design can improve the creation and availability of the expertise of knowledge workers.Research design/approach method: The researcher followed a qualitative case study research design and collected data in six focus group sessions (N = 25.Main findings: The findings showed that the shared services centre (SSC is not designed to enable its structure, culture and codifying system to optimise the expertise of knowledge workers. In addition, the SSC does not share the knowledge generated with other knowledge workers. Furthermore, it does not use the output of the knowledge workers to improve business processes.Practical/managerial implications: The expertise of knowledge workers is the basis of competitive advantage. Therefore, managers should create an organisational design that is conducive to optimising knowledge work expertise.Contribution/value add: This research highlights the important organisational design elements and supportive organisational structures for optimising the expertise of knowledge workers. The research also proposes a framework for optimising the expertise of knowledge workers and helping an organisation to achieve sustainable competitive advantage.

  6. Multicriteria Optimisation in Logistics Forwarder Activities

    Directory of Open Access Journals (Sweden)

    Tanja Poletan Jugović

    2007-05-01

    Full Text Available Logistics forwarder, as organizer and planner of coordinationand integration of all the transport and logistics chains elements,uses adequate ways and methods in the process of planningand decision-making. One of these methods, analysed inthis paper, which could be used in optimisation of transportand logistics processes and activities of logistics forwarder, isthe multicriteria optimisation method. Using that method, inthis paper is suggested model of multicriteria optimisation of logisticsforwarder activities. The suggested model of optimisationis justified in keeping with method principles of multicriteriaoptimization, which is included in operation researchmethods and it represents the process of multicriteria optimizationof variants. Among many different processes of multicriteriaoptimization, PROMETHEE (Preference Ranking OrganizationMethod for Enrichment Evaluations and Promcalc& Gaia V. 3.2., computer program of multicriteria programming,which is based on the mentioned process, were used.

  7. Topology Optimisation for Coupled Convection Problems

    DEFF Research Database (Denmark)

    Alexandersen, Joe; Andreasen, Casper Schousboe; Aage, Niels

    conduction governs in the solid parts of the design domain and couples to convection-dominated heat transfer to a surrounding fluid. Both loosely coupled and tightly coupled problems are considered. The loosely coupled problems are convection-diffusion problems, based on an advective velocity field from......The work focuses on applying topology optimisation to forced and natural convection problems in fluid dynamics and conjugate (fluid-structure) heat transfer. To the authors' knowledge, topology optimisation has not yet been applied to natural convection flow problems in the published literature...... and the current work is thus seen as contributing new results to the field. In the literature, most works on the topology optimisation of weakly coupled convection-diffusion problems focus on the temperature distribution of the fluid, but a selection of notable exceptions also focusing on the temperature...

  8. Optimisation of a large WWTP thanks to mathematical modelling.

    Science.gov (United States)

    Printemps, C; Baudin, A; Dormoy, T; Zug, M; Vanrolleghem, P A

    2004-01-01

    Better controlling and optimising the plant's processes has become a priority for WWTP (Wastewater Treatment Plant) managers. The main objective of this project is to develop a simplified mathematical tool able to reproduce and anticipate the behaviour of the Tougas WWTP (Nantes, France). This tool is aimed to be used directly by the managers of the site. The mathematical WWTP model was created using the software WEST. This paper describes the studied site and the modelling results obtained during the stage of the model calibration and validation. The good simulation results have allowed to show that despite a first very simple description of the WWTP, the model was able to correctly predict the nitrogen composition (ammonia and nitrate) of the effluent and the daily sludge extraction. Then, a second more detailed configuration of the WWTP was implemented. It has allowed to independently study the behaviour of each of four biological trains. Once this first stage will be completely achieved, the remainder of the study will focus on the operational use of a simplified simulator with the purpose of optimising the Tougas WWTP operation.

  9. Pulse generation and propagation in dispersion-managed ultralong erbium-doped fiber lasers mode-locked by carbon nanotubes.

    Science.gov (United States)

    Rosa, H G; Thoroh de Souza, E A

    2012-12-15

    We present a study of pulse generation and propagation in erbium-doped fiber lasers with cavity length varying from 8 m to 3.5 km. We demonstrate that soliton effect determines the pulse stabilization in ultralong cavities, measuring pulses with an average 7.0 ps pulsewidth for cavity lengths between 2.25 and 3.5 km. We also demonstrate that, by filling fundamental soliton requirements, pulsewidth can be determined by length and total dispersion cavity parameters.

  10. Spatially Dispersed Employee Recovery

    DEFF Research Database (Denmark)

    Hvass, Kristian Anders; Torfadóttir, Embla

    2014-01-01

    Employee recovery addresses either employee well-being or management's practices in aiding employees in recovering themselves following a service failure. This paper surveys the cabin crew at a small, European, low-cost carrier and investigates employees' perceptions of management practices to aid...... personnel achieve service recovery. Employee recovery within service research often focuses on front-line employees that work in a fixed location, however a contribution to the field is made by investigating the recovery of spatially dispersed personnel, such as operational personnel in the transport sector......, who have a work place away from a fixed or central location and have minimal management contact. Results suggest that the support employees receive from management, such as recognition, information sharing, training, and strategic awareness are all important for spatially dispersed front...

  11. A simulation-optimisation approach for designing water distribution networks under multiple objectives

    Science.gov (United States)

    Grundmann, Jens; Pham Van, Tinh; Müller, Ruben; Schütze, Niels

    2014-05-01

    Especially in arid and semi-arid regions, water distribution networks are of major importance for an integrated water resources management in order to convey water over long distances from sources to consumers. However, to design a network optimally is still a challenge which requires an appropriate determination of: (1) pipe/pump/tank characteristics - decision variables (2) cost/network reliability - objective functions including (3) a given set of constraints. Thereby, objective functions are contradicting, which means that by minimising costs network reliability is decreasing resulting in a higher risk of network failures. For solving this multi-objective design problem, a simulation-optimisation approach is developed. The approach couples a hydraulic network model (Epanet) with an optimiser, namely the covariance matrix adaptation evolution strategy (CMAES). The simulation-optimisation model is applied on international published benchmark cases for single and multi-objective optimisation and simultaneous optimisation of above mentioned decision variables as well as network layout. Results are encouraging. The proposed model performs with similar or better results, which means smaller costs and higher network reliability. Subsequently, the new model is applied for an optimal design and operation of a water distribution system to supply the coastal arid region of Al-Batinah (North of Oman) with water for agricultural production.

  12. Recent research development of process integration in analysis and optimisation of energy systems

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, F.X.X.; Vaideeswaran, L. [UMIST, Manchester (United Kingdom). Dept. of Process Integration

    2000-11-01

    The design of energy systems in a process plant requires a good understanding of each subsystem (e.g. processes, heat exchanger networks, utility systems),and their interactions in the context of an overall plant. An effective design method should be able to explore the synergy between the subsystems to the maximum extent and allow users to interact with the design process. To achieve this, the effective way is to combine physical insights with mathematical optimisation techniques. Physical insights are used as a wise man's brain and eyes, while optimisation techniques are employed as a superman's power in searching for optimal solutions. In the past, concepts and methods have been developed for handling grassroots design, operational management, retrofit and debottlenecking scenarios. This paper describes the recent research progress at UMIST in developing fundamental concepts and methodologies for analysis and optimisation of energy systems. (author)

  13. Dispersion Forces

    CERN Document Server

    Buhmann, Stefan Yoshi

    2012-01-01

    In this book, a modern unified theory of dispersion forces on atoms and bodies is presented which covers a broad range of advanced aspects and scenarios. Macroscopic quantum electrodynamics is shown to provide a powerful framework for dispersion forces which allows for discussing general properties like their non-additivity and the relation between microscopic and macroscopic interactions. It is demonstrated how the general results can be used to obtain dispersion forces on atoms in the presence of bodies of various shapes and materials. Starting with a brief recapitulation of volume I, this volume II deals especially with bodies of irregular shapes, universal scaling laws, dynamical forces on excited atoms, enhanced forces in cavity quantum electrodynamics, non-equilibrium forces in thermal environments and quantum friction. The book gives both the specialist and those new to the field a thorough overview over recent results in the field. It provides a toolbox for studying dispersion forces in various contex...

  14. Simulating stem growth using topological optimisation

    Directory of Open Access Journals (Sweden)

    Carlos Alberto Narváez

    2010-04-01

    Full Text Available Engineers are currently resorting to observations of nature for making new designs. Studying the functioning of bodies of plants and animals has required them to be modelled and simulated; however, some models born from engineering problems could be used for such purposes. This article shows how topological optimisation (a mathematical model for optimising designing structural elements can be used for modeling and simulating the way a stem grows in terms of carrying out its funtion of providing support for the leaves and a plant's other upper organs.

  15. Bat Algorithm for Multi-objective Optimisation

    CERN Document Server

    Yang, Xin-She

    2012-01-01

    Engineering optimization is typically multiobjective and multidisciplinary with complex constraints, and the solution of such complex problems requires efficient optimization algorithms. Recently, Xin-She Yang proposed a bat-inspired algorithm for solving nonlinear, global optimisation problems. In this paper, we extend this algorithm to solve multiobjective optimisation problems. The proposed multiobjective bat algorithm (MOBA) is first validated against a subset of test functions, and then applied to solve multiobjective design problems such as welded beam design. Simulation results suggest that the proposed algorithm works efficiently.

  16. Topology Optimisation of Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Thike Aye Min

    2016-01-01

    Full Text Available Wireless sensor networks are widely used in a variety of fields including industrial environments. In case of a clustered network the location of cluster head affects the reliability of the network operation. Finding of the optimum location of the cluster head, therefore, is critical for the design of a network. This paper discusses the optimisation approach, based on the brute force algorithm, in the context of topology optimisation of a cluster structure centralised wireless sensor network. Two examples are given to verify the approach that demonstrate the implementation of the brute force algorithm to find an optimum location of the cluster head.

  17. Impairment assessment of orthogonal frequency division multiplexing over dispersion-managed links in backbone and backhaul networks

    Science.gov (United States)

    Tamilarasan, Ilavarasan; Saminathan, Brindha; Murugappan, Meenakshi

    2016-04-01

    The past decade has seen the phenomenal usage of orthogonal frequency division multiplexing (OFDM) in the wired as well as wireless communication domains, and it is also proposed in the literature as a future proof technique for the implementation of flexible resource allocation in cognitive optical networks. Fiber impairment assessment and adaptive compensation becomes critical in such implementations. A comprehensive analytical model for impairments in OFDM-based fiber links is developed. The proposed model includes the combined impact of laser phase fluctuations, fiber dispersion, self phase modulation, cross phase modulation, four-wave mixing, the nonlinear phase noise due to the interaction of amplified spontaneous emission with fiber nonlinearities, and the photodetector noises. The bit error rate expression for the proposed model is derived based on error vector magnitude estimation. The performance analysis of the proposed model is presented and compared for dispersion compensated and uncompensated backbone/backhaul links. The results suggest that OFDM would perform better for uncompensated links than the compensated links due to the negligible FWM effects and there is a need for flexible compensation. The proposed model can be employed in cognitive optical networks for accurate assessment of fiber-related impairments.

  18. Optimisation of interventional cardiology procedures; Optimisation des procedures en cardiologie interventionnelle

    Energy Technology Data Exchange (ETDEWEB)

    Bar, Olivier [SELARL, Cardiologie Interventionnelle Imagerie Cardiaque - CIIC, 8, place de la Cathedrale - 37042 Tours (France)

    2011-07-15

    Radiation-guided procedures in interventional cardiology include diagnostic and/or therapeutic procedures, primarily coronary catheterization and coronary angioplasty. Application of the principles of radiation protection and the use of optimised procedures are contributing to dose reduction while maintaining the radiological image quality necessary for performance of the procedures. The mandatory training in patient radiation protection and technical training in the use of radiology devices mean that implementing continuous optimisation of procedures is possible in practice. This optimisation approach is the basis of patient radiation protection; when associated with the wearing of protective equipment it also contributes to the radiation protection of the cardiologists. (author)

  19. Extending Particle Swarm Optimisers with Self-Organized Criticality

    DEFF Research Database (Denmark)

    Løvbjerg, Morten; Krink, Thiemo

    2002-01-01

    Particle swarm optimisers (PSOs) show potential in function optimisation, but still have room for improvement. Self-organized criticality (SOC) can help control the PSO and add diversity. Extending the PSO with SOC seems promising reaching faster convergence and better solutions.......Particle swarm optimisers (PSOs) show potential in function optimisation, but still have room for improvement. Self-organized criticality (SOC) can help control the PSO and add diversity. Extending the PSO with SOC seems promising reaching faster convergence and better solutions....

  20. An efficient and flexible web services-based multidisciplinary design optimisation framework for complex engineering systems

    Science.gov (United States)

    Li, Liansheng; Liu, Jihong

    2012-08-01

    Multidisciplinary design optimisation (MDO) involves multiple disciplines, multiple coupled relationships and multiple processes, which is implemented by different specialists dispersed geographically on heterogeneous platforms with different analysis and optimisation tools. The product design data integration and data sharing among the participants hampers the development and applications of MDO in enterprises seriously. Therefore, a multi-hierarchical integrated product design data model (MH-iPDM) supporting the MDO in the web environment and a web services-based multidisciplinary design optimisation (Web-MDO) framework are proposed in this article. Based on the enabling technologies including web services, ontology, workflow, agent, XML and evidence theory, the proposed framework enables the designers geographically dispersed to work collaboratively in the MDO environment. The ontology-based workflow enables the logical reasoning of MDO to be processed dynamically. The evidence theory-based uncertainty reasoning and analysis supports the quantification, aggregation and analysis of the conflicting epistemic uncertainty from multiple sources, which improves the quality of product. Finally, a proof-of-concept prototype system is developed using J2EE and an example of supersonic business jet is demonstrated to verify the autonomous execution of MDO strategies and the effectiveness of the proposed approach.

  1. Topology optimisation of natural convection problems

    DEFF Research Database (Denmark)

    Alexandersen, Joe; Aage, Niels; Andreasen, Casper Schousboe

    2014-01-01

    This paper demonstrates the application of the density-based topology optimisation approach for the design of heat sinks and micropumps based on natural convection effects. The problems are modelled under the assumptions of steady-state laminar flow using the incompressible Navier-Stokes equation...

  2. Thermodynamic optimisation of a heat exchanger

    NARCIS (Netherlands)

    Cornelissen, R.L.; Hirs, G.G.

    1999-01-01

    The objective of this paper is to show that for the optimal design of an energy system, where there is a trade-off between exergy saving during operation and exergy use during construction of the energy system, exergy analysis and life cycle analysis should be combined. An exergy optimisation of a h

  3. Optimising insemination strategies in pigs

    NARCIS (Netherlands)

    Steverink, D.W.B.

    1999-01-01

    INTRODUCTIONReproductive efficiency shows large variation between farms. The origin of the variation between farms, with respect to these reproduction results, is very complex. Factors like health status, husbandry system, management and breed can have an influence on reproduction results. One of th

  4. An optimisation model for the warehouse design and product assignment and allocation problem

    OpenAIRE

    Geraldes, Carla A. S.; Carvalho, Sameiro; Pereira, Guilherme

    2013-01-01

    Warehouse design and planning is a great challenge in the field of Supply Chain Management. In this paper we discuss an optimisation model aiming to support some warehouse management decisions. In particular a mixed-integer programming model (MILP) is presented to determine product assignment and allocation to the functional areas, as well as the size of each area. Our aim is to capture the trade-offs among the different warehouse costs in order to achieve global optimal design satisfying th...

  5. Radiation protection optimisation techniques and their application in industry

    Energy Technology Data Exchange (ETDEWEB)

    Lefaure, C

    1996-12-31

    Since the International Commission on Radiation Protection (ICRP) recommendation 60, the optimisation principle appears to be the core of the radiation protection system. In practice applying it, means implementing an approach both predictive and evolutionary - that relies essentially on a prudent and responsible state of mind. the formal expression of this process, called optimization procedure, implies and indispensable tool for its implementation: the system of monetary values for the unit of collective dose. During the last few years, feed ALARA principle means that a global work management approach must be adopted, considering together all factors contributing to radiation dose. In the nuclear field, the ALARA approach appears to be more successful when implemented in the framework of a managerial approach through structure ALARA programmes. Outside the nuclear industry it is necessary to clearly define priorities through generic optimisation studies and ALARA audits. At the international level much efforts remain to be done to expand efficiently the ALARA process to internal exposure as well as to public exposure. (author) 2 graphs, 5 figs., 3 tabs.

  6. Evaluating critical dispersal rates for whale management under the IWCs Revised Management Procedure : An application for North Atlantic common minke whales

    NARCIS (Netherlands)

    van der Zee, Jurjan P.; Punt, André E.

    2014-01-01

    A key consideration for any Revised Management Procedure (RMP) and Aboriginal Whaling Management Procedure (AMWP) Implementation is the choice of stock structure hypotheses, and the weighting of alternative stock structure hypotheses using available data. The RMP/AWMP-lite framework is applied to th

  7. Optimisation of decision making under uncertainty throughout field lifetime: A fractured reservoir example

    Science.gov (United States)

    Arnold, Dan; Demyanov, Vasily; Christie, Mike; Bakay, Alexander; Gopa, Konstantin

    2016-10-01

    estimation with the appropriate optimisation at appraisal, development and reservoir management stages to maximise oil recovery under uncertainty.

  8. Dispersion Modeling.

    Science.gov (United States)

    Budiansky, Stephen

    1980-01-01

    This article discusses the need for more accurate and complete input data and field verification of the various models of air pollutant dispension. Consideration should be given to changing the form of air quality standards based on enhanced dispersion modeling techniques. (Author/RE)

  9. Chemical dispersants

    NARCIS (Netherlands)

    Rahsepar, Shokouhalsadat; Smit, Martijn P.J.; Murk, Albertinka J.; Rijnaarts, Huub H.M.; Langenhoff, Alette A.M.

    2016-01-01

    Chemical dispersants were used in response to the Deepwater Horizon oil spill in the Gulf of Mexico, both at the sea surface and the wellhead. Their effect on oil biodegradation is unclear, as studies showed both inhibition and enhancement. This study addresses the effect of Corexit on oil biodeg

  10. Chemical dispersants

    NARCIS (Netherlands)

    Rahsepar, Shokouhalsadat; Smit, Martijn P.J.; Murk, Albertinka J.; Rijnaarts, Huub H.M.; Langenhoff, Alette A.M.

    2016-01-01

    Chemical dispersants were used in response to the Deepwater Horizon oil spill in the Gulf of Mexico, both at the sea surface and the wellhead. Their effect on oil biodegradation is unclear, as studies showed both inhibition and enhancement. This study addresses the effect of Corexit on oil

  11. Public transport optimisation emphasising passengers’ travel behaviour

    DEFF Research Database (Denmark)

    Jensen, Jens Parbo

    to enhance the operations of public transport while explicitly emphasising passengers’ travel behaviour and preferences. Similar to economic theory, interactions between supply and demand are omnipresent in the context of public transport operations. In public transport, the demand is represented...... the published performance measures and what passengers actually experience, a large academic contribution of the current PhD study is the explicit consideration of passengers’ travel behaviour in optimisation studies and in the performance assessment. Besides the explicit passenger focus in transit planning...... at as the motivator for delay-robust railway timetables. Interestingly, passenger oriented optimisation studies considering robustness in railway planning typically limit their emphasis on passengers to the consideration of transfer maintenance. Clearly, passengers’ travel behaviour is more complex and multifaceted...

  12. Topology optimised planar photonic crystal building blocks

    DEFF Research Database (Denmark)

    Frandsen, Lars Hagedorn; Hede, K. K.; Borel, Peter Ingo

    A photonic crystal waveguide (PhCW) 1x4 splitter has been constructed from PhCW 60° bends1 and Y-splitters2 that have been designed individually by utilising topology optimisation3. The splitter has been fabricated in a silicon-on-insulator material (Fig. 1) and exhibits a broadband splitting...... for the TE-polarisation with an average excess loss of 1.55±0.54 dB for a 110 nm bandwidth. The 1x4 splitter demonstrates that individual topology-optimised parts can be used as building blocks to realise high-performance nanophotonic circuits. 1L. H. Frandsen et al., Opt. Express 12, 5916-5921 (2004) 2P. I...

  13. Self-optimising control of sewer systems

    DEFF Research Database (Denmark)

    Mauricio Iglesias, Miguel; Montero-Castro, I.; Mollerup, Ane Loft

    2013-01-01

    Self-optimising control is a useful concept to select optimal controlled variables from a set of candidate measurements in a systematic manner. In this study, use self-optimizing control tools and apply them to the specific features of sewer systems, e.g. the continuously transient dynamics......, the availability of a large number of measurements, the stochastic and unforeseeable character of the disturbances (rainfall). Using a subcatchment area in the Copenhagen sewer system as a case study we demonstrate, step by step, the formulation of the self-optimising control problem. The final result...... is an improved control structure aimed at optimizing the losses for a given control objective, here the minimization of the combined sewer overflows despite rainfall variations....

  14. Improved Squeaky Wheel Optimisation for Driver Scheduling

    CERN Document Server

    Aickelin, Uwe; Li, Jingpeng

    2008-01-01

    This paper presents a technique called Improved Squeaky Wheel Optimisation for driver scheduling problems. It improves the original Squeaky Wheel Optimisations effectiveness and execution speed by incorporating two additional steps of Selection and Mutation which implement evolution within a single solution. In the ISWO, a cycle of Analysis-Selection-Mutation-Prioritization-Construction continues until stopping conditions are reached. The Analysis step first computes the fitness of a current solution to identify troublesome components. The Selection step then discards these troublesome components probabilistically by using the fitness measure, and the Mutation step follows to further discard a small number of components at random. After the above steps, an input solution becomes partial and thus the resulting partial solution needs to be repaired. The repair is carried out by using the Prioritization step to first produce priorities that determine an order by which the following Construction step then schedul...

  15. Buckling optimisation of sandwich cylindrical panels

    Science.gov (United States)

    Abouhamzeh, M.; Sadighi, M.

    2016-06-01

    In this paper, the buckling load optimisation is performed on sandwich cylindrical panels. A finite element program is developed in MATLAB to solve the governing differential equations of the global buckling of the structure. In order to find the optimal solution, the genetic algorithm Toolbox in MATLAB is implemented. Verifications are made for both the buckling finite element code and also the results from the genetic algorithm by comparisons to the results available in literature. Sandwich cylindrical panels are optimised for the buckling strength with isotropic or orthotropic cores with different boundary conditions. Results are presented in terms of stacking sequence of fibers in the face sheets and core to face sheet thickness ratio.

  16. Applying the Theory of Optimising Professional Life

    Directory of Open Access Journals (Sweden)

    Lesley Margaret Piko

    2014-12-01

    Full Text Available Glaser (2014 wrote that “the application of grounded theory (GT is a relatively neglected topic” (p. 1 in the literature. Applying GT to purposely intervene and improve a situation is an important adjunct to our knowledge and understanding of GT. A recent workshop of family doctors and general practitioners provides a useful example. The theory of optimising professional life explains that doctors are concerned about sustainment in their career and, to resolve this concern, they implement solutions to optimise their personal situation. Sustainment is a new, overarching concept of three needs: the need for self-care to sustain well-being, the need for work interest to sustain motivation, and the need for income to sustain lifestyle. The objective of the workshop was to empower doctors to reinvent their careers using this theory. Working individually and in small groups, participants were able to analyse a problem and to identify potential solutions.

  17. Fermionic orbital optimisation in tensor network states

    CERN Document Server

    Krumnow, C; Eisert, J

    2015-01-01

    Tensor network states and specifically matrix-product states have proven to be a powerful tool for simulating ground states of strongly correlated spin models. Recently, they have also been applied to interacting fermionic problems, specifically in the context of quantum chemistry. A new freedom arising in such non-local fermionic systems is the choice of orbitals, it being far from clear what choice of fermionic orbitals to make. In this work, we propose a way to overcome this challenge. We suggest a method intertwining the optimisation over matrix product states with suitable fermionic Gaussian mode transformations, hence bringing the advantages of both approaches together. The described algorithm generalises basis changes in the spirit of the Hartree-Fock methods to matrix-product states, and provides a black box tool for basis optimisations in tensor network methods.

  18. Reservoir optimisation using El Niño information. Case study of Daule Peripa (Ecuador)

    Science.gov (United States)

    Gelati, Emiliano; Madsen, Henrik; Rosbjerg, Dan

    2010-05-01

    inflow forecasts, and by applying the base policy on a subsequent synthetic inflow scenario in order to account for long-term costs; (iv) the optimised release for the first month is implemented; (v) the state of the system is updated and (i), (ii), (iii), and (iv) are iterated for the following time step. The results highlight the advantages of using a climate-driven stochastic model to produce inflow scenarios and forecasts for reservoir optimisation, showing potential improvements with respect to the current management. Dynamic programming was used to find the best possible release time series given the inflow observations, in order to benchmark any possible operational improvement.

  19. Adaptive Java Optimisation using machine learning techniques

    OpenAIRE

    Long, Shun

    2004-01-01

    There is a continuing demand for higher performance, particularly in the area of scientific and engineering computation. In order to achieve high performance in the context of frequent hardware upgrading, software must be adaptable for portable performance. What is required is an optimising compiler that evolves and adapts itself to environmental change without sacrificing performance. Java has emerged as a dominant programming language widely used in a variety of application areas. Howeve...

  20. Optimised polarisation measurements on Bragg peaks

    Energy Technology Data Exchange (ETDEWEB)

    Lelievre-Berna, E. [Institut Laue Langevin, 6 rue Jules Horowitz, 38042 Grenoble Cedex 9 (France)]. E-mail: lelievre@ill.fr; Brown, P.J. [Institut Laue Langevin, 6 rue Jules Horowitz, 38042 Grenoble Cedex 9 (France); Tasset, F. [Institut Laue Langevin, 6 rue Jules Horowitz, 38042 Grenoble Cedex 9 (France)

    2007-07-15

    Experimentally the asymmetry A (or the flipping ratio R) is deduced from the two count rates observed for |+> and |-> neutron spin states. Since the count rates for the two spin states may be quite different and both require to be corrected for background, the optimum strategy for the measurement is important. We present here the theory for optimisation of the accuracy of measurement of A (or R) within the constraint of a fixed total measuring time.

  1. Optimisation structurelle des systemes energetiques

    Science.gov (United States)

    Saloux, Etienne

    The development of renewable energies is growing over the last decade to face environmental issues due to the world fossil fuel consumption increase. These energies are highly involved in houses and commercial buildings and numerous systems have been proposed to meet their energy demand. Therefore, improving both efficiency and use of systems, i.e. improving energy management, appears essential to limit the ecological footprint of humanity on the planet. However, system integration yields a very complex problem to be solved due to the large number of units and theirs technology, size, working conditions and interconnections. This situation highlights the lack of systematic analysis for comparing integrated system performance and for correctly pointing out their potential. As a result, the objective of this thesis is to develop and to present such a method, in other words the structural optimization of energy systems. It will be helpful to choose the optimal equipment by identifying all the possibilities of system arrangements and for comparing their performance. Combinations have then been subjected to environmental (climate), structural (available area) and economical constrains while assessment criteria have considered both energy, economic and ecological aspects. For that reason, as well as energy and economic analyses, the exergy concept has also been applied to the equipment. Nevertheless, the high degree of complexity of integrated systems and the tedious numerical calculations make the resolution by using standard software very difficult. It is clear that the whole optimization project would be considerable and the aim is to develop models and optimization tools. First of all, an exhaustive review of energy equipment including photovoltaic panels, solar collectors, heat pumps and thermal energy storage systems, has been performed. Afterwards, energy and exergy models have been developed and tested for two specific energy scenarios: a) a solar assisted heat

  2. Dispersion properties of photonic crystal fibres

    DEFF Research Database (Denmark)

    Bjarklev, Anders Overgaard; Broeng, Jes; Dridi, Kim;

    1998-01-01

    Approximate dispersion and bending properties of all-silica two-dimensional photonic crystal fibres are characterised by the combination of an effective-index model and classical analysis tools for optical fibres. We believe for the first time to have predicted the dispersion properties of photonic...... crystal fibres. The results strongly indicate that these fibres have potential applications as dispersion managing components...

  3. Exploration of automatic optimisation for CUDA programming

    KAUST Repository

    Al-Mouhamed, Mayez

    2014-09-16

    © 2014 Taylor & Francis. Writing optimised compute unified device architecture (CUDA) program for graphic processing units (GPUs) is complex even for experts. We present a design methodology for a restructuring tool that converts C-loops into optimised CUDA kernels based on a three-step algorithm which are loop tiling, coalesced memory access and resource optimisation. A method for finding possible loop tiling solutions with coalesced memory access is developed and a simplified algorithm for restructuring C-loops into an efficient CUDA kernel is presented. In the evaluation, we implement matrix multiply (MM), matrix transpose (M-transpose), matrix scaling (M-scaling) and matrix vector multiply (MV) using the proposed algorithm. We present the analysis of the execution time and GPU throughput for the above applications, which favourably compare to other proposals. Evaluation is carried out while scaling the problem size and running under a variety of kernel configurations. The obtained speedup is about 28-35% for M-transpose compared to NVIDIA Software Development Kit, 33% speedup for MV compared to general purpose computation on graphics processing unit compiler, and more than 80% speedup for MM and M-scaling compared to CUDA-lite.

  4. Designing Lead Optimisation of MMP-12 Inhibitors

    Directory of Open Access Journals (Sweden)

    Matteo Borrotti

    2014-01-01

    Full Text Available The design of new molecules with desired properties is in general a very difficult problem, involving heavy experimentation with high investment of resources and possible negative impact on the environment. The standard approach consists of iteration among formulation, synthesis, and testing cycles, which is a very long and laborious process. In this paper we address the so-called lead optimisation process by developing a new strategy to design experiments and modelling data, namely, the evolutionary model-based design for optimisation (EDO. This approach is developed on a very small set of experimental points, which change in relation to the response of the experimentation according to the principle of evolution and insights gained through statistical models. This new procedure is validated on a data set provided as test environment by Pickett et al. (2011, and the results are analysed and compared to the genetic algorithm optimisation (GAO as a benchmark. The very good performance of the EDO approach is shown in its capacity to uncover the optimum value using a very limited set of experimental points, avoiding unnecessary experimentation.

