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Sample records for optimisation senuf network

  1. Nuclear power plant maintenance optimisation SENUF network activity

    International Nuclear Information System (INIS)

    Ahlstrand, R.; Bieth, M.; Pla, P.; Rieg, C.; Trampus, P.

    2004-01-01

    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.)

  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. 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.

  4. Optimisation of milling parameters using neural network

    Directory of Open Access Journals (Sweden)

    Lipski Jerzy

    2017-01-01

    Full Text Available The purpose of this study was to design and test an intelligent computer software developed with the purpose of increasing average productivity of milling not compromising the design features of the final product. The developed system generates optimal milling parameters based on the extent of tool wear. The introduced optimisation algorithm employs a multilayer model of a milling process developed in the artificial neural network. The input parameters for model training are the following: cutting speed vc, feed per tooth fz and the degree of tool wear measured by means of localised flank wear (VB3. The output parameter is the surface roughness of a machined surface Ra. Since the model in the neural network exhibits good approximation of functional relationships, it was applied to determine optimal milling parameters in changeable tool wear conditions (VB3 and stabilisation of surface roughness parameter Ra. Our solution enables constant control over surface roughness parameters and productivity of milling process after each assessment of tool condition. The recommended parameters, i.e. those which applied in milling ensure desired surface roughness and maximal productivity, are selected from all the parameters generated by the model. The developed software may constitute an expert system supporting a milling machine operator. In addition, the application may be installed on a mobile device (smartphone, connected to a tool wear diagnostics instrument and the machine tool controller in order to supply updated optimal parameters of milling. The presented solution facilitates tool life optimisation and decreasing tool change costs, particularly during prolonged operation.

  5. Mutual information-based LPI optimisation for radar network

    Science.gov (United States)

    Shi, Chenguang; Zhou, Jianjiang; Wang, Fei; Chen, Jun

    2015-07-01

    Radar network can offer significant performance improvement for target detection and information extraction employing spatial diversity. For a fixed number of radars, the achievable mutual information (MI) for estimating the target parameters may extend beyond a predefined threshold with full power transmission. In this paper, an effective low probability of intercept (LPI) optimisation algorithm is presented to improve LPI performance for radar network. Based on radar network system model, we first provide Schleher intercept factor for radar network as an optimisation metric for LPI performance. Then, a novel LPI optimisation algorithm is presented, where for a predefined MI threshold, Schleher intercept factor for radar network is minimised by optimising the transmission power allocation among radars in the network such that the enhanced LPI performance for radar network can be achieved. The genetic algorithm based on nonlinear programming (GA-NP) is employed to solve the resulting nonconvex and nonlinear optimisation problem. Some simulations demonstrate that the proposed algorithm is valuable and effective to improve the LPI performance for radar network.

  6. 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

  7. Optimised Design and Analysis of All-Optical Networks

    DEFF Research Database (Denmark)

    Glenstrup, Arne John

    2002-01-01

    through various experiments and is shown to produce good results and to be able to scale up to networks of realistic sizes. A novel method, subpath wavelength grouping, for routing connections in a multigranular all-optical network where several wavelengths can be grouped and switched at band and fibre......This PhD thesis presents a suite of methods for optimising design and for analysing blocking probabilities of all-optical networks. It thus contributes methodical knowledge to the field of computer assisted planning of optical networks. A two-stage greenfield optical network design optimiser...... is developed, based on shortest-path algorithms and a comparatively new metaheuristic called simulated allocation. It is able to handle design of all-optical mesh networks with optical cross-connects, considers duct as well as fibre and node costs, and can also design protected networks. The method is assessed...

  8. 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

    of the EU FP 7 project DETECT. It evaluates the gamma dose rates that a proposed set of sensors might measure in an emergency and uses this information to optimise the sensor locations. The gamma dose rates are taken from a comprehensive library of simulations of atmospheric radioactive plumes from 64......Fast delivery of comprehensive information on the radiological situation is essential for decision-making in nuclear emergencies. Most national radiological agencies in Europe employ gamma dose rate sensor networks to monitor radioactive pollution of the atmosphere. Sensor locations were often...... source locations. These simulations cover the whole European Union, so the DOT allows evaluation and optimisation of sensor networks for all EU countries, as well as evaluation of fencing sensors around possible sources. Users can choose from seven cost functions to evaluate the capability of a given...

  9. 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.

  10. Optimising Transport in a Homogeneous Network

    OpenAIRE

    WEAIRE, DENIS LAWRENCE

    2004-01-01

    PUBLISHED Many situations in physics, biology, and engineering consist of the transport of some physical quantity through a network of narrow channels. The ability of a network to transport such a quantity in every direction can be described by the average conductivity associated with it. When the flow through each channel is conserved and derives from a potential function, we show that there exists an upper bound of the average conductivity and explicitly give the expression f...

  11. Modulation aware cluster size optimisation in wireless sensor networks

    Science.gov (United States)

    Sriram Naik, M.; Kumar, Vinay

    2017-07-01

    Wireless sensor networks (WSNs) play a great role because of their numerous advantages to the mankind. The main challenge with WSNs is the energy efficiency. In this paper, we have focused on the energy minimisation with the help of cluster size optimisation along with consideration of modulation effect when the nodes are not able to communicate using baseband communication technique. Cluster size optimisations is important technique to improve the performance of WSNs. It provides improvement in energy efficiency, network scalability, network lifetime and latency. We have proposed analytical expression for cluster size optimisation using traditional sensing model of nodes for square sensing field with consideration of modulation effects. Energy minimisation can be achieved by changing the modulation schemes such as BPSK, 16-QAM, QPSK, 64-QAM, etc., so we are considering the effect of different modulation techniques in the cluster formation. The nodes in the sensing fields are random and uniformly deployed. It is also observed that placement of base station at centre of scenario enables very less number of modulation schemes to work in energy efficient manner but when base station placed at the corner of the sensing field, it enable large number of modulation schemes to work in energy efficient manner.

  12. Power and delay optimisation in multi-hop wireless networks

    KAUST Repository

    Xia, Li

    2014-02-05

    In this paper, we study the optimisation problem of transmission power and delay in a multi-hop wireless network consisting of multiple nodes. The goal is to determine the optimal policy of transmission rates at various buffer and channel states in order to minimise the power consumption and the queueing delay of the whole network. With the assumptions of interference-free links and independently and identically distributed (i.i.d.) channel states, we formulate this problem using a semi-open Jackson network model for data transmission and a Markov model for channel states transition. We derive a difference equation of the system performance under any two different policies. The necessary and sufficient condition of optimal policy is obtained. We also prove that the system performance is monotonic with respect to (w.r.t.) the transmission rate and the optimal transmission rate can be either maximal or minimal. That is, the ‘bang-bang’ control is an optimal control. This optimality structure greatly reduces the problem complexity. Furthermore, we develop an iterative algorithm to find the optimal solution. Finally, we conduct the simulation experiments to demonstrate the effectiveness of our approach. We hope our work can shed some insights on solving this complicated optimisation problem.

  13. Optimised cross-layer synchronisation schemes for wireless sensor networks

    Science.gov (United States)

    Nasri, Nejah; Ben Fradj, Awatef; Kachouri, Abdennaceur

    2017-07-01

    This paper aims at synchronisation between the sensor nodes. Indeed, in the context of wireless sensor networks, it is necessary to take into consideration the energy cost induced by the synchronisation, which can represent the majority of the energy consumed. On communication, an already identified hard point consists in imagining a fine synchronisation protocol which must be sufficiently robust to the intermittent energy in the sensors. Hence, this paper worked on aspects of performance and energy saving, in particular on the optimisation of the synchronisation protocol using cross-layer design method such as synchronisation between layers. Our approach consists in balancing the energy consumption between the sensors and choosing the cluster head with the highest residual energy in order to guarantee the reliability, integrity and continuity of communication (i.e. maximising the network lifetime).

  14. Optimisation of Software-Defined Networks Performance Using a Hybrid Intelligent System

    Directory of Open Access Journals (Sweden)

    Ann Sabih

    2017-06-01

    Full Text Available This paper proposes a novel intelligent technique that has been designed to optimise the performance of Software Defined Networks (SDN. The proposed hybrid intelligent system has employed integration of intelligence-based optimisation approaches with the artificial neural network. These heuristic optimisation methods include Genetic Algorithms (GA and Particle Swarm Optimisation (PSO. These methods were utilised separately in order to select the best inputs to maximise SDN performance. In order to identify SDN behaviour, the neural network model is trained and applied. The maximal optimisation approach has been identified using an analytical approach that considered SDN performance and the computational time as objective functions. Initially, the general model of the neural network was tested with unseen data before implementing the model using GA and PSO to determine the optimal performance of SDN. The results showed that the SDN represented by Artificial Neural Network ANN, and optmised by PSO, generated a better configuration with regards to computational efficiency and performance index.

  15. Study on the evolutionary optimisation of the topology of network control systems

    Science.gov (United States)

    Zhou, Zude; Chen, Benyuan; Wang, Hong; Fan, Zhun

    2010-08-01

    Computer networks have been very popular in enterprise applications. However, optimisation of network designs that allows networks to be used more efficiently in industrial environment and enterprise applications remains an interesting research topic. This article mainly discusses the topology optimisation theory and methods of the network control system based on switched Ethernet in an industrial context. Factors that affect the real-time performance of the industrial control network are presented in detail, and optimisation criteria with their internal relations are analysed. After the definition of performance parameters, the normalised indices for the evaluation of the topology optimisation are proposed. The topology optimisation problem is formulated as a multi-objective optimisation problem and the evolutionary algorithm is applied to solve it. Special communication characteristics of the industrial control network are considered in the optimisation process. In respect to the evolutionary algorithm design, an improved arena algorithm is proposed for the construction of the non-dominated set of the population. In addition, for the evaluation of individuals, the integrated use of the dominative relation method and the objective function combination method, for reducing the computational cost of the algorithm, are given. Simulation tests show that the performance of the proposed algorithm is preferable and superior compared to other algorithms. The final solution greatly improves the following indices: traffic localisation, traffic balance and utilisation rate balance of switches. In addition, a new performance index with its estimation process is proposed.

  16. Optimising TCP for cloud-based mobile networks

    DEFF Research Database (Denmark)

    Artuso, Matteo; Christiansen, Henrik Lehrmann

    2016-01-01

    Cloud-based mobile networks are foreseen to be a technological enabler for the next generation of mobile networks. Their design requires substantial research as they pose unique challenges, especially from the point of view of additional delays in the fronthaul network. Commonly used network...... implementations of 3 popular operating systems are investigated in our network model. The results on the most influential parameters are used to design an optimized TCP for cloud-based mobile networks....

  17. Genetic algorithms and artificial neural networks for loading pattern optimisation of advanced gas-cooled reactors

    Energy Technology Data Exchange (ETDEWEB)

    Ziver, A.K. E-mail: a.k.ziver@imperial.ac.uk; Pain, C.C; Carter, J.N.; Oliveira, C.R.E. de; Goddard, A.J.H.; Overton, R.S

    2004-03-01

    A non-generational genetic algorithm (GA) has been developed for fuel management optimisation of Advanced Gas-Cooled Reactors, which are operated by British Energy and produce around 20% of the UK's electricity requirements. An evolutionary search is coded using the genetic operators; namely selection by tournament, two-point crossover, mutation and random assessment of population for multi-cycle loading pattern (LP) optimisation. A detailed description of the chromosomes in the genetic algorithm coded is presented. Artificial Neural Networks (ANNs) have been constructed and trained to accelerate the GA-based search during the optimisation process. The whole package, called GAOPT, is linked to the reactor analysis code PANTHER, which performs fresh fuel loading, burn-up and power shaping calculations for each reactor cycle by imposing station-specific safety and operational constraints. GAOPT has been verified by performing a number of tests, which are applied to the Hinkley Point B and Hartlepool reactors. The test results giving loading pattern (LP) scenarios obtained from single and multi-cycle optimisation calculations applied to realistic reactor states of the Hartlepool and Hinkley Point B reactors are discussed. The results have shown that the GA/ANN algorithms developed can help the fuel engineer to optimise loading patterns in an efficient and more profitable way than currently available for multi-cycle refuelling of AGRs. Research leading to parallel GAs applied to LP optimisation are outlined, which can be adapted to present day LWR fuel management problems.

  18. Design and Optimisation Problems in Wireless Sensor Networks

    Indian Academy of Sciences (India)

    Premkumar Karumbu,1.05 ECE,,+91-9448227167

    2010-11-14

    Nov 14, 2010 ... Wireless Networks of Multifunction Smart Sensors (WSNs). A smart sensor ... Energy and environment management networks in large buildings. Emerging ISA ... Monitoring mobile patients in hospitals and homes. Locating ...

  19. Quadratic head loss approximations for optimisation problems in water supply networks

    NARCIS (Netherlands)

    Pecci, Filippo; Abraham, E.; I, Stoianov

    2017-01-01

    This paper presents a novel analysis of the accuracy of quadratic approximations for the Hazen–Williams (HW) head loss formula, which enables the control of constraint violations in optimisation problems for water supply networks. The two smooth polynomial approximations considered here minimise the

  20. Integrated topology optimisation of multi-energy networks

    NARCIS (Netherlands)

    Mazairac, L.A.J.; Salenbien, R.; Vanhoudt, D.; Desmedt, J.; Vries, de B.

    2015-01-01

    Multi-carrier hybrid energy distribution net- works provide flexibility in case of network malfunctions, energy shortages and price fluctuations through energy conversion and storage. Therefore hybrid networks can cope with large-scale integration of distributed and intermittent renewable energy

  1. Energy efficiency optimisation for distillation column using artificial neural network models

    International Nuclear Information System (INIS)

    Osuolale, Funmilayo N.; Zhang, Jie

    2016-01-01

    This paper presents a neural network based strategy for the modelling and optimisation of energy efficiency in distillation columns incorporating the second law of thermodynamics. Real-time optimisation of distillation columns based on mechanistic models is often infeasible due to the effort in model development and the large computation effort associated with mechanistic model computation. This issue can be addressed by using neural network models which can be quickly developed from process operation data. The computation time in neural network model evaluation is very short making them ideal for real-time optimisation. Bootstrap aggregated neural networks are used in this study for enhanced model accuracy and reliability. Aspen HYSYS is used for the simulation of the distillation systems. Neural network models for exergy efficiency and product compositions are developed from simulated process operation data and are used to maximise exergy efficiency while satisfying products qualities constraints. Applications to binary systems of methanol-water and benzene-toluene separations culminate in a reduction of utility consumption of 8.2% and 28.2% respectively. Application to multi-component separation columns also demonstrate the effectiveness of the proposed method with a 32.4% improvement in the exergy efficiency. - Highlights: • Neural networks can accurately model exergy efficiency in distillation columns. • Bootstrap aggregated neural network offers improved model prediction accuracy. • Improved exergy efficiency is obtained through model based optimisation. • Reductions of utility consumption by 8.2% and 28.2% were achieved for binary systems. • The exergy efficiency for multi-component distillation is increased by 32.4%.

  2. CIME course on Modelling and Optimisation of Flows on Networks

    CERN Document Server

    Ambrosio, Luigi; Helbing, Dirk; Klar, Axel; Zuazua, Enrique

    2013-01-01

    In recent years flows in networks have attracted the interest of many researchers from different areas, e.g. applied mathematicians, engineers, physicists, economists. The main reason for this ubiquity is the wide and diverse range of applications, such as vehicular traffic, supply chains, blood flow, irrigation channels, data networks and others. This book presents an extensive set of notes by world leaders on the main mathematical techniques used to address such problems, together with investigations into specific applications. The main focus is on partial differential equations in networks, but ordinary differential equations and optimal transport are also included. Moreover, the modeling is completed by analysis, numerics, control and optimization of flows in networks. The book will be a valuable resource for every researcher or student interested in the subject.

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

    African Journals Online (AJOL)

    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 pumping systems. The variable frequency drive tracks the minimum head of the pumping system, while the control valves have the function of eliminating the excess pressure at ...

  4. Power and delay optimisation in multi-hop wireless networks

    KAUST Repository

    Xia, Li; Shihada, Basem

    2014-01-01

    in order to minimise the power consumption and the queueing delay of the whole network. With the assumptions of interference-free links and independently and identically distributed (i.i.d.) channel states, we formulate this problem using a semi

  5. An optimisation framework for determination of capacity in railway networks

    DEFF Research Database (Denmark)

    Jensen, Lars Wittrup

    2015-01-01

    network based on a mix of train types, the infrastructure and rolling stock used. The framework consist of two steps. In the first step the maximum number of trains is found according to the predefined mix of train types. In the second step additional trains are added based on weights assigned...

  6. User-friendly Tool for Power Flow Analysis and Distributed Generation Optimisation in Radial Distribution Networks

    Directory of Open Access Journals (Sweden)

    M. F. Akorede

    2017-06-01

    Full Text Available The intent of power distribution companies (DISCOs is to deliver electric power to their customers in an efficient and reliable manner – with minimal energy loss cost. One major way to minimise power loss on a given power system is to install distributed generation (DG units on the distribution networks. However, to maximise benefits, it is highly crucial for a DISCO to ensure that these DG units are of optimal size and sited in the best locations on the network. This paper gives an overview of a software package developed in this study, called Power System Analysis and DG Optimisation Tool (PFADOT. The main purpose of the graphical user interface-based package is to guide a DISCO in finding the optimal size and location for DG placement in radial distribution networks. The package, which is also suitable for load flow analysis, employs the GUI feature of MATLAB. Three objective functions are formulated into a single optimisation problem and solved with fuzzy genetic algorithm to simultaneously obtain DG optimal size and location. The accuracy and reliability of the developed tool was validated using several radial test systems, and the results obtained are evaluated against the existing similar package cited in the literature, which are impressive and computationally efficient.

  7. Improved head direction command classification using an optimised Bayesian neural network.

    Science.gov (United States)

    Nguyen, Son T; Nguyen, Hung T; Taylor, Philip B; Middleton, James

    2006-01-01

    Assistive technologies have recently emerged to improve the quality of life of severely disabled people by enhancing their independence in daily activities. Since many of those individuals have limited or non-existing control from the neck downward, alternative hands-free input modalities have become very important for these people to access assistive devices. In hands-free control, head movement has been proved to be a very effective user interface as it can provide a comfortable, reliable and natural way to access the device. Recently, neural networks have been shown to be useful not only for real-time pattern recognition but also for creating user-adaptive models. Since multi-layer perceptron neural networks trained using standard back-propagation may cause poor generalisation, the Bayesian technique has been proposed to improve the generalisation and robustness of these networks. This paper describes the use of Bayesian neural networks in developing a hands-free wheelchair control system. The experimental results show that with the optimised architecture, classification Bayesian neural networks can detect head commands of wheelchair users accurately irrespective to their levels of injuries.

  8. Comparison of the genetic algorithm and incremental optimisation routines for a Bayesian inverse modelling based network design

    Science.gov (United States)

    Nickless, A.; Rayner, P. J.; Erni, B.; Scholes, R. J.

    2018-05-01

    The design of an optimal network of atmospheric monitoring stations for the observation of carbon dioxide (CO2) concentrations can be obtained by applying an optimisation algorithm to a cost function based on minimising posterior uncertainty in the CO2 fluxes obtained from a Bayesian inverse modelling solution. Two candidate optimisation methods assessed were the evolutionary algorithm: the genetic algorithm (GA), and the deterministic algorithm: the incremental optimisation (IO) routine. This paper assessed the ability of the IO routine in comparison to the more computationally demanding GA routine to optimise the placement of a five-member network of CO2 monitoring sites located in South Africa. The comparison considered the reduction in uncertainty of the overall flux estimate, the spatial similarity of solutions, and computational requirements. Although the IO routine failed to find the solution with the global maximum uncertainty reduction, the resulting solution had only fractionally lower uncertainty reduction compared with the GA, and at only a quarter of the computational resources used by the lowest specified GA algorithm. The GA solution set showed more inconsistency if the number of iterations or population size was small, and more so for a complex prior flux covariance matrix. If the GA completed with a sub-optimal solution, these solutions were similar in fitness to the best available solution. Two additional scenarios were considered, with the objective of creating circumstances where the GA may outperform the IO. The first scenario considered an established network, where the optimisation was required to add an additional five stations to an existing five-member network. In the second scenario the optimisation was based only on the uncertainty reduction within a subregion of the domain. The GA was able to find a better solution than the IO under both scenarios, but with only a marginal improvement in the uncertainty reduction. These results suggest

  9. Monitoring groundwater: optimising networks to take account of cost effectiveness, legal requirements and enforcement realities

    Science.gov (United States)

    Allan, A.; Spray, C.