  5. Procedure for Application-Oriented Optimisation of Marine Propellers

    Directory of Open Access Journals (Sweden)

    Florian Vesting

    2016-11-01

    Full Text Available The use of automated optimisation in engineering applications is emerging. In particular, nature inspired algorithms are frequently used because of their variability and robust application in constraints and multi-objective optimisation problems. The purpose of this paper is the comparison of four different algorithms and several optimisation strategies on a set of seven test propellers in realistic industrial design setting. The propellers are picked from real commercial projects and the manual final designs were delivered to customers. The different approaches are evaluated and final results of the automated optimisation toolbox are compared with designs generated in a manual design process. We identify a two-stage optimisation for marine propellers, where the geometry is first modified by parametrised geometry distribution curves to gather knowledge of the test case. Here we vary the optimisation strategy in terms of applied algorithms, constraints and objectives. A second supporting optimisation aims to improve the design by locally changing the geometry, based on the results of the first optimisation. The optimisation algorithms and strategies yield propeller designs that are comparable to the manually designed propeller blade geometries, thus being suitable as robust and advanced design support tools. The supporting optimisation, with local modification of the blade geometry and the proposed cavity shape constraints, features particular good performance in modifying cavitation on the blade and is, with the AS NSGA-II (adaptive surrogate-assisted NSGA-II, superior in lead time.

  6. Generation of 1.024-Tb/s Nyquist-WDM phase-conjugated twin vector waves through polarization-insensitive optical parametric amplification enabling transmission over 4000-km dispersion-managed TWRS fiber

    DEFF Research Database (Denmark)

    Liu, Xiang; Hu, Hao; Chandrasekhar, S.;

    2013-01-01

    We experimentally demonstrate the first Tb/s Nyquist-WDM phase-conjugated twin waves, consisting of eight 128-Gb/s PDM-QPSK signals and their idlers, by a broadband polarization-insensitive fiber optical parametric amplifier, enabling more than doubled reach in dispersion-managed transmission. © ...

  7. Railway vehicle performance optimisation using virtual homologation

    Science.gov (United States)

    Magalhães, H.; Madeira, J. F. A.; Ambrósio, J.; Pombo, J.

    2016-09-01

    Unlike regular automotive vehicles, which are designed to travel in different types of roads, railway vehicles travel mostly in the same route during their life cycle. To accept the operation of a railway vehicle in a particular network, a homologation process is required according to local standard regulations. In Europe, the standards EN 14363 and UIC 518, which are used for railway vehicle acceptance, require on-track tests and/or numerical simulations. An important advantage of using virtual homologation is the reduction of the high costs associated with on-track tests by studying the railway vehicle performance in different operation conditions. This work proposes a methodology for the improvement of railway vehicle design with the objective of its operation in selected railway tracks by using optimisation. The analyses required for the vehicle improvement are performed under control of the optimisation method global and local optimisation using direct search. To quantify the performance of the vehicle, a new objective function is proposed, which includes: a Dynamic Performance Index, defined as a weighted sum of the indices obtained from the virtual homologation process; the non-compensated acceleration, which is related to the operational velocity; and a penalty associated with cases where the vehicle presents an unacceptable dynamic behaviour according to the standards. Thus, the optimisation process intends not only to improve the quality of the vehicle in terms of running safety and ride quality, but also to increase the vehicle availability via the reduction of the time for a journey while ensuring its operational acceptance under the standards. The design variables include the suspension characteristics and the operational velocity of the vehicle, which are allowed to vary in an acceptable range of variation. The results of the optimisation lead to a global minimum of the objective function in which the suspensions characteristics of the vehicle are

  8. A STUDY ON OPTIMISATION OF RESOURCES FOR MULTIPLE PROJECTS BY USING PRIMAVERA

    Directory of Open Access Journals (Sweden)

    B. S. K. REDDY

    2015-02-01

    Full Text Available Resources play vital role in construction projects. The performance of construction industry depends chiefly on how best the resources are managed. Optimisation play pivotal role in resource management, but task is highly haphazard and chaotic under the influence of complexities and vastness. Management always looks for optimum utility of resources available with them. Hence, the project management has got important place especially in resource allocation and smooth functioning with allocated budget. To achieve these goals and to exercise enhance optimisation certain tools are used for resource allocation optimally. Present work illustrates resource optimisation exercises on two ongoing projects in Dubai, UAE. Resource demands of project A & B are individually levelled and observed cumulative requirement is 17475. In other option demands of projects A & B are aggregated and then together levelled, the necessary resource observed is 16490. Comparison of individually levelled and then combined option with aggregated and then levelled clearly indicates reduction in demand of resources by 5.65% in later option, which could be best considered for economy.

  9. Source reconstruction using a bilevel optimisation method with a smooth weighted distance function

    CERN Document Server

    Brännström, Niklas

    2016-01-01

    We consider a bilevel optimatisation method for inverse linear atmospheric dispersion problems where both linear and non-linear model parameters are to be determined. We propose that a smooth weighted Mahalanobis distance function is used and derive sufficient conditions for when the follower problem has local strict convexity. A few toy-models are presented where local strict convexity and ill-posedness of the inverse problem are explored, indeed the smooth distance function is compared and contrasted to linear and piecewise linear ones. The bilevel optimisation method is then applied to sensor data collected in wind tunnel experiments of a neutral gas release in urban environments (MODITIC).

  10. Automatic optimisation of gamma dose rate sensor networks: The DETECT Optimisation Tool

    DEFF Research Database (Denmark)

    Helle, K.B.; Müller, T.O.; Astrup, Poul;

    2014-01-01

    chosen using regular grids or according to administrative constraints. Nowadays, however, the choice can be based on more realistic risk assessment, as it is possible to simulate potential radioactive plumes. To support sensor planning, we developed the DETECT Optimisation Tool (DOT) within the scope...... monitoring network for early detection of radioactive plumes or for the creation of dose maps. The DOT is implemented as a stand-alone easy-to-use JAVA-based application with a graphical user interface and an R backend. Users can run evaluations and optimisations, and display, store and download the results...

  11. Methods for Optimisation of the Laser Cutting Process

    DEFF Research Database (Denmark)

    Dragsted, Birgitte

    This thesis deals with the adaptation and implementation of various optimisation methods, in the field of experimental design, for the laser cutting process. The problem in optimising the laser cutting process has been defined and a structure for at Decision Support System (DSS......) for the optimisation of the laser cutting process has been suggested. The DSS consists of a database with the currently used and old parameter settings. Also one of the optimisation methods has been implemented in the DSS in order to facilitate the optimisation procedure for the laser operator. The Simplex Method has...... been adapted in two versions. A qualitative one, that by comparing the laser cut items optimise the process and a quantitative one that uses a weighted quality response in order to achieve a satisfactory quality and after that maximises the cutting speed thus increasing the productivity of the process...

  12. Design Optimisation and Conrol of a Pilot Operated Seat Valve

    DEFF Research Database (Denmark)

    Nielsen, Brian; Andersen, Torben Ole; Hansen, Michael Rygaard

    2004-01-01

    The paper gives an approach for optimisation of the bandwidth of a pilot operated seat valve for mobile applications. Physical dimensions as well as parameters of the implemented control loop are optimised simultaneously. The frequency response of the valve varies as a function of the pressure drop...... across the valve, and it is found to be necessary to scale the controller parameters in the optimised design as a function of pressure drop....

  13. Mechatronic System Design Based On An Optimisation Approach

    DEFF Research Database (Denmark)

    Andersen, Torben Ole; Pedersen, Henrik Clemmensen; Hansen, Michael Rygaard

    The envisaged objective of this paper project is to extend the current state of the art regarding the design of complex mechatronic systems utilizing an optimisation approach. We propose to investigate a novel framework for mechatronic system design. The novelty and originality being the use...... of optimisation techniques. The methods used to optimise/design within the classical disciplines will be identified and extended to mechatronic system design....

  14. Bt pollen dispersal and Bt kernel mosaics: integrity of non-Bt refugia for lepidopteran resistance management in maize.

    Science.gov (United States)

    Burkness, Eric C; Hutchison, W D

    2012-10-01

    Field trials were conducted at Rosemount, MN in 2009 and 2010, to measure pollen movement from Bt corn to adjacent blocks of non-Bt refuge corn. As the use of Bt corn hybrids continues to increase in the United States, and new insect resistance management (IRM) plans are implemented, it is necessary to measure the efficacy of these IRM plans. In Minnesota, the primary lepidopteran pests of corn include the European corn borer, Ostrinia nubilalis (Hübner) and corn earworm, Helicoverpa zea (Boddie). The primary IRM plan in transgenic corn is the use of hybrids expressing a high dose of insecticidal proteins and an insect refuge containing hybrids not expressing insecticidal proteins that produce susceptible insects. Wind-assisted pollen movement in corn occurs readily, and is the primary method of pollination for corn. The combination of pollen movement and viability determines the potential for cross pollination of refuge corn. In 2009 and 2010, cross pollination occurred with the highest frequency on the north and east sides of Bt corn fields, but was found at some level in all directions. Highest levels of cross pollination (75%) were found within the first four rows (3 m) of non-Bt corn adjacent to Bt corn, and in general decreasing levels of cross pollination were found the further the non-Bt corn was planted from the Bt corn. A mosaic of Bt cross-pollinated kernels was found throughout the ear, but in both years the ear tip had the highest percentage of cross-pollinated kernels; this pattern may be linked to the synchrony of pollen shed and silking between Bt and non-Bt corn hybrids. The dominant wind direction in both years was from WNW. However, in both years, there were also prevailing winds from SSW and WSW. Further studies are needed to quantify Bt levels in cross-pollinated kernels, measure the Bt dose of such kernels and associated lepidopteran pest survival, and measure the impact of Bt pollen on lepidopteran pests, particularly when considering the

  15. Best cost country sourcing : optimising the value of conveyor belts for coal mining companies

    OpenAIRE

    2014-01-01

    M.Com. (Business Management) Background Best cost country sourcing is a relatively new concept and not many organisations are utilising this specific process nor are they optimising this as their sourcing strategy. Best cost country sourcing is one of the most profound sourcing processes available, and it has the ability to increase an organisation’s efficiency and effectiveness if implemented correctly. Purpose The purpose of this study is to determine if best cost country sourcing should...

  16. State of the Art Review for Applying Computational Intelligence and Machine Learning Techniques to Portfolio Optimisation

    CERN Document Server

    Hurwitz, Evan

    2009-01-01

    Computational techniques have shown much promise in the field of Finance, owing to their ability to extract sense out of dauntingly complex systems. This paper reviews the most promising of these techniques, from traditional computational intelligence methods to their machine learning siblings, with particular view to their application in optimising the management of a portfolio of financial instruments. The current state of the art is assessed, and prospective further work is assessed and recommended

  17. Improving Vector Evaluated Particle Swarm Optimisation by incorporating nondominated solutions.

    Science.gov (United States)

    Lim, Kian Sheng; Ibrahim, Zuwairie; Buyamin, Salinda; Ahmad, Anita; Naim, Faradila; Ghazali, Kamarul Hawari; Mokhtar, Norrima

    2013-01-01

    The Vector Evaluated Particle Swarm Optimisation algorithm is widely used to solve multiobjective optimisation problems. This algorithm optimises one objective using a swarm of particles where their movements are guided by the best solution found by another swarm. However, the best solution of a swarm is only updated when a newly generated solution has better fitness than the best solution at the objective function optimised by that swarm, yielding poor solutions for the multiobjective optimisation problems. Thus, an improved Vector Evaluated Particle Swarm Optimisation algorithm is introduced by incorporating the nondominated solutions as the guidance for a swarm rather than using the best solution from another swarm. In this paper, the performance of improved Vector Evaluated Particle Swarm Optimisation algorithm is investigated using performance measures such as the number of nondominated solutions found, the generational distance, the spread, and the hypervolume. The results suggest that the improved Vector Evaluated Particle Swarm Optimisation algorithm has impressive performance compared with the conventional Vector Evaluated Particle Swarm Optimisation algorithm.

  18. Robust Optimisation Approach for Vehicle Routing Problems with Uncertainty

    Directory of Open Access Journals (Sweden)

    Liang Sun

    2015-01-01

    Full Text Available We formulated a solution procedure for vehicle routing problems with uncertainty (VRPU for short with regard to future demand and transportation cost. Unlike E-SDROA (expectation semideviation robust optimisation approach for solving the proposed problem, the formulation focuses on robust optimisation considering situations possibly related to bidding and capital budgets. Besides, numerical experiments showed significant increments in the robustness of the solutions without much loss in solution quality. The differences and similarities of the robust optimisation model and existing robust optimisation approaches were also compared.

  19. Hamiltonian dynamics of breathers with third-order dispersion

    OpenAIRE

    Mookherjea, Shayan; Yariv, Amnon

    2001-01-01

    We present a nonperturbative analysis of certain dynamical aspects of breathers (dispersion-managed solitons) including the effects of third-order dispersion. The analysis highlights the similarities to and differences from the well-known analogous procedures for second-order dispersion. We discuss in detail the phase-space evolution of breathers in dispersion-managed systems in the presence of third-order dispersion.

  20. Biorefinery plant design, engineering and process optimisation

    DEFF Research Database (Denmark)

    Holm-Nielsen, Jens Bo; Ehimen, Ehiazesebhor Augustine

    2014-01-01

    applicable for the planning and upgrading of intended biorefinery systems, and includes discussions on the operation of an existing lignocellulosic-based biorefinery platform. Furthermore, technical considerations and tools (i.e., process analytical tools) which could be applied to optimise the operations......Before new biorefinery systems can be implemented, or the modification of existing single product biomass processing units into biorefineries can be carried out, proper planning of the intended biorefinery scheme must be performed initially. This chapter outlines design and synthesis approaches...

  1. SIROCCO. Silent rotors by acoustic optimisation

    Energy Technology Data Exchange (ETDEWEB)

    Schepers, J.G.; Curvers, A. [ECN Wind Energy, Petten (Netherlands); Oerlemans, S. [National Aerospace Laboratory NLR, Amsterdam (Netherlands); Braun, K.; Lutz, T.; Herrig, A.; Wuerz, W. [University of Stuttgart, Stuttgart (Germany); Matesanz, A.; Garcillan, L. [Gamesa Eolica, Madrid (Spain); Fisher, M.; Koegler, K.; Maeder, T. [GE Wind Energy/GE Global Research (United States)

    2007-07-15

    In this paper the results from the European 5th Framework project 'SIROCCO' are described. The project started in January 2003 and will end in August 2007. The main aim of the SIROCCO project is to reduce wind-turbine aerodynamic noise significantly while maintaining the aerodynamic performance. This is achieved by designing new acoustically and aerodynamically optimised airfoils for the outer part of the blade. The project focussed primarily on reducing trailing edge noise, which was broadly believed to be the dominant noise mechanism of modern wind turbines.

  2. The remote management optimizes the geothermal district heating network of Chevilly-Larue and l'Hay-les-Roses; La telegestion optimise le reseau de chaleur geothermique de Chevilly-Larue et l'Hay-les-Roses

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2003-11-01

    The installation of a new remote control system for the management of the district heating network of Chevilly-Larue and l'Hay-les-Roses cities (Paris region, France) has permitted to optimize the use of the different energy sources (geothermal, cogeneration, fuel-oil and natural gas) supplying the network and to better adjust the control of the production means. (J.S.)

  3. Optimising Antibiotic Usage to Treat Bacterial Infections

    Science.gov (United States)

    Paterson, Iona K.; Hoyle, Andy; Ochoa, Gabriela; Baker-Austin, Craig; Taylor, Nick G. H.

    2016-11-01

    The increase in antibiotic resistant bacteria poses a threat to the continued use of antibiotics to treat bacterial infections. The overuse and misuse of antibiotics has been identified as a significant driver in the emergence of resistance. Finding optimal treatment regimens is therefore critical in ensuring the prolonged effectiveness of these antibiotics. This study uses mathematical modelling to analyse the effect traditional treatment regimens have on the dynamics of a bacterial infection. Using a novel approach, a genetic algorithm, the study then identifies improved treatment regimens. Using a single antibiotic the genetic algorithm identifies regimens which minimise the amount of antibiotic used while maximising bacterial eradication. Although exact treatments are highly dependent on parameter values and initial bacterial load, a significant common trend is identified throughout the results. A treatment regimen consisting of a high initial dose followed by an extended tapering of doses is found to optimise the use of antibiotics. This consistently improves the success of eradicating infections, uses less antibiotic than traditional regimens and reduces the time to eradication. The use of genetic algorithms to optimise treatment regimens enables an extensive search of possible regimens, with previous regimens directing the search into regions of better performance.

  4. Ant Colony Optimisation for Backward Production Scheduling

    Directory of Open Access Journals (Sweden)

    Leandro Pereira dos Santos

    2012-01-01

    Full Text Available The main objective of a production scheduling system is to assign tasks (orders or jobs to resources and sequence them as efficiently and economically (optimised as possible. Achieving this goal is a difficult task in complex environment where capacity is usually limited. In these scenarios, finding an optimal solution—if possible—demands a large amount of computer time. For this reason, in many cases, a good solution that is quickly found is preferred. In such situations, the use of metaheuristics is an appropriate strategy. In these last two decades, some out-of-the-shelf systems have been developed using such techniques. This paper presents and analyses the development of a shop-floor scheduling system that uses ant colony optimisation (ACO in a backward scheduling problem in a manufacturing scenario with single-stage processing, parallel resources, and flexible routings. This scenario was found in a large food industry where the corresponding author worked as consultant for more than a year. This work demonstrates the applicability of this artificial intelligence technique. In fact, ACO proved to be as efficient as branch-and-bound, however, executing much faster.

  5. Noise aspects at aerodynamic blade optimisation projects

    Energy Technology Data Exchange (ETDEWEB)

    Schepers, J.G. [Netherlands Energy Research Foundation, Petten (Netherlands)

    1997-12-31

    This paper shows an example of an aerodynamic blade optimisation, using the program PVOPT. PVOPT calculates the optimal wind turbine blade geometry such that the maximum energy yield is obtained. Using the aerodynamic optimal blade design as a basis, the possibilities of noise reduction are investigated. The aerodynamic optimised geometry from PVOPT is the `real` optimum (up to the latest decimal). The most important conclusion from this study is, that it is worthwhile to investigate the behaviour of the objective function (in the present case the energy yield) around the optimum: If the optimum is flat, there is a possibility to apply modifications to the optimum configuration with only a limited loss in energy yield. It is obvious that the modified configurations emits a different (and possibly lower) noise level. In the BLADOPT program (the successor of PVOPT) it will be possible to quantify the noise level and hence to assess the reduced noise emission more thoroughly. At present the most promising approaches for noise reduction are believed to be a reduction of the rotor speed (if at all possible), and a reduction of the tip angle by means of low lift profiles, or decreased twist at the outboard stations. These modifications were possible without a significant loss in energy yield. (LN)

  6. Smart Battery Thermal Management for PHEV Efficiency Une gestion avancée de la thermique de la batterie basse tension de traction pour optimiser l’efficacité d’un véhicule hybride électrique rechargeable

    Directory of Open Access Journals (Sweden)

    Lefebvre L.

    2013-03-01

    Full Text Available A smart battery thermal management is crucial for vehicle performances and battery lifetime targets achievements when electric and plug-in hybrid electric vehicles are concerned. The thermal system needs to be designed and tuned in accordance and compromises with powertrain and vehicle requirements, battery pack architecture, environmental constraints, costs, weight, etc., in a process that will be described in the first part of this paper. Among the portfolio of battery thermal management technologies, these items will be illustrated by two examples: thermal management by cabin air and by refrigerant in a direct cooling, enlightening a decision process. A simplified battery thermo-electric simulation model, which the second part of our work focuses on, has been built, first for both thermal and energetic balance dimensioning of the battery thermal management system. Examples are given on these two perspectives. That simplified simulation model has also identified some promising thermal management strategies for improving vehicle efficiency and performances and battery lifetime. That is the task of the last part of this paper. Battery heating has shown opportunities for improving energy and power availability at cold conditions and, thus, electric drive availability and autonomy. Post-cooling the battery at the end of a journey and its pre-conditioning before the following journey, not only improve vehicle efficiency, electric drive availability and autonomy, but also enhance battery lifetime and compromises with cabin thermal comfort. Others promising strategies optimizing the relation between vehicle performances and battery lifetime are still under investigations. L’atteinte des performances et des prestations requises d’un véhicule électrique ou hybride électrique rechargeable nécessite un thermomanagement intelligent de la batterie basse tension de traction. Ce thermomanagement est incontournable pour respecter dans le même temps

  7. ESTRATEGIC MANAGEMENT DURING THE TRANSICION PERIOD TO OPTIMISE PRODUCTIVITY AND REPRODUCTIVE PERFORMANCE IN THE DAIRY HERD MANEJO ESTRATÉGICO DURANTE EL PERIODO DE TRANSICIÓN PARA OPTIMIZAR LA PRODUCCIÓN Y EL COMPORTAMIENTO REPRODUCTIVO GANADO LECHERO

    Directory of Open Access Journals (Sweden)

    Risco Carlos

    2009-05-01

    Full Text Available In dairy herds, the interval between calving and pregnancy depend on many factors including preparation of the cow for calving, dietary management before and after calving. Factors such as hypocalcemia and body condition are determinant in the presentation of postpartum pathologies and ovarian activity resumption. Additionally, management of the dairy cattle should include fixed time artificial insemination protocols to increase the number of animals bred close to the voluntary waiting period and pregnancy rates. The following review will address topics related with cattle body condition and puerperal hypocalcemia that affect negatively postpartum reproductive performance and also will, address management alternatives to improve pregnancy rates y to reduce days open.Los días abiertos en el hato lechero dependen de muchos factores, dentro de los cuales se debe considerar, la preparación de la vaca preparto incluyendo el manejo dietario pre y postparto. Factores como la hipocalcemia y la condición corporal son determinantes en la presentación de patologías puerperales y en el inicio de la ciclicidad. Adicional a este manejo, se debe considerar la utilización de protocolos de inseminación a tiempo fijo que incrementa el número de animales servidos cerca del tiempo voluntario de espera y genera un incremento en las tasas de preñez. La presente revisión discutirá temas relacionados con la condición corporal y la presentación de hipocalcemia puerperal que afectan la fertilidad posparto de la vaca, así como alternativas para mejorar las tasa de preñez y reducir los días abiertos.

  8. Optimization of the ALARA principle for the management and elimination of very low level radioactive waste; Optimisation de principe ALARA en matiere de gestion et d'elimination de dechets radioactifs de tres faible activite

    Energy Technology Data Exchange (ETDEWEB)

    Regibeau, A.; Caussin, J.; De Spiegeleer, M.; Poelaert, M. [Univ. Catholique de Louvain, Service de Radioprotection, Louvain-la-Neuve (France)

    1992-07-01

    The management of low level solid radioactive waste, as proposed by the National Institutions, cannot be applied to waste produced in a University environment. The report from the Universite Catholique de Louvain (UCL) states the reasons and the procedure which has been set up by the radioprotection department. It describes the storage facilities and details the quality control tests carried out during the elimination process. The report outlines the difficulties encountered by the radioprotection departments due to the absence of normes for the disposal of solid radioactive waste. (author)

  9. Multi-objective evolutionary optimisation for product design and manufacturing

    CERN Document Server

    2011-01-01

    Presents state-of-the-art research in the area of multi-objective evolutionary optimisation for integrated product design and manufacturing Provides a comprehensive review of the literature Gives in-depth descriptions of recently developed innovative and novel methodologies, algorithms and systems in the area of modelling, simulation and optimisation

  10. Optimisation of GnRH antagonist use in ART

    NARCIS (Netherlands)

    Hamdine, O.

    2014-01-01

    This thesis focuses on the optimisation of controlled ovarian stimulation for IVF using exogenous FSH and GnRH antagonist co-treatment, by studying the timing of the initiation of GnRH antagonist co-medication and the role of ovarian reserve markers in optimising ovarian response and reproductive ou

  11. Aerodynamic shape parameterisation and optimisation of novel configurations

    NARCIS (Netherlands)

    Straathof, M.H.; Van Tooren, M.J.L.; Voskuijl, M.; Koren, B.

    2008-01-01

    The Multi-Disciplinary Design Optimisation (MDO) process can be supported by partial automation of analysis and optimisation steps. Design and Engineering Engines (DEE) are useful concepts to structure this type of automation. Within the DEE, a product can be parameterically defined using Knowledge

  12. DACIA LOGAN LIVE AXLE OPTIMISATION USING COMPUTER GRAPHICS

    Directory of Open Access Journals (Sweden)

    KIRALY Andrei

    2017-05-01

    Full Text Available The paper presents some contributions to the calculus and optimisation of a live axle used at Dacia Logan using computer graphics software for creating the model and afterwards using FEA evaluation to determine the effectiveness of the optimisation. Thus using specialized computer software, a simulation is made and the results were compared to the measured real prototype.

  13. There, and Back Again Quantum Theory and Global Optimisation

    CERN Document Server

    Audenaert, K M R

    2004-01-01

    We consider a problem in quantum theory that can be formulated as an optimisation problem and present a global optimisation algorithm for solving it, the foundation of which relies in turn on a theorem from quantum theory. To wit, we consider the maximal output purity $\

  14. Kriging based robust optimisation algorithm for minimax problems in electromagnetics

    Directory of Open Access Journals (Sweden)

    Li Yinjiang

    2016-12-01

    Full Text Available The paper discusses some of the recent advances in kriging based worst-case design optimisation and proposes a new two-stage approach to solve practical problems. The efficiency of the infill points allocation is improved significantly by adding an extra layer of optimisation enhanced by a validation process.

  15. GAOS: Spatial optimisation of crop and nature within agricultural fields

    NARCIS (Netherlands)

    Bruin, de S.; Janssen, H.; Klompe, A.; Lerink, P.; Vanmeulebrouk, B.

    2010-01-01

    This paper proposes and demonstrates a spatial optimiser that allocates areas of inefficient machine manoeuvring to field margins thus improving the use of available space and supporting map-based Controlled Traffic Farming. A prototype web service (GAOS) allows farmers to optimise tracks within the

  16. Parameter Optimisation for the Behaviour of Elastic Models over Time

    DEFF Research Database (Denmark)

    Mosegaard, Jesper

    2004-01-01

    Optimisation of parameters for elastic models is essential for comparison or finding equivalent behaviour of elastic models when parameters cannot simply be transferred or converted. This is the case with a large range of commonly used elastic models. In this paper we present a general method...... that will optimise parameters based on the behaviour of the elastic models over time....

  17. Multi-criterion scantling optimisation of cruise ships

    OpenAIRE

    2010-01-01

    A numerical tool for the optimisation of the scantlings of a ship is extended by considering production cost, weight and moment of iner tia in the objective function. A multi-criteria optimisation of a passenger ship is conducted to illustrate the analysis process. Pareto frontiers are obtained and results are verified with Bureau Veritas rules.

  18. A reliability-based maintenance technicians' workloads optimisation model with stochastic consideration

    Science.gov (United States)

    Ighravwe, D. E.; Oke, S. A.; Adebiyi, K. A.

    2016-12-01

    The growing interest in technicians' workloads research is probably associated with the recent surge in competition. This was prompted by unprecedented technological development that triggers changes in customer tastes and preferences for industrial goods. In a quest for business improvement, this worldwide intense competition in industries has stimulated theories and practical frameworks that seek to optimise performance in workplaces. In line with this drive, the present paper proposes an optimisation model which considers technicians' reliability that complements factory information obtained. The information used emerged from technicians' productivity and earned-values using the concept of multi-objective modelling approach. Since technicians are expected to carry out routine and stochastic maintenance work, we consider these workloads as constraints. The influence of training, fatigue and experiential knowledge of technicians on workload management was considered. These workloads were combined with maintenance policy in optimising reliability, productivity and earned-values using the goal programming approach. Practical datasets were utilised in studying the applicability of the proposed model in practice. It was observed that our model was able to generate information that practicing maintenance engineers can apply in making more informed decisions on technicians' management.

  19. Implementation of sustainable sanitation in existing urban areas: long-term strategies for an optimised solution.

    Science.gov (United States)

    Kaufmann, I; Meyer, T; Kalsch, M; Schmitt, T G; Hamacher, H W

    2007-01-01

    If technologies for decentralised sanitation and reuse (DESAR) and for natural stormwater management should at least partially replace existing systems, then intensive reconstruction work becomes essential. A conversion can only be realised successively over a long period due to high construction and financial expenses and requires new strategies. This paper presents the development and practical implementation of a mathematical tool to find an optimised strategy for the realisation of alternative and more decentralised drainage and sanitation concepts in existing urban areas. The succession of construction measures (e.g. the implementation of decentralised greywater recycling) for the whole period of consideration is determined based upon a mathematical optimisation model on the condition that the favoured future state is known. The model describes the complex interdependencies of the urban water and nutrient cycle and enables the minimisation of both financial efforts and ecological impacts on the way toward the future state. The results of the implementation for a rural area in Germany show that the mathematical optimisation is an adequate instrument to support decision-making processes in finding strategies for the realisation of sustainable urban water management.

  20. Modified cuckoo search: A new gradient free optimisation algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Walton, S., E-mail: 512465@swansea.ac.uk [College of Engineering, Swansea University, Swansea SA2 8PP, Wales (United Kingdom); Hassan, O.; Morgan, K.; Brown, M.R. [College of Engineering, Swansea University, Swansea SA2 8PP, Wales (United Kingdom)

    2011-09-15

    Highlights: > Modified cuckoo search (MCS) is a new gradient free optimisation algorithm. > MCS shows a high convergence rate, able to outperform other optimisers. > MCS is particularly strong at high dimension objective functions. > MCS performs well when applied to engineering problems. - Abstract: A new robust optimisation algorithm, which can be regarded as a modification of the recently developed cuckoo search, is presented. The modification involves the addition of information exchange between the top eggs, or the best solutions. Standard optimisation benchmarking functions are used to test the effects of these modifications and it is demonstrated that, in most cases, the modified cuckoo search performs as well as, or better than, the standard cuckoo search, a particle swarm optimiser, and a differential evolution strategy. In particular the modified cuckoo search shows a high convergence rate to the true global minimum even at high numbers of dimensions.

  1. Optimisation of a Crossdocking Distribution Centre Simulation Model

    CERN Document Server

    Adewunmi, Adrian

    2010-01-01

    This paper reports on continuing research into the modelling of an order picking process within a Crossdocking distribution centre using Simulation Optimisation. The aim of this project is to optimise a discrete event simulation model and to understand factors that affect finding its optimal performance. Our initial investigation revealed that the precision of the selected simulation output performance measure and the number of replications required for the evaluation of the optimisation objective function through simulation influences the ability of the optimisation technique. We experimented with Common Random Numbers, in order to improve the precision of our simulation output performance measure, and intended to use the number of replications utilised for this purpose as the initial number of replications for the optimisation of our Crossdocking distribution centre simulation model. Our results demonstrate that we can improve the precision of our selected simulation output performance measure value using C...