    2013-12-01

    regulator to ensure compliance with legal standards. On the other hand, it can be ruinously expensive to set up a monitoring network in remote areas and regulators must therefore balance the cost effectiveness of these networks against the chance that a court might question their fitness for purpose. This presentation will examine how regulators can balance legal standards for monitoring against the cost of developing and maintaining the requisite networks, while still producing observable improvements in water and ecosystem quality backed by legally enforceable sanctions for breaches. Reflecting the findings from the EU-funded GENESIS project, it will look at case law from around the world to assess how tribunals balance competing models, and the extent to which decisions may be revisited in the light of new scientific understanding. Finally, it will make recommendations to assist regulators in optimising their network designs for enforcement.

  10. Environomic multi-objective optimisation of a district heating network considering centralized and decentralized heat pumps

    International Nuclear Information System (INIS)

    Molyneaux, A.; Leyland, G.; Favrat, D.

    2010-01-01

    Concern for the environment has been steadily growing in recent years, and it is becoming more common to include environmental impact and pollution costs in the design problem along with construction, investment and operating costs. To economically respond to the global environmental problems ahead, progress must be made both on more sustainable technologies and on the design methodology, which needs to adopt a more holistic approach. Heat pumps and, in particular systems integrating heat pumps and cogeneration units, offer a significant potential for greenhouse gas reduction. This paper illustrates the application of a multi-objective and multi-modal evolutionary algorithm to facilitate the design and planning of a district heating network based on a combination of centralized and decentralized heat pumps combined with on-site cogeneration. Comparisons are made with an earlier study based on a single objective environomic optimisation of the same overall model.

  11. Optimising social information by game theory and ant colony method to enhance routing protocol in opportunistic networks

    Directory of Open Access Journals (Sweden)

    Chander Prabha

    2016-09-01

    Full Text Available The data loss and disconnection of nodes are frequent in the opportunistic networks. The social information plays an important role in reducing the data loss because it depends on the connectivity of nodes. The appropriate selection of next hop based on social information is critical for improving the performance of routing in opportunistic networks. The frequent disconnection problem is overcome by optimising the social information with Ant Colony Optimization method which depends on the topology of opportunistic network. The proposed protocol is examined thoroughly via analysis and simulation in order to assess their performance in comparison with other social based routing protocols in opportunistic network under various parameters settings.

  12. Automatic disease diagnosis using optimised weightless neural networks for low-power wearable devices.

    Science.gov (United States)

    Cheruku, Ramalingaswamy; Edla, Damodar Reddy; Kuppili, Venkatanareshbabu; Dharavath, Ramesh; Beechu, Nareshkumar Reddy

    2017-08-01

    Low-power wearable devices for disease diagnosis are used at anytime and anywhere. These are non-invasive and pain-free for the better quality of life. However, these devices are resource constrained in terms of memory and processing capability. Memory constraint allows these devices to store a limited number of patterns and processing constraint provides delayed response. It is a challenging task to design a robust classification system under above constraints with high accuracy. In this Letter, to resolve this problem, a novel architecture for weightless neural networks (WNNs) has been proposed. It uses variable sized random access memories to optimise the memory usage and a modified binary TRIE data structure for reducing the test time. In addition, a bio-inspired-based genetic algorithm has been employed to improve the accuracy. The proposed architecture is experimented on various disease datasets using its software and hardware realisations. The experimental results prove that the proposed architecture achieves better performance in terms of accuracy, memory saving and test time as compared to standard WNNs. It also outperforms in terms of accuracy as compared to conventional neural network-based classifiers. The proposed architecture is a powerful part of most of the low-power wearable devices for the solution of memory, accuracy and time issues.

  13. 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

  14. Optimisation models for decision support in the development of biomass-based industrial district-heating networks in Italy

    International Nuclear Information System (INIS)

    Chinese, Damiana; Meneghetti, Antonella

    2005-01-01

    A system optimisation approach is proposed to design biomass-based district-heating networks in the context of industrial districts, which are one of the main successful productive aspects of Italian industry. Two different perspectives are taken into account, that of utilities and of policy makers, leading to two optimisation models to be further integrated. A mixed integer linear-programming model is developed for a utility company's profit maximisation, while a linear-programming model aims at minimising the balance of greenhouse-gas emissions related to the proposed energy system and the avoided emissions due to the substitution of current fossil-fuel boilers with district-heating connections. To systematically compare their results, a sensitivity analysis is performed with respect to network size in order to identify how the optimal system configuration, in terms of selected boilers to be connected to a multiple energy-source network, may vary in the two cases and to detect possible optimal sizes. Then a factorial analysis is adopted to rank desirable client types under the two perspectives and identify proper marketing strategies. The proposed optimisation approach was applied to the design of a new district-heating network in the chair-manufacturing district of North-Eastern Italy. (Author)

  15. Structure and weights optimisation of a modified Elman network emotion classifier using hybrid computational intelligence algorithms: a comparative study

    Science.gov (United States)

    Sheikhan, Mansour; Abbasnezhad Arabi, Mahdi; Gharavian, Davood

    2015-10-01

    Artificial neural networks are efficient models in pattern recognition applications, but their performance is dependent on employing suitable structure and connection weights. This study used a hybrid method for obtaining the optimal weight set and architecture of a recurrent neural emotion classifier based on gravitational search algorithm (GSA) and its binary version (BGSA), respectively. By considering the features of speech signal that were related to prosody, voice quality, and spectrum, a rich feature set was constructed. To select more efficient features, a fast feature selection method was employed. The performance of the proposed hybrid GSA-BGSA method was compared with similar hybrid methods based on particle swarm optimisation (PSO) algorithm and its binary version, PSO and discrete firefly algorithm, and hybrid of error back-propagation and genetic algorithm that were used for optimisation. Experimental tests on Berlin emotional database demonstrated the superior performance of the proposed method using a lighter network structure.

  16. Transformer Incipient Fault Prediction Using Combined Artificial Neural Network and Various Particle Swarm Optimisation Techniques.

    Directory of Open Access Journals (Sweden)

    Hazlee Azil Illias

    Full Text Available It is important to predict the incipient fault in transformer oil accurately so that the maintenance of transformer oil can be performed correctly, reducing the cost of maintenance and minimise the error. Dissolved gas analysis (DGA has been widely used to predict the incipient fault in power transformers. However, sometimes the existing DGA methods yield inaccurate prediction of the incipient fault in transformer oil because each method is only suitable for certain conditions. Many previous works have reported on the use of intelligence methods to predict the transformer faults. However, it is believed that the accuracy of the previously proposed methods can still be improved. Since artificial neural network (ANN and particle swarm optimisation (PSO techniques have never been used in the previously reported work, this work proposes a combination of ANN and various PSO techniques to predict the transformer incipient fault. The advantages of PSO are simplicity and easy implementation. The effectiveness of various PSO techniques in combination with ANN is validated by comparison with the results from the actual fault diagnosis, an existing diagnosis method and ANN alone. Comparison of the results from the proposed methods with the previously reported work was also performed to show the improvement of the proposed methods. It was found that the proposed ANN-Evolutionary PSO method yields the highest percentage of correct identification for transformer fault type than the existing diagnosis method and previously reported works.

  17. Transformer Incipient Fault Prediction Using Combined Artificial Neural Network and Various Particle Swarm Optimisation Techniques.

    Science.gov (United States)

    Illias, Hazlee Azil; Chai, Xin Rui; Abu Bakar, Ab Halim; Mokhlis, Hazlie

    2015-01-01

    It is important to predict the incipient fault in transformer oil accurately so that the maintenance of transformer oil can be performed correctly, reducing the cost of maintenance and minimise the error. Dissolved gas analysis (DGA) has been widely used to predict the incipient fault in power transformers. However, sometimes the existing DGA methods yield inaccurate prediction of the incipient fault in transformer oil because each method is only suitable for certain conditions. Many previous works have reported on the use of intelligence methods to predict the transformer faults. However, it is believed that the accuracy of the previously proposed methods can still be improved. Since artificial neural network (ANN) and particle swarm optimisation (PSO) techniques have never been used in the previously reported work, this work proposes a combination of ANN and various PSO techniques to predict the transformer incipient fault. The advantages of PSO are simplicity and easy implementation. The effectiveness of various PSO techniques in combination with ANN is validated by comparison with the results from the actual fault diagnosis, an existing diagnosis method and ANN alone. Comparison of the results from the proposed methods with the previously reported work was also performed to show the improvement of the proposed methods. It was found that the proposed ANN-Evolutionary PSO method yields the highest percentage of correct identification for transformer fault type than the existing diagnosis method and previously reported works.

  18. Transformer Incipient Fault Prediction Using Combined Artificial Neural Network and Various Particle Swarm Optimisation Techniques

    Science.gov (United States)

    2015-01-01

    It is important to predict the incipient fault in transformer oil accurately so that the maintenance of transformer oil can be performed correctly, reducing the cost of maintenance and minimise the error. Dissolved gas analysis (DGA) has been widely used to predict the incipient fault in power transformers. However, sometimes the existing DGA methods yield inaccurate prediction of the incipient fault in transformer oil because each method is only suitable for certain conditions. Many previous works have reported on the use of intelligence methods to predict the transformer faults. However, it is believed that the accuracy of the previously proposed methods can still be improved. Since artificial neural network (ANN) and particle swarm optimisation (PSO) techniques have never been used in the previously reported work, this work proposes a combination of ANN and various PSO techniques to predict the transformer incipient fault. The advantages of PSO are simplicity and easy implementation. The effectiveness of various PSO techniques in combination with ANN is validated by comparison with the results from the actual fault diagnosis, an existing diagnosis method and ANN alone. Comparison of the results from the proposed methods with the previously reported work was also performed to show the improvement of the proposed methods. It was found that the proposed ANN-Evolutionary PSO method yields the highest percentage of correct identification for transformer fault type than the existing diagnosis method and previously reported works. PMID:26103634

  19. Classification of osteoporosis by artificial neural network based on monarch butterfly optimisation algorithm.

    Science.gov (United States)

    Devikanniga, D; Joshua Samuel Raj, R

    2018-04-01

    Osteoporosis is a life threatening disease which commonly affects women mostly after their menopause. It primarily causes mild bone fractures, which on advanced stage leads to the death of an individual. The diagnosis of osteoporosis is done based on bone mineral density (BMD) values obtained through various clinical methods experimented from various skeletal regions. The main objective of the authors' work is to develop a hybrid classifier model that discriminates the osteoporotic patient from healthy person, based on BMD values. In this Letter, the authors propose the monarch butterfly optimisation-based artificial neural network classifier which helps in earlier diagnosis and prevention of osteoporosis. The experiments were conducted using 10-fold cross-validation method for two datasets lumbar spine and femoral neck. The results were compared with other similar hybrid approaches. The proposed method resulted with the accuracy, specificity and sensitivity of 97.9% ± 0.14, 98.33% ± 0.03 and 95.24% ± 0.08, respectively, for lumbar spine dataset and 99.3% ± 0.16%, 99.2% ± 0.13 and 100, respectively, for femoral neck dataset. Further, its performance is compared using receiver operating characteristics analysis and Wilcoxon signed-rank test. The results proved that the proposed classifier is efficient and it outperformed the other approaches in all the cases.

  20. [Optimising care structures for severe hand trauma and replantation and chances of launching a national network].

    Science.gov (United States)

    Haas, E M; Volkmer, E; Holzbach, T; Wallmichrath, J; Engelhardt, T O; Giunta, R E

    2013-12-01

    Severe hand traumata have a significant impact on our health system and on insurance companies, respectively. It is estimated that 33% of all occupational injuries and 9% of all invalidity pensions are due to severe hand trauma. Unfortunately, these high numbers are not only due to the severity of the trauma but to organisational deficiencies. Usually, the patient is treated at the general surgical emergency in the first place and only then forwarded to a microsurgeon. This redirection increases the time that is required for the patient to finally arrive at an expert for hand surgery. On the one hand, this problem can be explained by the population's lack of awareness for distinguished experts for hand and microsurgery, on the other hand, the emergency network, or emergency doctors in particular are not well informed about where to take a patient with a severe hand trauma - clearly a problem of communication between the hospitals and the ambulance. It is possible to tackle this problem, but put participating hand trauma centres have to work hand in hand as a network and thus exploit synergy effects. The French system "FESUM" is a good example for such a network and even comprises centres in Belgium and Switzerland. To improve the treatment of severe hand trauma, a similar alliance was initiated in Germany just recently. The pilot project "Hand Trauma Alliance" (www.handverletzung.com) was started in April 2013 and currently comprises two hospitals within the region of upper Bavaria. The network provides hand trauma replantation service on a 24/7 basis and aims at shortening the way from the accident site to the fully qualified hand surgeon, to improve the therapy of severe hand injuries and to optimise acute patient care in general. In order to further increase the alliance's impact it is intended to extend the project's scope from regional to national coverage - nevertheless, such an endeavour can only be done in collaboration with the German Society for Hand

  1. Water quality modelling and optimisation of wastewater treatment network using mixed integer programming

    CSIR Research Space (South Africa)

    Mahlathi, Christopher

    2016-10-01

    Full Text Available Instream water quality management encompasses field monitoring and utilisation of mathematical models. These models can be coupled with optimisation techniques to determine more efficient water quality management alternatives. Among these activities...

  2. Manufacturing footprint optimisation: a necessity for manufacturing network in changing business environment

    DEFF Research Database (Denmark)

    Yang, Cheng; Farooq, Sami; Johansen, John

    2010-01-01

    Facing the unpredictable financial crisis, optimising the footprint can be the biggest and most important transformation a manufacturer can undertake. In order to realise the optimisation, fundamental understanding on manufacturing footprint is required. Different elements of manufacturing...... footprint have been investigated independently in the existing literature. In this paper, for the purpose of relationship exploration between different elements, manufacturing footprints of three industrial companies are traced historically. Based on them, four reasons for the transformation...

  3. Deep neural network for traffic sign recognition systems: An analysis of spatial transformers and stochastic optimisation methods.

    Science.gov (United States)

    Arcos-García, Álvaro; Álvarez-García, Juan A; Soria-Morillo, Luis M

    2018-03-01

    This paper presents a Deep Learning approach for traffic sign recognition systems. Several classification experiments are conducted over publicly available traffic sign datasets from Germany and Belgium using a Deep Neural Network which comprises Convolutional layers and Spatial Transformer Networks. Such trials are built to measure the impact of diverse factors with the end goal of designing a Convolutional Neural Network that can improve the state-of-the-art of traffic sign classification task. First, different adaptive and non-adaptive stochastic gradient descent optimisation algorithms such as SGD, SGD-Nesterov, RMSprop and Adam are evaluated. Subsequently, multiple combinations of Spatial Transformer Networks placed at distinct positions within the main neural network are analysed. The recognition rate of the proposed Convolutional Neural Network reports an accuracy of 99.71% in the German Traffic Sign Recognition Benchmark, outperforming previous state-of-the-art methods and also being more efficient in terms of memory requirements. Copyright © 2018 Elsevier Ltd. All rights reserved.

  4. Optimal and robust control of a class of nonlinear systems using dynamically re-optimised single network adaptive critic design

    Science.gov (United States)

    Tiwari, Shivendra N.; Padhi, Radhakant

    2018-01-01

    Following the philosophy of adaptive optimal control, a neural network-based state feedback optimal control synthesis approach is presented in this paper. First, accounting for a nominal system model, a single network adaptive critic (SNAC) based multi-layered neural network (called as NN1) is synthesised offline. However, another linear-in-weight neural network (called as NN2) is trained online and augmented to NN1 in such a manner that their combined output represent the desired optimal costate for the actual plant. To do this, the nominal model needs to be updated online to adapt to the actual plant, which is done by synthesising yet another linear-in-weight neural network (called as NN3) online. Training of NN3 is done by utilising the error information between the nominal and actual states and carrying out the necessary Lyapunov stability analysis using a Sobolev norm based Lyapunov function. This helps in training NN2 successfully to capture the required optimal relationship. The overall architecture is named as 'Dynamically Re-optimised single network adaptive critic (DR-SNAC)'. Numerical results for two motivating illustrative problems are presented, including comparison studies with closed form solution for one problem, which clearly demonstrate the effectiveness and benefit of the proposed approach.

  5. Optimisation of the addition of carrot dietary fibre to a dry fermented sausage (sobrassada) using artificial neural networks.

    Science.gov (United States)

    Eim, Valeria S; Simal, Susana; Rosselló, Carmen; Femenia, Antoni; Bon, José

    2013-07-01

    An optimisation problem was formulated to maximise the amount of carrot dietary fibre (CDF) in a dry fermented sausage, while maintaining product quality, by using 0-12% CDF as the decision variable, and limiting values of several physico-chemical and textural parameters (moisture content, water activity, pH, colour, non-protein nitrogen, free fatty acid, compression work and hardness) as constraints. The evolution of each quality parameter during the ripening process was estimated by developing a multi-layer feed forward artificial neural network (ANN), taking into consideration the CDF concentration and the ripening time as independent variables. Results indicate an optimum CDF concentration of 4.9% with a good correlation between experimental and estimated values (mean relative error≤3.35%). Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Optimising reverse logistics network to support policy-making in the case of Electrical and Electronic Equipment.

    Science.gov (United States)

    Achillas, Ch; Vlachokostas, Ch; Aidonis, D; Moussiopoulos, N; Iakovou, E; Banias, G

    2010-12-01

    Due to the rapid growth of Waste Electrical and Electronic Equipment (WEEE) volumes, as well as the hazardousness of obsolete electr(on)ic goods, this type of waste is now recognised as a priority stream in the developed countries. Policy-making related to the development of the necessary infrastructure and the coordination of all relevant stakeholders is crucial for the efficient management and viability of individually collected waste. This paper presents a decision support tool for policy-makers and regulators to optimise electr(on)ic products' reverse logistics network. To that effect, a Mixed Integer Linear Programming mathematical model is formulated taking into account existing infrastructure of collection points and recycling facilities. The applicability of the developed model is demonstrated employing a real-world case study for the Region of Central Macedonia, Greece. The paper concludes with presenting relevant obtained managerial insights. Copyright © 2010 Elsevier Ltd. All rights reserved.

  7. Optimisation in the Design of Environmental Sensor Networks with Robustness Consideration

    Science.gov (United States)

    Budi, Setia; de Souza, Paulo; Timms, Greg; Malhotra, Vishv; Turner, Paul

    2015-01-01

    This work proposes the design of Environmental Sensor Networks (ESN) through balancing robustness and redundancy. An Evolutionary Algorithm (EA) is employed to find the optimal placement of sensor nodes in the Region of Interest (RoI). Data quality issues are introduced to simulate their impact on the performance of the ESN. Spatial Regression Test (SRT) is also utilised to promote robustness in data quality of the designed ESN. The proposed method provides high network representativeness (fit for purpose) with minimum sensor redundancy (cost), and ensures robustness by enabling the network to continue to achieve its objectives when some sensors fail. PMID:26633392

  8. Services in wireless sensor networks modelling and optimisation for the efficient discovery of services

    CERN Document Server

    Becker, Markus

    2014-01-01

    In recent years, originally static and single purpose Wireless Sensor Networks have moved towards applications that need support for mobility and multiple purposes. These heterogeneous applications and services demand for a framework which distributes and discovers the various services, so that other pieces of equipment can use them. Markus Becker studies, extends, analytically models, simulates and employs the so called Trickle algorithm in measurements in a Wireless Sensor Network test bed for the service distribution. The obtained results apply to the application of the Trickle algorithm at

  9. A Stochastic After-Taxes Optimisation Model to Support Distribution Network Strategies

    DEFF Research Database (Denmark)

    Fernandes, Rui; Hvolby, Hans-Henrik; Gouveia, Borges

    2012-01-01

    The paper proposes a stochastic model to integrate tax issues into strategic distribution network decisions. Specifically, this study will explore the role of distribution models in business profitability, and how to use the network design to deliver additional bottom-line results, using...... distribution centres located in different countries. The challenge is also to reveal how financial and tax knowledge can help logistic leaders improving the value to their companies under global solutions and sources of business net profitability in a dynamic environment. In particular, based on inventory...

  10. Optimisation of the German moss monitoring network; Optimierung des Moosmonitoring-Messnetzes in Deutschland

    Energy Technology Data Exchange (ETDEWEB)

    Pesch, R.; Schroeder, W. [Hochschule Vechta (Germany). Lehrstuhl fuer Landschaftsoekologie; Dieffenbach-Fries, H. [Umweltbundesamt, Langen (Germany). Fachgebiet II 5.4; Genssler, L. [Landesamt fuer Natur, Umwelt und Verbraucherschutz Nordrhein-Westfalen, Recklinghausen (Germany)

    2008-02-15

    Germany participated in the Europen Heavy Metals in Mosses Surveys 1990, 1995 and 2000. The goal was to map the spatial distribution of the metal accumulation as a comparative measure for the metal deposition in terrestrial ecosystems. In the campaign in 2005, additionally nitrogen was monitored for the first time. It should be investigated how the monitoring network could be reduced from 1028 to 720 sites without any significant influence on chosen statistical criteria. Furthermore, the new network should be linked to other environmental monitoring programmes. (orig.)