  2. Open Cut resource Optimisation as applied to coal

    Institute of Scientific and Technical Information of China (English)

    Martin L.Smith

    2007-01-01

    Pit optimisation is the earliest and most established application of its kind in the minerals industry,but this has been primarily driven by metal,not coal.Coal has the same financiaI drivers for resource optimisation as does the metalliferous industry,yet pit optimisation is not common practice.Why? The following discussion presents the basics of pit optimisation as they relate to coal and illustrates how a technology developed for massive deposits is not suitable for thin.multi-seam deposits where mine planning is often driven more by product quality than by value drivers such as Net Present Value.An alternative methodology is presented that takes advantage of the data structure of bedded deposits to optimise resource recovery in terms of a production schedule that meets constraints on coal quality.

  3. Dispersed Indeterminacy

    CERN Document Server

    Fayngold, Moses

    2013-01-01

    A state of a single particle can be represented by a quantum blob in the corresponding phase space, or a patch (granule) in its 2-D subspace. Its area is frequently stated to be no less than, implying that such a granule is an indivisible quantum of the 2-D phase space. But this is generally not true, as is evident, for instance, from representation of some states in the basis of innately discrete observables like angular momentum. Here we consider some dispersed states involving the evanescent waves different from that in the total internal reflection. Such states are represented by a set of separated granules with individual areas, but with the total indeterminacy . An idealized model has a discrete Wigner function and is described by a superposition of eigenstates with eigenvalues and forming an infinite periodic array of dots on the phase plane. The question about the total indeterminacy in such state is discussed. We argue that the eigenstates corresponding to the considered EW cannot be singled out by a...

  4. An illness-focused interactive booklet to optimise management and medication for childhood fever and infections in out-of-hours primary care: study protocol for a cluster randomised trial.

    Science.gov (United States)

    de Bont, Eefje G P M; Dinant, Geert-Jan; Elshout, Gijs; van Well, Gijs; Francis, Nick A; Winkens, Bjorn; Cals, Jochen W L

    2016-11-17

    Fever is the most common reason for a child to be taken to a general practitioner (GP), especially during out-of-hours care. It is mostly caused by self-limiting infections. However, antibiotic prescription rates remain high, especially during out-of-hours care. Anxiety and lack of knowledge among parents, and perceived pressure to prescribe antibiotics amongst GPs, are important determinants of excessive antibiotic prescriptions. An illness-focused interactive booklet has the potential to improve this by providing parents with information about fever self-management strategies. The aim of this study is to develop and determine the effectiveness of an interactive booklet on management of children presenting with fever at Dutch GP out-of-hours cooperatives. We are conducting a cluster randomised controlled trial (RCT) with 20 GP out-of-hours cooperatives randomised to 1 of 2 arms: GP access to the illness-focused interactive booklet or care as usual. GPs working at intervention sites will have access to the booklet, which was developed in a multistage process. It consists of a traffic light system for parents on how to respond to fever-related symptoms, as well as information on natural course of infections, benefits and harms of (antibiotic) medications, self-management strategies and 'safety net' instructions. Children parent-reported or physician-measured fever are eligible for inclusion. The primary outcome is antibiotic prescribing during the initial consultation. Secondary outcomes are (intention to) (re)consult, antibiotic prescriptions during re-consultations, referrals, parental satisfaction and reassurance. In 6 months, 20,000 children will be recruited to find a difference in antibiotic prescribing rates of 25% in the control group and 19% in the intervention group. Statistical analysis will be performed using descriptive statistics and by fitting two-level (GP out-of-hours cooperative and patient) random intercept logistic regression models. This will

  5. Optimal risky bidding strategy for a generating company by self-organising hierarchical particle swarm optimisation

    Energy Technology Data Exchange (ETDEWEB)

    Boonchuay, Chanwit [Energy Field of Study, School of Environment, Resources and Development, Asian Institute of Technology (Thailand); Ongsakul, Weerakorn, E-mail: ongsakul@ait.asi [Energy Field of Study, School of Environment, Resources and Development, Asian Institute of Technology (Thailand)

    2011-02-15

    In this paper, an optimal risky bidding strategy for a generating company (GenCo) by self-organising hierarchical particle swarm optimisation with time-varying acceleration coefficients (SPSO-TVAC) is proposed. A significant risk index based on mean-standard deviation ratio (MSR) is maximised to provide the optimal bid prices and quantities. The Monte Carlo (MC) method is employed to simulate rivals' behaviour in competitive environment. Non-convex operating cost functions of thermal generating units and minimum up/down time constraints are taken into account. The proposed bidding strategy is implemented in a multi-hourly trading in a uniform price spot market and compared to other particle swarm optimisation (PSO). Test results indicate that the proposed SPSO-TVAC approach can provide a higher MSR than the other PSO methods. It is potentially applicable to risk management of profit variation of GenCo in spot market.

  6. Biofuels carbon footprints: Whole-systems optimisation for GHG emissions reduction.

    Science.gov (United States)

    Zamboni, Andrea; Murphy, Richard J; Woods, Jeremy; Bezzo, Fabrizio; Shah, Nilay

    2011-08-01

    A modelling approach for strategic design of ethanol production systems combining lifecycle analysis (LCA) and supply chain optimisation (SCO) can significantly contribute to assess their economic and environmental sustainability and to guide decision makers towards a more conscious implementation of ad hoc farming and processing practices. Most models applications so far have been descriptive in nature; the model proposed in this work is "normative" in that it aims to guide actions towards optimal outcomes (e.g. optimising the nitrogen balance through the whole supply chain). The modelling framework was conceived to steer strategic policies through a geographically specific design process considering economic and environmental criteria. Results shows how a crop management strategy devised from a whole systems perspective can significantly contribute to mitigate global warming even in first generation technologies.

  7. Load optimised piezoelectric generator for powering battery-less TPMS

    Science.gov (United States)

    Blažević, D.; Kamenar, E.; Zelenika, S.

    2013-05-01

    The design of a piezoelectric device aimed at harvesting the kinetic energy of random vibrations on a vehicle's wheel is presented. The harvester is optimised for powering a Tire Pressure Monitoring System (TPMS). On-road experiments are performed in order to measure the frequencies and amplitudes of wheels' vibrations. It is hence determined that the highest amplitudes occur in an unperiodic manner. Initial tests of the battery-less TPMS are performed in laboratory conditions where tuning and system set-up optimization is achieved. The energy obtained from the piezoelectric bimorph is managed by employing the control electronics which converts AC voltage to DC and conditions the output voltage to make it compatible with the load (i.e. sensor electronics and transmitter). The control electronics also manages the sleep/measure/transmit cycles so that the harvested energy is efficiently used. The system is finally tested in real on-road conditions successfully powering the pressure sensor and transmitting the data to a receiver in the car cockpit.

  8. Modelling the dispersion of treated wastewater in a shallow coastal wind-driven environment, Geographe Bay, Western Australia: implications for environmental management.

    Science.gov (United States)

    Dunn, Ryan J K; Zigic, Sasha; Shiell, Glenn R

    2014-10-01

    Numerical models are useful for predicting the transport and fate of contaminants in dynamic marine environments, and are increasingly a practical solution to environmental impact assessments. In this study, a three-dimensional hydrodynamic model and field data were used to validate a far-field dispersion model that, in turn, was used to determine the fate of treated wastewater (TWW) discharged to the ocean via a submarine ocean outfall under hypothetical TWW flows. The models were validated with respect to bottom and surface water current speed and direction, and in situ measurements of total nitrogen and faecal coliforms. Variations in surface and bottom currents were accurately predicted by the model as were nutrient and coliform concentrations. Results indicated that the ocean circulation was predominately wind driven, evidenced by relatively small oscillations in the current speeds along the time-scale of the tide, and that dilution mixing zones were orientated in a predominantly north-eastern direction from the outfall and parallel to the coastline. Outputs of the model were used to determine the 'footprint' of the TWW plume under a differing discharge scenario and, particularly, whether the resultant changes in TWW contaminants, total nitrogen and faecal coliforms would meet local environmental quality objectives (EQO) for ecosystem integrity, shellfish harvesting and primary recreation. Modelling provided a practical solution for predicting the dilution of contaminants under a hypothetical discharge scenario and a means for determining the aerial extent of exclusion zones, where the EQOs for shellfish harvesting and primary recreation may not always be met. Results of this study add to the understanding of regional discharge conditions and provide a practical case study for managing impacts to marine environments under a differing TWW discharge scenario, in comparison to an existing scenario.

  9. Delivering dispersion-managed soliton and Q-switched pulse in fiber laser based on graphene and nonlinear optical loop mirror

    Science.gov (United States)

    Wang, W. B.; Wang, F.; Yu, Q.; Zhang, X.; Lu, Y. X.; Gu, J.

    2016-11-01

    We propose and experimentally demonstrate a bidirectional erbium-doped fiber laser delivering dispersion-managed soliton (DMS) and Q-switched pulse based on a graphene-polyvinyl alcohol (PVA) and nonlinear optical loop mirror (NOLM) saturable absorbers (SAs). In proposed structure, the DMS is achieved in clockwise (CW) direction and Q-switched pulse is obtained in counter-clockwise (CCW) direction. By properly adjusting the intracavity attenuators (ATT) and polarizer controllers (PCs), DMS in the CW direction and Q-switched pulse in the CCW direction can be obtained, respectively or simultaneously. The DMS with full width at half maximum (FWHM) of ~480 fs, signal to noise ratio (SNR) of ~60 dB and repetition frequency about 3.907 MHz is obtained. The Q-switched pulse is established at a pump power of 180 mW with a repetition rate of ~43.5 kHz and FWHM of ~8.18 μs. When the pump power is increased to 700 mW, Q-switched pulse with a repetition rate of ~107.1 kHz and FWHM of ~2.15 μs is generated. When the two type pulses are formed simultaneously, the maximum repetition rate of Q-switched pulse is 55.8 kHz and minimum FWHM is 2.81 μs, the DMS can be formed by properly adjusting PC and ATT in this case. To the best of our knowledge, it is the first time that Q-switched pulse and DMS have been acquired respectively or simultaneously in a fiber laser.

  10. The use of LiDCO based fluid management in patients undergoing hip fracture surgery under spinal anaesthesia: Neck of femur optimisation therapy - targeted stroke volume (NOTTS: study protocol for a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Moran Chris G

    2011-09-01

    Full Text Available Abstract Background Approximately 70,000 patients/year undergo surgery for repair of a fractured hip in the United Kingdom. This is associated with 30-day mortality of 9% and survivors have a considerable length of acute hospital stay postoperatively (median 26 days. Use of oesophageal Doppler monitoring to guide intra-operative fluid administration in hip fracture repair has previously been associated with a reduction in hospital stay of 4-5 days. Most hip fracture surgery is now performed under spinal anaesthesia. Oesophageal Doppler monitoring may be unreliable in the presence of spinal anaesthesia and most patients would not tolerate the probes. An alternative method of guiding fluid administration (minimally-invasive arterial pulse contour analysis has been shown to reduce length of stay in high-risk surgical patients but has never been studied in hip fracture surgery. Methods Single-centre randomised controlled parallel group trial. Randomisation by website using computer generated concealed tables. Setting: University hospital in UK. Participants: 128 patients with acute primary hip fracture listed for operative repair under spinal anaesthesia and aged > 65 years. Intervention: Stroke volume guided intra-operative fluid management. Continuous measurement of SV recorded by a calibrated cardiac output monitor (LiDCOplus. Maintenance fluid and 250 ml colloid boluses given to achieve sustained 10% increases in stroke volume. Control group: fluid administration at the responsible (blinded anaesthetist's discretion. The intervention terminates at the end of the surgical procedure and post-operative fluid management is at the responsible anaesthetist's discretion. Primary outcome: length of acute hospital stay is determined by a blinded team of clinicians. Secondary outcomes include number of complications and total cost of care. Funding NIHR/RfPB: PB-PG-0407-13073. Trial registration number Trial registration: Current Controlled Trials ISRCTN

  11. Specification, Verification and Optimisation of Business Processes

    DEFF Research Database (Denmark)

    Herbert, Luke Thomas

    to model checking. This allows for a rich set of both qualitative and quantitative properties of a business process to be precisely determined in an automated fashion directly from the model of the business process. A number of advanced applications of this framework are presented which allow for automated...... Model and Notation (BPMN). The automated analysis of business processes is done by means of quantitative probabilistic model checking which allows verification of validation and performance properties through use of an algorithm for the translation of business process models into a format amenable......This thesis develops a unified framework wherein to specify, verify and optimise stochastic business processes. This framework provides for the modelling of business processes via a mathematical structure which captures business processes as a series of connected activities. This structure...

  12. FEM Optimisation of Spark Plasma Sintering Furnace

    CERN Document Server

    Kellari, Demetrios Vasili

    2013-01-01

    Coupled electro-thermal FEM analysis has been carried out on a sintering furnace used to produce new materials for LHC collimators. The analysis showed there exist margins for improvement of the current process and equipment through minor changes. To optimise the design of the furnace several design changes have been proposed including: optimization of material selection using copper cooling plates, control of convection in cooling plates by lowering the water flow rate, modifying the electrode shape using unsymmetrical electrodes and upgrading the thermal shielding to make use of multilayer graphite shields. The results show that we have a significant improvement in temperature gradient on the plate, from 453 to 258 °C and a reduction in power requirement from 62 to 44 kW.

  13. Niobium Cavity Electropolishing Modelling and Optimisation

    CERN Document Server

    Ferreira, L M A; Forel, S; Shirra, J A

    2013-01-01

    It’s widely accepted that electropolishing (EP) is the most suitable surface finishing process to achieve high performance bulk Nb accelerating cavities. At CERN and in preparation for the processing of the 704 MHz high-beta Superconducting Proton Linac (SPL) cavities a new vertical electropolishing facility has been assembled and a study is on-going for the modelling of electropolishing on cavities with COMSOL® software. In a first phase, the electrochemical parameters were taken into account for a fixed process temperature and flow rate, and are presented in this poster as well as the results obtained on a real SPL single cell cavity. The procedure to acquire the data used as input for the simulation is presented. The modelling procedure adopted to optimise the cathode geometry, aimed at a uniform current density distribution in the cavity cell for the minimum working potential and total current is explained. Some preliminary results on fluid dynamics is also briefly described.

  14. Improving and optimising road pricing in Copenhagen

    DEFF Research Database (Denmark)

    Nielsen, Otto Anker; Larsen, Marie Karen

    2008-01-01

    though quite a number of proposed charging systems have been examined only a few pricing strategies have been investigated. This paper deals with the optimisation of different designs for a road pricing system in the Greater Copenhagen area with respect to temporal and spatial differentiation......The question whether to introduce toll rings or road pricing in Copenhagen has been discussed intensively during the last 10 years. The main results of previous analyses are that none of the systems would make a positive contribution at present, when considered from a socio-economic view. Even...... of the pricing levels. A detailed transport model was used to describe the demand effects. The model was based on data from a real test of road pricing on 500 car drivers. The paper compares the price systems with regard to traffic effects and generalised costs for users and society. It is shown how important...

  15. A code for optimising triplet layout

    CERN Document Server

    Van Riesen-Haupt, Leon; Abelleira, Jose; Cruz Alaniz, Emilia

    2017-01-01

    One of the main challenges when designing final focus systems of particle accelerators is maximising the beam stay clear in the strong quadrupole magnets of the inner triplet. Moreover it is desirable to keep the quadrupoles in the inner triplet as short as possible for space and costs reasons but also to reduce chromaticity and simplify corrections schemes. An algorithm that explores the triplet parameter space to optimise both these aspects was written. It uses thin lenses as a first approximation for a broad parameter scan and MADX for more precise calculations. The thin lens algorithm is significantly faster than a full scan using MADX and relatively precise at indicating the approximate area where the optimum solution lies.

  16. Optimising Signalised Intersection Using Wireless Vehicle Detectors

    DEFF Research Database (Denmark)

    Adjin, Daniel Michael Okwabi; Torkudzor, Moses; Asare, Jack

    Traffic congestion on roads wastes travel times. In this paper, we developed a vehicular traffic model to optimise a signalised intersection in Accra, using wireless vehicle detectors. Traffic volume gathered was extrapolated to cover 2011 and 2016 and were analysed to obtain the peak hour traffic...... volume causing congestion. The intersection was modelled and simulated in Synchro7 as an actuated signalised model using results from the analysed data. The model for morning peak periods gave optimal cycle lengths of 100s and 150s with corresponding intersection delay of 48.9s and 90.6s in 2011 and 2016...... respectively while that for the evening was 55s giving delay of 14.2s and 16.3s respectively. It is shown that the model will improve traffic flow at the intersection....

  17. Simulation and optimisation of turbulence in stellarators

    Energy Technology Data Exchange (ETDEWEB)

    Xanthopoulos, Pavlos; Helander, Per; Turkin, Yuriy; Plunk, Gabriel G.; Bird, Thomas; Proll, Josefine H.E. [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, Wendelsteinstr. 1, 17491 Greifswald (Germany); Mynick, Harry [Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States); Jenko, Frank; Goerler, Tobias; Told, Daniel [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, Boltzmannstr. 2, 85748 Garching (Germany)

    2014-07-01

    In tokamaks and stellarators - two leading types of devices used in fusion research - magnetic field lines trace out toroidal surfaces on which the plasma density and temperature are constant, but turbulent fluctuations carry energy across these surfaces to the wall, thus degrading the plasma confinement. Using petaflop-scale simulations, we calculate for the first time the pattern of turbulent structures forming on stellarator magnetic surfaces, and find striking differences relative to tokamaks. The observed sensitivity of the turbulence to the magnetic geometry suggests that there is room for further confinement improvement, in addition to measures already taken to minimise the laminar transport. With an eye towards fully optimised stellarators, we present a proof-of-principle configuration with substantially reduced turbulence compared to an existing design.

  18. Optimisation of Multilayer Insulation an Engineering Approach

    CERN Document Server

    Chorowski, M; Parente, C; Riddone, G

    2001-01-01

    A mathematical model has been developed to describe the heat flux through multilayer insulation (MLI). The total heat flux between the layers is the result of three distinct heat transfer modes: radiation, residual gas conduction and solid spacer conduction. The model describes the MLI behaviour considering a layer-to-layer approach and is based on an electrical analogy, in which the three heat transfer modes are treated as parallel thermal impedances. The values of each of the transfer mode vary from layer to layer, although the total heat flux remains constant across the whole MLI blanket. The model enables the optimisation of the insulation with regard to different MLI parameters, such as residual gas pressure, number of layers and boundary temperatures. The model has been tested with experimental measurements carried out at CERN and the results revealed to be in a good agreement, especially for insulation vacuum between 10-5 Pa and 10-3 Pa.

  19. Common mode chokes and optimisation aspects

    Science.gov (United States)

    Kut, T.; Lücken, A.; Dickmann, S.; Schulz, D.

    2014-11-01

    Due to the increasing electrification of modern aircraft, as a result of the More Electric Aircraft concept, new strategies and approaches are required to fulfil the strict EMC aircraft standards (DO-160/ED-14-Sec. 20). Common mode chokes are a key component of electromagnetic filters and often oversized because of the unknown impedance of the surrounding power electronic system. This oversizing results in an increase of weight and volume. It has to be avoided as far as possible for mobile applications. In this context, an advanced method is presented to measure these impedances under operating conditions. Furthermore, the different parameters of the inductance design is explained and an optimisation for weight and volume is introduced.

  20. On the dispersion management of fluorite whispering-gallery mode resonators for Kerr optical frequency comb generation in the telecom and mid-infrared range

    CERN Document Server

    Lin, Guoping

    2015-01-01

    Optical whispering gallery mode (WGM) resonators have been very attracting platforms for versatile Kerr frequency comb generations. We report a systematic study on the material dispersion of various optical materials that are capable of supporting quality factors above $10^9$. Using an analytical approximation of WGM resonant frequencies in disk resonators, we investigate the effect of the geometry and transverse mode order on the total group-velocity dispersion ($GVD$). We demonstrate that the major radii and the radial mode indices play an important role in tailoring the $GVD$ of WGM resonators. In particular, our study shows that in WGM disk-resonators, the polar families of modes have very similar $GVD$, while the radial families of modes feature dispersion values that can differ by up to several orders of magnitude. The effect of these giant dispersion shifts are experimentally evidenced in Kerr comb generation with magnesium fluoride. From a more general perspective, this critical feature enables to pus...

  1. Seed dispersal in fens

    NARCIS (Netherlands)

    Middleton, Beth; van Diggelen, Rudy; Jensen, Kai

    2006-01-01

    Question: How does seed dispersal reduce fen isolation and contribute to biodiversity? Location: European and North American fens. Methods: This paper reviews the literature on seed dispersal to fens. Results: Landscape fragmentation may reduce dispersal opportunities thereby isolating fens and

  2. Profile control studies for JET optimised shear regime

    Energy Technology Data Exchange (ETDEWEB)

    Litaudon, X.; Becoulet, A.; Eriksson, L.G.; Fuchs, V.; Huysmans, G.; How, J.; Moreau, D.; Rochard, F.; Tresset, G.; Zwingmann, W. [Association Euratom-CEA, CEA/Cadarache, Dept. de Recherches sur la Fusion Controlee, DRFC, 13 - Saint-Paul-lez-Durance (France); Bayetti, P.; Joffrin, E.; Maget, P.; Mayorat, M.L.; Mazon, D.; Sarazin, Y. [JET Abingdon, Oxfordshire (United Kingdom); Voitsekhovitch, I. [Universite de Provence, LPIIM, Aix-Marseille 1, 13 (France)

    2000-03-01

    This report summarises the profile control studies, i.e. preparation and analysis of JET Optimised Shear plasmas, carried out during the year 1999 within the framework of the Task-Agreement (RF/CEA/02) between JET and the Association Euratom-CEA/Cadarache. We report on our participation in the preparation of the JET Optimised Shear experiments together with their comprehensive analyses and the modelling. Emphasis is put on the various aspects of pressure profile control (core and edge pressure) together with detailed studies of current profile control by non-inductive means, in the prospects of achieving steady, high performance, Optimised Shear plasmas. (authors)

  3. Genetic Algorithm Optimisation of a Ship Navigation System

    Directory of Open Access Journals (Sweden)

    E. Alfaro-Cid

    2001-01-01

    Full Text Available The optimisation of the PID controllers' gains for separate propulsion and heading control systems of CyberShip I, a scale model of an oil platform supply ship, using Genetic Algorithms is considered. During the initial design process both PID controllers have been manually tuned to improve their performance. However this tuning approach is a tedious and time consuming process. A solution to this problem is the use of optimisation techniques based on Genetic Algorithms to optimise the controllers' gain values. This investigation has been carried out through computer-generated simulations based on a non-linear hydrodynamic model of CyberShip I.

  4. Optimisation of sensing time and transmission time in cognitive radio-based smart grid networks

    Science.gov (United States)

    Yang, Chao; Fu, Yuli; Yang, Junjie

    2016-07-01

    Cognitive radio (CR)-based smart grid (SG) networks have been widely recognised as emerging communication paradigms in power grids. However, a sufficient spectrum resource and reliability are two major challenges for real-time applications in CR-based SG networks. In this article, we study the traffic data collection problem. Based on the two-stage power pricing model, the power price is associated with the efficient received traffic data in a metre data management system (MDMS). In order to minimise the system power price, a wideband hybrid access strategy is proposed and analysed, to share the spectrum between the SG nodes and CR networks. The sensing time and transmission time are jointly optimised, while both the interference to primary users and the spectrum opportunity loss of secondary users are considered. Two algorithms are proposed to solve the joint optimisation problem. Simulation results show that the proposed joint optimisation algorithms outperform the fixed parameters (sensing time and transmission time) algorithms, and the power cost is reduced efficiently.

  5. Optimising neuroimaging effectiveness in a district general hospital.

    Science.gov (United States)

    McCarron, M O; Wade, C; McCarron, P

    2014-01-01

    Diagnostic accuracy in neurology frequently depends on clinical assessment and neuroimaging interpretation. We assessed neuroimaging discrepancy rates in reported findings between general radiologists and neuroradiologists among patients from a district general hospital (DGH). A neuroradiologist's report was sought on selected DGH patients over 28 months. Pre-planned outcomes included comparisons of primary findings (main diagnosis or abnormality), secondary findings (differential diagnoses and incidental findings) and advice from neuroradiologists for further investigations. A total of 233 patients (119 men and 114 women), mean age 47.2 (SD 17.8) years were studied: 43 had a computed tomography (CT) brain scan only, 37 had CT and magnetic resonance imaging (MRI) scans and 153 had only MRI scans. Discrepancies in the primary diagnosis/abnormality were identified in 33 patients (14.2%). This included 7 of 43 patients (16.3%) who had a CT brain scan as their only neuroimaging. Secondary outcomes differed in 50 patients (21.5%). Neuroradiologists recommended further neuroimaging for 29 patients (12.4%). The most common discrepancies in the primary diagnosis/abnormality were misinterpreting normal for hippocampal sclerosis and missed posterior fossa lesions. There was no evidence of temporal changes in discrepancy rates. Selecting CT and MR neuroimaging studies from general hospitals for reviewing by neuroradiologists is an important and effective way of optimising management of neurological patients.

  6. Research progress in avian dispersal behavior

    Institute of Scientific and Technical Information of China (English)

    Yang LIU; Zhengwang ZHANG

    2008-01-01

    Dispersal, defined as a linear spreading move-ment of individuals away from others of the population is a fundamental characteristic of organisms in nature. Dispersal is a central concept in ecological, behavioral and evolutionary studies, driven by different forces such as avoidance of inbreeding depression, density-dependent competition and the need to change breeding locations. By effective dispersal, organisms can enlarge their geo-graphic range and adjust the dynamic, sex ratio and gen-etic compositions of a population. Birds are one of the groups that are studied intensively by human beings. Due to their diurnal habits, diverse life history strategies and complex movement, birds are also ideal models for the study of dispersal behaviors. Certain topics of avian dispersal including sex-biased, asymmetric dispersal caused by differences in body conditions, dispersal pro-cesses, habitat selection and long distance dispersal are discussed here. Bird-ringing or marking, radio-telemetry and genetic markers are useful tools widely applied in dispersal studies. There are three major challenges regard-ing theoretical study and methodology research of dis-persal: (1) improvement in research methodology is needed, (2) more in-depth theoretical research is neces-sary, and (3) application of theoretical research into the conservation efforts for threatened birds and the manage-ment of their habitats should be carried out immediately.

  7. Operational optimisation of water supply networks using a fuzzy ...

    African Journals Online (AJOL)

    Operational optimisation of water supply networks using a fuzzy system. ... This paper presents a fuzzy system to control the pressure in a water distribution network, by using valves and controlling the rotor speed of the ... Article Metrics.

  8. Exploring RSSI Dependency on Height in UHF for throughput optimisation

    CSIR Research Space (South Africa)

    Maliwatu, R

    2016-11-01

    Full Text Available International Conference on Advances in Computing & Communication Engineering (ICACCE), 28-29 November 2016, Durban, South Africa Exploring RSSI Dependency on Height in UHF for throughput optimisation Richard Maliwatu Albert Lysko David Johnson...

  9. Efficient topology optimisation of multiscale and multiphysics problems

    DEFF Research Database (Denmark)

    Alexandersen, Joe

    The aim of this Thesis is to present efficient methods for optimising high-resolution problems of a multiscale and multiphysics nature. The Thesis consists of two parts: one treating topology optimisation of microstructural details and the other treating topology optimisation of conjugate heat...... transfer problems. Part I begins with an introduction to the concept of microstructural details in the context of topology optimisation. Relevant literature is briefly reviewed and problems with existing methodologies are identified. The proposed methodology and its strengths are summarised. Details...... the computational cost of treating structures with fully-resolved microstructural details. The methodology is further applied to examples, where it is shown that it ensures connectivity of the microstructural details and that forced periodicity of the microstructural details can yield an implicit robustness to load...

  10. Share-of-Surplus Product Line Optimisation with Price Levels

    Directory of Open Access Journals (Sweden)

    X. G. Luo

    2014-01-01

    Full Text Available Kraus and Yano (2003 established the share-of-surplus product line optimisation model and developed a heuristic procedure for this nonlinear mixed-integer optimisation model. In their model, price of a product is defined as a continuous decision variable. However, because product line optimisation is a planning process in the early stage of product development, pricing decisions usually are not very precise. In this research, a nonlinear integer programming share-of-surplus product line optimization model that allows the selection of candidate price levels for products is established. The model is further transformed into an equivalent linear mixed-integer optimisation model by applying linearisation techniques. Experimental results in different market scenarios show that the computation time of the transformed model is much less than that of the original model.

  11. Open Pit Optimisation and Design: A Stepwise Approach*

    African Journals Online (AJOL)

    Michael

    2015-12-02

    Dec 2, 2015 ... holes were used for the analysis. ... retrieval and analysis, using Surpac software. .... economic and technical parameters were used to produce a set of nested pits. Fig. 4 depicts a summarised flow chart for the pit optimisation.

  12. Optimisation of patient protection and image quality in diagnostic ...

    African Journals Online (AJOL)

    Optimisation of patient protection and image quality in diagnostic radiology. ... The study leads to the introduction of the concept of plan- do-check-act on QC results ... (QA) programme and continues to collect data for establishment of DRL's.

  13. A Comparison of Existing Optimisation Techniques with the ...

    African Journals Online (AJOL)

    ... Existing Optimisation Techniques with the Univariate Marginal Distribution Algorithm ... graph colouring, neural networks, genetic algorithms and tabu search. ... optimization techniques and we show how the proposed algorithm performs in ...

  14. Elliptical Antenna Array Synthesis Using Backtracking Search Optimisation Algorithm

    Directory of Open Access Journals (Sweden)

    Kerim Guney

    2016-04-01

    Full Text Available The design of the elliptical antenna arrays is relatively new research area in the antenna array community. Backtracking search optimisation algorithm (BSA is employed for the synthesis of elliptical antenna arrays having different number of array elements. For this aim, BSA is used to calculate the optimum angular position and amplitude values of the array elements. BSA is a population-based iterative evolutionary algorithm. The remarkable properties of BSA are that it has a good optimisation performance, simple implementation structure, and few control parameters. The results of BSA are compared with those of self-adaptive differential evolution algorithm, firefly algorithm, biogeography based optimisation algorithm, and genetic algorithm. The results show that BSA can reach better solutions than the compared optimisation algorithms. Iterative performances of BSA are also compared with those of bacterial foraging algorithm and differential search algorithm.

  15. Construction and optimisation of a cartridge filter for removing ...

    African Journals Online (AJOL)

    Construction and optimisation of a cartridge filter for removing fluoride in drinking water. ... It was found that the optimal conditions for the F- filter that gave the best results in removing of F- from water with minimum ... Article Metrics.

  16. Weight Optimisation of Steel Monopile Foundations for Offshore Windfarms

    DEFF Research Database (Denmark)

    Fog Gjersøe, Nils; Bouvin Pedersen, Erik; Kristensen, Brian;

    2015-01-01

    The potential for mass reduction of monopiles in offshore windfarms using current design practice is investigated. Optimisation by sensitivity analysis is carried out for the following important parameters: wall thickness distribution between tower and monopile, soil stiffness, damping ratio and ...

  17. Optimal Management of Power Systems

    OpenAIRE

    Andreassi, Luca; Ubertini, Stefano

    2010-01-01

    The present chapter discusses the importance of energy systems proper management to reduce energy costs and environmental impact. A numerical model for the optimal management of a power plant in buildings and industrial plants is presented. The model allows evaluating different operating strategies for the power plant components. The different strategies are defined on the basis of a pure economic optimisation (minimisation of total cost) and/or of an energetic optimisation (minimisation of f...

  18. optPBN: An Optimisation Toolbox for Probabilistic Boolean Networks

    Science.gov (United States)

    Trairatphisan, Panuwat; Mizera, Andrzej; Pang, Jun; Tantar, Alexandru Adrian; Sauter, Thomas

    2014-01-01

    Background There exist several computational tools which allow for the optimisation and inference of biological networks using a Boolean formalism. Nevertheless, the results from such tools yield only limited quantitative insights into the complexity of biological systems because of the inherited qualitative nature of Boolean networks. Results We introduce optPBN, a Matlab-based toolbox for the optimisation of probabilistic Boolean networks (PBN) which operates under the framework of the BN/PBN toolbox. optPBN offers an easy generation of probabilistic Boolean networks from rule-based Boolean model specification and it allows for flexible measurement data integration from multiple experiments. Subsequently, optPBN generates integrated optimisation problems which can be solved by various optimisers. In term of functionalities, optPBN allows for the construction of a probabilistic Boolean network from a given set of potential constitutive Boolean networks by optimising the selection probabilities for these networks so that the resulting PBN fits experimental data. Furthermore, the optPBN pipeline can also be operated on large-scale computational platforms to solve complex optimisation problems. Apart from exemplary case studies which we correctly inferred the original network, we also successfully applied optPBN to study a large-scale Boolean model of apoptosis where it allows identifying the inverse correlation between UVB irradiation, NFκB and Caspase 3 activations, and apoptosis in primary hepatocytes quantitatively. Also, the results from optPBN help elucidating the relevancy of crosstalk interactions in the apoptotic network. Summary The optPBN toolbox provides a simple yet comprehensive pipeline for integrated optimisation problem generation in the PBN formalism that can readily be solved by various optimisers on local or grid-based computational platforms. optPBN can be further applied to various biological studies such as the inference of gene regulatory

  19. A supportive architecture for CFD-based design optimisation

    Science.gov (United States)

    Li, Ni; Su, Zeya; Bi, Zhuming; Tian, Chao; Ren, Zhiming; Gong, Guanghong

    2014-03-01

    Multi-disciplinary design optimisation (MDO) is one of critical methodologies to the implementation of enterprise systems (ES). MDO requiring the analysis of fluid dynamics raises a special challenge due to its extremely intensive computation. The rapid development of computational fluid dynamic (CFD) technique has caused a rise of its applications in various fields. Especially for the exterior designs of vehicles, CFD has become one of the three main design tools comparable to analytical approaches and wind tunnel experiments. CFD-based design optimisation is an effective way to achieve the desired performance under the given constraints. However, due to the complexity of CFD, integrating with CFD analysis in an intelligent optimisation algorithm is not straightforward. It is a challenge to solve a CFD-based design problem, which is usually with high dimensions, and multiple objectives and constraints. It is desirable to have an integrated architecture for CFD-based design optimisation. However, our review on existing works has found that very few researchers have studied on the assistive tools to facilitate CFD-based design optimisation. In the paper, a multi-layer architecture and a general procedure are proposed to integrate different CFD toolsets with intelligent optimisation algorithms, parallel computing technique and other techniques for efficient computation. In the proposed architecture, the integration is performed either at the code level or data level to fully utilise the capabilities of different assistive tools. Two intelligent algorithms are developed and embedded with parallel computing. These algorithms, together with the supportive architecture, lay a solid foundation for various applications of CFD-based design optimisation. To illustrate the effectiveness of the proposed architecture and algorithms, the case studies on aerodynamic shape design of a hypersonic cruising vehicle are provided, and the result has shown that the proposed architecture

  20. Multiobjective optimisation of bogie suspension to boost speed on curves

    Science.gov (United States)

    Milad Mousavi-Bideleh, Seyed; Berbyuk, Viktor

    2016-01-01

    To improve safety and maximum admissible speed on different operational scenarios, multiobjective optimisation of bogie suspension components of a one-car railway vehicle model is considered. The vehicle model has 50 degrees of freedom and is developed in multibody dynamics software SIMPACK. Track shift force, running stability, and risk of derailment are selected as safety objective functions. The improved maximum admissible speeds of the vehicle on curves are determined based on the track plane accelerations up to 1.5 m/s2. To attenuate the number of design parameters for optimisation and improve the computational efficiency, a global sensitivity analysis is accomplished using the multiplicative dimensional reduction method (M-DRM). A multistep optimisation routine based on genetic algorithm (GA) and MATLAB/SIMPACK co-simulation is executed at three levels. The bogie conventional secondary and primary suspension components are chosen as the design parameters in the first two steps, respectively. In the last step semi-active suspension is in focus. The input electrical current to magnetorheological yaw dampers is optimised to guarantee an appropriate safety level. Semi-active controllers are also applied and the respective effects on bogie dynamics are explored. The safety Pareto optimised results are compared with those associated with in-service values. The global sensitivity analysis and multistep approach significantly reduced the number of design parameters and improved the computational efficiency of the optimisation. Furthermore, using the optimised values of design parameters give the possibility to run the vehicle up to 13% faster on curves while a satisfactory safety level is guaranteed. The results obtained can be used in Pareto optimisation and active bogie suspension design problems.

  1. Optimisation of the Sekwa blended-wing-Body research UAV

    CSIR Research Space (South Africa)

    Broughton, BA

    2008-10-01

    Full Text Available candidate design to bring the total mass up to the target total mass of 3.2 kg. The location of the ballast mass could be adjusted by the design code, which allowed the static margin to be used as a design variable. Finally, a series of checks were.... Overview of optimisation process OPTIMISER Genetic Algorithms + Gradient Based Methods Natural FQ constraints Geometric constraints Control system constraints Stall behaviour Design with best cruise performance Design parameters Generate...

  2. Aerodynamic optimisation of an industrial axial fan blade

    OpenAIRE

    2006-01-01

    Numerical optimisation methods have successfully been used for a variety of aerodynamic design problems over quite a few years. However the application of these methods to the aerodynamic blade shape optimisation of industrial axial fans has received much less attention in the literature probably given the fact that the majority of resources available to develop these automated design approaches is to be found in the aerospace field. This work presents the develo...

  3. Spreadsheets In Function Of Optimisation Of Logistics Network

    OpenAIRE

    Drago Pupavac; Mimo Draskovic

    2007-01-01

    This scientific paper discusses how estimated spreadsheets functions in logistics networks optimisation. The suggested working hypothesis for efficacy of estimated spreadsheets in designing logistics networks is proved and a practical example. In this way the given model can be applied to all logistics networks of similar problem capacity. Logistics network model confronting estimated spreadsheets present a real world at a level needed for understanding the problem of optimisation of logistic...

  4. Optimisation study of a vehicle bumper subsystem with fuzzy parameters

    Science.gov (United States)

    Farkas, L.; Moens, D.; Donders, S.; Vandepitte, D.

    2012-10-01

    This paper deals with the design and optimisation for crashworthiness of a vehicle bumper subsystem, which is a key scenario for vehicle component design. The automotive manufacturers and suppliers have to find optimal design solutions for such subsystems that comply with the conflicting requirements of the regulatory bodies regarding functional performance (safety and repairability) and regarding the environmental impact (mass). For the bumper design challenge, an integrated methodology for multi-attribute design engineering of mechanical structures is set up. The integrated process captures the various tasks that are usually performed manually, this way facilitating the automated design iterations for optimisation. Subsequently, an optimisation process is applied that takes the effect of parametric uncertainties into account, such that the system level of failure possibility is acceptable. This optimisation process is referred to as possibility-based design optimisation and integrates the fuzzy FE analysis applied for the uncertainty treatment in crash simulations. This process is the counterpart of the reliability-based design optimisation used in a probabilistic context with statistically defined parameters (variabilities).

  5. Optimised control of coal-fired boilers

    Energy Technology Data Exchange (ETDEWEB)

    Owens, D.H.; MacConnell, P.F.A.; Neuffer, D.; Dando, R. [University of Exeter, Exeter (United Kingdom). Centre for System and Control Engineering

    1997-07-01

    The objective of the project is to develop and specify a control methodology that will enable existing coal combustion plant to take maximum advantage of modern control techniques. The research is specifically aimed at chain-grate stoker plant (such as the test facility at the Coal Research Establishment, Cheltenham) on which little work has been done for thirty years yet which still represents a large proportion of industrial coal-fired plant in operation worldwide. In detail, the project: reviewed existing control strategies for moving grate stokers, highlighting their limitations and areas for improvements; carried out plant trials to identify the system characteristics such as response time and input/output behaviour; developed a theoretical process based on physical and chemical laws and backed up by trial data; specified control strategies for a single boiler; simulated and evaluated the control strategies using model simulations; developed of an optimised. Control strategy for a single boiler; and assessed the applicability and effects of this control strategy on multiple boiler installations. 67 refs., 34 figs.

  6. ENERGY OPTIMISATION SCHEMES FOR WIRELESS SENSOR NETWORK

    Directory of Open Access Journals (Sweden)

    Vivekanand Jha

    2012-05-01

    Full Text Available A sensor network is composed of a large number of sensor nodes, which are densely deployed either inside the phenomenon or very close to it. Sensor nodes have sensing, processing and transmitting capability . They however have limited energy and measures need to be taken to make op- timum usage of their energy and save them from task of only receiving and transmitting data without processing. Various techniques for energy utilization optimisation have been proposed Ma jor players are however clustering and relay node placement. In the research related to relay node placement, it has been proposed to deploy some relay nodes such that the sensors can transmit the sensed data to a nearby relay node, which in turn delivers the data to the base stations. In general, the relay node placement problems aim to meet certain connectivity and/or survivabil- ity requirements of the network by deploying a minimum number of relay nodes. The other approach is grouping sensor nodes into clusters with each cluster having a cluster head (CH. The CH nodes aggregate the data and transmit them to the base station (BS. These two approaches has been widely adopted by the research community to satisfy the scala- bility objective and generally achieve high energy efficiency and prolong network lifetime in large-scale WSN environments and hence are discussed here along with single hop and multi hop characteristic of sensor node.

  7. Topological optimisation of rod-stirring devices

    CERN Document Server

    Finn, Matthew D

    2011-01-01

    There are many industrial situations where rods are used to stir a fluid, or where rods repeatedly stretch a material such as bread dough or taffy. The goal in these applications is to stretch either material lines (in a fluid) or the material itself (for dough or taffy) as rapidly as possible. The growth rate of material lines is conveniently given by the topological entropy of the rod motion. We discuss the problem of optimising such rod devices from a topological viewpoint. We express rod motions in terms of generators of the braid group, and assign a cost based on the minimum number of generators needed to write the braid. We show that for one cost function -- the topological entropy per generator -- the optimal growth rate is the logarithm of the golden ratio. For a more realistic cost function,involving the topological entropy per operation where rods are allowed to move together, the optimal growth rate is the logarithm of the silver ratio, $1+\\sqrt{2}$. We show how to construct devices that realise th...

  8. A Systematic Approach to Optimise Management in Global Sourcing Relationships

    NARCIS (Netherlands)

    Ponisio, Laura

    2009-01-01

    Despite a large number of studies, global IT sourcing projects are, in practice, performed ad-hoc and rely mostly on the manager’s experience. Outsourcing software development presents extra challenges because development is performed in an inter-organisational network. Although organisations

  9. Dispersal, growth and diet of stocked and wild northern pike fry in a shallow natural lake, with implications for management of stocking programs

    DEFF Research Database (Denmark)

    Skov, Christian; Koed, Anders; Baastrup-Spohr, Lars

    2011-01-01

    , growth, and food composition of advanced pike fry (∼30 mm) stocked at a high density at a common release site in a shallow natural lake that contained wild youngof- the-year (age-0) pike. The stocked pike fry colonized the entire lake shoreline within just a few days. Dispersal was inversely related...

  10. Dispersal of the invasive pasture pest Heteronychus arator into areas of low population density: effects of sex and season, and implications for pest management

    Directory of Open Access Journals (Sweden)

    Sarah Mansfield

    2016-08-01

    Full Text Available African black beetle, Heteronychus arator (Scarabaeidae, is an exotic pest of pastures in northern New Zealand. Both adults and larvae feed on pasture grasses. Adults disperse by walking (short range or flying (long range. Dispersal flights are triggered by warm night temperatures in spring and autumn. Short range adult dispersal in search of mates, food or oviposition sites is poorly understood. This study investigated walking activity of H. arator adults over three seasons in New Zealand pastures. Adult walking activity was monitored using pitfall traps along fence lines and in pasture plots on a dairy farm in Waikato, New Zealand, in spring 2013, spring 2014 and autumn 2015. Beetle populations were reduced by application of a biopesticide bait to compare walking activity between treated and control plots for up to 26 days post-treatment. Marked beetles were released into the pasture plots to measure the distance travelled by recaptured individuals. Trap catches along the fence lines were correlated with air temperatures in 2013. Trap catches were male biased in spring 2014 compared with autumn 2015. Trap numbers in the control plots were nearly double that of treated plots in both seasons. More beetles were caught in the pitfall traps at the edges of the treated plots than in the centre. Trap catches were consistent throughout the control plot in spring 2014, but in autumn 2015 more beetles were caught in the centre of the control plot than at the edges. Few marked beetles were recaptured with dispersal rates estimated as <0.5m per day. Warmer temperatures encouraged short range dispersal in H. arator. Males were more active than females during the spring mating season. Edge effects were strong and should be considered in the design of field experiments.

  11. Optimisation of the formulation of a bubble bath by a chemometric approach market segmentation and optimisation.

    Science.gov (United States)

    Marengo, Emilio; Robotti, Elisa; Gennaro, Maria Carla; Bertetto, Mariella

    2003-03-01

    The optimisation of the formulation of a commercial bubble bath was performed by chemometric analysis of Panel Tests results. A first Panel Test was performed to choose the best essence, among four proposed to the consumers; the best essence chosen was used in the revised commercial bubble bath. Afterwards, the effect of changing the amount of four components (the amount of primary surfactant, the essence, the hydratant and the colouring agent) of the bubble bath was studied by a fractional factorial design. The segmentation of the bubble bath market was performed by a second Panel Test, in which the consumers were requested to evaluate the samples coming from the experimental design. The results were then treated by Principal Component Analysis. The market had two segments: people preferring a product with a rich formulation and people preferring a poor product. The final target, i.e. the optimisation of the formulation for each segment, was obtained by the calculation of regression models relating the subjective evaluations given by the Panel and the compositions of the samples. The regression models allowed to identify the best formulations for the two segments ofthe market.

  12. Dispersion Properties of TIRPCF under Compton Scattering

    Institute of Scientific and Technical Information of China (English)

    HAO Dong-shan; YU Ding-chen

    2006-01-01

    The dispersion properties in the short wavelength region of total internal reflective photonic crystal fiber(TIRPCF) in Compton scattering have been studied by using the model of the equivalent twin waveguide soliton coupling,dispersion management solitons and effective refractive index. It is shown that the positive dispersion of the cladding waveguide of TIRPCF and the negative dispersion of its core waveguide are quickly increased by the square of the collision non-elastic composition between the electron and photons,and they are lessened by the increase of the electron absorption photon number. Under the one-photon nonlinear Compton scattering,the method of the compensated probing laser diffraction by the phase hole induced by the stationary pumping laser in the cladding waveguide enables the average dispersion value of TIRPCF to be close to zero,and the zero dispersion point quickly shifts to the short wavelength region.

  13. Multi-objective optimisation of aircraft flight trajectories in the ATM and avionics context

    Science.gov (United States)

    Gardi, Alessandro; Sabatini, Roberto; Ramasamy, Subramanian

    2016-05-01

    The continuous increase of air transport demand worldwide and the push for a more economically viable and environmentally sustainable aviation are driving significant evolutions of aircraft, airspace and airport systems design and operations. Although extensive research has been performed on the optimisation of aircraft trajectories and very efficient algorithms were widely adopted for the optimisation of vertical flight profiles, it is only in the last few years that higher levels of automation were proposed for integrated flight planning and re-routing functionalities of innovative Communication Navigation and Surveillance/Air Traffic Management (CNS/ATM) and Avionics (CNS+A) systems. In this context, the implementation of additional environmental targets and of multiple operational constraints introduces the need to efficiently deal with multiple objectives as part of the trajectory optimisation algorithm. This article provides a comprehensive review of Multi-Objective Trajectory Optimisation (MOTO) techniques for transport aircraft flight operations, with a special focus on the recent advances introduced in the CNS+A research context. In the first section, a brief introduction is given, together with an overview of the main international research initiatives where this topic has been studied, and the problem statement is provided. The second section introduces the mathematical formulation and the third section reviews the numerical solution techniques, including discretisation and optimisation methods for the specific problem formulated. The fourth section summarises the strategies to articulate the preferences and to select optimal trajectories when multiple conflicting objectives are introduced. The fifth section introduces a number of models defining the optimality criteria and constraints typically adopted in MOTO studies, including fuel consumption, air pollutant and noise emissions, operational costs, condensation trails, airspace and airport operations

  14. Evaluating future detriment from radioactive discharges Judgements and implications for optimisation of protection

    CERN Document Server

    Fleishman, A B

    1982-01-01

    For long-lived nuclides released into the environment, it is possible to calculate dose commitments extending over thousands or millions of years. The inclusion of this detriment to future populations in present day decision-making is not a technical matter, but represents an area where judgement must be applied. This report shows how different judgements on the relative valuation of future doses can have significant implications for the management of radioactive effluents. A quantitative framework for the expression of such judgements is proposed for optimisation studies, to clarify for decision-makers these implications in the assessment of alternative management options. This is based on the economic principles of discounting, but is related to the use of incomplete collective dose commitments (truncated in time), and includes a zero discount rate which assigns the same weight to doses whenever received. The framework is applied to a series of potential management options for the control of carbon-14, kryp...

  15. A conceptual optimisation strategy for radiography in a digital environment.

    Science.gov (United States)

    Båth, Magnus; Håkansson, Markus; Hansson, Jonny; Månsson, Lars Gunnar

    2005-01-01

    Using a completely digital environment for the entire imaging process leads to new possibilities for optimisation of radiography since many restrictions of screen/film systems, such as the small dynamic range and the lack of possibilities for image processing, do not apply any longer. However, at the same time these new possibilities lead to a more complicated optimisation process, since more freedom is given to alter parameters. This paper focuses on describing an optimisation strategy that concentrates on taking advantage of the conceptual differences between digital systems and screen/film systems. The strategy can be summarised as: (a) always include the anatomical background during the optimisation, (b) perform all comparisons at a constant effective dose and (c) separate the image display stage from the image collection stage. A three-step process is proposed where the optimal setting of the technique parameters is determined at first, followed by an optimisation of the image processing. In the final step the optimal dose level-given the optimal settings of the image collection and image display stages-is determined.

  16. CT dose optimisation and reduction in osteoarticular disease.

    Science.gov (United States)

    Gervaise, A; Teixeira, P; Villani, N; Lecocq, S; Louis, M; Blum, A

    2013-04-01

    With an improvement in the temporal and spatial resolution, computed tomography (CT) is indicated in the evaluation of a great many osteoarticular diseases. New exploration techniques such as the dynamic CT and CT bone perfusion also provide new indications. However, CT is still an irradiating imaging technique and dose optimisation and reduction remains primordial. In this paper, the authors first present the typical doses delivered during CT in osteoarticular disease. They then discuss the different ways to optimise and reduce these doses by distinguishing the behavioural factors from the technical factors. Among the latter, the optimisation of the milliamps and kilovoltage is indispensable and should be adapted to the type of exploration and the morphotype of each individual. These technical factors also benefit from recent technological evolutions with the distribution of iterative reconstructions. In this way, the dose may be divided by two and provide an image of equal quality. With these dose optimisation and reduction techniques, it is now possible, while maintaining an excellent quality of the image, to obtain low-dose or even very low-dose acquisitions with a dose sometimes similar that of a standard X-ray assessment. Nevertheless, although these technical factors provide a major reduction in the dose delivered, behavioural factors, such as compliance with the indications, remain fundamental. Finally, the authors describe how to optimise and reduce the dose with specific applications in musculoskeletal imaging such as the dynamic CT, CT bone perfusion and dual energy CT.

  17. Hybrid Genetic Algorithm with PSO Effect for Combinatorial Optimisation Problems

    Directory of Open Access Journals (Sweden)

    M. H. Mehta

    2012-12-01

    Full Text Available In engineering field, many problems are hard to solve in some definite interval of time. These problems known as “combinatorial optimisation problems” are of the category NP. These problems are easy to solve in some polynomial time when input size is small but as input size grows problems become toughest to solve in some definite interval of time. Long known conventional methods are not able to solve the problems and thus proper heuristics is necessary. Evolutionary algorithms based on behaviours of different animals and species have been invented and studied for this purpose. Genetic Algorithm is considered a powerful algorithm for solving combinatorial optimisation problems. Genetic algorithms work on these problems mimicking the human genetics. It follows principle of “survival of the fittest” kind of strategy. Particle swarm optimisation is a new evolutionary approach that copies behaviour of swarm in nature. However, neither traditional genetic algorithms nor particle swarm optimisation alone has been completely successful for solving combinatorial optimisation problems. Here a hybrid algorithm is proposed in which strengths of both algorithms are merged and performance of proposed algorithm is compared with simple genetic algorithm. Results show that proposed algorithm works definitely better than the simple genetic algorithm.

  18. Optimising treatment for COPD--new strategies for combination therapy.

    Science.gov (United States)

    Welte, T

    2009-08-01

    Chronic obstructive pulmonary disease (COPD) is a multi-component disease characterised by airflow limitation and airway inflammation. Exacerbations of COPD have a considerable impact on the quality of life, daily activities and general well-being of patients and are a great burden on the health system. Thus, the aims of COPD management include not only relieving symptoms and preventing disease progression but also preventing and treating exacerbations. Attention towards the day-to-day burden of the disease is also required in light of evidence that suggests COPD may be variable throughout the day with morning being the time when symptoms are most severe and patients' ability to perform regular morning activities the most problematic. While available therapies improve clinical symptoms and decrease airway inflammation, they do not unequivocally slow long-term progression or address all disease components. With the burden of COPD continuing to increase, research into new and improved treatment strategies to optimise pharmacotherapy is ongoing - in particular, combination therapies, with a view to their complementary modes of action enabling multiple components of the disease to be addressed. Evidence from recent clinical trials indicates that triple therapy, combining an anticholinergic with an inhaled corticosteroid and a long-acting beta(2)-agonist, may provide clinical benefits additional to those associated with each treatment alone in patients with more severe COPD. This article reviews the evidence for treatment strategies used in COPD with a focus on combination therapies and introduces the 3-month CLIMB study (Evaluation of Efficacy and Safety of Symbicort as an Add-on Treatment to Spiriva in Patients With Severe COPD) which investigated the potential treatment benefits of combining tiotropium with budesonide/formoterol in patients with COPD with regard to lung function, exacerbations, symptoms and morning activities.

  19. Decision support for optimised irrigation scheduling

    NARCIS (Netherlands)

    Anastasiou, A.; Sawas, D.; Pasgianos, G.; Sigrimis, N.; Stanghellini, C.; Kempkes, F.L.K.

    2009-01-01

    The system, developed under the FLOW-AID (an FP6 project), is a farm level water management system of special value in situations where the water availability and quality is limited. This market-ready precision irrigation management system features new models, hardware and software. The hardware pla

  20. Transmit Power Optimisation in Wireless Network

    Directory of Open Access Journals (Sweden)

    Besnik Terziu

    2011-09-01

    Full Text Available Transmit power optimisation in wireless networks based on beamforming have emerged as a promising technique to enhance the spectrum efficiency of present and future wireless communication systems. The aim of this study is to minimise the access point power consumption in cellular networks while maintaining a targeted quality of service (QoS for the mobile terminals. In this study, the targeted quality of service is delivered to a mobile station by providing a desired level of Signal to Interference and Noise Ratio (SINR. Base-stations are coordinated across multiple cells in a multi-antenna beamforming system. This study focuses on a multi-cell multi-antenna downlink scenario where each mobile user is equipped with a single antenna, but where multiple mobile users may be active simultaneously in each cell and are separated via spatial multiplexing using beamforming. The design criteria is to minimize the total weighted transmitted power across the base-stations subject to SINR constraints at the mobile users. The main contribution of this study is to define an iterative algorithm that is capable of finding the joint optimal beamformers for all basestations, based on a correlation-based channel model, the full-correlation model. Among all correlated channel models, the correlated channel model used in this study is the most accurate, giving the best performance in terms of power consumption. The environment here in this study is chosen to be Non-Light of- Sight (NLOS condition, where a signal from a wireless transmitter passes several obstructions before arriving at a wireless receiver. Moreover there are many scatterers local to the mobile, and multiple reflections can occur among them before energy arrives at the mobile. The proposed algorithm is based on uplink-downlink duality using the Lagrangian duality theory. Time-Division Duplex (TDD is chosen as the platform for this study since it has been adopted to the latest technologies in Fourth

  1. Multiobjective design optimisation of coronary stents.

    Science.gov (United States)

    Pant, Sanjay; Limbert, Georges; Curzen, Nick P; Bressloff, Neil W

    2011-11-01

    representative CYPHER stent are shown. The methodology and the results of this work could potentially be useful in further optimisation studies and development of a family of stents with increased resistance to in-stent restenosis and thrombosis.

  2. Dispersing powders in liquids

    CERN Document Server

    Nelson, RD

    1988-01-01

    This book provides powder technologists with laboratory procedures for selecting dispersing agents and preparing stable dispersions that can then be used in particle size characterization instruments. Its broader goal is to introduce industrial chemists and engineers to the phenomena, terminology, physical principles, and chemical considerations involved in preparing and handling dispersions on a commercial scale. The book introduces novices to: - industrial problems due to improper degree of dispersion; - the nomenclature used in describing particles; - the basic physica

  3. Dispersion y dinamica poblacional

    Science.gov (United States)

    Dispersal behavior of fruit flies is appetitive. Measures of dispersion involve two different parameter: the maximum distance and the standard distance. Standard distance is a parameter that describes the probalility of dispersion and is mathematically equivalent to the standard deviation around ...

  4. Seed dispersal in fens

    NARCIS (Netherlands)

    Middleton, Beth; van Diggelen, Rudy; Jensen, Kai

    2006-01-01

    Question: How does seed dispersal reduce fen isolation and contribute to biodiversity? Location: European and North American fens. Methods: This paper reviews the literature on seed dispersal to fens. Results: Landscape fragmentation may reduce dispersal opportunities thereby isolating fens and redu

  5. Topology Optimisation of Wideband Coaxial-to-Waveguide Transitions

    Science.gov (United States)

    Hassan, Emadeldeen; Noreland, Daniel; Wadbro, Eddie; Berggren, Martin

    2017-03-01

    To maximize the matching between a coaxial cable and rectangular waveguides, we present a computational topology optimisation approach that decides for each point in a given domain whether to hold a good conductor or a good dielectric. The conductivity is determined by a gradient-based optimisation method that relies on finite-difference time-domain solutions to the 3D Maxwell’s equations. Unlike previously reported results in the literature for this kind of problems, our design algorithm can efficiently handle tens of thousands of design variables that can allow novel conceptual waveguide designs. We demonstrate the effectiveness of the approach by presenting optimised transitions with reflection coefficients lower than -15 dB over more than a 60% bandwidth, both for right-angle and end-launcher configurations. The performance of the proposed transitions is cross-verified with a commercial software, and one design case is validated experimentally.

  6. Fabrication optimisation of carbon fiber electrode with Taguchi method.

    Science.gov (United States)

    Cheng, Ching-Ching; Young, Ming-Shing; Chuang, Chang-Lin; Chang, Ching-Chang

    2003-07-01

    In this study, we describe an optimised procedure for fabricating carbon fiber electrodes using Taguchi quality engineering method (TQEM). The preliminary results show a S/N ratio improvement from 22 to 30 db (decibel). The optimised parameter was tested by using a glass micropipette (0.3 mm outer/2.5 mm inner length of carbon fiber) dipped into PBS solution under 2.9 V triangle-wave electrochemical processing for 15 s, followed by coating treatment of micropipette on 2.6 V DC for 45 s in 5% Nafion solution. It is thus shown that Taguchi process optimisation can improve cost, manufacture time and quality of carbon fiber electrodes.

  7. Quasi-combinatorial energy landscapes for nanoalloy structure optimisation.

    Science.gov (United States)

    Schebarchov, D; Wales, D J

    2015-11-14

    We formulate nanoalloy structure prediction as a mixed-variable optimisation problem, where the homotops can be associated with an effective, quasi-combinatorial energy landscape in permutation space. We survey this effective landscape for a representative set of binary systems modelled by the Gupta potential. In segregating systems with small lattice mismatch, we find that homotops have a relatively straightforward landscape with few local optima - a scenario well-suited for local (combinatorial) optimisation techniques that scale quadratically with system size. Combining these techniques with multiple local-neighbourhood structures yields a search for multiminima, and we demonstrate that generalised basin-hopping with a metropolis acceptance criterion in the space of multiminima can then be effective for global optimisation of binary and ternary nanoalloys.

  8. Microfluidic converging/diverging channels optimised for homogeneous extensional deformation

    Science.gov (United States)

    Zografos, K.; Oliveira, M. S. N.