  11. Modelling self-optimised short term load forecasting for medium voltage loads using tunning fuzzy systems and Artificial Neural Networks

    International Nuclear Information System (INIS)

    Mahmoud, Thair S.; Habibi, Daryoush; Hassan, Mohammed Y.; Bass, Octavian

    2015-01-01

    Highlights: • A novel Short Term Medium Voltage (MV) Load Forecasting (STLF) model is presented. • A knowledge-based STLF error control mechanism is implemented. • An Artificial Neural Network (ANN)-based optimum tuning is applied on STLF. • The relationship between load profiles and operational conditions is analysed. - Abstract: This paper presents an intelligent mechanism for Short Term Load Forecasting (STLF) models, which allows self-adaptation with respect to the load operational conditions. Specifically, a knowledge-based FeedBack Tunning Fuzzy System (FBTFS) is proposed to instantaneously correlate the information about the demand profile and its operational conditions to make decisions for controlling the model’s forecasting error rate. To maintain minimum forecasting error under various operational scenarios, the FBTFS adaptation was optimised using a Multi-Layer Perceptron Artificial Neural Network (MLPANN), which was trained using Backpropagation algorithm, based on the information about the amount of error and the operational conditions at time of forecasting. For the sake of comparison and performance testing, this mechanism was added to the conventional forecasting methods, i.e. Nonlinear AutoRegressive eXogenous-Artificial Neural Network (NARXANN), Fuzzy Subtractive Clustering Method-based Adaptive Neuro Fuzzy Inference System (FSCMANFIS) and Gaussian-kernel Support Vector Machine (GSVM), and the measured forecasting error reduction average in a 12 month simulation period was 7.83%, 8.5% and 8.32% respectively. The 3.5 MW variable load profile of Edith Cowan University (ECU) in Joondalup, Australia, was used in the modelling and simulations of this model, and the data was provided by Western Power, the transmission and distribution company of the state of Western Australia.

  12. A comparison of aggregated models for simulation and operational optimisation of district heating networks

    DEFF Research Database (Denmark)

    Larsen, Helge V.; Bøhm, Benny; Wigbels, M.

    2004-01-01

    as a test case. For the 23 substations in Ishoej, heat loads and primary and secondary supply and return temperatures were available every 5 min for the period December 19–24, 2000. The accuracy of the aggregation models has been documented as the errors in heat production and in return temperature......Work on aggregation of district heating networks has been in progress during the last decade. Two methods have independently been developed in Denmark and Germany. In this article, a comparison of the two methods is first presented. Next, the district heating system Ishoej near Copenhagen is used...... at the DH plant between the physical network and the aggregated model. Both the Danish and the German aggregation methods work well. It is concluded that the number of pipes can be reduced from 44 to three when using the Danish method of aggregation without significantly increasing the error in heat...

  13. Data-flow Performance Optimisation on Unreliable Networks: the ATLAS Data-Acquisition Case

    CERN Document Server

    Colombo, T; The ATLAS collaboration

    2015-01-01

    Abstract The ATLAS detector at CERN records proton-proton collisions delivered by the Large Hadron Collider (LHC). The ATLAS Trigger and Data-Acquisition (TDAQ) system identifies, selects, and stores interesting collision data. These are received from the detector readout electronics at an average rate of 100 kHz. The typical event data size is 1 to 2 MB. Overall, the ATLAS TDAQ can be seen as a distributed software system executed on a farm of roughly 2000 commodity PCs. The worker nodes are interconnected by an Ethernet network that at the restart of the LHC in 2015 is expected to experience a sustained throughput of several 10 GB/s. Abstract A particular type of challenge posed by this system, and by DAQ systems in general, is the inherently bursty nature of the data traffic from the readout buffers to the worker nodes. This can cause instantaneous network congestion and therefore performance degradation. The effect is particularly pronounced for unreliable network interconnections, such as Ethernet. Abstr...

  14. Freeze-dried, mucoadhesive system for vaginal delivery of the HIV microbicide, dapivirine: optimisation by an artificial neural network.

    Science.gov (United States)

    Woolfson, A David; Umrethia, Manish L; Kett, Victoria L; Malcolm, R Karl

    2010-03-30

    Dapivirine mucoadhesive gels and freeze-dried tablets were prepared using a 3x3x2 factorial design. An artificial neural network (ANN) with multi-layer perception was used to investigate the effect of hydroxypropyl-methylcellulose (HPMC): polyvinylpyrrolidone (PVP) ratio (X1), mucoadhesive concentration (X2) and delivery system (gel or freeze-dried mucoadhesive tablet, X3) on response variables; cumulative release of dapivirine at 24h (Q(24)), mucoadhesive force (F(max)) and zero-rate viscosity. Optimisation was performed by minimising the error between the experimental and predicted values of responses by ANN. The method was validated using check point analysis by preparing six formulations of gels and their corresponding freeze-dried tablets randomly selected from within the design space of contour plots. Experimental and predicted values of response variables were not significantly different (p>0.05, two-sided paired t-test). For gels, Q(24) values were higher than their corresponding freeze-dried tablets. F(max) values for freeze-dried tablets were significantly different (2-4 times greater, p>0.05, two-sided paired t-test) compared to equivalent gels. Freeze-dried tablets having lower values for X1 and higher values for X2 components offered the best compromise between effective dapivirine release, mucoadhesion and viscosity such that increased vaginal residence time was likely to be achieved. Copyright (c) 2009 Elsevier B.V. All rights reserved.

  15. Improving the Reliability of Optimised Link State Routing in a Smart Grid Neighbour Area Network based Wireless Mesh Network Using Multiple Metrics

    Directory of Open Access Journals (Sweden)

    Yakubu Tsado

    2017-02-01

    Full Text Available Reliable communication is the backbone of advanced metering infrastructure (AMI. Within the AMI, the neighbourhood area network (NAN transports a multitude of traffic, each with unique requirements. In order to deliver an acceptable level of reliability and latency, the underlying network, such as the wireless mesh network(WMN, must provide or guarantee the quality-of-service (QoS level required by the respective application traffic. Existing WMN routing protocols, such as optimised link state routing (OLSR, typically utilise a single metric and do not consider the requirements of individual traffic; hence, packets are delivered on a best-effort basis. This paper presents a QoS-aware WMN routing technique that employs multiple metrics in OLSR optimal path selection for AMI applications. The problems arising from this approach are non deterministic polynomial time (NP-complete in nature, which were solved through the combined use of the analytical hierarchy process (AHP algorithm and pruning techniques. For smart meters transmitting Internet Protocol (IP packets of varying sizes at different intervals, the proposed technique considers the constraints of NAN and the applications’ traffic characteristics. The technique was developed by combining multiple OLSR path selection metrics with the AHP algorithminns-2. Compared with the conventional link metric in OLSR, the results show improvements of about 23% and 45% in latency and Packet Delivery Ratio (PDR, respectively, in a 25-node grid NAN.

  16. EDM - A model for optimising the short-term power operation of a complex hydroelectric network

    International Nuclear Information System (INIS)

    Tremblay, M.; Guillaud, C.

    1996-01-01

    In order to optimize the short-term power operation of a complex hydroelectric network, a new model called EDM was added to PROSPER, a water management analysis system developed by SNC-Lavalin. PROSPER is now divided into three parts: an optimization model (DDDP), a simulation model (ESOLIN), and an economic dispatch model (EDM) for the short-term operation. The operation of the KSEB hydroelectric system (located in southern India) with PROSPER was described. The long-term analysis with monthly time steps is assisted by the DDDP, and the daily analysis with hourly or half-hourly time steps is performed with the EDM model. 3 figs

  17. Artificial neural network optimisation for monthly average daily global solar radiation prediction

    International Nuclear Information System (INIS)

    Alsina, Emanuel Federico; Bortolini, Marco; Gamberi, Mauro; Regattieri, Alberto

    2016-01-01

    Highlights: • Prediction of the monthly average daily global solar radiation over Italy. • Multi-location Artificial Neural Network (ANN) model: 45 locations considered. • Optimal ANN configuration with 7 input climatologic/geographical parameters. • Statistical indicators: MAPE, NRMSE, MPBE. - Abstract: The availability of reliable climatologic data is essential for multiple purposes in a wide set of anthropic activities and operative sectors. Frequently direct measures present spatial and temporal lacks so that predictive approaches become of interest. This paper focuses on the prediction of the Monthly Average Daily Global Solar Radiation (MADGSR) over Italy using Artificial Neural Networks (ANNs). Data from 45 locations compose the multi-location ANN training and testing sets. For each location, 13 input parameters are considered, including the geographical coordinates and the monthly values for the most frequently adopted climatologic parameters. A subset of 17 locations is used for ANN training, while the testing step is against data from the remaining 28 locations. Furthermore, the Automatic Relevance Determination method (ARD) is used to point out the most relevant input for the accurate MADGSR prediction. The ANN best configuration includes 7 parameters, only, i.e. Top of Atmosphere (TOA) radiation, day length, number of rainy days and average rainfall, latitude and altitude. The correlation performances, expressed through statistical indicators as the Mean Absolute Percentage Error (MAPE), range between 1.67% and 4.25%, depending on the number and type of the chosen input, representing a good solution compared to the current standards.

  18. A Simple Approach to Dynamic Optimisation of Flexible Optical Networks with Practical Application

    Directory of Open Access Journals (Sweden)

    Vic Grout

    2017-05-01

    Full Text Available This paper provides an initial introduction to, and definition of, the ‘Dynamically Powered Relays for a Flexible Optical Network’ (DPR-FON problem for opto-electro-optical (OEO regenerators used in optical networks. In such networks, optical transmission parameters can be varied dynamically as traffic patterns change. This will provide different bandwidths, but also change the regeneration limits as a result. To support this flexibility, OEOs (‘relays’ may be switched on and off as required, thus saving power. DPR-FON is shown to be NP-complete; consequently, solving such a dynamic problem in real-time requires a fast heuristic capable of delivering an acceptable approximation to the optimal configuration with low complexity. In this paper, just such an algorithm is developed, implemented, and evaluated against more computationally-demanding alternatives for two known cases. A number of real-world extensions are considered as the paper develops, combining to produce the ‘Generalised Dynamically Powered Relays for a Flexible Optical Network’ (GDPR-FON problem. This, too, is analysed and an associated fast heuristic proposed, along with an exploration of the further research that is required.

  19. ISOE: an international occupational exposure database and communications network for dose optimisation

    International Nuclear Information System (INIS)

    Robinson, I.F.; Lazo, E.

    1995-01-01

    The Information System on Occupational Exposure (ISOE) was launched by the Nuclear Energy Agency (NEA) of the Organisation for Economic Co-operation and Development (OECD) on 1 January 1992 to facilitate the communication of dosimetry and ALARA implementation data among nuclear facilities around the world. Members of ISOE include 51 utilities from 17 countries and regulators from 11 countries, with four regional technical centres administering the system and a Steering Group which manages the work. ISOE includes three databases and a communications network at several levels. The three databases NEA1, NEA2 and NEA3 include varying levels of details, with NEA3 being the most detailed giving task and site specific ALARA practices and experiences. Utility membership of ISOE gives full access to the databases whereas regulators have more limited access. This paper reviews the current status of participation, describes the three databases and the communications network. Some dose data showing trends in particular countries are presented as well as dose data relating to operation cycle length and outage length. The advantages of membership are described, and it is concluded that ISOE holds the potential for both dose and cost savings. (author)

  20. A comparison of aggregated models for simulation and operational optimisation of district heating networks

    International Nuclear Information System (INIS)

    Larsen, Helge V.; Boehm, Benny; Wigbels, Michael

    2004-01-01

    Work on aggregation of district heating networks has been in progress during the last decade. Two methods have independently been developed in Denmark and Germany. In this article, a comparison of the two methods is first presented. Next, the district heating system Ishoej near Copenhagen is used as a test case. For the 23 substations in Ishoej, heat loads and primary and secondary supply and return temperatures were available every 5 min for the period December 19-24, 2000. The accuracy of the aggregation models has been documented as the errors in heat production and in return temperature at the DH plant between the physical network and the aggregated model. Both the Danish and the German aggregation methods work well. It is concluded that the number of pipes can be reduced from 44 to three when using the Danish method of aggregation without significantly increasing the error in heat production or return temperature at the plant. In the case of the German method, the number of pipes should not be reduced much below 10 in the Ishoej case

  1. Location-quality-aware policy optimisation for relay selection in mobile networks

    DEFF Research Database (Denmark)

    Nielsen, Jimmy Jessen; Olsen, Rasmus Løvenstein; Madsen, Tatiana Kozlova

    2016-01-01

    for resulting performance of such network optimizations. In mobile scenarios, the required information collection and forwarding causes delays that will additionally affect the reliability of the collected information and hence will influence the performance of the relay selection method. This paper analyzes...... the joint influence of these two factors in the decision process for the example of a mobile location-based relay selection approach using a continuous time Markov chain model. Efficient algorithms are developed based on this model to obtain optimal relay policies under consideration of localization errors....... Numerical results show how information update rates, forwarding delays, and location estimation errors affect these optimal policies and allow to conclude on the required accuracy of location-based systems for such mobile relay selection scenarios. A measurement-based indoor scenario with more complex...

  2. Optimisation of petroleum refinery water network systems retrofit incorporating reuse, regeneration and recycle strategies

    Energy Technology Data Exchange (ETDEWEB)

    Khor, Cheng Seong; Shah, Nilay [Imperial College London (United Kingdom); Mahadzir, Shuhaimi [Universiti Teknologi Petronas (Malaysia); Elkamel, Ali [University of Waterloo (Canada)

    2012-02-15

    Increasingly strict environmental regulations have given rise to higher requirements for operating efficiency and optimization and water has become a vital resource in the refining process and allied industries. Due to this high demand for water, plants may be exposed to supply interruptions and shortages in the future. Major concerns in the petroleum refining industry are the scarcity of fresh water supply and increasingly rigid rules on wastewater discharge, which have resulted from concerns over the environmental impact. This paper presents the efforts made to develop an optimization framework for design of petroleum refinery water network systems and retrofitting that incorporates reuse, regeneration, and recycling strategies. This framework includes the complementary advantage of water pinch analysis (WPA). Water minimization strategies were incorporated as first postulates in a superstructural representation that includes all feasible flow-sheet options for taking advantage of water reuse, regeneration and recycling opportunities. Additionally, a post-optimization analysis was carried out to evaluate the repeated treatment processes required to identify the most efficient retrofit option.

  3. Reducing passengers’ travel time by optimising stopping patterns in a large-scale network: A case-study in the Copenhagen Region

    DEFF Research Database (Denmark)

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

    2018-01-01

    Optimising stopping patterns in railway schedules is a cost-effective way to reduce passengers’ generalised travel costs without increasing train operators’ costs. The challenge consists in striking a balance between an increase in waiting time for passengers at skipped stations and a decrease...... in travel time for through-going passengers, with possible consequent changes in the passenger demand and route choices. This study presents the formulation of the skip-stop problem as a bi-level optimisation problem where the lower level is a schedule-based transit assignment model that delivers passengers...... is a mixed-integer problem, whereas the route choice model is a non-linear non-continuous mapping of the timetable. The method was tested on the suburban railway network in the Greater Copenhagen Region (Denmark): the reduction in railway passengers’ in-vehicle travel time was 5.5%, the reduction...

  4. Simulation optimisation

    International Nuclear Information System (INIS)

    Anon

    2010-01-01

    Over the past decade there has been a significant advance in flotation circuit optimisation through performance benchmarking using metallurgical modelling and steady-state computer simulation. This benchmarking includes traditional measures, such as grade and recovery, as well as new flotation measures, such as ore floatability, bubble surface area flux and froth recovery. To further this optimisation, Outotec has released its HSC Chemistry software with simulation modules. The flotation model developed by the AMIRA P9 Project, of which Outotec is a sponsor, is regarded by industry as the most suitable flotation model to use for circuit optimisation. This model incorporates ore floatability with flotation cell pulp and froth parameters, residence time, entrainment and water recovery. Outotec's HSC Sim enables you to simulate mineral processes in different levels, from comminution circuits with sizes and no composition, through to flotation processes with minerals by size by floatability components, to full processes with true particles with MLA data.

  5. Optimisation of Economic Order Quantity Using Neural Networks Approach = Yapay Sinir Ağları Yaklaşımı ile Ekonomik Düzenin Optimizasyonu

    Directory of Open Access Journals (Sweden)

    Osman Nuri UÇAN

    2001-01-01

    Full Text Available In this paper, a Back Propagation-Artificial Neural Network (BP-ANN has been adapted for predicting the required car parts quantities in a real and major auto parts supplier chain. The conventional approach to determine the parts requirements is the Economic Order Quantity (EOQ method. The ability of neural models to learn, particularly their capability of handling large amounts of data simultaneously as well as their fast response time, are the characteristics desired for predictive and forecasting purposes. Here, the actual data obtained from a major auto parts supplier chain, involving a multi-layer system of supplying auto parts to car dealers, have been used to optimise and develop a BP-ANN model. The model has shown promising results in predicting parts orders with high degree of accuracy.

  6. Potential of energy-oriented network optimisation: Switching off over-capacity in off-peak hours

    NARCIS (Netherlands)

    Litjens, R.; Jorguseski, L.

    2010-01-01

    Mobile communication networks are usually planned to provide some minimum service quality level during peak traffic hours. Consequently, in off-peak hours, when traffic loads are lower, the network is characterised by over-capacity, in the sense that same service quality targets can typically be

  7. Warranty optimisation based on the prediction of costs to the manufacturer using neural network model and Monte Carlo simulation

    Science.gov (United States)

    Stamenkovic, Dragan D.; Popovic, Vladimir M.

    2015-02-01

    Warranty is a powerful marketing tool, but it always involves additional costs to the manufacturer. In order to reduce these costs and make use of warranty's marketing potential, the manufacturer needs to master the techniques for warranty cost prediction according to the reliability characteristics of the product. In this paper a combination free replacement and pro rata warranty policy is analysed as warranty model for one type of light bulbs. Since operating conditions have a great impact on product reliability, they need to be considered in such analysis. A neural network model is used to predict light bulb reliability characteristics based on the data from the tests of light bulbs in various operating conditions. Compared with a linear regression model used in the literature for similar tasks, the neural network model proved to be a more accurate method for such prediction. Reliability parameters obtained in this way are later used in Monte Carlo simulation for the prediction of times to failure needed for warranty cost calculation. The results of the analysis make possible for the manufacturer to choose the optimal warranty policy based on expected product operating conditions. In such a way, the manufacturer can lower the costs and increase the profit.

  8. 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 tim...... 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)....

  9. Optimal reactive power and voltage control in distribution networks with distributed generators by fuzzy adaptive hybrid particle swarm optimisation method

    DEFF Research Database (Denmark)

    Chen, Shuheng; Hu, Weihao; Su, Chi

    2015-01-01

    A new and efficient methodology for optimal reactive power and voltage control of distribution networks with distributed generators based on fuzzy adaptive hybrid PSO (FAHPSO) is proposed. The objective is to minimize comprehensive cost, consisting of power loss and operation cost of transformers...... that the proposed method can search a more promising control schedule of all transformers, all capacitors and all distributed generators with less time consumption, compared with other listed artificial intelligent methods....... algorithm is implemented in VC++ 6.0 program language and the corresponding numerical experiments are finished on the modified version of the IEEE 33-node distribution system with two newly installed distributed generators and eight newly installed capacitors banks. The numerical results prove...

  10. 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...

  11. Optimal Optimisation in Chemometrics

    NARCIS (Netherlands)

    Hageman, J.A.

    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

  12. Optimised Renormalisation Group Flows

    CERN Document Server

    Litim, Daniel F

    2001-01-01

    Exact renormalisation group (ERG) flows interpolate between a microscopic or classical theory and the corresponding macroscopic or quantum effective theory. For most problems of physical interest, the efficiency of the ERG is constrained due to unavoidable approximations. Approximate solutions of ERG flows depend spuriously on the regularisation scheme which is determined by a regulator function. This is similar to the spurious dependence on the ultraviolet regularisation known from perturbative QCD. Providing a good control over approximated ERG flows is at the root for reliable physical predictions. We explain why the convergence of approximate solutions towards the physical theory is optimised by appropriate choices of the regulator. We study specific optimised regulators for bosonic and fermionic fields and compare the optimised ERG flows with generic ones. This is done up to second order in the derivative expansion at both vanishing and non-vanishing temperature. An optimised flow for a ``proper-time ren...