    2016-01-01

    In this work, we optimise microfluidic converging/diverging geometries in order to produce constant strain-rates along the centreline of the flow, for performing studies under homogeneous extension. The design is examined for both two-dimensional and three-dimensional flows where the effects of aspect ratio and dimensionless contraction length are investigated. Initially, pressure driven flows of Newtonian fluids under creeping flow conditions are considered, which is a reasonable approximation in microfluidics, and the limits of the applicability of the design in terms of Reynolds numbers are investigated. The optimised geometry is then used for studying the flow of viscoelastic fluids and the practical limitations in terms of Weissenberg number are reported. Furthermore, the optimisation strategy is also applied for electro-osmotic driven flows, where the development of a plug-like velocity profile allows for a wider region of homogeneous extensional deformation in the flow field. PMID:27478523

  9. Analysis and optimisation of heterogeneous real-time embedded systems

    DEFF Research Database (Denmark)

    Pop, Paul; Eles, Petru; Peng, Zebo

    2005-01-01

    . The success of such new design methods depends on the availability of analysis and optimisation techniques. Analysis and optimisation techniques for heterogeneous real-time embedded systems are presented in the paper. The authors address in more detail a particular class of such systems called multi......An increasing number of real-time applications are today implemented using distributed heterogeneous architectures composed of interconnected networks of processors. The systems are heterogeneous, not only in terms of hardware components, but also in terms of communication protocols and scheduling......-clusters, composed of several networks interconnected via gateways. They present a schedulability analysis for safety-critical applications distributed on multi-cluster systems and briefly highlight characteristic design optimisation problems: the partitioning and mapping of functionality, and the packing...

  10. Analysis and optimisation of heterogeneous real-time embedded systems

    DEFF Research Database (Denmark)

    Pop, Paul; Eles, Petru; Peng, Zebo

    2006-01-01

    . The success of such new design methods depends on the availability of analysis and optimisation techniques. Analysis and optimisation techniques for heterogeneous real-time embedded systems are presented in the paper. The authors address in more detail a particular class of such systems called multi......An increasing number of real-time applications are today implemented using distributed heterogeneous architectures composed of interconnected networks of processors. The systems are heterogeneous, not only in terms of hardware components, but also in terms of communication protocols and scheduling......-clusters, composed of several networks interconnected via gateways. They present a schedulability analysis for safety-critical applications distributed on multi-cluster systems and briefly highlight characteristic design optimisation problems: the partitioning and mapping of functionality, and the packing...

  11. Numerical optimisation of friction stir welding: review of future challenges

    DEFF Research Database (Denmark)

    Tutum, Cem Celal; Hattel, Jesper Henri

    2011-01-01

    During the last decade, the combination of increasingly more advanced numerical simulation software with high computational power has resulted in models for friction stir welding (FSW), which have improved the understanding of the determining physical phenomena behind the process substantially....... This has made optimisation of certain process parameters possible and has in turn led to better performing friction stir welded products, thus contributing to a general increase in the popularity of the process and its applications. However, most of these optimisation studies do not go well beyond manual...

  12. Alternatives for optimisation of rumen fermentation in ruminants

    Directory of Open Access Journals (Sweden)

    T. Slavov

    2017-06-01

    Full Text Available Abstract. The proper knowledge on the variety of events occurring in the rumen makes possible their optimisation with respect to the complete feed conversion and increasing the productive performance of ruminants. The inclusion of various dietary additives (supplements, biologically active substances, nutritional antibiotics, probiotics, enzymatic preparations, plant extracts etc. has an effect on the intensity and specific pathway of fermentation, and thus, on the general digestion and systemic metabolism. The optimisation of rumen digestion is a method with substantial potential for improving the efficiency of ruminant husbandry, increasing of quality of their produce and health maintenance.

  13. Separative power of an optimised concurrent gas centrifuge

    Energy Technology Data Exchange (ETDEWEB)

    Bogovalov, Sergey; Boman, Vladimir [National Research Nuclear University (MEPHI), Moscow (Russian Federation)

    2016-06-15

    The problem of separation of isotopes in a concurrent gas centrifuge is solved analytically for an arbitrary binary mixture of isotopes. The separative power of the optimised concurrent gas centrifuges for the uranium isotopes equals to δU = 12.7 (V/700 m/s)2(300 K/T)(L/1 m) kg·SWU/yr, where L and V are the length and linear velocity of the rotor of the gas centrifuge and T is the temperature. This equation agrees well with the empirically determined separative power of optimised counter-current gas centrifuges.

  14. Separative Power of an Optimised Concurrent Gas Centrifuge

    Directory of Open Access Journals (Sweden)

    Sergey Bogovalov

    2016-06-01

    Full Text Available The problem of separation of isotopes in a concurrent gas centrifuge is solved analytically for an arbitrary binary mixture of isotopes. The separative power of the optimised concurrent gas centrifuges for the uranium isotopes equals to δU = 12.7 (V/700 m/s2(300 K/T(L/1 m kg·SWU/yr, where L and V are the length and linear velocity of the rotor of the gas centrifuge and T is the temperature. This equation agrees well with the empirically determined separative power of optimised counter-current gas centrifuges.

  15. Multiscale Analysis and Optimisation of Photosynthetic Solar Energy Systems

    CERN Document Server

    Ringsmuth, Andrew K

    2014-01-01

    This work asks how light harvesting in photosynthetic systems can be optimised for economically scalable, sustainable energy production. Hierarchy theory is introduced as a system-analysis and optimisation tool better able to handle multiscale, multiprocess complexities in photosynthetic energetics compared with standard linear-process analysis. Within this framework, new insights are given into relationships between composition, structure and energetics at the scale of the thylakoid membrane, and also into how components at different scales cooperate under functional objectives of the whole photosynthetic system. Combining these reductionistic and holistic analyses creates a platform for modelling multiscale-optimal, idealised photosynthetic systems in silico.

  16. Optimisation of BPMN Business Models via Model Checking

    DEFF Research Database (Denmark)

    Herbert, Luke Thomas; Sharp, Robin

    2013-01-01

    We present a framework for the optimisation of business processes modelled in the business process modelling language BPMN, which builds upon earlier work, where we developed a model checking based method for the analysis of BPMN models. We define a structure for expressing optimisation goals...... candidate improved processes based on the fittest of the previous generation. The evaluation of the fitness of each candidate in a generation is performed via model checking, detailed in previous work. At each iteration, this allows the determination of the precise numerical evaluation of the performance...

  17. Optimisation of beam-orientations in conformal radiotherapy treatment planning

    Energy Technology Data Exchange (ETDEWEB)

    Rowbottom, C.G

    1999-07-01

    Many synergistic advances have led to the beginnings of the routine use of conformal radiotherapy. These include advances in diagnostic imaging, in 3D treatment planning, in the technology for complex treatment delivery and in computer assessment of rival treatment plans. A conformal radiotherapy treatment plan more closely conforms the high-dose volume to the target volume, reducing the dose to normal healthy tissue. Traditionally, human planners have devised the treatment parameters used in radiotherapy treatment plans via a manually iterative process. Computer 'optimisation' algorithms have been shown to improve treatment plans as they can explore much more of the search space in a relatively short time. This thesis examines beam-orientation computer 'optimisation' in radiotherapy treatment planning and several new techniques were developed. Using these techniques a comparison was performed between treatment plans with 'standard', fixed beam-orientations and treatment plans with 'optimised' beam-orientations for patients with cancer of the prostate, oesophagus and brain. Plans were compared on the basis of dose-distributions and in some cases biological models for the probability of damage to the target volume and the major organs-at-risk (OARs) in each patient group. A cohort of patients was considered in each group to avoid bias from a specific patient geometry. In the case of the patient cohort with cancer of the prostate, a coplanar beam-orientation 'optimisation' scheme led to an average increase in the TCP of (5.7{+-}1.4)% compared to the standard plans after the dose to the isocentre had been scaled to produce a rectal NTCP of 1%. For the patient cohort with cancer of the oesophagus, the beam-orientation 'optimisation' scheme reduced the average lung NTCP by (0.7{+-}0.2)% at the expense of a modest increase in the average spinal cord NTCP of (0.1{+-}0.2)%. A non-coplanar beam-orientation 'optimisation

  18. Plant-wide performance optimisation – The refrigeration system case

    DEFF Research Database (Denmark)

    Izadi-Zamanabadi, Roozbeh; Green, Torben; Razavi-Far, Roozbeh

    2012-01-01

    This paper investigates the problem of plant-wide performance optimisation seen from an industrial perspective. The refrigeration system is used as a case study, because it has a distributed control architecture and operates in steady state conditions, which is common for many industrial applicat......This paper investigates the problem of plant-wide performance optimisation seen from an industrial perspective. The refrigeration system is used as a case study, because it has a distributed control architecture and operates in steady state conditions, which is common for many industrial...

  19. Optimising a shaft's geometry by applying genetic algorithms

    Directory of Open Access Journals (Sweden)

    María Alejandra Guzmán

    2010-04-01

    Full Text Available Many engnieering design tasks involve optimising several conflicting goals; these types of problem are known as Multiobjective Optimisation Problems (MOPs. Evolutionary techniques have proved to be an effective tool for finding solutions to these MOPs during the last decade, Variations on the basic generic algorithm have been particulary proposed by different researchers for finding rapid optimal solutions to MOPs. The NSGA (Non-dominated Sorting Generic Algorithm has been implemented in this paper for finding an optimal design for a shaft subjected to cyclic loads, the conflycting goals being minimum weight and minimum lateral deflection.

  20. An Improved Lower Bound Limit State Optimisation Algorithm

    DEFF Research Database (Denmark)

    Frier, Christian; Damkilde, Lars

    2010-01-01

    Limit State analysis has been used in engineering practice for many years e.g. the yield-line method for concrete slabs and slip-line solutions in geotechnics. In the recent years there has been an increased interest in numerical Limit State analysis, and today algorithms take into account the non......-linear yield criteria. The aim of the paper is to refine an earlier presented effective method which reduces the number of optimisation variables considerably by eliminating the equilibrium equations a priori and improvements are made on the interior point optimisation algorithm....

  1. Robust eigenstructure clustering by non-smooth optimisation

    Science.gov (United States)

    Dao, Minh Ngoc; Noll, Dominikus; Apkarian, Pierre

    2015-08-01

    We extend classical eigenstructure assignment to more realistic problems, where additional performance and robustness specifications arise. Our aim is to combine time-domain constraints, as reflected by pole location and eigenvector structure, with frequency-domain objectives such as the H2, H∞ or Hankel norms. Using pole clustering, we allow poles to move in polydisks of prescribed size around their nominal values, driven by optimisation. Eigenelements, that is poles and eigenvectors, are allowed to move simultaneously and serve as decision variables in a specialised non-smooth optimisation technique. Two aerospace applications illustrate the power of the new method.

  2. Optimisation of Oil Production in Two – Phase Flow Reservoir Using Simultaneous Method and Interior Point Optimiser

    DEFF Research Database (Denmark)

    2012-01-01

    in the reservoir. A promising decrease of these remained resources can be provided by smart wells applying water injections to sustain satisfactory pressure level in the reservoir throughout the whole process of oil production. Basically to enhance secondary recovery of the remaining oil after drilling, water...... fields, or closed loop optimisation, can be used for optimising the reservoir performance in terms of net present value of oil recovery or another economic objective. In order to solve an optimal control problem we use a direct collocation method where we translate a continuous problem into a discrete...... for large scale nonlinear optimisation was applied. Because of its versatile compatibility with programming technologies, a C++ programming language in Microsoft Visual Studio integrated development environment was used for modelling the optimal control problem. Thanks to object oriented features...

  3. Solving dynamic multi-objective problems with vector evaluated particle swarm optimisation

    CSIR Research Space (South Africa)

    Greeff, M

    2008-06-01

    Full Text Available Many optimisation problems are multi-objective and change dynamically. Many methods use a weighted average approach to the multiple objectives. This paper introduces the usage of the vector evaluated particle swarm optimiser (VEPSO) to solve dynamic...

  4. Agent-Based Decision Control—How to Appreciate Multivariate Optimisation in Architecture

    DEFF Research Database (Denmark)

    Negendahl, Kristoffer; Perkov, Thomas Holmer; Kolarik, Jakub

    2015-01-01

    in the early design stage. The main focus is to demonstrate the optimisation method, which is done in two ways. Firstly, the newly developed agent-based optimisation algorithm named Moth is tested on three different single objective search spaces. Here Moth is compared to two evolutionary algorithms. Secondly......, the method is applied to a multivariate optimisation problem. The aim is specifically to demonstrate optimisation for entire building energy consumption, daylight distribution and capital cost. Based on the demonstrations Moth’s ability to find local minima is discussed. It is concluded that agent-based...... optimisation algorithms like Moth open up for new uses of optimisation in the early design stage. With Moth the final outcome is less dependent on pre- and post-processing, and Moth allows user intervention during optimisation. Therefore, agent-based models for optimisation such as Moth can be a powerful...

  5. The trajectory of dispersal research in conservation biology. Systematic review.

    Directory of Open Access Journals (Sweden)

    Don A Driscoll

    Full Text Available Dispersal knowledge is essential for conservation management, and demand is growing. But are we accumulating dispersal knowledge at a pace that can meet the demand? To answer this question we tested for changes in dispersal data collection and use over time. Our systematic review of 655 conservation-related publications compared five topics: climate change, habitat restoration, population viability analysis, land planning (systematic conservation planning and invasive species. We analysed temporal changes in the: (i questions asked by dispersal-related research; (ii methods used to study dispersal; (iii the quality of dispersal data; (iv extent that dispersal knowledge is lacking, and; (v likely consequences of limited dispersal knowledge. Research questions have changed little over time; the same problems examined in the 1990s are still being addressed. The most common methods used to study dispersal were occupancy data, expert opinion and modelling, which often provided indirect, low quality information about dispersal. Although use of genetics for estimating dispersal has increased, new ecological and genetic methods for measuring dispersal are not yet widely adopted. Almost half of the papers identified knowledge gaps related to dispersal. Limited dispersal knowledge often made it impossible to discover ecological processes or compromised conservation outcomes. The quality of dispersal data used in climate change research has increased since the 1990s. In comparison, restoration ecology inadequately addresses large-scale process, whilst the gap between knowledge accumulation and growth in applications may be increasing in land planning. To overcome apparent stagnation in collection and use of dispersal knowledge, researchers need to: (i improve the quality of available data using new approaches; (ii understand the complementarities of different methods and; (iii define the value of different kinds of dispersal information for supporting

  6. SLA-based optimisation of virtualised resource for multi-tier web applications in cloud data centres

    Science.gov (United States)

    Bi, Jing; Yuan, Haitao; Tie, Ming; Tan, Wei

    2015-10-01

    Dynamic virtualised resource allocation is the key to quality of service assurance for multi-tier web application services in cloud data centre. In this paper, we develop a self-management architecture of cloud data centres with virtualisation mechanism for multi-tier web application services. Based on this architecture, we establish a flexible hybrid queueing model to determine the amount of virtual machines for each tier of virtualised application service environments. Besides, we propose a non-linear constrained optimisation problem with restrictions defined in service level agreement. Furthermore, we develop a heuristic mixed optimisation algorithm to maximise the profit of cloud infrastructure providers, and to meet performance requirements from different clients as well. Finally, we compare the effectiveness of our dynamic allocation strategy with two other allocation strategies. The simulation results show that the proposed resource allocation method is efficient in improving the overall performance and reducing the resource energy cost.

  7. Non-linear Total Energy Optimisation of a Fleet of Power Plants

    Science.gov (United States)

    Nolle, Lars; Biegler-König, Friedrich; Deeskow, Peter

    In order to optimise the energy production in a fleet of power plants, it is necessary to solve a mixed integer optimisation problem. Traditionally, the continuous parts of the problem are linearized and a Simplex scheme is applied. Alternatively, heuristic "bionic" optimisation methods can be used without having to linearize the problem. Weare going to demonstrate this approach by modelling power plant blocks with fast Neural Networks and optimising the operation of multi-block power plants over one day with Simulated Annealing.

  8. Optimisation of a novel trailing edge concept for a high lift device

    CSIR Research Space (South Africa)

    Botha, JDM

    2014-09-01

    Full Text Available A novel concept (referred to as the flap extension) is implemented on the leading edge of the flap of a three element high lift device. The concept is optimised using two optimisation approaches based on Genetic Algorithm optimisations. A zero order...

  9. hydroPSO: A Versatile Particle Swarm Optimisation R Package for Calibration of Environmental Models

    Science.gov (United States)

    Zambrano-Bigiarini, M.; Rojas, R.

    2012-04-01

    Particle Swarm Optimisation (PSO) is a recent and powerful population-based stochastic optimisation technique inspired by social behaviour of bird flocking, which shares similarities with other evolutionary techniques such as Genetic Algorithms (GA). In PSO, however, each individual of the population, known as particle in PSO terminology, adjusts its flying trajectory on the multi-dimensional search-space according to its own experience (best-known personal position) and the one of its neighbours in the swarm (best-known local position). PSO has recently received a surge of attention given its flexibility, ease of programming, low memory and CPU requirements, and efficiency. Despite these advantages, PSO may still get trapped into sub-optimal solutions, suffer from swarm explosion or premature convergence. Thus, the development of enhancements to the "canonical" PSO is an active area of research. To date, several modifications to the canonical PSO have been proposed in the literature, resulting into a large and dispersed collection of codes and algorithms which might well be used for similar if not identical purposes. In this work we present hydroPSO, a platform-independent R package implementing several enhancements to the canonical PSO that we consider of utmost importance to bring this technique to the attention of a broader community of scientists and practitioners. hydroPSO is model-independent, allowing the user to interface any model code with the calibration engine without having to invest considerable effort in customizing PSO to a new calibration problem. Some of the controlling options to fine-tune hydroPSO are: four alternative topologies, several types of inertia weight, time-variant acceleration coefficients, time-variant maximum velocity, regrouping of particles when premature convergence is detected, different types of boundary conditions and many others. Additionally, hydroPSO implements recent PSO variants such as: Improved Particle Swarm

  10. Mobile app and app store analysis, testing and optimisation

    OpenAIRE

    Harman, M.; Al-Subaihin, A.; Jia, Y.; Martin, W.; Sarro, F.; Zhang, Y.

    2016-01-01

    This talk presents results on analysis and testing of mobile apps and app stores, reviewing the work of the UCL App Analysis Group (UCLappA) on App Store Mining and Analysis. The talk also covers the work of the UCL CREST centre on Genetic Improvement, applicable to app improvement and optimisation.

  11. Optimisation of sampling windows design for population pharmacokinetic experiments.

    Science.gov (United States)

    Ogungbenro, Kayode; Aarons, Leon

    2008-08-01

    This paper describes an approach for optimising sampling windows for population pharmacokinetic experiments. Sampling windows designs are more practical in late phase drug development where patients are enrolled in many centres and in out-patient clinic settings. Collection of samples under the uncontrolled environment at these centres at fixed times may be problematic and can result in uninformative data. Population pharmacokinetic sampling windows design provides an opportunity to control when samples are collected by allowing some flexibility and yet provide satisfactory parameter estimation. This approach uses information obtained from previous experiments about the model and parameter estimates to optimise sampling windows for population pharmacokinetic experiments within a space of admissible sampling windows sequences. The optimisation is based on a continuous design and in addition to sampling windows the structure of the population design in terms of the proportion of subjects in elementary designs, number of elementary designs in the population design and number of sampling windows per elementary design is also optimised. The results obtained showed that optimal sampling windows designs obtained using this approach are very efficient for estimating population PK parameters and provide greater flexibility in terms of when samples are collected. The results obtained also showed that the generalized equivalence theorem holds for this approach.

  12. Plant-wide performance optimisation – The refrigeration system case

    DEFF Research Database (Denmark)

    Green, Torben; Razavi-Far, Roozbeh; Izadi-Zamanabadi, Roozbeh;

    2012-01-01

    This paper investigates the problem of plant-wide performance optimisation seen from an industrial perspective. The refrigeration system is used as a case study, because it has a distributed control architecture and operates in steady state conditions, which is common for many industrial applicat...

  13. Evaluation of a high throughput starch analysis optimised for wood.

    Directory of Open Access Journals (Sweden)

    Chandra Bellasio

    Full Text Available Starch is the most important long-term reserve in trees, and the analysis of starch is therefore useful source of physiological information. Currently published protocols for wood starch analysis impose several limitations, such as long procedures and a neutralization step. The high-throughput standard protocols for starch analysis in food and feed represent a valuable alternative. However, they have not been optimised or tested with woody samples. These have particular chemical and structural characteristics, including the presence of interfering secondary metabolites, low reactivity of starch, and low starch content. In this study, a standard method for starch analysis used for food and feed (AOAC standard method 996.11 was optimised to improve precision and accuracy for the analysis of starch in wood. Key modifications were introduced in the digestion conditions and in the glucose assay. The optimised protocol was then evaluated through 430 starch analyses of standards at known starch content, matrix polysaccharides, and wood collected from three organs (roots, twigs, mature wood of four species (coniferous and flowering plants. The optimised protocol proved to be remarkably precise and accurate (3%, suitable for a high throughput routine analysis (35 samples a day of specimens with a starch content between 40 mg and 21 µg. Samples may include lignified organs of coniferous and flowering plants and non-lignified organs, such as leaves, fruits and rhizomes.

  14. Evaluation of a high throughput starch analysis optimised for wood.

    Science.gov (United States)

    Bellasio, Chandra; Fini, Alessio; Ferrini, Francesco

    2014-01-01

    Starch is the most important long-term reserve in trees, and the analysis of starch is therefore useful source of physiological information. Currently published protocols for wood starch analysis impose several limitations, such as long procedures and a neutralization step. The high-throughput standard protocols for starch analysis in food and feed represent a valuable alternative. However, they have not been optimised or tested with woody samples. These have particular chemical and structural characteristics, including the presence of interfering secondary metabolites, low reactivity of starch, and low starch content. In this study, a standard method for starch analysis used for food and feed (AOAC standard method 996.11) was optimised to improve precision and accuracy for the analysis of starch in wood. Key modifications were introduced in the digestion conditions and in the glucose assay. The optimised protocol was then evaluated through 430 starch analyses of standards at known starch content, matrix polysaccharides, and wood collected from three organs (roots, twigs, mature wood) of four species (coniferous and flowering plants). The optimised protocol proved to be remarkably precise and accurate (3%), suitable for a high throughput routine analysis (35 samples a day) of specimens with a starch content between 40 mg and 21 µg. Samples may include lignified organs of coniferous and flowering plants and non-lignified organs, such as leaves, fruits and rhizomes.

  15. Evaluation of a High Throughput Starch Analysis Optimised for Wood

    Science.gov (United States)

    Bellasio, Chandra; Fini, Alessio; Ferrini, Francesco

    2014-01-01

    Starch is the most important long-term reserve in trees, and the analysis of starch is therefore useful source of physiological information. Currently published protocols for wood starch analysis impose several limitations, such as long procedures and a neutralization step. The high-throughput standard protocols for starch analysis in food and feed represent a valuable alternative. However, they have not been optimised or tested with woody samples. These have particular chemical and structural characteristics, including the presence of interfering secondary metabolites, low reactivity of starch, and low starch content. In this study, a standard method for starch analysis used for food and feed (AOAC standard method 996.11) was optimised to improve precision and accuracy for the analysis of starch in wood. Key modifications were introduced in the digestion conditions and in the glucose assay. The optimised protocol was then evaluated through 430 starch analyses of standards at known starch content, matrix polysaccharides, and wood collected from three organs (roots, twigs, mature wood) of four species (coniferous and flowering plants). The optimised protocol proved to be remarkably precise and accurate (3%), suitable for a high throughput routine analysis (35 samples a day) of specimens with a starch content between 40 mg and 21 µg. Samples may include lignified organs of coniferous and flowering plants and non-lignified organs, such as leaves, fruits and rhizomes. PMID:24523863

  16. Optimisation of Kinematics for Tracked Vehicle Hydro Gas Suspension System

    Directory of Open Access Journals (Sweden)

    S. Sridhar

    2006-11-01

    Full Text Available The modern-day armoured fighting vehicles (AFVs are basically tracked vehicles equippedwith hydro gas suspensions, in lieu of conventional mechanical suspensions like torsion barand coil spring bogie suspensions. The uniqueness of hydro gas suspension is that it offersa nonlinear spring rate, which is very much required for the cross-country moveability of atracked vehicle. The AFVs have to negotiate different cross-country terrains like sandy, rocky,riverbed, etc. and the road irregularities provide enumerable problems during dynamic loadingsto the design of hydro gas suspension system. Optimising various design parameters demandsinnovative design methodologies to achieve better ride performance. Hence, a comprehensivekinematic analysis is needed. In this study, a methodology has been derived to optimise thekinematics of the suspension by reorienting the cylinder axis and optimising the loadtransferringleverage factor so that the side thrust on the cylinder is minimised to a greaterextent. The optimisation ultimately increases the life of the high-pressure and high-temperaturepiston seals, resulting in enhanced system life for better dependability.

  17. Cluster Optimisation using Cgroups at a Tier-2

    Science.gov (United States)

    Qin, G.; Roy, G.; Crooks, D.; Skipsey, S. C.; Stewart, G. P.; Britton, D.

    2016-10-01

    The Linux kernel feature Control Groups (cgroups) has been used to gather metrics on the resource usage of single and eight-core ATLAS workloads. It has been used to study the effects on performance of a reduction in the amount of physical memory. The results were used to optimise cluster performance, and consequently increase cluster throughput by up to 10%.

  18. Smart optimisation and sensitivity analysis in water distribution systems

    CSIR Research Space (South Africa)

    Page, Philip R

    2015-12-01

    Full Text Available stream_source_info Page_16028_2015.pdf.txt stream_content_type text/plain stream_size 1806 Content-Encoding ISO-8859-1 stream_name Page_16028_2015.pdf.txt Content-Type text/plain; charset=ISO-8859-1 SMART OPTIMISATION...

  19. Computational optimisation of targeted DNA sequencing for cancer detection

    DEFF Research Database (Denmark)

    Martinez, Pierre; McGranahan, Nicholas; Birkbak, Nicolai Juul

    2013-01-01

    circulating tumour DNA (ctDNA) might represent a non-invasive method to detect mutations in patients, facilitating early detection. In this article, we define reduced gene panels from publicly available datasets as a first step to assess and optimise the potential of targeted ctDNA scans for early tumour...

  20. Application of Surpac and Whittle Software in Open Pit Optimisation ...

    African Journals Online (AJOL)

    Michael

    2015-06-01

    Jun 1, 2015 ... Optimisation and Design”, Ghana Mining Journal, Vol. 15, No. 1, pp. 35 - 43. Abstract ... reduction in metal price in the market. The work involved in open .... also aided in viewing the model in graphics. A constraint is a logical ...

  1. Optimising Microbial Growth with a Bench-Top Bioreactor

    Science.gov (United States)

    Baker, A. M. R.; Borin, S. L.; Chooi, K. P.; Huang, S. S.; Newgas, A. J. S.; Sodagar, D.; Ziegler, C. A.; Chan, G. H. T.; Walsh, K. A. P.

    2006-01-01

    The effects of impeller size, agitation and aeration on the rate of yeast growth were investigated using bench-top bioreactors. This exercise, carried out over a six-month period, served as an effective demonstration of the importance of different operating parameters on cell growth and provided a means of determining the optimisation conditions…

  2. Deterministic and robust optimisation strategies for metal forming proceesses

    NARCIS (Netherlands)

    Bonte, M.H.A.; Boogaard, van den A.H.; Huetink, J.

    2007-01-01

    Product improvement and cost reduction have always been important goals in the metal forming industry. The rise of Finite Element simulations for metal forming processes has contributed to these goals in a major way. More recently, coupling FEM simulations to mathematical optimisation techniques has

  3. A Bayesian Approach for Sensor Optimisation in Impact Identification

    Directory of Open Access Journals (Sweden)

    Vincenzo Mallardo

    2016-11-01

    Full Text Available This paper presents a Bayesian approach for optimizing the position of sensors aimed at impact identification in composite structures under operational conditions. The uncertainty in the sensor data has been represented by statistical distributions of the recorded signals. An optimisation strategy based on the genetic algorithm is proposed to find the best sensor combination aimed at locating impacts on composite structures. A Bayesian-based objective function is adopted in the optimisation procedure as an indicator of the performance of meta-models developed for different sensor combinations to locate various impact events. To represent a real structure under operational load and to increase the reliability of the Structural Health Monitoring (SHM system, the probability of malfunctioning sensors is included in the optimisation. The reliability and the robustness of the procedure is tested with experimental and numerical examples. Finally, the proposed optimisation algorithm is applied to a composite stiffened panel for both the uniform and non-uniform probability of impact occurrence.

  4. Optimising a fall out dust monitoring sampling programme at a ...

    African Journals Online (AJOL)

    GREG

    The aim of this study at the specific cement manufacturing plant and open cast mine was ... Key words: Fall out dust monitoring, cement plant, optimising, air pollution sampling, ..... meters as this is in line with the height of a typical fall out dust.

  5. Optimisation of searches for Supersymmetry with the ATLAS detector

    Energy Technology Data Exchange (ETDEWEB)

    Zvolsky, Milan

    2012-01-15

    The ATLAS experiment is one of the four large experiments at the Large Hadron Collider which is specifically designed to search for the Higgs boson and physics beyond the Standard Model. The aim of this thesis is the optimisation of searches for Supersymmetry in decays with two leptons and missing transverse energy in the final state. Two different optimisation studies have been performed for two important analysis aspects: The final signal region selection and the choice of the trigger selection. In the first part of the analysis, a cut-based optimisation of signal regions is performed, maximising the signal for a minimal background contamination. By this, the signal yield can in parts be more than doubled. The second approach is to introduce di-lepton triggers which allow to lower the lepton transverse momentum threshold, thus enhancing the number of selected signal events significantly. The signal region optimisation was considered for the choice of the final event selection in the ATLAS di-lepton analyses. The trigger study contributed to the incorporation of di-lepton triggers to the ATLAS trigger menu. (orig.)

  6. Optimised prefactored compact schemes for linear wave propagation phenomena

    Science.gov (United States)

    Rona, A.; Spisso, I.; Hall, E.; Bernardini, M.; Pirozzoli, S.

    2017-01-01

    A family of space- and time-optimised prefactored compact schemes are developed that minimise the computational cost for given levels of numerical error in wave propagation phenomena, with special reference to aerodynamic sound. This work extends the approach of Pirozzoli [1] to the MacCormack type prefactored compact high-order schemes developed by Hixon [2], in which their shorter Padé stencil from the prefactorisation leads to a simpler enforcement of numerical boundary conditions. An explicit low-storage multi-step Runge-Kutta integration advances the states in time. Theoretical predictions for spatial and temporal error bounds are derived for the cost-optimised schemes and compared against benchmark schemes of current use in computational aeroacoustic applications in terms of computational cost for a given relative numerical error value. One- and two-dimensional test cases are presented to examine the effectiveness of the cost-optimised schemes for practical flow computations. An effectiveness up to about 50% higher than the standard schemes is verified for the linear one-dimensional advection solver, which is a popular baseline solver kernel for computational physics problems. A substantial error reduction for a given cost is also obtained in the more complex case of a two-dimensional acoustic pulse propagation, provided the optimised schemes are made to operate close to their nominal design points.

  7. Using break quantities for tactical optimisation in multistage distribution systems

    NARCIS (Netherlands)

    M.J. Kleijn (Marcel); R. Dekker (Rommert)

    1997-01-01

    textabstractIn this chapter we discuss a tactical optimisation problem that arises in a multistage distribution system where customer orders can be delivered from any stockpoint. A simple rule to allocate orders to locations is a break quantity rule, which routes large orders to higher-stage stockpo

  8. Wear/comfort Pareto optimisation of bogie suspension

    Science.gov (United States)

    Milad Mousavi Bideleh, Seyed; Berbyuk, Viktor; Persson, Rickard

    2016-08-01

    Pareto optimisation of bogie suspension components is considered for a 50 degrees of freedom railway vehicle model to reduce wheel/rail contact wear and improve passenger ride comfort. Several operational scenarios including tracks with different curve radii ranging from very small radii up to straight tracks are considered for the analysis. In each case, the maximum admissible speed is applied to the vehicle. Design parameters are categorised into two levels and the wear/comfort Pareto optimisation is accordingly accomplished in a multistep manner to improve the computational efficiency. The genetic algorithm (GA) is employed to perform the multi-objective optimisation. Two suspension system configurations are considered, a symmetric and an asymmetric in which the primary or secondary suspension elements on the right- and left-hand sides of the vehicle are not the same. It is shown that the vehicle performance on curves can be significantly improved using the asymmetric suspension configuration. The Pareto-optimised values of the design parameters achieved here guarantee wear reduction and comfort improvement for railway vehicles and can also be utilised in developing the reference vehicle models for design of bogie active suspension systems.

  9. Adaptive optimisation of a generalised beam shaping system

    DEFF Research Database (Denmark)

    Kenny, F.; Choi, F. S.; Glückstad, Jesper

    2015-01-01

    filter were generated by the SLM. This provided extra flexibility and control over the parameters of the system including the phase step magnitude, shape, radius and position of the filter. A feedback method for the on-line optimisation of these properties was also developed. Using feedback from images...

  10. Multi-disciplinary design optimisation via dashboard portals

    NARCIS (Netherlands)

    Uijtenhaak, T.; Coenders, J.L.

    2012-01-01

    This paper will present the opportunities a dashboard-based system provides to gather information on alternatives and display this in such a way that it will help the user making decisions by making use of multi-disciplinary optimisation (MDO) technology. The multi-disciplinary set up of the program

  11. A metamodel based optimisation algorithm for metal forming processes

    NARCIS (Netherlands)

    Bonte, M.H.A.; Boogaard, van den A.H.; Huetink, J.; Banabic, Dorel

    2007-01-01

    Cost saving and product improvement have always been important goals in the metal forming industry. To achieve these goals, metal forming processes need to be optimised. During the last decades, simulation software based on the Finite Element Method (FEM) has significantly contributed to designing f

  12. Optimised cantilever biosensor with piezoresistive read-out

    DEFF Research Database (Denmark)

    Rasmussen, Peter; Thaysen, J.; Hansen, Ole

    2003-01-01

    We present a cantilever-based biochemical sensor with piezoresistive read-out which has been optimised for measuring surface stress. The resistors and the electrical wiring on the chip are encapsulated in low-pressure chemical vapor deposition (LPCVD) silicon nitride, so that the chip is well sui...

  13. Optimisation of selective breeding program for Nile tilapia (Oreochromis niloticus)

    NARCIS (Netherlands)

    Trong, T.Q.

    2013-01-01

      The aim of this thesis was to optimise the selective breeding program for Nile tilapia in the Mekong Delta region of Vietnam. Two breeding schemes, the “classic” BLUP scheme following the GIFT method (with pair mating) and a rotational mating scheme with own performance selection

  14. SINGLE FIXED CRANE OPTIMISATION WITHIN A DISTRIBUTION CENTRE

    Directory of Open Access Journals (Sweden)

    J. Matthews

    2012-01-01

    Full Text Available

    ENGLISH ABSTRACT: This paper considersthe optimisation of the movement of a fixed crane operating in a single aisle of a distribution centre. The crane must move pallets in inventory between docking bays, storage locations, and picking lines. Both a static and a dynamic approach to the problem are presented. The optimisation is performed by means of tabu search, ant colony metaheuristics,and hybrids of these two methods. All these solution approaches were tested on real life data obtained from an operational distribution centre. Results indicate that the hybrid methods outperform the other approaches.

    AFRIKAANSE OPSOMMING: Die optimisering van die beweging van 'n vaste hyskraan in 'n enkele gang van 'n distribusiesentrum word in hierdie artikel beskou. Die hyskraan moet pallette vervoer tussen dokhokke, stoorposisies, en opmaaklyne. Beide 'n statiese en 'n dinamiese benadering tot die probleem word aangebied. Die optimisering word gedoen met behulp van tabu-soektogte, mierkolonieoptimisering,en hibriede van hierdie twee metodes. Al die oplossingsbenaderings is getoets met werklike data wat van 'n operasionele distribusiesentrum verkry is. Die resultate toon aan dat die hibriedmetodes die beste oplossings lewer.

  15. Hierarchical optimisation on scissor seat suspension characteristic and structure

    Science.gov (United States)

    Wang, Chunlei; Zhang, Xinjie; Guo, Konghui; Lv, Jiming; Yang, Yi

    2016-11-01

    Scissor seat suspension has been applied widely to attenuate the cab vibrations of commercial vehicles, while its design generally needs a trade-off between the seat acceleration and suspension travel, which creates a typical optimisation issue. A complexity for this issue is that the optimal dynamics parameters are not easy to approach solutions fast and unequivocally. Hence, the hierarchical optimisation on scissor seat suspension characteristic and structure is proposed, providing a top-down methodology with the globally optimal and fast convergent solutions to compromise these design contradictions. In details, a characteristic-oriented non-parametric dynamics model of the scissor seat suspension is formulated firstly via databases, describing its vertical dynamics accurately. Then, the ideal vertical stiffness-damping characteristic is cascaded via the characteristic-oriented model, and the structure parameters are optimised in accordance with a structure-oriented multi-body dynamics model of the scissor seat suspension. Eventually, the seat effective amplitude transmissibility factor, suspension travel and the CPU time for solving are evaluated. The results show the seat suspension performance and convergent speed of the globally optimal solutions are improved well. Hence, the proposed hierarchical optimisation methodology regarding characteristic and structure of the scissor seat suspension is promising for its virtual development.

  16. Multi-disciplinary design optimisation via dashboard portals

    NARCIS (Netherlands)

    Uijtenhaak, T.; Coenders, J.L.

    2012-01-01

    This paper will present the opportunities a dashboard-based system provides to gather information on alternatives and display this in such a way that it will help the user making decisions by making use of multi-disciplinary optimisation (MDO) technology. The multi-disciplinary set up of the program

  17. Analysing the performance of dynamic multi-objective optimisation algorithms

    CSIR Research Space (South Africa)

    Helbig, M

    2013-06-01

    Full Text Available Congress on Evolutionary Computation, 20-23 June 2013, Cancún, México Analysing the Performance of Dynamic Multi-objective Optimisation Algorithms Marde Helbig CSIR: Meraka Institute, Brummeria, South Africa; and University of Pretoria Computer...

  18. Self-organising sensor web using cell-fate optimisation

    CSIR Research Space (South Africa)

    Van Zyl, TL

    2009-07-01

    Full Text Available may be doing so both dynamically and stochastically. When presented by a dynamic and stochastic changing environment, such as a sensor resource unexpectedly going down, a self-adaptive system should exhibit robustness. Cell-fate optimisation and signal...

  19. Optimisation and sizing methodology for electromechanical actuators

    Energy Technology Data Exchange (ETDEWEB)

    Leconte, V.; Mazauric, V.; Roussin, B. [Schneider Electric Research Center, Grenoble (France); Atienza, E. [Lab. d' Electrotechnique de Grenoble, INPG/UJF-CNRS UMR, St-Martin-d' Heres (France)

    2000-08-01

    In this paper, we will present a multimodelling problem, and the design process that we manage to associate with. In the first part, the different models are described. The reasons for those modelling are also exposed. Then, the applied design process will be detailed and justified. At last, the final device will be introduced. (orig.)

  20. TIME SHIFT AND TIMING JITTER INDUCED BY RAMAN EFFECT IN DISPERSION-MANAGED SOLITONS%色散管理孤子中Raman效应引起的时移及定时抖动

    Institute of Scientific and Technical Information of China (English)

    张帆; 叶培大; 伍剑; 林金桐

    2002-01-01

    给出了色散管理孤子中Raman效应所引起的脉冲中心位置时移的解析表达式并讨论了孤子脉宽的波动所引起的Raman定时抖动.结果表明:时移的演化和不同的色散配置有关,并且色散管理孤子Raman时移和常规孤子一样与传输距离及平均色散的平方成正比,但是比常规孤子的比例大.%The analytical expression of time shift of the pulse central position induced by Raman effect in dispersion-managed solitons is deduced and Raman timing jitter due to pulse width fluctuation is also discussed.The results show that the time shift evolution depends on map scheme one chooses and increases with both the square of transmission distance and the square of the average dispersion just like the conventional soliton but with an enhanced ratio.

  1. Ability Dispersion and Team Performance

    DEFF Research Database (Denmark)

    Hoogendoorn, Sander; Parker, Simon C.; Van Praag, Mirjam

    What is the effect of dispersed levels of cognitive ability of members of a (business) team on their team's performance? This paper reports the results of a field experiment in which 573 students in 49 teams start up and manage real companies under identical circumstances for one year. We ensured...... exogenous variation in -otherwise random- team composition by assigning students to teams based on their measured cognitive abilities (Raven test). Each team performs a variety of tasks, often involving complex decision making. The key result of the experiment is that the performance of business teams first...... increases and then decreases with ability dispersion. We seek to understand this finding by developing a model in which team members of different ability levels form sub-teams with other team members with similar ability levels to specialize in different productive tasks. Diversity spreads production over...

  2. Ability Dispersion and Team Performance

    DEFF Research Database (Denmark)

    Hoogendoorn, Sander; Parker, Simon C.; Van Praag, Mirjam

    What is the effect of dispersed levels of cognitive ability of members of a (business) team on their team's performance? This paper reports the results of a field experiment in which 573 students in 49 (student) teams start up and manage real companies under identical circumstances for one year. We...... ensured exogenous variation in otherwise random team composition by assigning students to teams based on their measured cognitive abilities. Each team performs a variety of tasks, often involving complex decision making. The key result of the experiment is that the performance of business teams first...... increases and then decreases with ability dispersion. We seek to understand this finding by developing a model in which team members of different ability levels form sub- teams with other team members with similar ability levels to specialize in different productive tasks. Diversity spreads production over...

  3. Ability Dispersion and Team Performance

    DEFF Research Database (Denmark)

    Hoogendoorn, Sander; Parker, Simon C.; Van Praag, Mirjam

    What is the effect of dispersed levels of cognitive ability of members of a (business) team on their team's performance? This paper reports the results of a field experiment in which 573 students in 49 teams start up and manage real companies under identical circumstances. We ensured exogenous...... variation in - otherwise random - team composition by assigning students to teams based on their measured cognitive abilities (Raven test). Each team performs a variety of tasks, often involving complex decision making. The key result of the experiment is that the performance of business teams first...... increases and then decreases with ability dispersion. We seek to understand this finding by developing a model in which team members of different ability levels form sub-teams with other team members with similar ability levels to specialize in different productive tasks. Diversity spreads production over...

  4. Vowel dispersion in Truku

    OpenAIRE

    Chiang, Wen-yu; Chiang, Fang-mei

    2013-01-01

    This study investigates the dispersion of vowel space in Truku, an endangered Austronesian language in Taiwan. Adaptive Dispersion (Liljencrants and Lindblom, 1972; Lindblom, 1986, 1990) proposes that the distinctive sounds of a language tend to be positioned in phonetic space in a way that maximizes perceptual contrast. For example, languages with large vowel inventories tend to expand the overall acoustic vowel space. Adaptive Dispersion predicts that the distance between the point vowels w...

  5. Are dispersal mechanisms changing the host-parasite relationship and increasing the virulence of Varroa destructor [Acari:Varroidae] in managed honey bee [Hymenoptera: Apidae] colonies?

    Science.gov (United States)

    Varroa mites are the most serious pest of honey bees worldwide, and difficult to control in managed colonies. We show in a longitudinal study that even with multiple miticide treatments in the summer and fall, mite numbers remained high and colony losses exceeded 55%. Furthermore, large heavily infe...

  6. Prediction of road traffic death rate using neural networks optimised by genetic algorithm.

    Science.gov (United States)

    Jafari, Seyed Ali; Jahandideh, Sepideh; Jahandideh, Mina; Asadabadi, Ebrahim Barzegari

    2015-01-01

    Road traffic injuries (RTIs) are realised as a main cause of public health problems at global, regional and national levels. Therefore, prediction of road traffic death rate will be helpful in its management. Based on this fact, we used an artificial neural network model optimised through Genetic algorithm to predict mortality. In this study, a five-fold cross-validation procedure on a data set containing total of 178 countries was used to verify the performance of models. The best-fit model was selected according to the root mean square errors (RMSE). Genetic algorithm, as a powerful model which has not been introduced in prediction of mortality to this extent in previous studies, showed high performance. The lowest RMSE obtained was 0.0808. Such satisfactory results could be attributed to the use of Genetic algorithm as a powerful optimiser which selects the best input feature set to be fed into the neural networks. Seven factors have been known as the most effective factors on the road traffic mortality rate by high accuracy. The gained results displayed that our model is very promising and may play a useful role in developing a better method for assessing the influence of road traffic mortality risk factors.

  7. Optimising the diagnosis of ectopic pregnancy.

    Science.gov (United States)

    Berry, Janet; Davey, Mark; Hon, Mei-See; Behrens, Renée

    2016-05-01

    This retrospective cohort study reviewed the diagnosis of all ectopic pregnancies within a district general hospital over a 5-year period after the establishment of a dedicated Early Pregnancy Assessment Unit (EPAU). Of 215 ectopic pregnancies identified, notes were available for 208 (97%). Two-hundred and two cases were determined to have been diagnosed and managed as ectopic pregnancies. Six cases were excluded as they were pregnancies of unknown location managed as such. Overall, 91% were diagnosed by ultrasound scan, 5% were diagnosed clinically and 3% were diagnosed on serial human chorionic gonadotrophin (hCG) levels. This study found that the introduction of a dedicated, multi-professional, EPAU with a stable workforce improved ultrasound visualisation of ectopic pregnancies at first ultrasound scan from 22% prior to its commencement, to 61% over this period. The improvement in positive scan diagnosis of ectopic pregnancy was associated with a reduction in negative laparoscopy rate from 13% to 6%.

  8. Dispersion Properties in Total Internal Reflective Photonic Crystal Fiber

    Institute of Scientific and Technical Information of China (English)

    WEN Hua; HAO Dong-shan

    2004-01-01

    The dispersion properties in the short wavelength region of total internal reflective photonic crystal fiber have been studied by using the models of the equivalent twin waveguide soliton coupling,effective refractive index, effective normalized frequency and dispersion management solitons. It is shown that the dispersion in the cladding waveguide of the total internal reflective photonic crystal fiber is a positive dispersion,and the dispersion of its core waveguide is a negative dispersion. The method of the compensated probing laser diffraction by the phase hole induced by the stationary pumping laser in the cladding waveguide enables the average dispersion value of the total internal reflective photonic crystal fiber to be close to zero and the zero dispersion point to shift to the short wavelength region.

  9. Methodical approach to financial stimulation of logistics managers

    Directory of Open Access Journals (Sweden)

    Melnykova Kateryna V.

    2014-01-01

    Full Text Available The article offers a methodical approach to financial stimulation of logistics managers, which allows calculation of the incentive amount with consideration of profit obtained from introduction of optimisation logistics solutions. The author generalises measures, which would allow increase of stimulation of labour of logistics managers by the enterprise top managers. The article marks out motivation factors, which exert influence upon relation of logistics managers to execution of optimisation logistical solutions, which minimise logistical costs. The author builds a scale of financial encouragement for introduction of optimisation logistical solutions proposed by logistics managers. This scale is basic for functioning of the encouragement system and influences the increase of efficiency of logistics managers operation and also optimisation of enterprise logistical solutions.

  10. A methodological approach to the design of optimising control strategies for sewer systems

    DEFF Research Database (Denmark)

    Mollerup, Ane Loft; Mikkelsen, Peter Steen; Sin, Gürkan

    2016-01-01

    This study focuses on designing an optimisation based control for sewer system in a methodological way and linking itto a regulatory control. Optimisation based design is found to depend on proper choice of a model, formulation of objective function and tuning of optimisation parameters. Accordin......This study focuses on designing an optimisation based control for sewer system in a methodological way and linking itto a regulatory control. Optimisation based design is found to depend on proper choice of a model, formulation of objective function and tuning of optimisation parameters...... control; a rule based expert system. On the other hand, compared with a regulatory control technique designed earlier in Mollerup et al. (2015), the optimisation showed similar performance with respect to minimising overflow volume. Hence for operation of small sewer systems, regulatory control strategies...... can offer promising potential and should be considered along more advanced strategies when identifying novel solutions....

  11. Mesh dependence in PDE-constrained optimisation an application in tidal turbine array layouts

    CERN Document Server

    Schwedes, Tobias; Funke, Simon W; Piggott, Matthew D

    2017-01-01

    This book provides an introduction to PDE-constrained optimisation using finite elements and the adjoint approach. The practical impact of the mathematical insights presented here are demonstrated using the realistic scenario of the optimal placement of marine power turbines, thereby illustrating the real-world relevance of best-practice Hilbert space aware approaches to PDE-constrained optimisation problems. Many optimisation problems that arise in a real-world context are constrained by partial differential equations (PDEs). That is, the system whose configuration is to be optimised follows physical laws given by PDEs. This book describes general Hilbert space formulations of optimisation algorithms, thereby facilitating optimisations whose controls are functions of space. It demonstrates the importance of methods that respect the Hilbert space structure of the problem by analysing the mathematical drawbacks of failing to do so. The approaches considered are illustrated using the optimisation problem arisin...

  12. Modelling and genetic algorithm based optimisation of inverse supply chain

    Science.gov (United States)

    Bányai, T.

    2009-04-01

    The design and control of recycling systems of products with environmental risk have been discussed in the world already for a long time. The main reasons to address this subject are the followings: reduction of waste volume, intensification of recycling of materials, closing the loop, use of less resource, reducing environmental risk [1, 2]. The development of recycling systems is based on the integrated solution of technological and logistic resources and know-how [3]. However the financial conditions of recycling systems is partly based on the recovery, disassembly and remanufacturing options of the used products [4, 5, 6], but the investment and operation costs of recycling systems can be characterised with high logistic costs caused by the geographically wide collection system with more collection level and a high number of operation points of the inverse supply chain. The reduction of these costs is a popular area of the logistics researches. These researches include the design and implementation of comprehensive environmental waste and recycling program to suit business strategies (global system), design and supply all equipment for production line collection (external system), design logistics process to suit the economical and ecological requirements (external system) [7]. To the knowledge of the author, there has been no research work on supply chain design problems that purpose is the logistics oriented optimisation of inverse supply chain in the case of non-linear total cost function consisting not only operation costs but also environmental risk cost. The antecedent of this research is, that the author has taken part in some research projects in the field of closed loop economy ("Closing the loop of electr(on)ic products and domestic appliances from product planning to end-of-life technologies), environmental friendly disassembly (Concept for logistical and environmental disassembly technologies) and design of recycling systems of household appliances

  13. Optimisation of transport processes in city logistics

    Directory of Open Access Journals (Sweden)

    2011-03-01

    Full Text Available The problem of the rationalization of the flow of people and goods in urban areas is discussed in the presented paper. Due to the increasing traffic congestion, this is one of the most important problems of the effective city management, especially in line with the principles of the sustainable development. The paper presents local conditionings for urban agglomeration of Pozna?, with particular attention paid to difficulties of the distribution of goods in urban areas. The available sources for obtaining the good practice for local authorities are presented, e.g. European projects like SUGAR Project (Sustainable Urban Goods Logistics Achieved by Regional and local policies.

  14. Seed dispersal in fens

    Science.gov (United States)

    Middleton, B.; Van Diggelen, R.; Jensen, K.

    2006-01-01

    Question: How does seed dispersal reduce fen isolation and contribute to biodiversity? Location: European and North American fens. Methods: This paper reviews the literature on seed dispersal to fens. Results: Landscape fragmentation may reduce dispersal opportunities thereby isolating fens and reducing genetic exchange. Species in fragmented wetlands may have lower reproductive success, which can lead to biodiversity loss. While fens may have always been relatively isolated from each other, they have become increasingly fragmented in modern times within agricultural and urban landscapes in both Europe and North America. Dispersal by water, animals and wind has been hampered by changes related to development in landscapes surrounding fens. Because the seeds of certain species are long-lived in the seed bank, frequent episodes of dispersal are not always necessary to maintain the biodiversity of fens. However, of particular concern to restoration is that some dominant species, such as the tussock sedge Carex stricta, may not disperse readily between fens. Conclusions: Knowledge of seed dispersal can be used to maintain and restore the biodiversity of fens in fragmented landscapes. Given that development has fragmented landscapes and that this situation is not likely to change, the dispersal of seeds might be enhanced by moving hay or cattle from fens to damaged sites, or by reestablishing lost hydrological connections. ?? IAVS; Opulus Press.

  15. Visualizing Dispersion Interactions

    Science.gov (United States)

    Gottschalk, Elinor; Venkataraman, Bhawani

    2014-01-01

    An animation and accompanying activity has been developed to help students visualize how dispersion interactions arise. The animation uses the gecko's ability to walk on vertical surfaces to illustrate how dispersion interactions play a role in macroscale outcomes. Assessment of student learning reveals that students were able to develop…

  16. Visualizing Dispersion Interactions

    Science.gov (United States)

    Gottschalk, Elinor; Venkataraman, Bhawani

    2014-01-01

    An animation and accompanying activity has been developed to help students visualize how dispersion interactions arise. The animation uses the gecko's ability to walk on vertical surfaces to illustrate how dispersion interactions play a role in macroscale outcomes. Assessment of student learning reveals that students were able to develop…

  17. Perfect Dispersive Medium

    CERN Document Server

    Gupta, Shulabh

    2015-01-01

    Dispersion is at the heart of all ultrafast real-time signal processing systems across the entire electromagnetic spectrum ranging from radio-frequencies to optics. However, following Kramer-Kronig relations, these signal processing systems have been plagued with the parasitic amplitude distortions due to frequency dependent, and non-flat amplitude transmission of naturally dispersive media. This issue puts a serious limitation on the applicability and performance of these signal processing systems. To solve the above mentioned issue, a perfect dispersive medium is proposed in this work, which artificially violates the Kramer-Kronig relations, while satisfying all causality requirements. The proposed dispersive metamaterial is based on loss-gain metasurface pairs and exhibit a perfectly flat transmission response along with arbitrary dispersion in a broad bandwidth, thereby solving a seemingly unavoidable issue in all ultrafast signal processing systems. Such a metamaterial is further shown using sub-waveleng...

  18. Evolution of dispersal distance.

    Science.gov (United States)

    Durrett, Rick; Remenik, Daniel

    2012-03-01

    The problem of how often to disperse in a randomly fluctuating environment has long been investigated, primarily using patch models with uniform dispersal. Here, we consider the problem of choice of seed size for plants in a stable environment when there is a trade off between survivability and dispersal range. Ezoe (J Theor Biol 190:287-293, 1998) and Levin and Muller-Landau (Evol Ecol Res 2:409-435, 2000) approached this problem using models that were essentially deterministic, and used calculus to find optimal dispersal parameters. Here we follow Hiebeler (Theor Pop Biol 66:205-218, 2004) and use a stochastic spatial model to study the competition of different dispersal strategies. Most work on such systems is done by simulation or nonrigorous methods such as pair approximation. Here, we use machinery developed by Cox et al. (Voter model perturbations and reaction diffusion equations 2011) to rigorously and explicitly compute evolutionarily stable strategies.

  19. A CONCEPTUAL FRAMEWORK FOR MANAGING RADIATION DOSE TO PATIENTS IN DIAGNOSTIC RADIOLOGY USING REFERENCE DOSE LEVELS.

    Science.gov (United States)

    Almén, Anja; Båth, Magnus

    2016-06-01

    The overall aim of the present work was to develop a conceptual framework for managing radiation dose in diagnostic radiology with the intention to support optimisation. An optimisation process was first derived. The framework for managing radiation dose, based on the derived optimisation process, was then outlined. The outset of the optimisation process is four stages: providing equipment, establishing methodology, performing examinations and ensuring quality. The optimisation process comprises a series of activities and actions at these stages. The current system of diagnostic reference levels is an activity in the last stage, ensuring quality. The system becomes a reactive activity only to a certain extent engaging the core activity in the radiology department, performing examinations. Three reference dose levels-possible, expected and established-were assigned to the three stages in the optimisation process, excluding ensuring quality. A reasonably achievable dose range is also derived, indicating an acceptable deviation from the established dose level. A reasonable radiation dose for a single patient is within this range. The suggested framework for managing radiation dose should be regarded as one part of the optimisation process. The optimisation process constitutes a variety of complementary activities, where managing radiation dose is only one part. This emphasises the need to take a holistic approach integrating the optimisation process in different clinical activities.

  20. Optimising investment performance through international diversification

    Directory of Open Access Journals (Sweden)

    J. Swart

    2014-01-01

    Full Text Available International portfolio diversification is often advocated as a way of enhancing portfolio performance particularly through the reduction of portfolio risk. Portfolio managers in Europe have for decades routinely invested a substantial portion of their portfolios in securities that were issued in other countries. During the last decade US investors have held a significant amount of foreign securities with over a trillion dollars invested in foreign assets by 1994. South African institutions have been allowed some freedom to diversify internationally since mid 1995 and individual investors since July 1997. In this paper the potential diversification benefits for South African investors are considered. The stability over time of the correlation structure is investigated and simple ex-ante investment strategies are formulated and evaluated.

  1. Performance optimisations for distributed analysis in ALICE

    CERN Document Server

    Betev, L; Gheata, M; Grigoras, C; Hristov, P

    2014-01-01

    Performance is a critical issue in a production system accommodating hundreds of analysis users. Compared to a local session, distributed analysis is exposed to services and network latencies, remote data access and heterogeneous computing infrastructure, creating a more complex performance and efficiency optimization matrix. During the last 2 years, ALICE analysis shifted from a fast development phase to the more mature and stable code. At the same time, the framewo rks and tools for deployment, monitoring and management of large productions have evolved considerably too. The ALICE Grid production system is currently used by a fair share of organized and individual user analysis, consuming up to 30% or the available r esources and ranging from fully I/O - bound analysis code to CPU intensive correlations or resonances studies. While the intrinsic analysis performance is unlikely to improve by a large factor during the LHC long shutdown (LS1), the overall efficiency of the system has still to be improved by a...

  2. Rapidly absorbed orodispersible tablet containing molecularly dispersed felodipine for management of hypertensive crisis: development, optimization and in vitro/in vivo studies.

    Science.gov (United States)

    Basalious, Emad B; El-Sebaie, Wessam; El-Gazayerly, Omaima

    2013-01-01

    A liquisolid orodispersible tablet of felodipine, a BCS Class II drug, was developed to improve drug dissolution and absorption through the buccal mucosa for management of hypertensive crisis. A 24 full-factorial design was applied to optimize felodipine liquisolid systems (FLSs) having acceptable flow properties and possessing enhanced drug dissolution rates. Four formulation variables; The liquid type, X1 (PG or PEG), drug concentration, X2 (10% and 20%), type of coat, X3 (Aerosil® and Aeroperl®) and excipients ratio, X4 (10 and 20) were included in the design. The systems were assessed for dissolution and flow properties. Following optimization, the formulation components (X1, X2, X3 and X4) were PEG, 10%, Aerosil® and 20, respectively. The optimized FLS was compressed into felodipine liquisolid orodispersible tablet using Prosolv® as carrier material (FLODT-2). The in vitro and in vivo disintegration times of FLODT-2 were 9 and 7 s, respectively. The in vivo pharmacokinetic study using human volunteers showed a significant increase in dissolution and absorption rates of the formulation of FLODT-2 compared to soft gelatin capsules filled with felodipine solution in PEG under the same conditions. Our results proposed that the optimized FLODT formulation could be promising to manage hypertensive crisis.

  3. Optimising steel production schedules via a hierarchical genetic algorithm

    Directory of Open Access Journals (Sweden)

    Worapradya, Kiatkajohn

    2014-08-01

    Full Text Available This paper presents an effective scheduling in a steel-making continuous casting (SCC plant. The main contribution of this paper is the formulation of a new optimisation model that more closely represents real-world situations, and a hierarchical genetic algorithm (HGA tailored particularly for searching for an optimal SCC schedule. The optimisation model is developed by integrating two main planning phases of traditional scheduling: (1 planning cast sequence, and (2 scheduling of steel-making and timing of all jobs. A novel procedure is given for genetic algorithm (GA chromosome coding that maps Gantt chart and hierarchical chromosomes. The performance of the proposed methodology is illustrated and compared with a two-phase traditional scheduling and a standard GA toolbox. Both qualitative and quantitative performance measures are investigated.

  4. CAE process to simulate and optimise engine noise and vibration

    Science.gov (United States)

    Junhong, Zhang; Jun, Han

    2006-08-01

    The vibratory and acoustic behaviour of the internal combustion engine is a highly complex one, consisting of many components that are subject to loads that vary greatly in magnitude and which operate at wide range of speed. CAE tools development will lead to a significant reduction in the duration of the development period for engine as well as ensure a dramatic increase in product quality. This paper presents today's state-of-the-art CAE capabilities in the simulation of the dynamic and acoustic behaviour of engine and focuses on the relative merits of modification and full-scale structural/acoustic optimisation of engine, together with the creation of new low-noise designs. Modern CAE tools allow the analysis, assessment and acoustic optimisation of the engine.

  5. Optimisation of metal charge material for electric arc furnace

    Directory of Open Access Journals (Sweden)

    T. Lis

    2011-10-01

    Full Text Available The analysis of the changes in the crude steel production volumes implies gradual increase of production since the mid 20th century. This tendency has been slightly hampered by the economic depression. At the same time, the market requirements enforce improvement of the quality of the products manufactured on simultaneous minimisation of the production costs. One of the tools applied to solve these problems is mathematical optimisation. The author of this paper has presented an example of application of the multi-criteria optimisation method to improvement of efficiency of steel smelting in an electric arc furnace (EAF through appropriate choice of the charge scrap. A measurable effect of applying such a methodology of choosing the metal charge is the ability to reduce the unit cost of steel smelting.