  13. Optimising Magnetostatic Assemblies

    DEFF Research Database (Denmark)

    Insinga, Andrea Roberto; Smith, Anders

    theorem. This theorem formulates an energy equivalence principle with several implications concerning the optimisation of objective functionals that are linear with respect to the magnetic field. Linear functionals represent different optimisation goals, e.g. maximising a certain component of the field...... approached employing a heuristic algorithm, which led to new design concepts. Some of the procedures developed for linear objective functionals have been extended to non-linear objectives, by employing iterative techniques. Even though most the optimality results discussed in this work have been derived...

  14. Optimisation of radiation protection

    International Nuclear Information System (INIS)

    1988-01-01

    Optimisation of radiation protection is one of the key elements in the current radiation protection philosophy. The present system of dose limitation was issued in 1977 by the International Commission on Radiological Protection (ICRP) and includes, in addition to the requirements of justification of practices and limitation of individual doses, the requirement that all exposures be kept as low as is reasonably achievable, taking social and economic factors into account. This last principle is usually referred to as optimisation of radiation protection, or the ALARA principle. The NEA Committee on Radiation Protection and Public Health (CRPPH) organised an ad hoc meeting, in liaison with the NEA committees on the safety of nuclear installations and radioactive waste management. Separate abstracts were prepared for individual papers presented at the meeting

  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. Optimisation of Heterogeneous Migration Paths to High Bandwidth Home Connections

    NARCIS (Netherlands)

    Phillipson, F.

    2017-01-01

    Operators are building architectures and systems for delivering voice, audio, and data services at the required speed for now and in the future. For fixed access networks, this means in many countries a shift from copper based to fibre based access networks. This paper proposes a method to optimise

  17. Advanced optimisation - coal fired power plant operations

    Energy Technology Data Exchange (ETDEWEB)

    Turney, D.M.; Mayes, I. [E.ON UK, Nottingham (United Kingdom)

    2005-03-01

    The purpose of this unit optimization project is to develop an integrated approach to unit optimisation and develop an overall optimiser that is able to resolve any conflicts between the individual optimisers. The individual optimisers have been considered during this project are: on-line thermal efficiency package, GNOCIS boiler optimiser, GNOCIS steam side optimiser, ESP optimisation, and intelligent sootblowing system. 6 refs., 7 figs., 3 tabs.

  18. Optimisation in radiotherapy II: Programmed and inversion optimisation algorithms

    International Nuclear Information System (INIS)

    Ebert, M.

    1997-01-01

    This is the second article in a three part examination of optimisation in radiotherapy. The previous article established the bases of optimisation in radiotherapy, and the formulation of the optimisation problem. This paper outlines several algorithms that have been used in radiotherapy, for searching for the best irradiation strategy within the full set of possible strategies. Two principle classes of algorithm are considered - those associated with mathematical programming which employ specific search techniques, linear programming type searches or artificial intelligence - and those which seek to perform a numerical inversion of the optimisation problem, finishing with deterministic iterative inversion. (author)

  19. Optimisation of monochrome images

    International Nuclear Information System (INIS)

    Potter, R.

    1983-01-01

    Gamma cameras with modern imaging systems usually digitize the signals to allow storage and processing of the image in a computer. Although such computer systems are widely used for the extraction of quantitative uptake estimates and the analysis of time variant data, the vast majority of nuclear medicine images is still interpreted on the basis of an observer's visual assessment of a photographic hardcopy image. The optimisation of hardcopy devices is therefore vital and factors such as resolution, uniformity, noise grey scales and display matrices are discussed. Once optimum display parameters have been determined, routine procedures for quality control need to be established; suitable procedures are discussed. (U.K.)

  20. Heuristic approach to the passive optical network with fibre duct ...

    African Journals Online (AJOL)

    Integer programming, network flow optimisation, passive optical network, ... This paper uses concepts from network flow optimisation to incorporate fibre duct shar ... [4] studied the survivable constrained ConFL problem and solved a number of.

  1. Beam position optimisation for IMRT

    International Nuclear Information System (INIS)

    Holloway, L.; Hoban, P.

    2001-01-01

    Full text: The introduction of IMRT has not generally resulted in the use of optimised beam positions because to find the global solution of the problem a time consuming stochastic optimisation method must be used. Although a deterministic method may not achieve the global minimum it should achieve a superior dose distribution compared to no optimisation. This study aimed to develop and test such a method. The beam optimisation method developed relies on an iterative process to achieve the desired number of beams from a large initial number of beams. The number of beams is reduced in a 'weeding-out' process based on the total fluence which each beam delivers. The process is gradual, with only three beams removed each time (following a small number of iterations), ensuring that the reduction in beams does not dramatically affect the fluence maps of those remaining. A comparison was made between the dose distributions achieved when the beams positions were optimised in this fashion and when the beams positions were evenly distributed. The method has been shown to work quite effectively and efficiently. The Figure shows a comparison in dose distribution with optimised and non optimised beam positions for 5 beams. It can be clearly seen that there is an improvement in the dose distribution delivered to the tumour and a reduction in the dose to the critical structure with beam position optimisation. A method for beam position optimisation for use in IMRT optimisations has been developed. This method although not necessarily achieving the global minimum in beam position still achieves quite a dramatic improvement compared with no beam position optimisation and is very efficiently achieved. Copyright (2001) Australasian College of Physical Scientists and Engineers in Medicine

  2. Optimization of the telecommunication network of a gas utility; Optimisation d'un reseau de telecommunications d'un operateur gazier

    Energy Technology Data Exchange (ETDEWEB)

    Vinas, Ch.; Abadie, J. [GSO, Gaz Sud-Ouest, 64 - Pau (France)

    2001-07-01

    The information system of Gaz du Sud-Ouest (GSO) utility, which includes the real time systems for the exploitation of the gas transport and distribution system and its management, is based on heterogenous and separated telecommunication infrastructures. A project has been started which aims at optimizing the architecture of this communication network taking into consideration the technical aspects but also the security and costs constraints. (J.S.)

  3. Multi-criteria optimization of dryers: use of neural networks and genetical algorithms; Optimisation multi-criteres de sechoirs: utilisation des reseaux de neurones et algorithmes genetiques

    Energy Technology Data Exchange (ETDEWEB)

    Hugget, A.; Nadeau, J.P.; Sabastian, P. [Ecole Nationale Superieure des Arts et Metiers, 33 - Talence (France)

    1997-12-31

    Drying remains a complex process to model and thus to optimize. In this paper a new approach is proposed which allows to perform a compression in the drying model in order to integrate it using neural networks. The simulation times become very small and allow to test a great number of configurations. This decisive advantage allows to perform a multi-criteria optimization using hybrid genetical algorithms based on technical-economical criteria like drying cost, production or final product quality. (J.S.) 10 refs.

  4. Optimisation of occupational exposure

    International Nuclear Information System (INIS)

    Webb, G.A.M.; Fleishman, A.B.

    1982-01-01

    The general concept of the optimisation of protection of the public is briefly described. Some ideas being developed for extending the cost benefit framework to include radiation workers with full implementation of the ALARA criterion are described. The role of cost benefit analysis in radiological protection and the valuation of health detriment including the derivation of monetary values and practical implications are discussed. Cost benefit analysis can lay out for inspection the doses, the associated health detriment costs and the costs of protection for alternative courses of action. However it is emphasised that the cost benefit process is an input to decisions on what is 'as low as reasonably achievable' and not a prescription for making them. (U.K.)

  5. Standardised approach to optimisation

    International Nuclear Information System (INIS)

    Warren-Forward, Helen M.; Beckhaus, Ronald

    2004-01-01

    Optimisation of radiographic images is said to have been obtained if the patient has achieved an acceptable level of dose and the image is of diagnostic value. In the near future, it will probably be recommended that radiographers measure patient doses and compare them to reference levels. The aim of this paper is to describe a standardised approach to optimisation of radiographic examinations in a diagnostic imaging department. A three-step approach is outlined with specific examples for some common examinations (chest, abdomen, pelvis and lumbar spine series). Step One: Patient doses are calculated. Step Two: Doses are compared to existing reference levels and the technique used compared to image quality criteria. Step Three: Appropriate action is taken if doses are above the reference level. Results: Average entrance surface doses for two rooms were as follows AP Abdomen (6.3mGy and 3.4mGy); AP Lumbar Spine (6.4mGy and 4.1mGy) for AP Pelvis (4.8mGy and 2.6mGy) and PA chest (0.19mGy and 0.20mGy). Comparison with the Commission of the European Communities (CEC) recommended techniques identified large differences in the applied potential. The kVp values in this study were significantly lower (by up to lOkVp) than the CEC recommendations. The results of this study have indicated that there is a need to monitor radiation doses received by patients undergoing diagnostic radiography examinations. Not only has the assessment allowed valuable comparison with International Diagnostic Reference Levels and Radiography Good Practice but has demonstrated large variations in mean doses being delivered from different rooms of the same radiology department. Following the simple 3-step approach advocated in this paper should either provide evidence that department are practising the ALARA principle or assist in making suitable changes to current practice. Copyright (2004) Australian Institute of Radiography

  6. Optimisation of a bioindicator monitoring network using geostatic methods and a geographic information system; Optimierung eines Bioindikator-Messnetzes mit Hilfe geostatischer Methoden und eines Geographischen Informationssystems

    Energy Technology Data Exchange (ETDEWEB)

    Forster, E.M.

    1994-04-01

    Since 1981 the Bavarian State Authority for Environment Protection has used mosses (hypnum cupressiforme) as bioindicators for determining atmospheric background pollution. Covering all of Bavaria the monitoring network comprises more than 370 sampling sites spaced 8 km apart in urban regions and otherwise 16 km. The extremely labour-intensive and costly operation of the network led to the idea to thin it in such a way that the loss of information on regional background pollution would be kept as small as possible and remain within acceptable bounds. The geostatic methods used for this purpose permit an areal estimation of pollution load giving due consideration to local values as well as a calculation of the forecast error. The present report is divided into two sections: The first deals with the determination of spatial dependences, while the second concens the selection of sampling sites. (orig./KW) [Deutsch] Seit 1981 werden Moose (Hypnum cupressiforme) als Bioindikatoren zur Ermittlung der atmosphaerischen Hintergrundbelastung vom Bayerischen Landesamt fuer Umweltschutz eingesetzt. Das landesweite Messnetz umfasst mehr als 370 Probenahmestandorte, die 16 km bzw. in Verdichtungsregionen 8 km von einander entfernt liegen. Der erhebliche personelle und finanzielle Aufwand fuehrte zu der Ueberlegung das Messnetz mit moeglichst geringem, noch aktzeptablen Informationsverlust bezueglich der grossraeumigen Hintergrundbelastung zu reduzieren. Hierbei kamen geostatistische Methoden zum Einsatz, da sie eine flaechenhafte Schaetzung der Immissionsbelastung unter Beruecksichtigung der Umgebungswerte ermoeglichen. Zudem kann der Schaetzfehler berechnet werden. Die vorliegende Arbeit gliedert sich daher in zwei Bereiche: Einerseits das Feststellen raeumlicher Abhaengigkeiten und andererseits die Auswahl der Probenahmestandorte. (orig./KW)

  7. 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...

  8. Multi-period MINLP model for optimising operation and structural changes to CHP plants in district heating networks with long-term thermal storage

    International Nuclear Information System (INIS)

    Tveit, Tor-Martin; Savola, Tuula; Gebremedhin, Alemayehu; Fogelholm, Carl-Johan

    2009-01-01

    By using thermal storages it is possible to decouple the generation of power and heat, and it can also lead to an reduction in investments, as the storage can be used to cover the peak load periods. This work presents a MINLP model that can be used for analysing new investments and the long-term operation of CHP plants in a district heating network with long-term thermal storage. The model presented in this work includes the non-linear off-design behaviour of the CHP plants as well as a generic mathematical model of the thermal storage, without the need to fix temperatures and pressure. The model is formulated in such a way that it is suitable for deterministic MINLP solvers. The model is non-convex, and subsequently global optimality cannot be guaranteed with local solvers. In order to reduce the chance of obtaining a poor local optimum compared to the global optimum, the model should be solved many times with the initial values varying randomly. It is possible to extract a lot of results from the model, for instance total annual profit, the optimal selection of process options, mass flow through the plant, and generated power from each plant. The formulation of the model makes it suitable for deterministic MINLP solvers

  9. 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...

  10. 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.

  11. Optimisation of load control

    International Nuclear Information System (INIS)

    Koponen, P.

    1998-01-01

    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

  12. 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

  13. SPS batch spacing optimisation

    CERN Document Server

    Velotti, F M; Carlier, E; Goddard, B; Kain, V; Kotzian, G

    2017-01-01

    Until 2015, the LHC filling schemes used the batch spac-ing as specified in the LHC design report. The maximumnumber of bunches injectable in the LHC directly dependson the batch spacing at injection in the SPS and hence onthe MKP rise time.As part of the LHC Injectors Upgrade project for LHCheavy ions, a reduction of the batch spacing is needed. In thisdirection, studies to approach the MKP design rise time of150ns(2-98%) have been carried out. These measurementsgave clear indications that such optimisation, and beyond,could be done also for higher injection momentum beams,where the additional slower MKP (MKP-L) is needed.After the successful results from 2015 SPS batch spacingoptimisation for the Pb-Pb run [1], the same concept wasthought to be used also for proton beams. In fact, thanksto the SPS transverse feed back, it was already observedthat lower batch spacing than the design one (225ns) couldbe achieved. For the 2016 p-Pb run, a batch spacing of200nsfor the proton beam with100nsbunch spacing wasreque...

  14. Vaccine strategies: Optimising outcomes.

    Science.gov (United States)

    Hardt, Karin; Bonanni, Paolo; King, Susan; Santos, Jose Ignacio; El-Hodhod, Mostafa; Zimet, Gregory D; Preiss, Scott

    2016-12-20

    factors that encourage success, which often include strong support from government and healthcare organisations, as well as tailored, culturally-appropriate local approaches to optimise outcomes. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  15. Multi-Optimisation Consensus Clustering

    Science.gov (United States)

    Li, Jian; Swift, Stephen; Liu, Xiaohui

    Ensemble Clustering has been developed to provide an alternative way of obtaining more stable and accurate clustering results. It aims to avoid the biases of individual clustering algorithms. However, it is still a challenge to develop an efficient and robust method for Ensemble Clustering. Based on an existing ensemble clustering method, Consensus Clustering (CC), this paper introduces an advanced Consensus Clustering algorithm called Multi-Optimisation Consensus Clustering (MOCC), which utilises an optimised Agreement Separation criterion and a Multi-Optimisation framework to improve the performance of CC. Fifteen different data sets are used for evaluating the performance of MOCC. The results reveal that MOCC can generate more accurate clustering results than the original CC algorithm.

  16. Isogeometric Analysis and Shape Optimisation

    DEFF Research Database (Denmark)

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

    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...... will explain how the validity of a parametrisation can be checked and we will describe various ways to parametrise a domain. We will in particular study the Winslow functional which turns out to have some desirable properties. Other problems we touch upon is clustering of boundary control points (design...

  17. HVAC system optimisation-in-building section

    Energy Technology Data Exchange (ETDEWEB)

    Lu, L.; Cai, W.; Xie, L.; Li, S.; Soh, Y.C. [School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore (Singapore)

    2004-07-01

    This paper presents a practical method to optimise in-building section of centralised Heating, Ventilation and Air-Conditioning (HVAC) systems which consist of indoor air loops and chilled water loops. First, through component characteristic analysis, mathematical models associated with cooling loads and energy consumption for heat exchangers and energy consuming devices are established. By considering variation of cooling load of each end user, adaptive neuro-fuzzy inference system (ANFIS) is employed to model duct and pipe networks and obtain optimal differential pressure (DP) set points based on limited sensor information. A mix-integer nonlinear constraint optimization of system energy is formulated and solved by a modified genetic algorithm. The main feature of our paper is a systematic approach in optimizing the overall system energy consumption rather than that of individual component. A simulation study for a typical centralized HVAC system is provided to compare the proposed optimisation method with traditional ones. The results show that the proposed method indeed improves the system performance significantly. (author)

  18. 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.

  19. 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...

  20. Optimisation algorithms for ECG data compression.

    Science.gov (United States)

    Haugland, D; Heber, J G; Husøy, J H

    1997-07-01

    The use of exact optimisation algorithms for compressing digital electrocardiograms (ECGs) is demonstrated. As opposed to traditional time-domain methods, which use heuristics to select a small subset of representative signal samples, the problem of selecting the subset is formulated in rigorous mathematical terms. This approach makes it possible to derive algorithms guaranteeing the smallest possible reconstruction error when a bounded selection of signal samples is interpolated. The proposed model resembles well-known network models and is solved by a cubic dynamic programming algorithm. When applied to standard test problems, the algorithm produces a compressed representation for which the distortion is about one-half of that obtained by traditional time-domain compression techniques at reasonable compression ratios. This illustrates that, in terms of the accuracy of decoded signals, existing time-domain heuristics for ECG compression may be far from what is theoretically achievable. The paper is an attempt to bridge this gap.

  1. Optimising training data for ANNs with Genetic Algorithms

    OpenAIRE

    Kamp , R. G.; Savenije , H. H. G.

    2006-01-01

    International audience; Artificial Neural Networks (ANNs) have proved to be good modelling tools in hydrology for rainfall-runoff modelling and hydraulic flow modelling. Representative datasets are necessary for the training phase in which the ANN learns the model's input-output relations. Good and representative training data is not always available. In this publication Genetic Algorithms (GA) are used to optimise training datasets. The approach is tested with an existing hydraulic model in ...

  2. Optimising training data for ANNs with Genetic Algorithms

    OpenAIRE

    R. G. Kamp; R. G. Kamp; H. H. G. Savenije

    2006-01-01

    Artificial Neural Networks (ANNs) have proved to be good modelling tools in hydrology for rainfall-runoff modelling and hydraulic flow modelling. Representative datasets are necessary for the training phase in which the ANN learns the model's input-output relations. Good and representative training data is not always available. In this publication Genetic Algorithms (GA) are used to optimise training datasets. The approach is tested with an existing hydraulic model in The Netherlands. An...

  3. Optimising Comprehensibility in Interlingual Translation

    DEFF Research Database (Denmark)

    Nisbeth Jensen, Matilde

    2015-01-01

    The increasing demand for citizen engagement in areas traditionally belonging exclusively to experts, such as health, law and technology has given rise to the necessity of making expert knowledge available to the general public through genres such as instruction manuals for consumer goods, patien...... 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....

  4. TEM turbulence optimisation in stellarators

    Science.gov (United States)

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

    2016-01-01

    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 addressed 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 (Beidler et al 1990 Fusion Technol. 17 148) 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 (Spong et al 2001 Nucl. Fusion 41 711) code without extensive turbulence simulations. A first proof-of-principle optimised equilibrium stemming from the TEM-dominated stellarator experiment HSX (Anderson et al 1995 Fusion Technol. 27 273) is presented for which a reduction of the linear growth rates is achieved over a broad range of the operational parameter space. As an important consequence of this property, the turbulent heat flux levels are reduced compared with the initial configuration.

  5. Maintenance Issues in Long Term Operation of Nuclear Power Plant

    International Nuclear Information System (INIS)

    Contri, P.; Bieth, M.; Rieg, C.

    2006-01-01

    Due to current social and economical framework, in last years many nuclear power plant owners started a program for the Long Term Operation (LTO)/PLEX (Plant Life Extension) of their older nuclear facilities. This process has many nuclear safety implications, other than strategic and political ones. The need for tailoring the available safety assessment tools to such applications has become urgent in recent years and triggered many research actions. The review of regular maintenance and ageing management programs are tools widely used in LTO/PLEX context in many Countries. However, most of these tools are rather general and in many cases they need reshaping in an LTO/PLEX framework before application, with focus to the safety implications of the LTO/PLEX. Many Countries and plants radically modified their maintenance rules towards a condition based approach as a precondition for the implementation of LTO/PLEX programs. In 2004 a network of European Organisations operating Nuclear Power Plants, SENUF, under the coordination of the JRC-IE, carried out an extensive questionnaire on maintenance practice in their facilities aiming at capturing the aspects of the maintenance programs where research is mostly needed. This paper uses some results of the questionnaire, which was not oriented to LTO/PLEX, to draw some conclusions on how the current maintenance programs could support a potential LTO/PLEX, among the other programs running at NPPs. In this sense, it is spin-off of the SENUF WG on maintenance. The paper aims at identifying the technical attributes of the maintenance programs more directly affecting the decision for a long-term safe operation of a nuclear facility, the issues related to their implementation and safety review. The paper includes an analysis of the questionnaire circulated among the SENUF participants and a discussion on the implications of optimised maintenance programs in existing plants. Some examples at WWER plants taken by sources other than

  6. Particle swarm optimisation classical and quantum perspectives

    CERN Document Server

    Sun, Jun; Wu, Xiao-Jun

    2016-01-01

    IntroductionOptimisation Problems and Optimisation MethodsRandom Search TechniquesMetaheuristic MethodsSwarm IntelligenceParticle Swarm OptimisationOverviewMotivationsPSO Algorithm: Basic Concepts and the ProcedureParadigm: How to Use PSO to Solve Optimisation ProblemsSome Harder Examples Some Variants of Particle Swarm Optimisation Why Does the PSO Algorithm Need to Be Improved? Inertia and Constriction-Acceleration Techniques for PSOLocal Best ModelProbabilistic AlgorithmsOther Variants of PSO Quantum-Behaved Particle Swarm Optimisation OverviewMotivation: From Classical Dynamics to Quantum MechanicsQuantum Model: Fundamentals of QPSOQPSO AlgorithmSome Essential ApplicationsSome Variants of QPSOSummary Advanced Topics Behaviour Analysis of Individual ParticlesConvergence Analysis of the AlgorithmTime Complexity and Rate of ConvergenceParameter Selection and PerformanceSummaryIndustrial Applications Inverse Problems for Partial Differential EquationsInverse Problems for Non-Linear Dynamical SystemsOptimal De...

  7. 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....

  8. Optimisation of technical specifications using probabilistic methods

    International Nuclear Information System (INIS)

    Ericsson, G.; Knochenhauer, M.; Hultqvist, G.

    1986-01-01

    During the last few years the development of methods for modifying and optimising nuclear power plant Technical Specifications (TS) for plant operations has received increased attention. Probalistic methods in general, and the plant and system models of probabilistic safety assessment (PSA) in particular, seem to provide the most forceful tools for optimisation. This paper first gives some general comments on optimisation, identifying important parameters and then gives a description of recent Swedish experiences from the use of nuclear power plant PSA models and results for TS optimisation

  9. Layout Optimisation of Wave Energy Converter Arrays

    DEFF Research Database (Denmark)

    Ruiz, Pau Mercadé; Nava, Vincenzo; Topper, Mathew B. R.

    2017-01-01

    This paper proposes an optimisation strategy for the layout design of wave energy converter (WEC) arrays. Optimal layouts are sought so as to maximise the absorbed power given a minimum q-factor, the minimum distance between WECs, and an area of deployment. To guarantee an efficient optimisation......, a four-parameter layout description is proposed. Three different optimisation algorithms are further compared in terms of performance and computational cost. These are the covariance matrix adaptation evolution strategy (CMA), a genetic algorithm (GA) and the glowworm swarm optimisation (GSO) algorithm...

  10. 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.

  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. 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.

  13. 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.

  14. Evolutionary programming for neutron instrument optimisation

    International Nuclear Information System (INIS)

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

    2006-01-01

    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

  15. Dose optimisation in computed radiography

    International Nuclear Information System (INIS)

    Schreiner-Karoussou, A.

    2005-01-01

    After the installation of computed radiography (CR) systems in three hospitals in Luxembourg a patient dose survey was carried out for three radiographic examinations, thorax, pelvis and lumbar spine. It was found that the patient doses had changed in comparison with the patient doses measured for conventional radiography in the same three hospitals. A close collaboration between the manufacturers of the X-ray installations, the CR imaging systems and the medical physicists led to the discovery that the speed class with which each radiographic examination was to be performed, had been ignored, during installation of the digital imaging systems. A number of procedures were carried out in order to calibrate and program the X-ray installations in conjunction with the CR systems. Following this optimisation procedure, a new patient dose survey was carried out for the three radiographic examinations. It was found that patient doses for the three hospitals were reduced. (authors)

  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. Technical Network

    CERN Multimedia

    2007-01-01

    In order to optimise the management of the Technical Network (TN), to facilitate understanding of the purpose of devices connected to the TN and to improve security incident handling, the Technical Network Administrators and the CNIC WG have asked IT/CS to verify the "description" and "tag" fields of devices connected to the TN. Therefore, persons responsible for systems connected to the TN will receive e-mails from IT/CS asking them to add the corresponding information in the network database at "network-cern-ch". Thank you very much for your cooperation. The Technical Network Administrators & the CNIC WG

  18. The optimisation of a water distribution system using Bentley WaterGEMS software

    Directory of Open Access Journals (Sweden)

    Świtnicka Karolina

    2017-01-01

    Full Text Available The proper maintenance of water distribution systems (WDSs requires from operators multiple actions in order to ensure optimal functioning. Usually, all requirements should be adjusted simultaneously. Therefore, the decision-making process is often supported by multi-criteria optimisation methods. Significant improvements of exploitation conditions of WDSs functioning can be achieved by connecting small water supply networks into group systems. Among many potential tools supporting advanced maintenance and management of WDSs, significant improvements have tools that can find the optimal solution by the implemented mechanism of metaheuristic methods, such as the genetic algorithm. In this paper, an exemplary WDS functioning optimisation is presented, in relevance to a group water supply system. The action range of optimised parameters included: maximisation of water flow velocity, regulation of pressure head, minimisation of water retention time in a network (water age and minimisation of pump energy consumption. All simulations were performed in Bentley WaterGEMS software.

  19. Use of artificial intelligence techniques for optimisation of co-combustion of coal with biomass

    Energy Technology Data Exchange (ETDEWEB)

    Tan, C.K.; Wilcox, S.J.; Ward, J. [University of Glamorgan, Pontypridd (United Kingdom). Division of Mechanical Engineering

    2006-03-15

    The optimisation of burner operation in conventional pulverised-coal-fired boilers for co-combustion applications represents a significant challenge This paper describes a strategic framework in which Artificial Intelligence (AI) techniques can be applied to solve such an optimisation problem. The effectiveness of the proposed system is demonstrated by a case study that simulates the co-combustion of coal with sewage sludge in a 500-kW pilot-scale combustion rig equipped with a swirl stabilised low-NOx burner. A series of Computational Fluid Dynamics (CFD) simulations were performed to generate data for different operating conditions, which were then used to train several Artificial Neural Networks (ANNs) to predict the co-combustion performance. Once trained, the ANNs were able to make estimations of unseen situations in a fraction of the time taken by the CFD simulation. Consequently, the networks were capable of representing the underlying physics of the CFD models and could be executed efficiently for a large number of iterations as required by optimisation techniques based on Evolutionary Algorithms (EAs). Four operating parameters of the burner, namely the swirl angles and flow rates of the secondary and tertiary combustion air were optimised with the objective of minimising the NOx and CO emissions as well as the unburned carbon at the furnace exit. The results suggest that ANNs combined with EAs provide a useful tool for optimising co-combustion processes.

  20. Power supply of Eurotunnel. Optimisation based on traffic and simulation studies

    Energy Technology Data Exchange (ETDEWEB)

    Marie, Stephane [SNCF, Direction de l' Ingenierie, Saint-Denis (France). Dept. des Installations Fixes de Traction Electrique; Dupont, Jean-Pierre; Findinier, Bertrand; Maquaire, Christian [Eurotunnel, Coquelles (France)

    2010-12-15

    In order to reduce electrical power costs and also to cope with the significant traffic increase, a new study was carried on feeding the tunnel section from the French power station, thus improving and reinforcing the existing network. Based on a design study established by SNCF engineering department, EUROTUNNEL chose a new electrical scheme to cope with the traffic increase and optimise investments. (orig.)

  1. Combining simulation and multi-objective optimisation for equipment quantity optimisation in container terminals

    OpenAIRE

    Lin, Zhougeng

    2013-01-01

    This thesis proposes a combination framework to integrate simulation and multi-objective optimisation (MOO) for container terminal equipment optimisation. It addresses how the strengths of simulation and multi-objective optimisation can be integrated to find high quality solutions for multiple objectives with low computational cost. Three structures for the combination framework are proposed respectively: pre-MOO structure, integrated MOO structure and post-MOO structure. The applications of ...

  2. Layout Optimisation of Wave Energy Converter Arrays

    Directory of Open Access Journals (Sweden)

    Pau Mercadé Ruiz

    2017-08-01

    Full Text Available This paper proposes an optimisation strategy for the layout design of wave energy converter (WEC arrays. Optimal layouts are sought so as to maximise the absorbed power given a minimum q-factor, the minimum distance between WECs, and an area of deployment. To guarantee an efficient optimisation, a four-parameter layout description is proposed. Three different optimisation algorithms are further compared in terms of performance and computational cost. These are the covariance matrix adaptation evolution strategy (CMA, a genetic algorithm (GA and the glowworm swarm optimisation (GSO algorithm. The results show slightly higher performances for the latter two algorithms; however, the first turns out to be significantly less computationally demanding.

  3. 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 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...

  4. 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...

  5. 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...

  6. Credit price optimisation within retail banking

    African Journals Online (AJOL)

    2014-02-14

    Feb 14, 2014 ... cost based pricing, where the price of a product or service is based on the .... function obtained from fitting a logistic regression model .... Note that the proposed optimisation approach below will allow us to also incorporate.

  7. Methodological principles for optimising functional MRI experiments

    International Nuclear Information System (INIS)

    Wuestenberg, T.; Giesel, F.L.; Strasburger, H.

    2005-01-01

    Functional magnetic resonance imaging (fMRI) is one of the most common methods for localising neuronal activity in the brain. Even though the sensitivity of fMRI is comparatively low, the optimisation of certain experimental parameters allows obtaining reliable results. In this article, approaches for optimising the experimental design, imaging parameters and analytic strategies will be discussed. Clinical neuroscientists and interested physicians will receive practical rules of thumb for improving the efficiency of brain imaging experiments. (orig.) [de

  8. Optimisation: how to develop stake holder involvement

    International Nuclear Information System (INIS)

    Weiss, W.

    2003-01-01

    The Precautionary Principle is an internationally recognised approach for dealing with risk situations characterised by uncertainties and potential irreversible damages. Since the late fifties, ICRP has adopted this prudent attitude because of the lack of scientific evidence concerning the existence of a threshold at low doses for stochastic effects. The 'linear, no-threshold' model and the 'optimisation of protection' principle have been developed as a pragmatic response for the management of the risk. The progress in epidemiology and radiobiology over the last decades have affirmed the initial assumption and the optimisation remains the appropriate response for the application of the precautionary principle in the context of radiological protection. The basic objective of optimisation is, for any source within the system of radiological protection, to maintain the level of exposure as low as reasonably achievable, taking into account social and economical factors. Methods tools and procedures have been developed over the last two decades to put into practice the optimisation principle with a central role given to the cost-benefit analysis as a means to determine the optimised level of protection. However, with the advancement in the implementation of the principle more emphasis was progressively given to good practice, as well as on the importance of controlling individual levels of exposure through the optimisation process. In the context of the revision of its present recommendations, the Commission is reenforcing the emphasis on protection of the individual with the adoption of an equity-based system that recognizes individual rights and a basic level of health protection. Another advancement is the role that is now recognised to 'stakeholders involvement' in the optimisation process as a mean to improve the quality of the decision aiding process for identifying and selecting protection actions considered as being accepted by all those involved. The paper

  9. Dose optimisation in single plane interstitial brachytherapy

    DEFF Research Database (Denmark)

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

    2006-01-01

    patients,       treated for recurrent rectal and cervical cancer, flexible catheters were       sutured intra-operatively to the tumour bed in areas with compromised       surgical margin. Both non-optimised, geometrically and graphically       optimised CT -based dose plans were made. The overdose index...... on the       regularity of the implant, such that the benefit of optimisation was       larger for irregular implants. OI and HI correlated strongly with target       volume limiting the usability of these parameters for comparison of dose       plans between patients. CONCLUSIONS: Dwell time optimisation significantly......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...

  10. Thermal performance monitoring and optimisation

    International Nuclear Information System (INIS)

    Sunde, Svein; Berg; Oeyvind

    1998-01-01

    Monitoring of the thermal efficiency of nuclear power plants is expected to become increasingly important as energy-market liberalisation exposes plants to increasing availability requirements and fiercer competition. The general goal in thermal performance monitoring is straightforward: to maximise the ratio of profit to cost under the constraints of safe operation. One may perceive this goal to be pursued in two ways, one oriented towards fault detection and cost-optimal predictive maintenance, and another determined at optimising target values of parameters in response to any component degradation detected, changes in ambient conditions, or the like. Annual savings associated with effective thermal-performance monitoring are expected to be in the order of $ 100 000 for power plants of representative size. A literature review shows that a number of computer systems for thermal-performance monitoring exists, either as prototypes or commercially available. The characteristics and needs of power plants may vary widely, however, and decisions concerning the exact scope, content and configuration of a thermal-performance monitor may well follow a heuristic approach. Furthermore, re-use of existing software modules may be desirable. Therefore, we suggest here the design of a flexible workbench for easy assembly of an experimental thermal-performance monitor at the Halden Project. The suggested design draws heavily on our extended experience in implementing control-room systems featured by assets like high levels of customisation, flexibility in configuration and modularity in structure, and on a number of relevant adjoining activities. The design includes a multi-computer communication system and a graphical user's interface, and aims at a system adaptable to any combination of in-house or end user's modules, as well as commercially available software. (author)

  11. Strategic optimisation of microgrid by evolving a unitised regenerative fuel cell system operational criterion

    Science.gov (United States)

    Bhansali, Gaurav; Singh, Bhanu Pratap; Kumar, Rajesh

    2016-09-01

    In this paper, the problem of microgrid optimisation with storage has been addressed in an unaccounted way rather than confining it to loss minimisation. Unitised regenerative fuel cell (URFC) systems have been studied and employed in microgrids to store energy and feed it back into the system when required. A value function-dependent on line losses, URFC system operational cost and stored energy at the end of the day are defined here. The function is highly complex, nonlinear and multi dimensional in nature. Therefore, heuristic optimisation techniques in combination with load flow analysis are used here to resolve the network and time domain complexity related with the problem. Particle swarm optimisation with the forward/backward sweep algorithm ensures optimal operation of microgrid thereby minimising the operational cost of the microgrid. Results are shown and are found to be consistently improving with evolution of the solution strategy.

  12. Optimisation of electrical system for offshore wind farms via genetic algorithm

    DEFF Research Database (Denmark)

    Chen, Zhe; Zhao, Menghua; Blaabjerg, Frede

    2009-01-01

    An optimisation platform based on genetic algorithm (GA) is presented, where the main components of a wind farm and key technical specifications are used as input parameters and the electrical system design of the wind farm is optimised in terms of both production cost and system reliability....... The power losses, wind power production, initial investment and maintenance costs are considered in the production cost. The availability of components and network redundancy are included in the reliability evaluation. The method of coding an electrical system to a binary string, which is processed by GA......, is developed. Different GA techniques are investigated based on a real example offshore wind farm. This optimisation platform has been demonstrated as a powerful tool for offshore wind farm design and evaluation....

  13. 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.

  14. Optimising electrical system architecture using genetic algorithms; Optimierung der Bordnetzarchitektur mit Hilfe genetischer Algorithmen

    Energy Technology Data Exchange (ETDEWEB)

    Luebke, A. [Volkswagen AG, Wolfsburg (Germany). Fahrzeug-Elektrik/ -Elektronik Vorentwicklung; Reuss, H.C. [Technische Univ. Dresden (Germany). Inst. fuer Verbrennungsmotoren und Kraftfahrzeuge

    2000-06-01

    Control units in vehicles are increasingly being networked. Framework conditions, for example the cost of network nodes, change so rapidly that an optimised network rarely survives one model generation. This article describes the possible applications of a genetic algorithm which can be used to optimise the architecture of the datanet quickly and easily. (orig.) [German] Die Vernetzung der Steuergeraete im Kraftfahrzeug nimmt staendig zu. Dabei aendern sich die Randbedingungen, zum Beispiel die Kosten von Netzknoten, laufend, so dass eine einmal optimierte Architektur der Vernetzung schon fuer das naechste Fahrzeugmodell nicht mehr das Optimum darstellt. Der vorliegende Artikel beschreibt die Anwendungsmoeglichkeit eines genetischen Algorithmus, mit dessen Hilfe sich die Architektur des Datennetzes schnell und zuverlaessig optimieren laesst. (orig.)

  15. 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.

  16. Noise aspects at aerodynamic blade optimisation projects

    International Nuclear Information System (INIS)

    Schepers, J.G.

    1997-06-01

    The Netherlands Energy Research Foundation (ECN) has often been involved in industrial projects, in which blade geometries are created automatic by means of numerical optimisation. Usually, these projects aim at the determination of the aerodynamic optimal wind turbine blade, i.e. the goal is to design a blade which is optimal with regard to energy yield. In other cases, blades have been designed which are optimal with regard to cost of generated energy. However, it is obvious that the wind turbine blade designs which result from these optimisations, are not necessarily optimal with regard to noise emission. In this paper an example is shown of an aerodynamic blade optimisation, using the ECN-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. 11 figs., 8 refs

  17. Merchandise and Replenishment Planning Optimisation for Fashion Retail

    Directory of Open Access Journals (Sweden)

    Raffaele Iannone

    2013-08-01

    Full Text Available The integration among different companies functions, collaborative planning and the elaboration of focused distribution plans are critical to the success of each kind of company working in the complex retail sector. In this contest, the present work proposes the description of a model able to support coordinated strategic choices continually made by Supply Chain (SC actors. The final objective is achievement of the full optimisation of Merchandise & Replenishment Planning phases, identifying the right replenishment quantities and periods. To test the proposed model’s effectiveness, it was applied to an important Italian fashion company in the complex field of fast-fashion, a sector in which promptness is a main competitive leverage and, therefore, the planning cannot exclude the time variable. The passage from a total push strategy, currently used by the company, to a push-pull one, suggested by the model, allowed us not only to estimate a reduction in goods quantities to purchase at the beginning of a sales period (with considerable economic savings, but also elaborate a focused replenishment plan that permits reduction and optimisation of departures from network warehouses to Points of Sale (POS.

  18. Optimisation of Storage for Concentrated Solar Power Plants

    Directory of Open Access Journals (Sweden)

    Luigi Cirocco

    2014-12-01

    Full Text Available The proliferation of non-scheduled generation from renewable electrical energy sources such concentrated solar power (CSP presents a need for enabling scheduled generation by incorporating energy storage; either via directly coupled Thermal Energy Storage (TES or Electrical Storage Systems (ESS distributed within the electrical network or grid. The challenges for 100% renewable energy generation are: to minimise capitalisation cost and to maximise energy dispatch capacity. The aims of this review article are twofold: to review storage technologies and to survey the most appropriate optimisation techniques to determine optimal operation and size of storage of a system to operate in the Australian National Energy Market (NEM. Storage technologies are reviewed to establish indicative characterisations of energy density, conversion efficiency, charge/discharge rates and costings. A partitioning of optimisation techniques based on methods most appropriate for various time scales is performed: from “whole of year”, seasonal, monthly, weekly and daily averaging to those best suited matching the NEM bid timing of five minute dispatch bidding, averaged on the half hour as the trading settlement spot price. Finally, a selection of the most promising research directions and methods to determine the optimal operation and sizing of storage for renewables in the grid is presented.

  19. Application of Surpac and Whittle Software in Open Pit Optimisation ...

    African Journals Online (AJOL)

    Application of Surpac and Whittle Software in Open Pit Optimisation and Design. ... This paper studies the Surpac and Whittle software and their application in designing an optimised pit. ... EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT

  20. (MBO) algorithm in multi-reservoir system optimisation

    African Journals Online (AJOL)

    A comparative study of marriage in honey bees optimisation (MBO) algorithm in ... A practical application of the marriage in honey bees optimisation (MBO) ... to those of other evolutionary algorithms, such as the genetic algorithm (GA), ant ...

  1. 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....

  2. Operational Radiological Protection and Aspects of Optimisation

    International Nuclear Information System (INIS)

    Lazo, E.; Lindvall, C.G.

    2005-01-01

    Since 1992, the Nuclear Energy Agency (NEA), along with the International Atomic Energy Agency (IAEA), has sponsored the Information System on Occupational Exposure (ISOE). ISOE collects and analyses occupational exposure data and experience from over 400 nuclear power plants around the world and is a forum for radiological protection experts from both nuclear power plants and regulatory authorities to share lessons learned and best practices in the management of worker radiation exposures. In connection to the ongoing work of the International Commission on Radiological Protection (ICRP) to develop new recommendations, the ISOE programme has been interested in how the new recommendations would affect operational radiological protection application at nuclear power plants. Bearing in mind that the ICRP is developing, in addition to new general recommendations, a new recommendation specifically on optimisation, the ISOE programme created a working group to study the operational aspects of optimisation, and to identify the key factors in optimisation that could usefully be reflected in ICRP recommendations. In addition, the Group identified areas where further ICRP clarification and guidance would be of assistance to practitioners, both at the plant and the regulatory authority. The specific objective of this ISOE work was to provide operational radiological protection input, based on practical experience, to the development of new ICRP recommendations, particularly in the area of optimisation. This will help assure that new recommendations will best serve the needs of those implementing radiation protection standards, for the public and for workers, at both national and international levels. (author)

  3. Optimisation of surgical care for rectal cancer

    NARCIS (Netherlands)

    Borstlap, W.A.A.