  6. Compressed Sensing with Nonlinear Observations and Related Nonlinear Optimisation Problems

    CERN Document Server

    Blumensath, Thomas

    2012-01-01

    Non-convex constraints have recently proven a valuable tool in many optimisation problems. In particular sparsity constraints have had a significant impact on sampling theory, where they are used in Compressed Sensing and allow structured signals to be sampled far below the rate traditionally prescribed. Nearly all of the theory developed for Compressed Sensing signal recovery assumes that samples are taken using linear measurements. In this paper we instead address the Compressed Sensing recovery problem in a setting where the observations are non-linear. We show that, under conditions similar to those required in the linear setting, the Iterative Hard Thresholding algorithm can be used to accurately recover sparse or structured signals from few non-linear observations. Similar ideas can also be developed in a more general non-linear optimisation framework. In the second part of this paper we therefore present related result that show how this can be done under sparsity and union of subspaces constraints, wh...

  7. Optimisation of VSC-HVDC Transmission for Wind Power Plants

    DEFF Research Database (Denmark)

    Silva, Rodrigo Da

    Connection of Wind Power Plants (WPP), typically oshore, using VSCHVDC transmission is an emerging solution with many benefits compared to the traditional AC solution, especially concerning the impact on control architecture of the wind farms and the grid. The VSC-HVDC solution is likely to meet...... more stringent grid codes than a conventional AC transmission connection. The purpose of this project is to analyse how HVDC solution, considering the voltage-source converter based technology, for grid connection of large wind power plants can be designed and optimised. By optimisation, the project...... the requirements established by the operators in the multiterminal VSC-HVDC transmission system. Moreover, the possibility in minimising the overall transmission losses can be a solution for small grids and the minimisation in the dispatch error is a new solution for power deliver maximisation. The second study...

  8. Comparing and Optimising Parallel Haskell Implementations for Multicore Machines

    DEFF Research Database (Denmark)

    Berthold, Jost; Marlow, Simon; Hammond, Kevin

    2009-01-01

    by our testing: for example, we implemented a work-stealing approach to task allocation. Our optimisations improved the performance of the shared-heap GpH implementation by as much as 30% on eight cores. Secondly, the shared heap approach is, rather surprisingly, not superior to a distributed heap......H implementation investigated here uses a physically-shared heap, which should be well-suited to multicore architectures. In contrast, the Eden implementation adopts an approach that has been designed for use on distributed-memory parallel machines: a system of multiple, independent heaps (one per core......), with inter-core communication handled by message-passing rather than through shared heap cells. We report two main results. Firstly, we report on the effect of a number of optimisations that we applied to the shared-memory GpH implementation in order to address some performance issues that were revealed...

  9. Optimising stroke volume and oxygen delivery in abdominal aortic surgery

    DEFF Research Database (Denmark)

    Bisgaard, J; Gilsaa, T; Rønholm, E

    2012-01-01

    group, stroke volume was optimised by 250 ml colloid boluses intraoperatively and for the first 6 h post-operatively. The optimisation aimed at an oxygen delivery of 600 ml/min/m(2) in the post-operative period. Haemodynamic data were collected at pre-defined time points, including baseline......BACKGROUND: Post-operative complications after open elective abdominal aortic surgery are common, and individualised goal-directed therapy may improve outcome in high-risk surgery. We hypothesised that individualised goal-directed therapy, targeting stroke volume and oxygen delivery, can reduce......, intraoperatively and post-operatively. Patients were followed up for 30 days. RESULTS: Stroke volume index and oxygen delivery index were both higher in the post-operative period in the intervention group. In this group, 27 of 32 achieved the post-operative oxygen delivery index target vs. 18 of 32 in the control...

  10. Eyes Wide Open - Optimising Cosmological Surveys in a Crowded Market

    CERN Document Server

    Bassett, B A

    2004-01-01

    Optimising the major next-generation cosmological surveys (such as SNAP, KAOS etc...) is a key problem given our ignorance of the physics underlying cosmic acceleration and the plethora of surveys planned. We propose a Bayesian design framework which (1) maximises the discrimination power of a survey without assuming any underlying dark energy model, (2) finds the best niche survey geometry given current data and future competing experiments, (3) maximises the cross-section for serendipitous discoveries and (4) can be adapted to answer specific questions (such as `is dark energy dynamical?'). Integrated Parameter Space Optimisation (IPSO) is a design framework that integrates projected parameter errors over an entire dark energy parameter space and then extremises a figure of merit (such as Shannon entropy gain wich we show is stable to off-diagonal covariance matrix perturbations) as a function of survey parameters using analytical, grid or MCMC techniques. IPSO is thus a flexible, model-independent and scal...

  11. Biomass supply chain optimisation for Organosolv-based biorefineries.

    Science.gov (United States)

    Giarola, Sara; Patel, Mayank; Shah, Nilay

    2014-05-01

    This work aims at providing a Mixed Integer Linear Programming modelling framework to help define planning strategies for the development of sustainable biorefineries. The up-scaling of an Organosolv biorefinery was addressed via optimisation of the whole system economics. Three real world case studies were addressed to show the high-level flexibility and wide applicability of the tool to model different biomass typologies (i.e. forest fellings, cereal residues and energy crops) and supply strategies. Model outcomes have revealed how supply chain optimisation techniques could help shed light on the development of sustainable biorefineries. Feedstock quality, quantity, temporal and geographical availability are crucial to determine biorefinery location and the cost-efficient way to supply the feedstock to the plant. Storage costs are relevant for biorefineries based on cereal stubble, while wood supply chains present dominant pretreatment operations costs.

  12. Optimised Calibration Method for Six-Port Junction

    Institute of Scientific and Technical Information of China (English)

    XIONG Xiang-zheng; LIAO Cheng; XIAO Hua-qing

    2008-01-01

    A dual-tone technique is used to produce multi-samples in optimising calibration of six-port junction. More accurate results are achieved by using the least-square method and excluding those samples which may cause bigger errors. A 0.80 1.10 GHz microwave integrated circuit (MIC) six-port reflectometer is constructed. Nine test samples are used in the measurement. With Engens calibration procedure, the difference between the HP8510 and the six-port reflectrometer is in the order of 0.20 dB/1.5° for most cases, above 0.50 dB/5.0° at boundary frequency . With the optimised method, the difference is less than 0.10 dB/1.0° for most cases, and the biggest error is 0.42 dB/2.1° for boundary frequencies.

  13. An Experimental Approach for Optimising Mobile Agent Migrations

    CERN Document Server

    Gavalas, Damianos

    2010-01-01

    The field of mobile agent (MA) technology has been intensively researched during the past few years, resulting in the phenomenal proliferation of available MA platforms, all sharing several common design characteristics. Research projects have mainly focused on identifying applications where the employment of MAs is preferable compared to centralised or alternative distributed computing models. Very little work has been made on examining how MA platforms design can be optimised so as the network traffic and latency associated with MA transfers are minimised. The work presented in this paper addresses these issues by investigating the effect of several optimisation ideas applied on our MA platform prototype. Furthermore, we discuss the results of a set of timing experiments that offers a better understanding of the agent migration process and recommend new techniques for reducing MA transfers delay.

  14. Topology Optimised Broadband Photonic Crystal Y-Splitter

    DEFF Research Database (Denmark)

    Borel, Peter Ingo; Frandsen, Lars Hagedorn; Harpøth, Anders

    2005-01-01

    A planar photonic crystal waveguide Y-splitter that exhibits large-bandwidth low-loss 3 dB splitting for TE-polarised light has been fabricated in silicon-on-insulator material. The high performance is achieved by utilising topology optimisation to design the Y-junction and by using topology...... optimised low-loss 60° bends. The average excess loss of the entire component is found to be 0.44±0.29 dB for a 100 nm bandwidth, and the excess loss due to the Y-junction is found to be 0.34±0.30 dB in a 175 nm bandwidth....

  15. Development and optimisation of electrodematerials in solid oxide fuel cells

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Solid oxide fuel cell (SOFC) is an all solid electrochemical device to convert fuels such as hydrogen and natural gas to electricity with high efficiency and very low greenhouse gas emission compared to traditional thermal power generation plants. Moreover, the reliability and efficiency of SOFC is critically dependent on the performance and stability of its components including anode, cathode and electrolyte. This in turn is largely dependent on the material selection and the fabrication processes. In this paper, specific examples are given to demonstrate strategy and process in the development and optimisation of electrode materials such as Ni/Y2O3-ZrO2 cermet anodes and (LaSr)MnO3 based cathodes. The results also demonstrate the importance of fabrication processes and that the understanding of the electrode process plays a very important role in the optimisation process of electrode materials.

  16. Computed tomography dose optimisation in cystic fibrosis: A review.

    LENUS (Irish Health Repository)

    Ferris, Helena

    2016-04-28

    Cystic fibrosis (CF) is the most common autosomal recessive disease of the Caucasian population worldwide, with respiratory disease remaining the most relevant source of morbidity and mortality. Computed tomography (CT) is frequently used for monitoring disease complications and progression. Over the last fifteen years there has been a six-fold increase in the use of CT, which has lead to a growing concern in relation to cumulative radiation exposure. The challenge to the medical profession is to identify dose reduction strategies that meet acceptable image quality, but fulfil the requirements of a diagnostic quality CT. Dose-optimisation, particularly in CT, is essential as it reduces the chances of patients receiving cumulative radiation doses in excess of 100 mSv, a dose deemed significant by the United Nations Scientific Committee on the Effects of Atomic Radiation. This review article explores the current trends in imaging in CF with particular emphasis on new developments in dose optimisation.

  17. Training for Internationalization through Domestic Geographical Dispersion

    DEFF Research Database (Denmark)

    Santangelo, Grazia D.; Stucchi, Tamara

    organizational learning, we seek to solve this puzzle in relation to the internationalization of Indian BGs. In particular, we argue that in heterogeneous domestic emerging markets BG’s geographical dispersion across sub-national states provides training for internationalization. To internationalize successfully......, BGs need to develop the capability of managing geographically dispersed units in institutional heterogeneous contexts. Domestic geographical dispersion would indeed help the BG dealing with different regulations, customers and infrastructures. However, there is less scope for such training as BGs...... become more internationally experienced, and the benefits of domestic geographical dispersions are limited by the degree of urbanization of sub-national states. We test our argument on a sample of 693 Indian BGs over the period 2001-2010....

  18. Integrated planning tool for optimisation in municipal home care

    OpenAIRE

    Røhne, Mette; Sandåker, Torjus; Ausen, Dag; Grut, Lisbet

    2016-01-01

    Purpose: The objective is to improve collaboration and enhance quality of care services in municipal, home care services by implementing and developing an integrated planning tool making use of optimisation technology for better decision support. The project will through piloting and action based research establish knowledge on change in work processes to improve collaboration and efficiency. Context: A planning tool called Spider has been piloted in home care in Horten municipality since 201...

  19. Optimising automation of a manual enzyme-linked immunosorbent assay

    OpenAIRE

    Corena de Beer; Monika Esser; Wolfgang Preiser

    2011-01-01

    Objective: Enzyme-linked immunosorbent assays (ELISAs) are widely used to quantify immunoglobulin levels induced by infection or vaccination. Compared to conventional manual assays, automated ELISA systems offer more accurate and reproducible results, faster turnaround times and cost effectiveness due to the use of multianalyte reagents.Design: The VaccZyme™ Human Anti-Haemophilus influenzae type B (Hib) kit (MK016) from The Binding Site Company was optimised to be used on an automated BioRad...

  20. Optimisation of brain SPET and portability of normal databases

    Energy Technology Data Exchange (ETDEWEB)

    Barnden, Leighton R.; Behin-Ain, Setayesh; Goble, Elizabeth A. [The Queen Elizabeth Hospital, Adelaide (Australia); Hatton, Rochelle L.; Hutton, Brian F. [Westmead Hospital, Sydney (Australia)

    2004-03-01

    Use of a normal database in quantitative regional analysis of brain single-photon emission tomography (SPET) facilitates the detection of functional defects in individual or group studies by accounting for inter-subject variability. Different reconstruction methods and suboptimal attenuation and scatter correction methods can introduce additional variance that will adversely affect such analysis. Similarly, processing differences across different instruments and/or institutions may invalidate the use of external normal databases. The object of this study was to minimise additional variance by comparing reconstructions of a physical phantom with its numerical template so as to optimise processing parameters. Age- and gender-matched normal scans acquired on two different systems were compared using SPM99 after processing with both standard and optimised parameters. For three SPET systems we have optimised parameters for attenuation correction, lower window scatter subtraction, reconstructed pixel size and fanbeam focal length for both filtered back-projection (FBP) and iterative (OSEM) reconstruction. Both attenuation and scatter correction improved accuracy for all systems. For single-iteration Chang attenuation correction the optimum attenuation coefficient (mu) was 0.45-0.85 of the narrow beam value (Nmu) before, and 0.75-0.85 Nmu after, scatter subtraction. For accurately modelled OSEM attenuation correction, optimum mu was 0.6-0.9 Nmu before and 0.9-1.1 Nmu after scatter subtraction. FBP appeared to change in-plane voxel dimensions by about 2% and this was confirmed by line phantom measurements. Improvement in accuracy with scatter subtraction was most marked for the highest spatial resolution system. Optimised processing reduced but did not remove highly significant regional differences between normal databases acquired on two different SPET systems. (orig.)

  1. Geometrical optimisation of a biochip microchannel fluidic separator.

    Science.gov (United States)

    Xue, Xiangdong; Patel, Mayur K; Bailey, Chris; Desmulliez, Marc P Y

    2012-01-01

    This article reports on the geometric optimisation of a T-shaped biochip microchannel fluidic separator aiming to maximise the separation efficiency of plasma from blood through the improvement of the unbalanced separation performance among different channel bifurcations. For this purpose, an algebraic analysis is firstly implemented to identify the key parameters affecting fluid separation. A numerical optimisation is then carried out to search the key parameters for improved separation performance of the biochip. Three parameters, the interval length between bifurcations, the main channel length from the outlet to the bifurcation region and the side channel geometry, are identified as the key characteristic sizes and defined as optimisation variables. A balanced flow rate ratio between the main and side channels, which is an indication of separation effectiveness, is defined as the objective. It is found that the degradation of the separation performance is caused by the unbalanced channel resistance ratio between the main and side channel routes from bifurcations to outlets. The effects of the three key parameters can be summarised as follows: (a) shortening the interval length between bifurcations moderately reduces the differences in the flow rate ratios; (b) extending the length of the main channel from the main outlet is effective for achieving a uniformity of flow rate ratio but ineffective in changing the velocity difference of the side channels and (c) decreasing the lengths of side channels from upstream to downstream is effective for both obtaining a uniform flow rate ratio and reducing the differences in the flow velocities between the side branch channels. An optimisation process combining the three parameters is suggested as this integration approach leads to fast convergent process and also offers flexible design options for satisfying different requirements.

  2. Integrated planning tool for optimisation in municipal home care

    OpenAIRE

    Røhne, Mette; Sandåker, Torjus; Ausen, Dag; Grut, Lisbet

    2016-01-01

    Purpose: The objective is to improve collaboration and enhance quality of care services in municipal, home care services by implementing and developing an integrated planning tool making use of optimisation technology for better decision support. The project will through piloting and action based research establish knowledge on change in work processes to improve collaboration and efficiency. Context: A planning tool called Spider has been piloted in home care in Horten municipality since 201...

  3. LHCb: Optimising query execution time in LHCb Bookkeeping System using partition pruning and partition wise joins

    CERN Multimedia

    Mathe, Z

    2013-01-01

    The LHCb experiment produces a huge amount of data which has associated metadata such as run number, data taking condition (detector status when the data was taken), simulation condition, etc. The data are stored in files, replicated on the Computing Grid around the world. The LHCb Bookkeeping System provides methods for retrieving datasets based on their metadata. The metadata is stored in a hybrid database model, which is a mixture of Relational and Hierarchical database models and is based on the Oracle Relational Database Management System (RDBMS). The database access has to be reliable and fast. In order to achieve a high timing performance, the tables are partitioned and the queries are executed in parallel. When we store large amounts of data the partition pruning is essential for database performance, because it reduces the amount of data retrieved from the disk and optimises the resource utilisation. This research presented here is focusing on the extended composite partitioning strategy such as rang...

  4. Application and Development of Energy System Optimisation Models to Meet Challenges of the Future

    DEFF Research Database (Denmark)

    Balyk, Olexandr

    Climate change, security of supply and local air pollution are among the challenges that are shaping the future of energy systems worldwide. In response to these challenges, various goals are set nationally and internationally that energy systems are supposed to fulfil. These include e.g. EU 20...... them. The challenges of climate change, security of supply, and local air pollution are addressed in the papers by focusing on renewable energy systems, demand side management options, climate change mitigation and resource potentials. In the process of the study the energy system optimisation models...... energy, and an increased climate change mitigation potential.Other results highlight among others, the possible future roles of individual technologies (i.e. wind power in Denmark and carbon capture and storage in China) in the climate constrained world, the difficulty to achieve the 2°C target agreed...

  5. Rates of Gravel Dispersion

    Science.gov (United States)

    Haschenburger, J. K.

    2010-12-01

    Sediment transfers in gravel-bed rivers involve the three-dimensional dispersion of mixed size sediment. From a kinematics standpoint, few studies are available to inform on the streamwise and vertical rates of sediment dispersion in natural channels. This research uses a gravel tracing program to quantify dispersion rates over 19 flood seasons. Empirical observations come from Carnation Creek, a small gravel-bed river with large woody debris located on the west coast of Vancouver Island, Canada. Frequent floods and the relatively limited armor layer facilitate streambed activity and relatively high bedload transport rates, typically under partial sediment transport conditions. Over 2500 magnetically tagged stones, ranging in size from 16 to 180 mm, were deployed on the bed surface between 1989 and 1992 in four generations. To quantify gravel dispersion over distances up to 2.6 km, observations are taken from 11 recoveries. Over 280 floods capable of moving bedload occurred during this period, with five exceeding the estimated bankfull discharge. Streamwise dispersion is quantified by virtual velocity, while dispersion into the streambed is quantified by a vertical burial rate. The temporal trend in streamwise dispersion rates is described by a power function. Initial virtual velocities decline rapidly from around 1.4 m/hr to approach an asymptote value of about 0.2 m/hr. The rapid change corresponds to a significant increase in the proportion of buried tracers due to vertical mixing. Initial burial rates reflect the magnitude of the first flood after tracer deployment and range from 0.07 to 0.46 cm/hr depending on tracer generation. Burial rates converge to about 0.06 cm/hr after the fourth flood season and then gradually decline to about 0.01 cm/hr. Thus, the rate of streamwise dispersion exceeds that of vertical dispersion by three orders of magnitude when the movement of sediment routinely activated by floods is considered.

  6. Parameter Screening and Optimisation for ILP Using Designed Experiments

    Science.gov (United States)

    Srinivasan, Ashwin; Ramakrishnan, Ganesh

    Reports of experiments conducted with an Inductive Logic Programming system rarely describe how specific values of parameters of the system are arrived at when constructing models. Usually, no attempt is made to identify sensitive parameters, and those that are used are often given "factory-supplied" default values, or values obtained from some non-systematic exploratory analysis. The immediate consequence of this is, of course, that it is not clear if better models could have been obtained if some form of parameter selection and optimisation had been performed. Questions follow inevitably on the experiments themselves: specifically, are all algorithms being treated fairly, and is the exploratory phase sufficiently well-defined to allow the experiments to be replicated? In this paper, we investigate the use of parameter selection and optimisation techniques grouped under the study of experimental design. Screening and "response surface" methods determine, in turn, sensitive parameters and good values for these parameters. This combined use of parameter selection and response surface-driven optimisation has a long history of application in industrial engineering, and its role in ILP is investigated using two well-known benchmarks. The results suggest that computational overheads from this preliminary phase are not substantial, and that much can be gained, both on improving system performance and on enabling controlled experimentation, by adopting well-established procedures such as the ones proposed here.

  7. Statistical optimisation techniques in fatigue signal editing problem

    Energy Technology Data Exchange (ETDEWEB)

    Nopiah, Z. M.; Osman, M. H. [Fundamental Engineering Studies Unit Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600 UKM (Malaysia); Baharin, N.; Abdullah, S. [Department of Mechanical and Materials Engineering Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600 UKM (Malaysia)

    2015-02-03

    Success in fatigue signal editing is determined by the level of length reduction without compromising statistical constraints. A great reduction rate can be achieved by removing small amplitude cycles from the recorded signal. The long recorded signal sometimes renders the cycle-to-cycle editing process daunting. This has encouraged researchers to focus on the segment-based approach. This paper discusses joint application of the Running Damage Extraction (RDE) technique and single constrained Genetic Algorithm (GA) in fatigue signal editing optimisation.. In the first section, the RDE technique is used to restructure and summarise the fatigue strain. This technique combines the overlapping window and fatigue strain-life models. It is designed to identify and isolate the fatigue events that exist in the variable amplitude strain data into different segments whereby the retention of statistical parameters and the vibration energy are considered. In the second section, the fatigue data editing problem is formulated as a constrained single optimisation problem that can be solved using GA method. The GA produces the shortest edited fatigue signal by selecting appropriate segments from a pool of labelling segments. Challenges arise due to constraints on the segment selection by deviation level over three signal properties, namely cumulative fatigue damage, root mean square and kurtosis values. Experimental results over several case studies show that the idea of solving fatigue signal editing within a framework of optimisation is effective and automatic, and that the GA is robust for constrained segment selection.

  8. Optimising the Target and Capture Sections of the Neutrino Factory

    CERN Document Server

    Hansen, Ole Martin; Stapnes, Steinar

    The Neutrino Factory is designed to produce an intense high energy neutrino beam from stored muons. The majority of the muons are obtained from the decay of pions, produced by a proton beam impinging on a free-flowing mercury-jet target and captured by a high magnetic field. It is important to capture a large fraction of the produced pions to maximize the intensity of the neutrino beam. Various optimisation studies have been performed with the aim of maximising the muon influx to the accelerator and thus the neutrino beam intensity. The optimisation studies were performed with the use of Monte Carlo simulation tools. The production of secondary particles, by interactions between the incoming proton beam and the mercury target, was optimised by varying the proton beam impact position and impact angles on the target. The proton beam and target interaction region was studied and showed to be off the central axis of the capture section in the baseline configuration. The off-centred interaction region resulted in ...

  9. Direct and Indirect Gradient Control for Static Optimisation

    Institute of Scientific and Technical Information of China (English)

    Yi Cao

    2005-01-01

    Static "self-optimising" control is an important concept, which provides a link between static optimisation and control[1]. According to the concept, a dynamic control system could be configured in such a way that when a set of certain variables are maintained at their setpoints, the overall process operation is automatically optimal or near optimal at steadystate in the presence of disturbances. A novel approach using constrained gradient control to achieve "self-optimisation" has been proposed by Cao[2]. However, for most process plants, the information required to get the gradient measure may not be available in real-time. In such cases, controlled variable selection has to be carried out based on measurable candidates. In this work, the idea of direct gradient control has been extended to controlled variable selection based on gradient sensitivity analysis (indirect gradient control). New criteria, which indicate the sensitivity of the gradient function to disturbances and implementation errors, have been derived for selection. The particular case study shows that the controlled variables selected by gradient sensitivity measures are able to achieve near optimal performance.

  10. Optimisation of Lilla Edet Landslide GPS Monitoring Network

    Science.gov (United States)

    Alizadeh-Khameneh, M. A.; Eshagh, M.; Sjöberg, L. E.

    2015-06-01

    Since the year 2000, some periodic investigations have been performed in the Lilla Edet region to monitor and possibly determine the landslide of the area with GPS measurements. The responsible consultant has conducted this project by setting up some stable stations for GPS receivers in the risky areas of Lilla Edet and measured the independent baselines amongst the stations according to their observation plan. Here, we optimise the existing surveying network and determine the optimal configuration of the observation plan based on different criteria.We aim to optimise the current network to become sensitive to detect 5 mm possible displacements in each net point. The network quality criteria of precision, reliability and cost are used as object functions to perform single-, bi- and multi-objective optimisation models. It has been shown in the results that the single-objective model of reliability, which is constrained to the precision, provides much higher precision than the defined criterion by preserving almost all of the observations. However, in this study, the multi-objective model can fulfil all the mentioned quality criteria of the network by 17% less measurements than the original observation plan, meaning 17%of saving time, cost and effort in the project.

  11. Module detection in complex networks using integer optimisation

    Directory of Open Access Journals (Sweden)

    Tsoka Sophia

    2010-11-01

    Full Text Available Abstract Background The detection of modules or community structure is widely used to reveal the underlying properties of complex networks in biology, as well as physical and social sciences. Since the adoption of modularity as a measure of network topological properties, several methodologies for the discovery of community structure based on modularity maximisation have been developed. However, satisfactory partitions of large graphs with modest computational resources are particularly challenging due to the NP-hard nature of the related optimisation problem. Furthermore, it has been suggested that optimising the modularity metric can reach a resolution limit whereby the algorithm fails to detect smaller communities than a specific size in large networks. Results We present a novel solution approach to identify community structure in large complex networks and address resolution limitations in module detection. The proposed algorithm employs modularity to express network community structure and it is based on mixed integer optimisation models. The solution procedure is extended through an iterative procedure to diminish effects that tend to agglomerate smaller modules (resolution limitations. Conclusions A comprehensive comparative analysis of methodologies for module detection based on modularity maximisation shows that our approach outperforms previously reported methods. Furthermore, in contrast to previous reports, we propose a strategy to handle resolution limitations in modularity maximisation. Overall, we illustrate ways to improve existing methodologies for community structure identification so as to increase its efficiency and applicability.

  12. Customisable 3D printed microfluidics for integrated analysis and optimisation.

    Science.gov (United States)

    Monaghan, T; Harding, M J; Harris, R A; Friel, R J; Christie, S D R

    2016-08-16

    The formation of smart Lab-on-a-Chip (LOC) devices featuring integrated sensing optics is currently hindered by convoluted and expensive manufacturing procedures. In this work, a series of 3D-printed LOC devices were designed and manufactured via stereolithography (SL) in a matter of hours. The spectroscopic performance of a variety of optical fibre combinations were tested, and the optimum path length for performing Ultraviolet-visible (UV-vis) spectroscopy determined. The information gained in these trials was then used in a reaction optimisation for the formation of carvone semicarbazone. The production of high resolution surface channels (100-500 μm) means that these devices were capable of handling a wide range of concentrations (9 μM-38 mM), and are ideally suited to both analyte detection and process optimisation. This ability to tailor the chip design and its integrated features as a direct result of the reaction being assessed, at such a low time and cost penalty greatly increases the user's ability to optimise both their device and reaction. As a result of the information gained in this investigation, we are able to report the first instance of a 3D-printed LOC device with fully integrated, in-line monitoring capabilities via the use of embedded optical fibres capable of performing UV-vis spectroscopy directly inside micro channels.

  13. MOPTOP: a multi-colour optimised optical polarimeter

    Science.gov (United States)

    Jermak, Helen; Steele, Iain A.; Smith, Robert J.

    2016-08-01

    We present the design and science case for the Liverpool Telescope's fourth-generation polarimeter; MOPTOP: a Multicolour OPTimised Optical Polarimeter which is optimised for sensitivity and bi-colour observations. We introduce an optimised polarimeter which is as far as possible limited only by the photon counting efficiency of the detectors. Using a combination of CMOS cameras, a continuously rotating half-wave plate and a wire grid polarising beamsplitter, we predict we can accurately measure the polarisation of sources to 1% at 19th magnitude in 10 minutes on a 2 metre telescope. For brighter sources we anticipate much low systematics (design also gives the ability to measure polarization and photometric variability on timescales as short as a few seconds. Overall the instrument will allow accurate measurements of the intra-nightly variability of the polarisation of sources such as gamma-ray bursts and blazars (AGN orientated with the jet pointing toward the observer), allowing the constraint of magnetic field models revealing more information about the formation, ejection and collimation of jets.

  14. Crystal structure optimisation using an auxiliary equation of state.

    Science.gov (United States)

    Jackson, Adam J; Skelton, Jonathan M; Hendon, Christopher H; Butler, Keith T; Walsh, Aron

    2015-11-14

    Standard procedures for local crystal-structure optimisation involve numerous energy and force calculations. It is common to calculate an energy-volume curve, fitting an equation of state around the equilibrium cell volume. This is a computationally intensive process, in particular, for low-symmetry crystal structures where each isochoric optimisation involves energy minimisation over many degrees of freedom. Such procedures can be prohibitive for non-local exchange-correlation functionals or other "beyond" density functional theory electronic structure techniques, particularly where analytical gradients are not available. We present a simple approach for efficient optimisation of crystal structures based on a known equation of state. The equilibrium volume can be predicted from one single-point calculation and refined with successive calculations if required. The approach is validated for PbS, PbTe, ZnS, and ZnTe using nine density functionals and applied to the quaternary semiconductor Cu2ZnSnS4 and the magnetic metal-organic framework HKUST-1.

  15. Crystal structure optimisation using an auxiliary equation of state

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, Adam J.; Skelton, Jonathan M.; Hendon, Christopher H.; Butler, Keith T. [Centre for Sustainable Chemical Technologies and Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY (United Kingdom); Walsh, Aron, E-mail: a.walsh@bath.ac.uk [Centre for Sustainable Chemical Technologies and Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY (United Kingdom); Global E" 3 Institute and Department of Materials Science and Engineering, Yonsei University, Seoul 120-749 (Korea, Republic of)

    2015-11-14

    Standard procedures for local crystal-structure optimisation involve numerous energy and force calculations. It is common to calculate an energy–volume curve, fitting an equation of state around the equilibrium cell volume. This is a computationally intensive process, in particular, for low-symmetry crystal structures where each isochoric optimisation involves energy minimisation over many degrees of freedom. Such procedures can be prohibitive for non-local exchange-correlation functionals or other “beyond” density functional theory electronic structure techniques, particularly where analytical gradients are not available. We present a simple approach for efficient optimisation of crystal structures based on a known equation of state. The equilibrium volume can be predicted from one single-point calculation and refined with successive calculations if required. The approach is validated for PbS, PbTe, ZnS, and ZnTe using nine density functionals and applied to the quaternary semiconductor Cu{sub 2}ZnSnS{sub 4} and the magnetic metal-organic framework HKUST-1.

  16. Numerical optimisation of an axial turbine; Numerische Optimierung einer Axialturbine

    Energy Technology Data Exchange (ETDEWEB)

    Welzel, B.