    2017-01-01

    Optimisation of surgical care means weighing the risk of treatment related morbidity against the patients’ potential benefits of a surgical intervention. The first part of this thesis focusses on the anaemic patient undergoing colorectal surgery. Hypothesizing that a more profound haemoglobin

  4. On optimal development and becoming an optimiser

    NARCIS (Netherlands)

    de Ruyter, D.J.

    2012-01-01

    The article aims to provide a justification for the claim that optimal development and becoming an optimiser are educational ideals that parents should pursue in raising their children. Optimal development is conceptualised as enabling children to grow into flourishing persons, that is persons who

  5. 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...

  6. OPTIMISATION OF COMPRESSIVE STRENGTH OF PERIWINKLE ...

    African Journals Online (AJOL)

    In this paper, a regression model is developed to predict and optimise the compressive strength of periwinkle shell aggregate concrete using Scheffe's regression theory. The results obtained from the derived regression model agreed favourably with the experimental data. The model was tested for adequacy using a student ...

  7. An efficient optimisation method in groundwater resource ...

    African Journals Online (AJOL)

    DRINIE

    2003-10-04

    Oct 4, 2003 ... theories developed in the field of stochastic subsurface hydrology. In reality, many ... Recently, some researchers have applied the multi-stage ... Then a robust solution of the optimisation problem given by Eqs. (1) to (3) is as ...

  8. Water distribution systems design optimisation using metaheuristics ...

    African Journals Online (AJOL)

    The topic of multi-objective water distribution systems (WDS) design optimisation using metaheuristics is investigated, comparing numerous modern metaheuristics, including several multi-objective evolutionary algorithms, an estimation of distribution algorithm and a recent hyperheuristic named AMALGAM (an evolutionary ...

  9. Optimisation of efficiency of axial fans

    NARCIS (Netherlands)

    Kruyt, Nicolaas P.; Pennings, P.C.; Faasen, R.

    2014-01-01

    A three-stage research project has been executed to develop ducted axial-fans with increased efficiency. In the first stage a design method has been developed in which various conflicting design criteria can be incorporated. Based on this design method, an optimised design has been determined

  10. Thermodynamic optimisation of a heat exchanger

    NARCIS (Netherlands)

    Cornelissen, Rene; Hirs, Gerard

    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

  11. Self-optimising control of sewer systems

    DEFF Research Database (Denmark)

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

    2013-01-01

    . The definition of an optimal performance was carried out by through a two-stage optimisation (stochastic and deterministic) to take into account both the overflow during the current rain event as well as the expected overflow, given the probability of a future rain event. The methodology is successfully applied...

  12. Optimising Shovel-Truck Fuel Consumption using Stochastic ...

    African Journals Online (AJOL)

    Optimising the fuel consumption and truck waiting time can result in significant fuel savings. The paper demonstrates that stochastic simulation is an effective tool for optimising the utilisation of fossil-based fuels in mining and related industries. Keywords: Stochastic, Simulation Modelling, Mining, Optimisation, Shovel-Truck ...

  13. Design of optimised backstepping controller for the synchronisation ...

    Indian Academy of Sciences (India)

    Ehsan Fouladi

    2017-12-18

    Dec 18, 2017 ... for the proposed optimised method compared to PSO optimised controller or any non-optimised backstepping controller. Keywords. Colpitts oscillator; backstepping controller; chaos synchronisation; shark smell algorithm; particle .... The velocity model is based on the gradient of the objective function, tilting ...

  14. 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...

  15. Automation of route identification and optimisation based on data-mining and chemical intuition.

    Science.gov (United States)

    Lapkin, A A; Heer, P K; Jacob, P-M; Hutchby, M; Cunningham, W; Bull, S D; Davidson, M G

    2017-09-21

    Data-mining of Reaxys and network analysis of the combined literature and in-house reactions set were used to generate multiple possible reaction routes to convert a bio-waste feedstock, limonene, into a pharmaceutical API, paracetamol. The network analysis of data provides a rich knowledge-base for generation of the initial reaction screening and development programme. Based on the literature and the in-house data, an overall flowsheet for the conversion of limonene to paracetamol was proposed. Each individual reaction-separation step in the sequence was simulated as a combination of the continuous flow and batch steps. The linear model generation methodology allowed us to identify the reaction steps requiring further chemical optimisation. The generated model can be used for global optimisation and generation of environmental and other performance indicators, such as cost indicators. However, the identified further challenge is to automate model generation to evolve optimal multi-step chemical routes and optimal process configurations.

  16. Optimisation of warpage on thin shell plastic part using response surface methodology (RSM) and glowworm swarm optimisation (GSO)

    Science.gov (United States)

    Asyirah, B. N.; Shayfull, Z.; Nasir, S. M.; Fathullah, M.; Hazwan, M. H. M.

    2017-09-01

    In manufacturing a variety of parts, plastic injection moulding is widely use. The injection moulding process parameters have played important role that affects the product's quality and productivity. There are many approaches in minimising the warpage ans shrinkage such as artificial neural network, genetic algorithm, glowworm swarm optimisation and hybrid approaches are addressed. In this paper, a systematic methodology for determining a warpage and shrinkage in injection moulding process especially in thin shell plastic parts are presented. To identify the effects of the machining parameters on the warpage and shrinkage value, response surface methodology is applied. In thos study, a part of electronic night lamp are chosen as the model. Firstly, experimental design were used to determine the injection parameters on warpage for different thickness value. The software used to analyse the warpage is Autodesk Moldflow Insight (AMI) 2012.

  17. 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...... in the downstream part of the Red River, and at the same time to increase hydropower generation and to save water for the dry season. The real-time optimisation procedure further improves the efficiency of the reservoir operation and enhances the flexibility for the decision-making. Finally, the quality......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...

  18. Reference voltage calculation method based on zero-sequence component optimisation for a regional compensation DVR

    Science.gov (United States)

    Jian, Le; Cao, Wang; Jintao, Yang; Yinge, Wang

    2018-04-01

    This paper describes the design of a dynamic voltage restorer (DVR) that can simultaneously protect several sensitive loads from voltage sags in a region of an MV distribution network. A novel reference voltage calculation method based on zero-sequence voltage optimisation is proposed for this DVR to optimise cost-effectiveness in compensation of voltage sags with different characteristics in an ungrounded neutral system. Based on a detailed analysis of the characteristics of voltage sags caused by different types of faults and the effect of the wiring mode of the transformer on these characteristics, the optimisation target of the reference voltage calculation is presented with several constraints. The reference voltages under all types of voltage sags are calculated by optimising the zero-sequence component, which can reduce the degree of swell in the phase-to-ground voltage after compensation to the maximum extent and can improve the symmetry degree of the output voltages of the DVR, thereby effectively increasing the compensation ability. The validity and effectiveness of the proposed method are verified by simulation and experimental results.

  19. Acoustic Resonator Optimisation for Airborne Particle Manipulation

    Science.gov (United States)

    Devendran, Citsabehsan; Billson, Duncan R.; Hutchins, David A.; Alan, Tuncay; Neild, Adrian

    Advances in micro-electromechanical systems (MEMS) technology and biomedical research necessitate micro-machined manipulators to capture, handle and position delicate micron-sized particles. To this end, a parallel plate acoustic resonator system has been investigated for the purposes of manipulation and entrapment of micron sized particles in air. Numerical and finite element modelling was performed to optimise the design of the layered acoustic resonator. To obtain an optimised resonator design, careful considerations of the effect of thickness and material properties are required. Furthermore, the effect of acoustic attenuation which is dependent on frequency is also considered within this study, leading to an optimum operational frequency range. Finally, experimental results demonstrated good particle levitation and capture of various particle properties and sizes ranging to as small as 14.8 μm.

  20. Techno-economic optimisation of energy systems

    International Nuclear Information System (INIS)

    Mansilla Pellen, Ch.

    2006-07-01

    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)

  1. Pre-operative optimisation of lung function

    Directory of Open Access Journals (Sweden)

    Naheed Azhar

    2015-01-01

    Full Text Available The anaesthetic management of patients with pre-existing pulmonary disease is a challenging task. It is associated with increased morbidity in the form of post-operative pulmonary complications. Pre-operative optimisation of lung function helps in reducing these complications. Patients are advised to stop smoking for a period of 4–6 weeks. This reduces airway reactivity, improves mucociliary function and decreases carboxy-haemoglobin. The widely used incentive spirometry may be useful only when combined with other respiratory muscle exercises. Volume-based inspiratory devices have the best results. Pharmacotherapy of asthma and chronic obstructive pulmonary disease must be optimised before considering the patient for elective surgery. Beta 2 agonists, inhaled corticosteroids and systemic corticosteroids, are the main drugs used for this and several drugs play an adjunctive role in medical therapy. A graded approach has been suggested to manage these patients for elective surgery with an aim to achieve optimal pulmonary function.

  2. Networking

    OpenAIRE

    Rauno Lindholm, Daniel; Boisen Devantier, Lykke; Nyborg, Karoline Lykke; Høgsbro, Andreas; Fries, de; Skovlund, Louise

    2016-01-01

    The purpose of this project was to examine what influencing factor that has had an impact on the presumed increasement of the use of networking among academics on the labour market and how it is expressed. On the basis of the influence from globalization on the labour market it can be concluded that the globalization has transformed the labour market into a market based on the organization of networks. In this new organization there is a greater emphasis on employees having social qualificati...

  3. Optimised dipper fine tunes shovel performance

    Energy Technology Data Exchange (ETDEWEB)

    Fiscor, S.

    2005-06-01

    Joint efforts between mine operators, OEMs, and researchers yields unexpected benefits from dippers for shovels for coal, oil, or hardrock mining that can now be tailored to meet site-specific conditions. The article outlines a process being developed by CRCMining and P & H MIning Equipment to optimise the dipper that involves rapid prototyping and scale modelling of the dipper and the mine conditions. Scale models have been successfully field tested. 2 photos.

  4. Public transport optimisation emphasising passengers’ travel behaviour.

    OpenAIRE

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

    2015-01-01

    Passengers in public transport complaining about their travel experiences are not uncommon. This might seem counterintuitive since several operators worldwide are presenting better key performance indicators year by year. The present PhD study focuses on developing optimisation algorithms 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 ...

  5. 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

  6. Natural Erosion of Sandstone as Shape Optimisation.

    Science.gov (United States)

    Ostanin, Igor; Safonov, Alexander; Oseledets, Ivan

    2017-12-11

    Natural arches, pillars and other exotic sandstone formations have always been attracting attention for their unusual shapes and amazing mechanical balance that leave a strong impression of intelligent design rather than the result of a stochastic process. It has been recently demonstrated that these shapes could have been the result of the negative feedback between stress and erosion that originates in fundamental laws of friction between the rock's constituent particles. Here we present a deeper analysis of this idea and bridge it with the approaches utilized in shape and topology optimisation. It appears that the processes of natural erosion, driven by stochastic surface forces and Mohr-Coulomb law of dry friction, can be viewed within the framework of local optimisation for minimum elastic strain energy. Our hypothesis is confirmed by numerical simulations of the erosion using the topological-shape optimisation model. Our work contributes to a better understanding of stochastic erosion and feasible landscape formations that could be found on Earth and beyond.

  7. 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.

  8. Exploration of automatic optimisation for CUDA programming

    KAUST Repository

    Al-Mouhamed, Mayez; Khan, Ayaz ul Hassan

    2014-01-01

    © 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.

  9. Optimisation and symmetry in experimental radiation physics

    International Nuclear Information System (INIS)

    Ghose, A.

    1988-01-01

    The present monograph is concerned with the optimisation of geometric factors in radiation physics experiments. The discussions are essentially confined to those systems in which optimisation is equivalent to symmetrical configurations of the measurement systems. They include, measurements of interaction cross section of diverse types, determination of polarisations, development of detectors with almost ideal characteristics, production of radiations with continuously variable energies and development of high efficiency spectrometers etc. The monograph is intended for use by experimental physicists investigating primary interactions of radiations with matter and associated technologies. We have illustrated the various optimisation procedures by considering the cases of the so-called ''14 MeV'' on d-t neutrons and gamma rays with energies less than 3 MeV. Developments in fusion technology are critically dependent on the availability accurate cross sections of nuclei for fast neutrons of energies at least as high as d-t neutrons. In this monograph we have discussed various techniques which can be used to improve the accuracy of such measurements and have also presented a method for generating almost monoenergetic neutrons in the 8 MeV to 13 MeV energy range which can be used to measure cross sections in this sparingly investigated region

  10. A generic methodology for the optimisation of sewer systems using stochastic programming and self-optimizing control

    DEFF Research Database (Denmark)

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

    2015-01-01

    . Such controller is aimed at keeping the system close to the optimal performance, thanks to an optimal selection of controlled variables. The definition of an optimal performance was carried out by a two-stage optimisation (stochastic and deterministic) to take into account both the overflow during the current......The design of sewer system control is a complex task given the large size of the sewer networks, the transient dynamics of the water flow and the stochastic nature of rainfall. This contribution presents a generic methodology for the design of a self-optimising controller in sewer systems...

  11. State of the art concerning optimum location of capacitors and studying the exhaustive search approach for optimising a given solution

    Directory of Open Access Journals (Sweden)

    Sergio Raúl Rivera Rodríguez

    2004-09-01

    Full Text Available The present article reviews the state of the art of optimum capacitor location in distribution systems, provideing guidelines for planners engaged in optimising tension profiles and controlling reagents in distribution networks.Optimising a given solution by exhastive search is studied here; the dimensions of a given problem are determined by evaluating the different possibilities for resolving it and the solution algorithm's computational times and requierements are visualised. An example system (9 node, IEEE is used for illustrating the exhaustive search approach, where it was found that methods used in the literature regarding this topic do not always lead to the optimum solution.

  12. Achieving a Sustainable Urban Form through Land Use Optimisation: Insights from Bekasi City’s Land-Use Plan (2010–2030

    Directory of Open Access Journals (Sweden)

    Rahmadya Trias Handayanto

    2017-02-01

    Full Text Available Cities worldwide have been trying to achieve a sustainable urban form to handle their rapid urban growth. Many sustainable urban forms have been studied and two of them, the compact city and the eco city, were chosen in this study as urban form foundations. Based on these forms, four sustainable city criteria (compactness, compatibility, dependency, and suitability were considered as necessary functions for land use optimisation. This study presents a land use optimisation as a method for achieving a sustainable urban form. Three optimisation methods (particle swarm optimisation, genetic algorithms, and a local search method were combined into a single hybrid optimisation method for land use in Bekasi city, Indonesia. It was also used for examining Bekasi city’s land-use-plan (2010–2030 after optimising current (2015 and future land use (2030. After current land use optimisation, the score of sustainable city criteria increased significantly. Three important centres of land use (commercial, industrial, and residential were also created through clustering the results. These centres were slightly different from centres of the city plan zones. Additional land uses in 2030 were predicted using a nonlinear autoregressive neural network with external input. Three scenarios were used for allocating these additional land uses including sustainable development, government policy, and business-as-usual. Future land use allocation in 2030 found that the sustainable development scenario showed better performance compared to government policy and business-as-usual scenarios.

  13. 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...

  14. Robust optimisation of forest transportation networks: a case study ...

    African Journals Online (AJOL)

    Forest transportation costs are the major cost component for many forest product supply chains. In order to minimise these costs, many organisations have turned ... The simulation results are then evaluated for robustness by means of seven robustness performance measures. For our case study, the results show that (1) the ...

  15. A generic methodology for the optimisation of sewer systems using stochastic programming and self-optimizing control.

    Science.gov (United States)

    Mauricio-Iglesias, Miguel; Montero-Castro, Ignacio; Mollerup, Ane L; Sin, Gürkan

    2015-05-15

    The design of sewer system control is a complex task given the large size of the sewer networks, the transient dynamics of the water flow and the stochastic nature of rainfall. This contribution presents a generic methodology for the design of a self-optimising controller in sewer systems. Such controller is aimed at keeping the system close to the optimal performance, thanks to an optimal selection of controlled variables. The definition of an optimal performance was carried out by a two-stage optimisation (stochastic and deterministic) to take into account both the overflow during the current rain event as well as the expected overflow given the probability of a future rain event. The methodology is successfully applied to design an optimising control strategy for a subcatchment area in Copenhagen. The results are promising and expected to contribute to the advance of the operation and control problem of sewer systems. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. 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....

  17. 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...... of application messages to frames. Optimisation heuristics for frame packing aimed at producing a schedulable system are presented. Extensive experiments and a real-life example show the efficiency of the frame-packing approach....

  18. 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...... of application messages to frames. Optimisation heuristics for frame packing aimed at producing a schedulable system are presented. Extensive experiments and a real-life example show the efficiency of the frame-packing approach....

  19. Flotation process control optimisation at Prominent Hill

    International Nuclear Information System (INIS)

    Lombardi, Josephine; Muhamad, Nur; Weidenbach, M.

    2012-01-01

    OZ Minerals' Prominent Hill copper- gold concentrator is located 130 km south east of the town of Coober Pedy in the Gawler Craton of South Australia. The concentrator was built in 2008 and commenced commercial production in early 2009. The Prominent Hill concentrator is comprised of a conventional grinding and flotation processing plant with a 9.6 Mtpa ore throughput capacity. The flotation circuit includes six rougher cells, an IseMill for regrinding the rougher concentrate and a Jameson cell heading up the three stage conventional cell cleaner circuit. In total there are four level controllers in the rougher train and ten level controllers in the cleaning circuit for 18 cells. Generic proportional — integral and derivative (PID) control used on the level controllers alone propagated any disturbances downstream in the circuit that were generated from the grinding circuit, hoppers, between cells and interconnected banks of cells, having a negative impact on plant performance. To better control such disturbances, FloatStar level stabiliser was selected for installation on the flotation circuit to account for the interaction between the cells. Multivariable control was also installed on the five concentrate hoppers to maintain consistent feed to the cells and to the IsaMill. An additional area identified for optimisation in the flotation circuit was the mass pull rate from the rougher cells. FloatStar flow optimiser was selected to be installed subsequent to the FloatStar level stabiliser. This allowed for a unified, consistent and optimal approach to running the rougher circuit. This paper describes the improvement in the stabilisation of the circuit achieved by the FloatStar level stabiliser by using the interaction matrix between cell level controllers and the results and benefits of implementing the FloatStar flow optimiser on the rougher train.

  20. Risk based test interval and maintenance optimisation - Application and uses

    International Nuclear Information System (INIS)

    Sparre, E.

    1999-10-01

    The project is part of an IAEA co-ordinated Research Project (CRP) on 'Development of Methodologies for Optimisation of Surveillance Testing and Maintenance of Safety Related Equipment at NPPs'. The purpose of the project is to investigate the sensitivity of the results obtained when performing risk based optimisation of the technical specifications. Previous projects have shown that complete LPSA models can be created and that these models allow optimisation of technical specifications. However, these optimisations did not include any in depth check of the result sensitivity with regards to methods, model completeness etc. Four different test intervals have been investigated in this study. Aside from an original, nominal, optimisation a set of sensitivity analyses has been performed and the results from these analyses have been compared to the original optimisation. The analyses indicate that the result of an optimisation is rather stable. However, it is not possible to draw any certain conclusions without performing a number of sensitivity analyses. Significant differences in the optimisation result were discovered when analysing an alternative configuration. Also deterministic uncertainties seem to affect the result of an optimisation largely. The sensitivity of failure data uncertainties is important to investigate in detail since the methodology is based on the assumption that the unavailability of a component is dependent on the length of the test interval

  1. 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.

  2. Improving Vector Evaluated Particle Swarm Optimisation by Incorporating Nondominated Solutions

    Directory of Open Access Journals (Sweden)

    Kian Sheng Lim

    2013-01-01

    Full Text Available 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.

  3. Optimising end of generation of Magnox reactors

    International Nuclear Information System (INIS)

    Hall, D.; Hopper, E.D.A.

    2014-01-01

    Designing, justifying and gaining regulatory approval for optimised, terminal fuel cycles for the last 4 of the 13 strong Magnox Fleet is described, covering: - constraints set by the plant owner's integrated closure plan, opportunities for innovative fuel cycles while preserving flexibility to respond to business changes; - methods of collectively determining best options for each site; - selected strategies including lower fuel element retention and inter-reactor transfer of fuel; - the required work scope, its technical, safety case and resource challenges and how they were met; - achieving additional electricity generation worth in excess of Pound 1 b from 4 sites (a total of 8 reactors); - the keys to success. (authors)

  4. Advanced manufacturing: optimising the factories of tomorrow

    International Nuclear Information System (INIS)

    Philippon, Patrick

    2013-01-01

    Faced with competition Patrick Philippon - Les Defis du CEA no.179 - April 2013 from the emerging countries, the competitiveness of the industrialised nations depends on the ability of their industries to innovate. This strategy necessarily entails the reorganisation and optimisation of the production systems. This is the whole challenge for 'advanced manufacturing', which relies on the new information and communication technologies. Interactive robotics, virtual reality and non-destructive testing are all technological building blocks developed by CEA, now approved within a cross-cutting programme, to meet the needs of industry and together build the factories of tomorrow. (author)

  5. Biorefinery plant design, engineering and process optimisation

    DEFF Research Database (Denmark)

    Holm-Nielsen, Jens Bo; Ehimen, Ehiazesebhor Augustine

    2014-01-01

    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...... 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...... of existing and potential biorefinery plants are elucidated....

  6. Specification, Verification and Optimisation of Business Processes

    DEFF Research Database (Denmark)

    Herbert, Luke Thomas

    is extended with stochastic branching, message passing and reward annotations which allow for the modelling of resources consumed during the execution of a business process. Further, it is shown how this structure can be used to formalise the established business process modelling language Business Process...... fault tree analysis and the automated optimisation of business processes by means of an evolutionary algorithm. This work is motivated by problems that stem from the healthcare sector, and examples encountered in this field are used to illustrate these developments....

  7. Topology Optimisation for Coupled Convection Problems

    DEFF Research Database (Denmark)

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

    stabilised finite elements implemented in a parallel multiphysics analysis and optimisation framework DFEM [1], developed and maintained in house. Focus is put on control of the temperature field within the solid structure and the problems can therefore be seen as conjugate heat transfer problems, where heat...... 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...

  8. Cost optimisation studies of high power accelerators

    Energy Technology Data Exchange (ETDEWEB)

    McAdams, R.; Nightingale, M.P.S.; Godden, D. [AEA Technology, Oxon (United Kingdom)] [and others

    1995-10-01

    Cost optimisation studies are carried out for an accelerator based neutron source consisting of a series of linear accelerators. The characteristics of the lowest cost design for a given beam current and energy machine such as power and length are found to depend on the lifetime envisaged for it. For a fixed neutron yield it is preferable to have a low current, high energy machine. The benefits of superconducting technology are also investigated. A Separated Orbit Cyclotron (SOC) has the potential to reduce capital and operating costs and intial estimates for the transverse and longitudinal current limits of such machines are made.

  9. MODELLING AND OPTIMISATION OF A BIMORPH PIEZOELECTRIC CANTILEVER BEAM IN AN ENERGY HARVESTING APPLICATION

    Directory of Open Access Journals (Sweden)

    CHUNG KET THEIN

    2016-02-01

    Full Text Available Piezoelectric materials are excellent transducers in converting vibrational energy into electrical energy, and vibration-based piezoelectric generators are seen as an enabling technology for wireless sensor networks, especially in selfpowered devices. This paper proposes an alternative method for predicting the power output of a bimorph cantilever beam using a finite element method for both static and dynamic frequency analyses. Experiments are performed to validate the model and the simulation results. In addition, a novel approach is presented for optimising the structure of the bimorph cantilever beam, by which the power output is maximised and the structural volume is minimised simultaneously. Finally, the results of the optimised design are presented and compared with other designs.

  10. Lost in Optimisation of Water Distribution Systems? A Literature Review of System Design

    Directory of Open Access Journals (Sweden)

    Helena Mala-Jetmarova

    2018-03-01

    Full Text Available Optimisation of water distribution system design is a well-established research field, which has been extremely productive since the end of the 1980s. Its primary focus is to minimise the cost of a proposed pipe network infrastructure. This paper reviews in a systematic manner articles published over the past three decades, which are relevant to the design of new water distribution systems, and the strengthening, expansion and rehabilitation of existing water distribution systems, inclusive of design timing, parameter uncertainty, water quality, and operational considerations. It identifies trends and limits in the field, and provides future research directions. Exclusively, this review paper also contains comprehensive information from over one hundred and twenty publications in a tabular form, including optimisation model formulations, solution methodologies used, and other important details.

  11. Sampling design optimisation for rainfall prediction using a non-stationary geostatistical model

    Science.gov (United States)

    Wadoux, Alexandre M. J.-C.; Brus, Dick J.; Rico-Ramirez, Miguel A.; Heuvelink, Gerard B. M.

    2017-09-01

    The accuracy of spatial predictions of rainfall by merging rain-gauge and radar data is partly determined by the sampling design of the rain-gauge network. Optimising the locations of the rain-gauges may increase the accuracy of the predictions. Existing spatial sampling design optimisation methods are based on minimisation of the spatially averaged prediction error variance under the assumption of intrinsic stationarity. Over the past years, substantial progress has been made to deal with non-stationary spatial processes in kriging. Various well-documented geostatistical models relax the assumption of stationarity in the mean, while recent studies show the importance of considering non-stationarity in the variance for environmental processes occurring in complex landscapes. We optimised the sampling locations of rain-gauges using an extension of the Kriging with External Drift (KED) model for prediction of rainfall fields. The model incorporates both non-stationarity in the mean and in the variance, which are modelled as functions of external covariates such as radar imagery, distance to radar station and radar beam blockage. Spatial predictions are made repeatedly over time, each time recalibrating the model. The space-time averaged KED variance was minimised by Spatial Simulated Annealing (SSA). The methodology was tested using a case study predicting daily rainfall in the north of England for a one-year period. Results show that (i) the proposed non-stationary variance model outperforms the stationary variance model, and (ii) a small but significant decrease of the rainfall prediction error variance is obtained with the optimised rain-gauge network. In particular, it pays off to place rain-gauges at locations where the radar imagery is inaccurate, while keeping the distribution over the study area sufficiently uniform.

  12. A national optimisation model for energy wood streams; Energiapuuvirtojen valtakunnallinen optimointimalli

    Energy Technology Data Exchange (ETDEWEB)

    Iikkanen, P.; Keskinen, S.; Korpilahti, A.; Raesaenen, T.; Sirkiae, A.

    2011-07-01

    In 2010 a total of 12,5 terawatt hours of forest energy was used in Finland's heat and power plants. According to studies by Metsaeteho and Poeyry, use of energy wood will nearly double to 21.6 terawatt hours by 2020. There are also plans to use energy wood as a raw material for biofuel plants. The techno-ecological supply potential of energy wood in 2020 is estimated at 42.9 terawatt hours. Energy wood has been transported almost entirely by road. The situation is changing, however, because growing demand for energy wood will expand raw wood procurement areas and lengthen transport distances. A cost-effective transport system therefore also requires the use of rail and waterway transports. In Finland, however, there is almost a complete absence of the terminals required for the use of rail and waterway transports; where energy wood is chipped, temporarily stored and loaded onto railway wagons and vessels for further transport. A national optimisation model for energy wood has been developed to serve transport system planning in particular. The linear optimisation model optimises, on a national level, goods streams between supply points and usage points based on forest energy procurement costs. The model simultaneously covers deliveries of forest chips, stumps and small-sized thinning wood. The procurement costs used in the optimisation include the costs of the energy wood's roadside price, chipping, transport and terminal handling. The transport system described in the optimisation model consists of wood supply points (2007 municipality precision), wood usage points, railway terminals and the connections between them along the main road and rail network. Elements required for the examination of waterway transports can also be easily added to the model. The optimisation model can be used to examine, for example, the effects of changes of energy wood demand and supply as well as transport costs on energy wood goods streams, the relative use of different

  13. 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)

  14. Optimising polarised neutron scattering measurements--XYZ and polarimetry analysis

    International Nuclear Information System (INIS)

    Cussen, L.D.; Goossens, D.J.

    2002-01-01

    The analytic optimisation of neutron scattering measurements made using XYZ polarisation analysis and neutron polarimetry techniques is discussed. Expressions for the 'quality factor' and the optimum division of counting time for the XYZ technique are presented. For neutron polarimetry the optimisation is identified as analogous to that for measuring the flipping ratio and reference is made to the results already in the literature

  15. Optimising polarised neutron scattering measurements--XYZ and polarimetry analysis

    CERN Document Server

    Cussen, L D

    2002-01-01

    The analytic optimisation of neutron scattering measurements made using XYZ polarisation analysis and neutron polarimetry techniques is discussed. Expressions for the 'quality factor' and the optimum division of counting time for the XYZ technique are presented. For neutron polarimetry the optimisation is identified as analogous to that for measuring the flipping ratio and reference is made to the results already in the literature.

  16. Application of ant colony optimisation in distribution transformer sizing

    African Journals Online (AJOL)

    This study proposes an optimisation method for transformer sizing in power system using ant colony optimisation and a verification of the process by MATLAB software. The aim is to address the issue of transformer sizing which is a major challenge affecting its effective performance, longevity, huge capital cost and power ...

  17. 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

  18. 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...

  19. 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.

  20. Spatial-structural interaction and strain energy structural optimisation

    NARCIS (Netherlands)

    Hofmeyer, H.; Davila Delgado, J.M.; Borrmann, A.; Geyer, P.; Rafiq, Y.; Wilde, de P.

    2012-01-01

    A research engine iteratively transforms spatial designs into structural designs and vice versa. Furthermore, spatial and structural designs are optimised. It is suggested to optimise a structural design by evaluating the strain energy of its elements and by then removing, adding, or changing the

  1. Adjoint Optimisation of the Turbulent Flow in an Annular Diffuser

    DEFF Research Database (Denmark)

    Gotfredsen, Erik; Agular Knudsen, Christian; Kunoy, Jens Dahl

    2017-01-01

    In the present study, a numerical optimisation of guide vanes in an annular diffuser, is performed. The optimisation is preformed for the purpose of improving the following two parameters simultaneously; the first parameter is the uniformity perpen-dicular to the flow direction, a 1/3 diameter do...

  2. Optimising of Steel Fiber Reinforced Concrete Mix Design | Beddar ...

    African Journals Online (AJOL)

    Optimising of Steel Fiber Reinforced Concrete Mix Design. ... as a result of the loss of mixture workability that will be translated into a difficult concrete casting in site. ... An experimental study of an optimisation method of fibres in reinforced ...

  3. 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

  4. Artificial neural network modelling

    CERN Document Server

    Samarasinghe, Sandhya

    2016-01-01

    This book covers theoretical aspects as well as recent innovative applications of Artificial Neural networks (ANNs) in natural, environmental, biological, social, industrial and automated systems. It presents recent results of ANNs in modelling small, large and complex systems under three categories, namely, 1) Networks, Structure Optimisation, Robustness and Stochasticity 2) Advances in Modelling Biological and Environmental Systems and 3) Advances in Modelling Social and Economic Systems. The book aims at serving undergraduates, postgraduates and researchers in ANN computational modelling. .

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

    International Nuclear Information System (INIS)

    Walton, S.; Hassan, O.; Morgan, K.; Brown, M.R.

    2011-01-01

    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.

  6. Results of the 2010 IGSC Topical Session on Optimisation

    International Nuclear Information System (INIS)

    Bailey, Lucy

    2014-01-01

    Document available in abstract form only. Full text follows: The 2010 IGSC topical session on optimisation explored a wide range of issues concerning optimisation throughout the radioactive waste management process. Philosophical and ethical questions were discussed, such as: - To what extent is the process of optimisation more important than the end result? - How do we balance long-term environmental safety with near-term operational safety? - For how long should options be kept open? - In balancing safety and excessive cost, when is BAT achieved and who decides on this? * How should we balance the needs of current society with those of future generations? It was clear that optimisation is about getting the right balance between a range of issues that cover: radiation protection, environmental protection, operational safety, operational requirements, social expectations and cost. The optimisation process will also need to respect various constraints, which are likely to include: regulatory requirements, site restrictions, community-imposed requirements or restrictions and resource constraints. These issues were explored through a number of presentations that discussed practical cases of optimisation occurring at different stages of international radioactive waste management programmes. These covered: - Operations and decommissioning - management of large disused components, from the findings of an international study, presented by WPDD; - Concept option selection, prior to site selection - upstream and disposal system optioneering in the UK; - Siting decisions - examples from both Germany and France, explaining how optimisation is being used to support site comparisons and communicate siting decisions; - Repository design decisions - comparison of KBS-3 horizontal and vertical deposition options in Finland; and - On-going optimisation during repository operation - operational experience from WIPP in the US. The variety of the remarks and views expressed during the

  7. Work management to optimise occupational radiological protection

    International Nuclear Information System (INIS)

    Ahier, B.

    2009-01-01

    Although work management is no longer a new concept, continued efforts are still needed to ensure that good performance, outcomes and trends are maintained in the face of current and future challenges. The ISOE programme thus created an Expert Group on Work Management in 2007 to develop an updated report reflecting the current state of knowledge, technology and experience in the occupational radiological protection of workers at nuclear power plants. Published in 2009, the new ISOE report on Work Management to Optimise Occupational Radiological Protection in the Nuclear Power Industry provides up-to-date practical guidance on the application of work management principles. Work management measures aim at optimising occupational radiological protection in the context of the economic viability of the installation. Important factors in this respect are measures and techniques influencing i) dose and dose rate, including source- term reduction; ii) exposure, including amount of time spent in controlled areas for operations; and iii) efficiency in short- and long-term planning, worker involvement, coordination and training. Equally important due to their broad, cross-cutting nature are the motivational and organisational arrangements adopted. The responsibility for these aspects may reside in various parts of an installation's organisational structure, and thus, a multi-disciplinary approach must be recognised, accounted for and well-integrated in any work. Based on the operational experience within the ISOE programme, the following key areas of work management have been identified: - regulatory aspects; - ALARA management policy; - worker involvement and performance; - work planning and scheduling; - work preparation; - work implementation; - work assessment and feedback; - ensuring continuous improvement. The details of each of these areas are elaborated and illustrated in the report through examples and case studies arising from ISOE experience. They are intended to

  8. A comparison of forward planning and optimised inverse planning

    International Nuclear Information System (INIS)

    Oldham, Mark; Neal, Anthony; Webb, Steve

    1995-01-01

    A radiotherapy treatment plan optimisation algorithm has been applied to 48 prostate plans and the results compared with those of an experienced human planner. Twelve patients were used in the study, and a 3, 4, 6 and 8 field plan (with standard coplanar beam angles for each plan type) were optimised by both the human planner and the optimisation algorithm. The human planner 'optimised' the plan by conventional forward planning techniques. The optimisation algorithm was based on fast-simulated-annealing. 'Importance factors' assigned to different regions of the patient provide a method for controlling the algorithm, and it was found that the same values gave good results for almost all plans. The plans were compared on the basis of dose statistics and normal-tissue-complication-probability (NTCP) and tumour-control-probability (TCP). The results show that the optimisation algorithm yielded results that were at least as good as the human planner for all plan types, and on the whole slightly better. A study of the beam-weights chosen by the optimisation algorithm and the planner will be presented. The optimisation algorithm showed greater variation, in response to individual patient geometry. For simple (e.g. 3 field) plans it was found to consistently achieve slightly higher TCP and lower NTCP values. For more complicated (e.g. 8 fields) plans the optimisation also achieved slightly better results with generally less numbers of beams. The optimisation time was always ≤5 minutes; a factor of up to 20 times faster than the human planner

  9. Optimal operation of water distribution networks by predictive control ...

    African Journals Online (AJOL)

    This paper presents an approach for the operational optimisation of potable water distribution networks. The maximisation of the use of low-cost power (e.g. overnight pumping) and the maintenance of a target chlorine concentration at final delivery points were defined as important optimisation objectives. The first objective ...

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

    Directory of Open Access Journals (Sweden)

    Alexander May

    2014-04-01

    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.

  11. Methodology implementation for multi objective optimisation for nuclear fleet evolution scenarios

    International Nuclear Information System (INIS)

    Freynet, David

    2016-01-01

    The issue of the evolution French nuclear fleet can be considered through the study of nuclear transition scenarios. These studies are of paramount importance as their results can greatly affect the decision making process, given that they take into account industrial concerns, investments, time, and nuclear system complexity. Such studies can be performed with the COSI code (developed at the CEA/DEN), which enables the calculation of matter inventories and fluxes across the fuel cycle (nuclear reactors and associated facilities), especially when coupled with the CESAR depletion code. The studies today performed with COSI require the definition of the various scenarios' input parameters, in order to fulfil different objectives such as minimising natural uranium consumption, waste production and so on. These parameters concern the quantities and the scheduling of spent fuel destined for reprocessing, and the number, the type and the commissioning dates of deployed reactors.This work aims to develop, validate and apply an optimisation methodology coupled with COSI, in order to determine optimal nuclear transition scenarios for a multi-objective platform. Firstly, this methodology is based on the acceleration of scenario evaluation, enabling the use of optimisation methods in a reasonable time-frame. With this goal in mind, artificial neural network irradiation surrogate models are created with the URANIE platform (developed at the CEA/DEN) and are implemented within COSI. The next step in this work is to use, adapt and compare different optimisation methods, such as URANIE's genetic algorithm and particle swarm methods, in order to define a methodology suited to this type of study. This methodology development is based on an incremental approach which progressively adds objectives, constraints and decision variables to the optimisation problem definition. The variables added, which are related to reactor deployment and spent fuel reprocessing strategies, are chosen

  12. VEHICLE DRIVING CYCLE OPTIMISATION ON THE HIGHWAY

    Directory of Open Access Journals (Sweden)

    Zinoviy STOTSKO

    2016-06-01

    Full Text Available This paper is devoted to the problem of reducing vehicle energy consumption. The authors consider the optimisation of highway driving cycle a way to use the kinetic energy of a car more effectively at various road conditions. The model of a vehicle driving control at the highway which consists of elementary cycles, such as accelerating, free rolling and deceleration under forces of external resistance, was designed. Braking, as an energy dissipation regime, was not included. The influence of the various longitudinal profiles of the road was taken into consideration and included in the model. Ways to use the results of monitoring road and traffic conditions are presented. The method of non-linear programming is used to design the optimal vehicle control function and phase trajectory. The results are presented by improved typical driving cycles that present energy saving as a subject of choice at a specified schedule.

  13. Optimisation and constraints - a view from ICRP

    International Nuclear Information System (INIS)

    Dunster, H.J.

    1994-01-01

    The optimisation of protection has been the major policy underlying the recommendations of the International Commission on Radiological Protection for more than 20 years. In earlier forms, the concept can be traced back to 1951. Constraints are more recent, appearing in their present form only in the 1990 recommendations of the Commission. The requirement to keep all exposures as low as reasonably achievable applies to both normal and potential exposures. The policy and the techniques are well established for normal exposures, i.e. exposures that are certain to occur. The application to potential exposures, i.e. exposures that have a probability of occurring that is less than unity, is more difficult and is still under international discussion. Constraints are needed to limit the inequity associated with the use of collective dose in cost-benefit analysis and to provide a margin to protect individuals who may be exposed to more than one source. (author)

  14. Optimising Impact in Astronomy for Development Projects

    Science.gov (United States)

    Grant, Eli

    2015-08-01

    Positive outcomes in the fields of science education and international development are notoriously difficult to achieve. Among the challenges facing projects that use astronomy to improve education and socio-economic development is how to optimise project design in order to achieve the greatest possible benefits. Over the past century, medical scientists along with statisticians and economists have progressed an increasingly sophisticated and scientific approach to designing, testing and improving social intervention and public health education strategies. This talk offers a brief review of the history and current state of `intervention science'. A similar framework is then proposed for astronomy outreach and education projects, with applied examples given of how existing evidence can be used to inform project design, predict and estimate cost-effectiveness, minimise the risk of unintended negative consequences and increase the likelihood of target outcomes being achieved.

  15. 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.

  16. Public transport optimisation emphasising passengers’ travel behaviour

    DEFF Research Database (Denmark)

    Jensen, Jens Parbo

    to the case where the two problems are solved sequentially without taking into account interdependencies. Figure 1 - Planning public transport The PhD study develops a metaheuristic algorithm to adapt the line plan configuration in order better to match passengers’ travel demand in terms of transfers as well......Passengers in public transport complaining about their travel experiences are not uncommon. This might seem counterintuitive since several operators worldwide are presenting better key performance indicators year by year. The present PhD study focuses on developing optimisation algorithms...... 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...