    1998-12-31

    The author presents a method for automatic shape optimisation of components with internal or external flow. The method combines a program for numerical calculation of frictional turbulent flow with an optimisation algorithm. Algorithms are a simplex search strategy and an evolution strategy. The shape of the component to be optimized is variable due to shape parameters modified by the algorithm. For each shape, a flow calculation is carried out on whose basis a functional value like performance, loss, lift or resistivity is calculated. For validation, the optimisation method is used in simple examples with known solutions. It is applied. It is applied to the components of a slow-running axial turbine. Components with accelerated and delayed rotationally symmetric flow and 2D blade profiles are optimized. [Deutsch] Es wird eine Methode zur automatischen Formoptimierung durchstroemter oder umstroemter Bauteile vorgestellt. Diese koppelt ein Programm zur numerischen Berechnung reibungsbehafteter turbulenter Stroemungen mit einem Optimierungsalgorithmus. Dabei kommen als Algorithmen eine Simplex-Suchstrategie und eine Evolutionsstrategie zum Einsatz. Die Form des zu optimierenden Koerpers ist durch Formparameter, die vom Algorithmus veraendert werden, variabel. Fuer jede Form wird eine Stroemungsberechnung durchgefuehrt und mit dieser ein Funktionswert wie Wirkungsgrad, Verlust, Auftrieb oder Widerstandskraft berechnet. Die Optimierungsmethode wird zur Validierung in einfachen Beispielen mit bekannter Loesung eingesetzt. Zur Anwendung kommt sie in den einzelnen Komponenten einer langsamlaeufigen Axialturbine. Es werden Bauteile mit beschleunigter und verzoegerter rotationssymmetrischer Stroemung und 2D-Schaufelprofile optimiert. (orig.)

  17. Dispersal behavior of Tetranychus evansi and T. urticae on tomato at several spatial scales and densities: implications for integrated pest management.

    Science.gov (United States)

    Azandémè-Hounmalon, Ginette Y; Fellous, Simon; Kreiter, Serge; Fiaboe, Komi K M; Subramanian, Sevgan; Kungu, Miriam; Martin, Thibaud

    2014-01-01

    Studying distribution is necessary to understand and manage the dynamics of species with spatially structured populations. Here we studied the distribution in Tetranychus evansi and T. urticae, two mite pests of tomato, in the scope of evaluating factors that can influence the effectiveness of Integrated Pest Management strategies. We found greater positive density-dependent distribution with T. evansi than T. urticae when assayed on single, detached tomato leaves. Indeed, T. evansi distribution among leaflets increased with initial population density while it was high even at low T. urticae densities. Intensity and rate of damage to whole plants was higher with T. evansi than T. urticae. We further studied the circadian migration of T. evansi within plant. When T. evansi density was high the distribution behavior peaked between 8 am and 3 pm and between 8 pm and 3 am local time of Kenya. Over 24 h the total number of mites ascending and descending was always similar and close to the total population size. The gregarious behavior of T. evansi combined with its rapid population growth rate, may explain why few tomato plants can be severely damaged by T. evansi and how suddenly all the crop can be highly infested. However the localisation and elimination of the first infested plants damaged by T. evansi could reduce the risk of outbreaks in the entire crop. These findings suggest also that an acaricide treated net placed on the first infested plants could be very effective to control T. evansi. Moreover circadian migration would therefore accentuate the efficiency of an acaricide treated net covering the infested plants.

  18. Dispersive hydrodynamics: Preface

    Science.gov (United States)

    Biondini, G.; El, G. A.; Hoefer, M. A.; Miller, P. D.

    2016-10-01

    This Special Issue on Dispersive Hydrodynamics is dedicated to the memory and work of G.B. Whitham who was one of the pioneers in this field of physical applied mathematics. Some of the papers appearing here are related to work reported on at the workshop "Dispersive Hydrodynamics: The Mathematics of Dispersive Shock Waves and Applications" held in May 2015 at the Banff International Research Station. This Preface provides a broad overview of the field and summaries of the various contributions to the Special Issue, placing them in a unified context.

  19. Tropospheric vertical column densities of NO2 over managed dryland ecosystems (Xinjiang, China): MAX-DOAS measurements vs. 3-D dispersion model simulations based on laboratory-derived NO emission from soil samples

    Science.gov (United States)

    Mamtimin, B.; Behrendt, T.; Badawy, M. M.; Wagner, T.; Qi, Y.; Wu, Z.; Meixner, F. X.

    2015-01-01

    We report on MAX-DOAS observations of NO2 over an oasis-ecotone-desert ecosystem in NW China. There, local ambient NO2 concentrations originate from enhanced biogenic NO emission of intensively managed soils. Our target oasis "Milan" is located at the southern edge of the Taklimakan desert, very remote and well isolated from other potential anthropogenic and biogenic NOx sources. Four observation sites for MAX-DOAS measurements were selected, at the oasis centre, downwind and upwind of the oasis, and in the desert. Biogenic NO emissions in terms of (i) soil moisture and (ii) soil temperature of Milan oasis (iii) different land-cover type sub-units (cotton, Jujube trees, cotton/Jujube mixture, desert) were quantified by laboratory incubation of corresponding soil samples. Net potential NO fluxes were up-scaled to oasis scale by areal distribution and classification of land-cover types derived from satellite images using GIS techniques. A Lagrangian dispersion model (LASAT, Lagrangian Simulation of Aerosol Transport) was used to calculate the dispersion of soil emitted NO into the atmospheric boundary layer over Milan oasis. Three-dimensional (3-D) NO concentrations (30 m horizontal resolution) have been converted to 3-D NO2 concentrations, assuming photostationary state conditions. NO2 column densities were simulated by suitable vertical integration of modelled 3-D NO2 concentrations at those downwind and upwind locations, where the MAX-DOAS measurements were performed. Downwind-upwind differences (a direct measure of Milan oasis' contribution to the areal increase of ambient NO2 concentration) of measured and simulated slant (as well as vertical) NO2 column densities show excellent agreement. This agreement is considered as the first successful attempt to prove the validity of the chosen approach to up-scale laboratory-derived biogenic NO fluxes to ecosystem field conditions, i.e. from the spatial scale of a soil sample (cm2) to the size of an entire agricultural

  20. Tropospheric vertical column densities of NO2 over managed dryland ecosystems (Xinjiang, China): MAX-DOAS measurements vs. 3-D dispersion model simulations based on laboratory derived NO emission from soil samples

    Science.gov (United States)

    Mamtimin, B.; Behrendt, T.; Badawy, M. M.; Wagner, T.; Qi, Y.; Wu, Z.; Meixner, F. X.

    2014-07-01

    We report on MAX-DOAS observations of NO2 over an oasis-ecotone-desert ecosystem in NW-China. There, local ambient NO2 concentrations originate from enhanced biogenic NO emission of intensively managed soils. Our target oasis "Milan" is located at the southern edge of the Taklimakan desert, very remote and well isolated from other potential anthropogenic and biogenic NOx sources. Four observation sites for MAX-DOAS measurements were selected, at the oasis center, downwind and upwind of the oasis, and in the desert. Biogenic NO emissions in terms of (i) soil moisture and (ii) soil temperature of Milan oasis' (iii) different land-cover type sub-units (cotton, Jujube trees, cotton/Jujube mixture, desert) were quantified by laboratory incubation of corresponding soil samples. Net potential NO fluxes were up-scaled to oasis scale by areal distribution and classification of land-cover types derived from satellite images using GIS techniques. A Lagrangian dispersion model (LASAT, Lagrangian Simulation of Aerosol-Transport) was used to calculate the dispersion of soil emitted NO into the atmospheric boundary layer over Milan oasis. Three dimensional NO concentrations (30 m horizontal resolution) have been converted to 3-D NO2 concentrations, assuming photostationary state conditions. NO2 column densities were simulated by suitable vertical integration of modeled 3-D NO2 concentrations at those downwind and upwind locations, where the MAX-DOAS measurements were performed. Downwind-upwind differences (a direct measure of Milan oasis' contribution to the areal increase of ambient NO2 concentration) of measured and simulated slant (as well as vertical) NO2 column densities show excellent agreement. This agreement is considered as the first successful attempt to prove the validity of the chosen approach to up-scale laboratory derived biogenic NO fluxes to ecosystem field conditions, i.e. from the spatial scale of a soil sample (cm2) to the size of an entire agricultural

  1. Tropospheric vertical column densities of NO2 over managed dryland ecosystems (Xinjiang, China: MAX-DOAS measurements vs. 3-D dispersion model simulations based on laboratory derived NO emission from soil samples

    Directory of Open Access Journals (Sweden)

    B. Mamtimin

    2014-07-01

    Full Text Available We report on MAX-DOAS observations of NO2 over an oasis-ecotone-desert ecosystem in NW-China. There, local ambient NO2 concentrations originate from enhanced biogenic NO emission of intensively managed soils. Our target oasis "Milan" is located at the southern edge of the Taklimakan desert, very remote and well isolated from other potential anthropogenic and biogenic NOx sources. Four observation sites for MAX-DOAS measurements were selected, at the oasis center, downwind and upwind of the oasis, and in the desert. Biogenic NO emissions in terms of (i soil moisture and (ii soil temperature of Milan oasis' (iii different land-cover type sub-units (cotton, Jujube trees, cotton/Jujube mixture, desert were quantified by laboratory incubation of corresponding soil samples. Net potential NO fluxes were up-scaled to oasis scale by areal distribution and classification of land-cover types derived from satellite images using GIS techniques. A Lagrangian dispersion model (LASAT, Lagrangian Simulation of Aerosol-Transport was used to calculate the dispersion of soil emitted NO into the atmospheric boundary layer over Milan oasis. Three dimensional NO concentrations (30 m horizontal resolution have been converted to 3-D NO2 concentrations, assuming photostationary state conditions. NO2 column densities were simulated by suitable vertical integration of modeled 3-D NO2 concentrations at those downwind and upwind locations, where the MAX-DOAS measurements were performed. Downwind-upwind differences (a direct measure of Milan oasis' contribution to the areal increase of ambient NO2 concentration of measured and simulated slant (as well as vertical NO2 column densities show excellent agreement. This agreement is considered as the first successful attempt to prove the validity of the chosen approach to up-scale laboratory derived biogenic NO fluxes to ecosystem field conditions, i.e. from the spatial scale of a soil sample (cm2 to the size of an entire

  2. Semantic Query Optimisation with Ontology Simulation

    Directory of Open Access Journals (Sweden)

    Siddharth Gupta

    2010-11-01

    Full Text Available Semantic Web is, without a doubt, gaining momentum in both industry and academia. The word“Semantic” refers to “meaning” – a semantic web is a web of meaning. In this fast changing and resultoriented practical world, gone are the days where an individual had to struggle for finding informationon the Internet where knowledge management was the major issue. The semantic web has a vision oflinking, integrating and analysing data from various data sources and forming a new information stream,hence a web of databases connected with each other and machines interacting with other machines toyield results which are user oriented and accurate. With the emergence of Semantic Web framework thenaïve approach of searching information on the syntactic web is cliché. This paper proposes an optimisedsemantic searching of keywords exemplified by simulation an ontology of Indian universities with aproposed algorithm which ramifies the effective semantic retrieval of information which is easy to accessand time saving.

  3. Use of physiological information and process optimisation enhances production of extracellular nuclease by a marine strain of Bacillus licheniformis.

    Science.gov (United States)

    Rajarajan, Nithyalakshmy; Ward, Alan C; Burgess, J Grant; Glassey, Jarka

    2013-02-01

    The extracellular nuclease, NucB, from Bacillus licheniformis, can digest extracellular DNA in biofilms, causing biofilm dispersal, and may therefore be used commercially to remove biofilms. However, producing quantities of this secreted peptide is difficult and our aim was therefore to improve its laboratory scale production. This study builds on our understanding of B. licheniformis physiology to enhance NucB production. The addition of manganese, which triggers sporulation and enhances NucB expression, lead to a 5-fold increase in NucB production. Optimisation via Placket-Burman design of experiments identified 3 significant medium components and a subsequent Central Composite Design, to determine the optimum levels of these components, resulted in a 10-fold increase to 471U/ml. The optimal phosphate concentration was less than 0.3mM as this is known to inhibit nuclease production. The use of physiologically relevant information combined with optimisation represents a promising approach to increased enzyme production, which may also be widely applicable.

  4. A decomposition approach for optimal management of groundwater resources and irrigated agriculture in arid coastal regions

    Science.gov (United States)

    Grundmann, Jens; Schütze, Niels; Heck, Vera

    2013-04-01

    For ensuring an optimal sustainable water resources management in arid coastal environments, we develop a new simulation based integrated water management system. It aims at achieving best possible solutions for groundwater withdrawals for agricultural and municipal water use including saline water management together with a substantial increase of the water use efficiency in irrigated agriculture. To achieve a robust and fast operation of the management system, it unites process modelling with artificial intelligence tools and evolutionary optimisation techniques for managing both, water quality and water quantity of a strongly coupled groundwater-agriculture system. However, such systems are characterized by a large number of decision variables if abstraction schemes, cropping patterns and cultivated acreages are optimised simultaneously for multiple years. Therefore, we apply the principle of decomposition to separate the original large optimisation problem into smaller, independent optimisation problems which finally allow for a faster and more reliable solution. At first, within an inner optimisation loop, cropping patterns and cultivated acreages are optimised to achieve a most profitable agricultural production for a given amount of water. Thereby, the behaviour of farms is described by crop-water-production functions which can be derived analytically. Secondly, within an outer optimisation loop, a simulation based optimisation is performed to find optimal groundwater abstraction pattern by coupling an evolutionary optimisation algorithm with an artificial neural network for modelling the aquifer response, inclusive the seawater interface. We demonstrate the decomposition approach by an exemplary application of the south Batinah region in the Sultanate of Oman which is affected by saltwater intrusion into a coastal aquifer system due to excessive groundwater withdrawal for irrigated agriculture. We show the effectiveness of our methodology for the evaluation

  5. Techno-economic optimisation of energy systems; Contribution a l'optimisation technico-economique de systemes energetiques

    Energy Technology Data Exchange (ETDEWEB)

    Mansilla Pellen, Ch

    2006-07-15

    The traditional approach currently used to assess the economic interest of energy systems is based on a defined flow-sheet. Some studies have shown that the flow-sheets corresponding to the best thermodynamic efficiencies do not necessarily lead to the best production costs. A method called techno-economic optimisation was proposed. This method aims at minimising the production cost of a given energy system, including both investment and operating costs. It was implemented using genetic algorithms. This approach was compared to the heat integration method on two different examples, thus validating its interest. Techno-economic optimisation was then applied to different energy systems dealing with hydrogen as well as electricity production. (author)

  6. Interdependence between Inventory Management and Employees’ Satisfaction

    Directory of Open Access Journals (Sweden)

    Dubravko Tomašić

    2013-06-01

    Full Text Available The study determines the correlation between the application of advanced models and methods of inventory optimisation in the supply chain in relation to the satisfaction of employees who are responsible for managing the inventory optimisation processes. The previous studies confirm that the optimisation of inventory management in the supply chain insures competitive advantages on the market. There is space for further research of impact of the achieved inventory optimisation in the supply chain on the change of the employees’ satisfaction. The paper establishes the interrelation of the interdependence of the achieved inventory optimisations on the satisfaction of the employees and the related synergy effects of acquiring added value of the companies on the market oriented to the satisfaction of the buyers and service users. The research has defined new knowledge in interdependence of inventory management optimisation on the change of indicators of employees’ satisfaction. Based on the performed research an assumption has been created for the design of an application package (so-called XaaS-based services for the management of interaction processes of inventory optimization in the supply chain, satisfaction of service users and employees.

  7. Shape optimisation and performance analysis of flapping wings

    KAUST Repository

    Ghommem, Mehdi

    2012-09-04

    In this paper, shape optimisation of flapping wings in forward flight is considered. This analysis is performed by combining a local gradient-based optimizer with the unsteady vortex lattice method (UVLM). Although the UVLM applies only to incompressible, inviscid flows where the separation lines are known a priori, Persson et al. [1] showed through a detailed comparison between UVLM and higher-fidelity computational fluid dynamics methods for flapping flight that the UVLM schemes produce accurate results for attached flow cases and even remain trend-relevant in the presence of flow separation. As such, they recommended the use of an aerodynamic model based on UVLM to perform preliminary design studies of flapping wing vehicles Unlike standard computational fluid dynamics schemes, this method requires meshing of the wing surface only and not of the whole flow domain [2]. From the design or optimisation perspective taken in our work, it is fairly common (and sometimes entirely necessary, as a result of the excessive computational cost of the highest fidelity tools such as Navier-Stokes solvers) to rely upon such a moderate level of modelling fidelity to traverse the design space in an economical manner. The objective of the work, described in this paper, is to identify a set of optimised shapes that maximise the propulsive efficiency, defined as the ratio of the propulsive power over the aerodynamic power, under lift, thrust, and area constraints. The shape of the wings is modelled using B-splines, a technology used in the computer-aided design (CAD) field for decades. This basis can be used to smoothly discretize wing shapes with few degrees of freedom, referred to as control points. The locations of the control points constitute the design variables. The results suggest that changing the shape yields significant improvement in the performance of the flapping wings. The optimisation pushes the design to "bird-like" shapes with substantial increase in the time

  8. Dispersion forces in methane

    NARCIS (Netherlands)

    Lekkerkerker, H.N.W.; Coulon, P.; Luyckx, R.

    1977-01-01

    The coefficients of the R-6 and R-7 terms in the series representation of the dispersion interaction between two methane molecules and between methane and helium, neon and argon are calculated by a variation method.

  9. Fickian dispersion is anomalous

    Science.gov (United States)

    Cushman, John H.; O'Malley, Dan

    2015-12-01

    The thesis put forward here is that the occurrence of Fickian dispersion in geophysical settings is a rare event and consequently should be labeled as anomalous. What people classically call anomalous is really the norm. In a Lagrangian setting, a process with mean square displacement which is proportional to time is generally labeled as Fickian dispersion. With a number of counter examples we show why this definition is fraught with difficulty. In a related discussion, we show an infinite second moment does not necessarily imply the process is super dispersive. By employing a rigorous mathematical definition of Fickian dispersion we illustrate why it is so hard to find a Fickian process. We go on to employ a number of renormalization group approaches to classify non-Fickian dispersive behavior. Scaling laws for the probability density function for a dispersive process, the distribution for the first passage times, the mean first passage time, and the finite-size Lyapunov exponent are presented for fixed points of both deterministic and stochastic renormalization group operators. The fixed points of the renormalization group operators are p-self-similar processes. A generalized renormalization group operator is introduced whose fixed points form a set of generalized self-similar processes. Power-law clocks are introduced to examine multi-scaling behavior. Several examples of these ideas are presented and discussed.

  10. Optimisation of the self-assembly process: production of stable, alginate-based polyelectrolyte nanocomplexes with protamine

    Science.gov (United States)

    Dul, Maria; Paluch, Krzysztof J.; Healy, Anne Marie; Sasse, Astrid; Tajber, Lidia

    2017-06-01

    The aim of this work was to investigate the possibility of covalent cross-linker-free, polyelectrolyte complex formation at the nanoscale between alginic acid (as sodium alginate, ALG) and protamine (PROT). Optimisation of the self-assembly conditions was performed by varying the type of polymer used, pH of component solutions, mass mixing ratio of the components and the speed and order of component addition on the properties of complexes. Homogenous particles with nanometric sizes resulted when an aqueous dispersion of ALG was rapidly mixed with a solution of PROT. The polyelectrolyte complex between ALG and PROT was confirmed by infrared spectroscopy. To facilitate incorporation of drugs soluble at low pH, pH of ALG dispersion was decreased to 2; however, no nanoparticles (NPs) were formed upon complexation with PROT. Adjusting pH of PROT solution to 3 resulted in the formation of cationic or anionic NPs with a size range 70-300 nm. Colloidal stability of selected alginic acid low/PROT formulations was determined upon storage at room temperature and in liquid media at various pH. Physical stability of NPs correlated with the initial surface charge of particles and was time- and pH-dependent. Generally, better stability was observed for anionic NPs stored as native dispersions and in liquids covering a range of pH.

  11. Optimisation of groundwater level monitoring networks using geostatistical modelling based on the Spartan family variogram and a genetic algorithm method

    Science.gov (United States)

    Parasyris, Antonios E.; Spanoudaki, Katerina; Kampanis, Nikolaos A.

    2016-04-01

    Groundwater level monitoring networks provide essential information for water resources management, especially in areas with significant groundwater exploitation for agricultural and domestic use. Given the high maintenance costs of these networks, development of tools, which can be used by regulators for efficient network design is essential. In this work, a monitoring network optimisation tool is presented. The network optimisation tool couples geostatistical modelling based on the Spartan family variogram with a genetic algorithm method and is applied to Mires basin in Crete, Greece, an area of high socioeconomic and agricultural interest, which suffers from groundwater overexploitation leading to a dramatic decrease of groundwater levels. The purpose of the optimisation tool is to determine which wells to exclude from the monitoring network because they add little or no beneficial information to groundwater level mapping of the area. Unlike previous relevant investigations, the network optimisation tool presented here uses Ordinary Kriging with the recently-established non-differentiable Spartan variogram for groundwater level mapping, which, based on a previous geostatistical study in the area leads to optimal groundwater level mapping. Seventy boreholes operate in the area for groundwater abstraction and water level monitoring. The Spartan variogram gives overall the most accurate groundwater level estimates followed closely by the power-law model. The geostatistical model is coupled to an integer genetic algorithm method programmed in MATLAB 2015a. The algorithm is used to find the set of wells whose removal leads to the minimum error between the original water level mapping using all the available wells in the network and the groundwater level mapping using the reduced well network (error is defined as the 2-norm of the difference between the original mapping matrix with 70 wells and the mapping matrix of the reduced well network). The solution to the

  12. Optimisation of the Nonlinear Suspension Characteristics of a Light Commercial Vehicle

    Directory of Open Access Journals (Sweden)

    Dinçer Özcan

    2013-01-01

    Full Text Available The optimum functional characteristics of suspension components, namely, linear/nonlinear spring and nonlinear damper characteristic functions are determined using simple lumped parameter models. A quarter car model is used to represent the front independent suspension, and a half car model is used to represent the rear solid axle suspension of a light commercial vehicle. The functional shapes of the suspension characteristics used in the optimisation process are based on typical shapes supplied by a car manufacturer. The complexity of a nonlinear function optimisation problem is reduced by scaling it up or down from the aforementioned shape in the optimisation process. The nonlinear optimised suspension characteristics are first obtained using lower complexity lumped parameter models. Then, the performance of the optimised suspension units are verified using the higher fidelity and more realistic Carmaker model. An interactive software module is developed to ease the nonlinear suspension optimisation process using the Matlab Graphical User Interface tool.

  13. Equilibrium Star Formation In A Constant Q Disk: Model Optimisation and Initial Tests

    CERN Document Server

    Zheng, Zheng; Heckman, Timothy; Thilker, David; Zwaan, Martin

    2013-01-01

    We develop a model for the distribution of the ISM and star formation in galaxies based on recent studies that indicate that galactic disks stabilise to a constant stability parameter, which we combine with prescriptions of how the phases of the ISM are determined and for the Star Formation Law (SFL). The model predicts the gas surface mass density and star formation intensity of a galaxy given its rotation curve, stellar surface mass density and the gas velocity dispersion. This model is tested on radial profiles of neutral and molecular ISM surface mass density and star formation intensity of 12 galaxies selected from the THINGS sample. Our tests focus on intermediate radii. Nevertheless, the model produces reasonable agreement with ISM mass and star formation rate integrated over the central region in all but one case. To optimise the model, we evaluate four recipes for the stability parameter, three recipes for apportioning the ISM into molecular and neutral components, and eight versions of the SFL. We f...

  14. Software tools overview : process integration, modelling and optimisation for energy saving and pollution reduction

    OpenAIRE

    Lam, Hon Loong; Klemeš, Jiri; Kravanja, Zdravko; Varbanov, Petar

    2012-01-01

    This paper provides an overview of software tools based on long experience andapplications in the area of process integration, modelling and optimisation. The first part reviews the current design practice and the development of supporting software tools. Those are categorised as: (1) process integration and retrofit analysis tools, (2) general mathematical modelling suites with optimisation libraries, (3) flowsheeting simulation and (4) graph-based process optimisation tools. The second part...

  15. Stacking sequence optimisation of composite panels subjected to slamming impact loads using a genetic algorithm

    OpenAIRE

    Khedmati,Mohammad Reza; Sangtabi,Mohammad Rezai; Fakoori,Mehdi

    2013-01-01

    Optimisation of stacking sequence for composite panels under slamming impact loads using a genetic algorithm method is studied in this paper. For this purpose, slamming load is assumed to have a uniform distribution with a triangular-pulse type of intensity function. In order to perform optimisation based on a genetic algorithm, a special code is written in MATLAB software environment. The optimiser is coupled with the commercial software ANSYS in order to analyse the composite panel under st...

  16. Optimisation of logistics processes of energy grass collection

    Science.gov (United States)

    Bányai, Tamás.

    2010-05-01

    The collection of energy grass is a logistics-intensive process [1]. The optimal design and control of transportation and collection subprocesses is a critical point of the supply chain. To avoid irresponsible decisions by right of experience and intuition, the optimisation and analysis of collection processes based on mathematical models and methods is the scientific suggestible way. Within the frame of this work, the author focuses on the optimisation possibilities of the collection processes, especially from the point of view transportation and related warehousing operations. However the developed optimisation methods in the literature [2] take into account the harvesting processes, county-specific yields, transportation distances, erosion constraints, machinery specifications, and other key variables, but the possibility of more collection points and the multi-level collection were not taken into consideration. The possible areas of using energy grass is very wide (energetically use, biogas and bio alcohol production, paper and textile industry, industrial fibre material, foddering purposes, biological soil protection [3], etc.), so not only a single level but also a multi-level collection system with more collection and production facilities has to be taken into consideration. The input parameters of the optimisation problem are the followings: total amount of energy grass to be harvested in each region; specific facility costs of collection, warehousing and production units; specific costs of transportation resources; pre-scheduling of harvesting process; specific transportation and warehousing costs; pre-scheduling of processing of energy grass at each facility (exclusive warehousing). The model take into consideration the following assumptions: (1) cooperative relation among processing and production facilties, (2) capacity constraints are not ignored, (3) the cost function of transportation is non-linear, (4) the drivers conditions are ignored. The

  17. Optimisation of fertiliser rates in crop production against energy use indicators

    DEFF Research Database (Denmark)

    Rossner, Helis; Ritz, Christian; Astover, Alar

    2014-01-01

    Optimising mineral nitrogen (N) use in crop production is inevitable target as mineral fertilisers reflectone of the highest inputs both in terms of economy and energy. The aim of the study was to comparethe relationship between the rate of N fertiliser application and different measures of energy.......05) optimisation. Both the new combined indices gave optimum N norms in between the rate ofER an EG. Composted cow manure background did not affect mineral N optimisation significantly. Wesuggest optimisation of mineral N according to bi-dimensional parameters as they capture important fea-tures of production...

  18. An Inverse Robust Optimisation Approach for a Class of Vehicle Routing Problems under Uncertainty

    Directory of Open Access Journals (Sweden)

    Liang Sun

    2016-01-01

    Full Text Available There is a trade-off between the total penalty paid to customers (TPC and the total transportation cost (TTC in depot for vehicle routing problems under uncertainty (VRPU. The trade-off refers to the fact that the TTC in depot inevitably increases when the TPC decreases and vice versa. With respect to this issue, the vehicle routing problem (VRP with uncertain customer demand and travel time was studied to optimise the TPC and the TTC in depot. In addition, an inverse robust optimisation approach was proposed to solve this kind of VRPU by combining the ideas of inverse optimisation and robust optimisation so as to improve both the TPC and the TTC in depot. The method aimed to improve the corresponding TTC of the robust optimisation solution under the minimum TPC through minimising the adjustment of benchmark road transportation cost. According to the characteristics of the inverse robust optimisation model, a genetic algorithm (GA and column generation algorithm are combined to solve the problem. Moreover, 39 test problems are solved by using an inverse robust optimisation approach: the results show that both the TPC and TTC obtained by using the inverse robust optimisation approach are less than those calculated using a robust optimisation approach.

  19. Research on the Management of Dispersion Covering Internship in the Major of Manufacturing in Vocational High School%高职制造类专业分散顶岗实习管理研究

    Institute of Scientific and Technical Information of China (English)

    吕莹; 张静; 辛庆旭

    2015-01-01

    Covering internship is an important part in the process of higher vocational education. In the article, it studied the main problems existing in the process of covering internship in the major of manufacturing in vocational high school, presented to fulfill practice process supervision by the participation of school, enterprises and students, and build up the dispersion practice management mechanism by establishing evaluation index system and perfecting operation conditions, provided the guarantee for the teaching quality of covering internship.%顶岗实习是高等职业教育过程中的重要组成部分。针对高职院校制造类专业顶岗实习过程中所出现的主要问题,提出学校、企业、学生三方共同参与并完成实习过程监督的顶岗实习管理方法。通过建立评价指标体系、完善运行条件等途径,构建协同创新的分散实习管理机制,为顶岗实习的教学质量提供保障。

  20. Optimising survey effort to monitor environmental variables: A case study using New Zealand kiwifruit orchards.

    Science.gov (United States)

    MacLeod, Catriona J; Green, Peter; Tompkins, Daniel M; Benge, Jayson; Moller, Henrik

    2016-12-01

    Environmental monitoring is increasingly used to assess spatial and temporal trends in agricultural sustainability, and test the effectiveness of farm management policies. However, detecting changes in environmental variables is often technically and logistically challenging. To demonstrate how survey effort for environmental monitoring can be optimised, we applied the new statistical power analysis R package simr to pilot survey data. Specifically, we identified the amount of survey effort required to have an 80% chance of detecting specified trends (-1 to -4% pa) in 13 environmental variables on New Zealand kiwifruit orchards within an 11-year period. The variables assessed were related to soil status, agricultural pests (birds), or ecosystem composition (birds). Analyses were conducted on average values (for each orchard and year combination) to provide a consistent scale for comparison among variables. Survey frequency varied from annual (11 surveys) to every 5 years (3 surveys). Survey size was set at either 30, 60, 150 or 300 orchards. In broad terms, we show the power to detect a specified range of trends over an 11-year period in this sector is much higher for 'soil status' than for 'agricultural pest' or 'ecosystem composition'. Changes in one subset of native bird species (nectar-feeders) requiring a particularly high level of relative survey effort to detect with confidence. Monitoring soil status can thus be smaller and less frequent than those which also want to detect changes in agricultural pests or ecosystem composition (with the latter requiring the most effort) but will depend on the magnitude of changes that is meaningful to detect. This assessment thus allows kiwifruit industry in New Zealand to optimise survey design to the desired information, and provides a template for other industries to do likewise. Power analyses are now more accessible through the provision of the simr package, so deploying and integrating them into design and decision