  17. Value Chain Optimisation of Biogas Production

    DEFF Research Database (Denmark)

    Jensen, Ida Græsted

    economically feasible. In this PhD thesis, the focus is to create models for investigating the profitability of biogas projects by: 1) including the whole value chain in a mathematical model and considering mass and energy changes on the upstream part of the chain; and 2) including profit allocation in a value......, the costs on the biogas plant has been included in the model using economy of scale. For the second point, a mathematical model considering profit allocation was developed applying three allocation mechanisms. This mathematical model can be applied as a second step after the value chain optimisation. After...... in the energy systems model to find the optimal end use of each type of gas and fuel. The main contributions of this thesis are the methods developed on plant level. Both the mathematical model for the value chain and the profit allocation model can be generalised and used in other industries where mass...

  18. Expect systems and optimisation in process control

    Energy Technology Data Exchange (ETDEWEB)

    Mamdani, A.; Efstathiou, J. (eds.)

    1986-01-01

    This report brings together recent developments both in expert systems and in optimisation, and deals with current applications in industry. Part One is concerned with Artificial Intellegence in planning and scheduling and with rule-based control implementation. The tasks of control maintenance, rescheduling and planning are each discussed in relation to new theoretical developments, techniques available, and sample applications. Part Two covers model based control techniques in which the control decisions are used in a computer model of the process. Fault diagnosis, maintenance and trouble-shooting are just some of the activities covered. Part Three contains case studies of projects currently in progress, giving details of the software available and the likely future trends. One of these, on qualitative plant modelling as a basis for knowledge-based operator aids in nuclear power stations is indexed separately.

  19. Expert systems and optimisation in process control

    International Nuclear Information System (INIS)

    Mamdani, A.; Efstathiou, J.

    1986-01-01

    This report brings together recent developments both in expert systems and in optimisation, and deals with current applications in industry. Part One is concerned with Artificial Intellegence in planning and scheduling and with rule-based control implementation. The tasks of control maintenance, rescheduling and planning are each discussed in relation to new theoretical developments, techniques available, and sample applications. Part Two covers model based control techniques in which the control decisions are used in a computer model of the process. Fault diagnosis, maintenance and trouble-shooting are just some of the activities covered. Part Three contains case studies of projects currently in progress, giving details of the software available and the likely future trends. One of these, on qualitative plant modelling as a basis for knowledge-based operator aids in nuclear power stations is indexed separately. (author)

  20. 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...

  1. A code for optimising triplet layout

    CERN Document Server

    AUTHOR|(CDS)2141109; Seryi, Andrei; 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.

  2. 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....

  3. Dynamic optimisation of an industrial web process

    Directory of Open Access Journals (Sweden)

    M Soufian

    2008-09-01

    Full Text Available An industrial web process has been studied and it is shown that theunderlying physics of such processes governs by the Navier-Stokes partialdifferential equations with moving boundary conditions, which in turn have tobe determined by the solution of the thermodynamics equations. Thedevelopment of a two-dimensional continuous-discrete model structurebased on this study is presented. Other models are constructed based onthis model for better identification and optimisation purposes. Theparameters of the proposed models are then estimated using real dataobtained from the identification experiments with the process plant. Varioussimulation tests for validation are accompanied with the design, developmentand real-time industrial implementation of an optimal controller for dynamicoptimisation of this web process. It is shown that in comparison with thetraditional controller, the new controller resulted in a better performance, animprovement in film quality and saving in raw materials. This demonstrates theefficiency and validation of the developed models.

  4. Recent perspectives on optimisation of radiological protection

    International Nuclear Information System (INIS)

    Robb, J.D.; Croft, J.R.

    1992-01-01

    The ALARA principle as a requirement in radiological protection has evolved from its theoretical roots. Based on several years work, this paper provides a backdrop to practical approaches to ALARA for the 1990s. The key step, developing ALARA thinking so that it becomes an integral part of radiological protection programmes, is discussed using examples from the UK and France, as is the role of tools to help standardise judgements for decision-making. In its latest recommendations, ICRP have suggested that the optimisation of protection should be constrained by restrictions on the doses to individuals. This paper also considers the function of such restrictions for occupational, public and medical exposure, and in the design process. (author)

  5. Optimisation of parameters of DCD for PHWRs

    International Nuclear Information System (INIS)

    Velmurugan, S.; Sathyaseelan, V.S.; Narasimhan, S.V.; Mathur, P.K.

    1991-01-01

    Decontamination formulation based on EDTA, Oxalic acid, Citric acid was evaluated for its efficacy in removing oxide layers of PHWR. An ion exchange system which was specifically suitable for fission product dominated contamination in PHWRs was optimised for the reagent regeneration stage of the decontamination process. An analysis of the nature of the complexed metal species formed in the dissolution process and Electrochemical measurements were employed as a tool to follow the course of oxide removal during the dissolution process. An attempt was made to understand the redeposition behaviour of various isotopes during the decontamination process. SEM and ESCA studies of metal coupons before and after the dissolution process were used to analyse the deposits in the above context. The pick up of DCD reagents on the ion exchangers and material compatibility tests on Carbon steel, Monel-400 and Zircaloy-2 with the decontaminant under the conditions of decontamination experiment are reported. (author)

  6. Optimisation of Inulinase Production by Kluyveromyces bulgaricus

    Directory of Open Access Journals (Sweden)

    Darija Vranešić

    2002-01-01

    Full Text Available The present work is based on observation of the effects of pH and temperature of fermentation on the production of microbial enzyme inulinase by Kluyveromyces marxianus var. bulgaricus. Inulinase hydrolyzes inulin, a polysaccharide which can be isolated from plants such as Jerusalem artichoke, chicory or dahlia, and transformed into pure fructose or fructooligosaccharides. Fructooligosaccharides have great potential in food industry because they can be used as calorie-reduced compounds and noncariogenic sweeteners as well as soluble fibre and prebiotic compounds. Fructose formation from inulin is a single step enzymatic reaction and yields are up to 95 % the fructose. On the contrary, conventional fructose production from starch needs at least three enzymatic steps, yielding only 45 % of fructose. The process of inulinase production was optimised by using experimental design method. pH value of the cultivation medium showed to be the most significant variable and it should be maintained at optimum value of 3.6. The effect of temperature was slightly lower and optimal values were between 30 and 33 °C. At a low pH value of the cultivation medium, the microorganism was not able to producem enough enzyme and enzyme activities were low. Similar effect was caused by high temperature. The highest values of enzyme activities were achieved at optimal fermentation conditions and the values were: 100.16–124.36 IU/mL (with sucrose as substrate for determination of enzyme activity or 8.6–11.6 IU/mL (with inulin as substrate, respectively. The method of factorial design and response surface analysis makes it possible to study several factors simultaneously, to quantify the individual effect of each factor and to investigate their possible interactions. As a comparison to this method, optimisation of a physiological enzyme activity model depending on pH and temperature was also studied.

  7. MULTI-OBJECTIVE OPTIMISATION OF LASER CUTTING USING CUCKOO SEARCH ALGORITHM

    Directory of Open Access Journals (Sweden)

    M. MADIĆ

    2015-03-01

    Full Text Available Determining of optimal laser cutting conditions for improving cut quality characteristics is of great importance in process planning. This paper presents multi-objective optimisation of the CO2 laser cutting process considering three cut quality characteristics such as surface roughness, heat affected zone (HAZ and kerf width. It combines an experimental design by using Taguchi’s method, modelling the relationships between the laser cutting factors (laser power, cutting speed, assist gas pressure and focus position and cut quality characteristics by artificial neural networks (ANNs, formulation of the multiobjective optimisation problem using weighting sum method, and solving it by the novel meta-heuristic cuckoo search algorithm (CSA. The objective is to obtain optimal cutting conditions dependent on the importance order of the cut quality characteristics for each of four different case studies presented in this paper. The case studies considered in this study are: minimisation of cut quality characteristics with equal priority, minimisation of cut quality characteristics with priority given to surface roughness, minimisation of cut quality characteristics with priority given to HAZ, and minimisation of cut quality characteristics with priority given to kerf width. The results indicate that the applied CSA for solving the multi-objective optimisation problem is effective, and that the proposed approach can be used for selecting the optimal laser cutting factors for specific production requirements.

  8. Methodology for the economic optimisation of energy storage systems for frequency support in wind power plants

    International Nuclear Information System (INIS)

    Johnston, Lewis; Díaz-González, Francisco; Gomis-Bellmunt, Oriol; Corchero-García, Cristina; Cruz-Zambrano, Miguel

    2015-01-01

    Highlights: • Optimisation of energy storage system with wind power plant for frequency response. • Energy storage option considered could be economically viable. • For a 50 MW wind farm, an energy storage system of 5.3 MW and 3 MW h was found. - Abstract: This paper proposes a methodology for the economic optimisation of the sizing of Energy Storage Systems (ESSs) whilst enhancing the participation of Wind Power Plants (WPP) in network primary frequency control support. The methodology was designed flexibly, so it can be applied to different energy markets and to include different ESS technologies. The methodology includes the formulation and solving of a Linear Programming (LP) problem. The methodology was applied to the particular case of a 50 MW WPP, equipped with a Vanadium Redox Flow battery (VRB) in the UK energy market. Analysis is performed considering real data on the UK regular energy market and the UK frequency response market. Data for wind power generation and energy storage costs are estimated from literature. Results suggest that, under certain assumptions, ESSs can be profitable for the operator of a WPP that is providing frequency response. The ESS provides power reserves such that the WPP can generate close to the maximum energy available. The solution of the optimisation problem establishes that an ESS with a power rating of 5.3 MW and energy capacity of about 3 MW h would be enough to provide such service whilst maximising the incomes for the WPP operator considering the regular and frequency regulation UK markets

  9. Optimisation on processing parameters for minimising warpage on side arm using response surface methodology (RSM) and particle swarm optimisation (PSO)

    Science.gov (United States)

    Rayhana, N.; Fathullah, M.; Shayfull, Z.; Nasir, S. M.; Hazwan, M. H. M.; Sazli, M.; Yahya, Z. R.

    2017-09-01

    This study presents the application of optimisation method to reduce the warpage of side arm part. Autodesk Moldflow Insight software was integrated into this study to analyse the warpage. The design of Experiment (DOE) for Response Surface Methodology (RSM) was constructed and by using the equation from RSM, Particle Swarm Optimisation (PSO) was applied. The optimisation method will result in optimised processing parameters with minimum warpage. Mould temperature, melt temperature, packing pressure, packing time and cooling time was selected as the variable parameters. Parameters selection was based on most significant factor affecting warpage stated by previous researchers. The results show that warpage was improved by 28.16% for RSM and 28.17% for PSO. The warpage improvement in PSO from RSM is only by 0.01 %. Thus, the optimisation using RSM is already efficient to give the best combination parameters and optimum warpage value for side arm part. The most significant parameters affecting warpage are packing pressure.

  10. Seasonal optimisation of panel surfaces in a photovoltaic plant; Optimisation saisonniere de la surface des panneaux dans une installation photovoltaique

    Energy Technology Data Exchange (ETDEWEB)

    Affolter, P.; Keller, L. [Bureau d`Etudes Keller-Burnier, Lavigny (CH)

    1991-02-01

    By carefully calculating the panel surface in a photovoltaic plant connected to the network, energy can be obtained at a minimum cost price. This has been discussed in a survey entitled `Optimisating the surface of photo= voltaic panels according to the static inverter`. This survey does not however describe how the price of energy varies during the year. This gap is filled by the present work which is helping show how to make optimum calculations in winter. Most of the simulations made during the course of the first study have been repeated. This has allowed new elements to be brought in. One example is the importance of the crystalline cell output-temperature characteristic. It is noted that the winter potential of a photovoltaic plant is greater than that of a solar power plant. This study has also facilitated better definition of the behaviour of the plant`s production-surface characteristic. This shows the importance of having a static inverter capable, in the event of intense periods of sunshine, of limiting the energy injected at rated power. Many parametric studies are helping to show the important parameters of this type of plant for the period from October to March. figs., 3 refs.

  11. A COMPARATIVE STUDY ON MULTI-SWARM OPTIMISATION AND BAT ALGORITHM FOR UNCONSTRAINED NON LINEAR OPTIMISATION PROBLEMS

    Directory of Open Access Journals (Sweden)

    Evans BAIDOO

    2016-12-01

    Full Text Available A study branch that mocks-up a population of network of swarms or agents with the ability to self-organise is Swarm intelligence. In spite of the huge amount of work that has been done in this area in both theoretically and empirically and the greater success that has been attained in several aspects, it is still ongoing and at its infant stage. An immune system, a cloud of bats, or a flock of birds are distinctive examples of a swarm system. . In this study, two types of meta-heuristics algorithms based on population and swarm intelligence - Multi Swarm Optimization (MSO and Bat algorithms (BA - are set up to find optimal solutions of continuous non-linear optimisation models. In order to analyze and compare perfect solutions at the expense of performance of both algorithms, a chain of computational experiments on six generally used test functions for assessing the accuracy and the performance of algorithms, in swarm intelligence fields are used. Computational experiments show that MSO algorithm seems much superior to BA.

  12. AllAboard: Visual Exploration of Cellphone Mobility Data to Optimise Public Transport.

    Science.gov (United States)

    Di Lorenzo, G; Sbodio, M; Calabrese, F; Berlingerio, M; Pinelli, F; Nair, R

    2016-02-01

    The deep penetration of mobile phones offers cities the ability to opportunistically monitor citizens' mobility and use data-driven insights to better plan and manage services. With large scale data on mobility patterns, operators can move away from the costly, mostly survey based, transportation planning processes, to a more data-centric view, that places the instrumented user at the center of development. In this framework, using mobile phone data to perform transit analysis and optimization represents a new frontier with significant societal impact, especially in developing countries. In this paper we present AllAboard, an intelligent tool that analyses cellphone data to help city authorities in visually exploring urban mobility and optimizing public transport. This is performed within a self contained tool, as opposed to the current solutions which rely on a combination of several distinct tools for analysis, reporting, optimisation and planning. An interactive user interface allows transit operators to visually explore the travel demand in both space and time, correlate it with the transit network, and evaluate the quality of service that a transit network provides to the citizens at very fine grain. Operators can visually test scenarios for transit network improvements, and compare the expected impact on the travellers' experience. The system has been tested using real telecommunication data for the city of Abidjan, Ivory Coast, and evaluated from a data mining, optimisation and user prospective.

  13. Design optimisation of a flywheel hybrid vehicle

    Energy Technology Data Exchange (ETDEWEB)

    Kok, D.B.

    1999-11-04

    This thesis describes the design optimisation of a flywheel hybrid vehicle with respect to fuel consumption and exhaust gas emissions. The driveline of this passenger car uses two power sources: a small spark ignition internal combustion engine with three-way catalyst, and a highspeed flywheel system for kinetic energy storage. A custom-made continuously variable transmission (CVT) with so-called i{sup 2} control transports energy between these power sources and the vehicle wheels. The driveline includes auxiliary systems for hydraulic, vacuum and electric purposes. In this fully mechanical driveline, parasitic energy losses determine the vehicle's fuel saving potential to a large extent. Practicable energy loss models have been derived to quantify friction losses in bearings, gearwheels, the CVT, clutches and dynamic seals. In addition, the aerodynamic drag in the flywheel system and power consumption of auxiliaries are charted. With the energy loss models available, a calculation procedure is introduced to optimise the flywheel as a subsystem in which the rotor geometry, the safety containment, and the vacuum system are designed for minimum energy use within the context of automotive applications. A first prototype of the flywheel system was tested experimentally and subsequently redesigned to improve rotordynamics and safety aspects. Coast-down experiments with the improved version show that the energy losses have been lowered significantly. The use of a kinetic energy storage device enables the uncoupling of vehicle wheel power and engine power. Therefore, the engine can be smaller and it can be chosen to operate in its region of best efficiency in start-stop mode. On a test-rig, the measured engine fuel consumption was reduced with more than 30 percent when the engine is intermittently restarted with the aid of the flywheel system. Although the start-stop mode proves to be advantageous for fuel consumption, exhaust gas emissions increase temporarily

  14. 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)

  15. 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...

  16. Protection against natural radiation: Optimisation and decision exercises

    International Nuclear Information System (INIS)

    O'Riordan, M.C.

    1984-02-01

    Six easy exercises are presented in which cost-benefit analysis is used to optimise protection against natural radiation or to decide whether protection is appropriate. The exercises are illustrative only and do not commit the Board. (author)

  17. Optimisation of wheat-sprouted soybean flour bread using response ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-11-16

    Nov 16, 2009 ... Full Length Research Paper. Optimisation of ... Victoria A. Jideani1* and Felix C. Onwubali2. 1Department of Food Technology, Cape Peninsula University of Technology, P. O. Box 652, Cape Town 8000, South. Africa.

  18. Optimised intake stroke analysis for flat and dome head pistons ...

    African Journals Online (AJOL)

    Optimised intake stroke analysis for flat and dome head pistons. ... in understanding the performance characteristics optioned between flat head and dome head pistons in engine design. ... EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT

  19. Distributed optimisation problem with communication delay and external disturbance

    Science.gov (United States)

    Tran, Ngoc-Tu; Xiao, Jiang-Wen; Wang, Yan-Wu; Yang, Wu

    2017-12-01

    This paper investigates the distributed optimisation problem for the multi-agent systems (MASs) with the simultaneous presence of external disturbance and the communication delay. To solve this problem, a two-step design scheme is introduced. In the first step, based on the internal model principle, the internal model term is constructed to compensate the disturbance asymptotically. In the second step, a distributed optimisation algorithm is designed to solve the distributed optimisation problem based on the MASs with the simultaneous presence of disturbance and communication delay. Moreover, in the proposed algorithm, each agent interacts with its neighbours through the connected topology and the delay occurs during the information exchange. By utilising Lyapunov-Krasovskii functional, the delay-dependent conditions are derived for both slowly and fast time-varying delay, respectively, to ensure the convergence of the algorithm to the optimal solution of the optimisation problem. Several numerical simulation examples are provided to illustrate the effectiveness of the theoretical results.

  20. Shape optimisation and performance analysis of flapping wings

    KAUST Repository

    Ghommem, Mehdi; Collier, Nathan; Niemi, Antti; Calo, Victor M.

    2012-01-01

    optimised shapes produce efficient flapping flights, the wake pattern and its vorticity strength are examined. This work described in this paper should facilitate better guidance for shape design of engineered flying systems.

  1. 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.

  2. Optimising a fall out dust monitoring sampling programme at a ...

    African Journals Online (AJOL)

    GREG

    Key words: Fall out dust monitoring, cement plant, optimising, air pollution sampling, fall out dust sampler locations. .... applied for those areas where controls are in place. Sampling ..... mass balance in the total cement manufacturing process.

  3. Issues with performance measures for dynamic multi-objective optimisation

    CSIR Research Space (South Africa)

    Helbig, M

    2013-06-01

    Full Text Available Symposium on Computational Intelligence in Dynamic and Uncertain Environments (CIDUE), Mexico, 20-23 June 2013 Issues with Performance Measures for Dynamic Multi-objective Optimisation Mard´e Helbig CSIR: Meraka Institute Brummeria, South Africa...

  4. Optimisation Study on the Production of Anaerobic Digestate ...

    African Journals Online (AJOL)

    DR. AMIN

    optimise the production of ADC from organic fractions of domestic wastes and the effects of ADC amendments on soil .... (22%), cooked meat (9%), lettuce (11%), carrots. (3%), potato (44%) ... seed was obtained from a mesophilic anaerobic.

  5. Algorithm for optimisation of paediatric chest radiography

    International Nuclear Information System (INIS)

    Kostova-Lefterova, D.

    2016-01-01

    The purpose of this work is to assess the current practice and patient doses in paediatric chest radiography in a large university hospital. The X-ray unit is used in the paediatric department for respiratory diseases. Another purpose was to recommend and apply optimized protocols to reduce patient dose while maintaining diagnostic image quality for the x-ray images. The practice of two different radiographers was studied. The results were compared with the existing practice in paediatric chest radiography and the opportunities for optimization were identified in order to reduce patient doses. A methodology was developed for optimization of the x-ray examinations by grouping children in age groups or according to other appropriate indication and creating an algorithm for proper selection of the exposure parameters for each group. The algorithm for the optimisation of paediatric chest radiography reduced patient doses (PKA, organ dose, effective dose) between 1.5 and 6 times for the different age groups, the average glandular dose up to 10 times and the dose for the lung between 2 and 5 times. The resulting X-ray images were of good diagnostic quality. The subjectivity in the choice of exposure parameters was reduced and standardization has been achieved in the work of the radiographers. The role of the radiologist, the medical physicist and radiographer in the process of optimization was shown. It was proven the effect of teamwork in reducing patient doses at keeping adequate image quality. Key words: Chest Radiography. Paediatric Radiography. Optimization. Radiation Exposure. Radiation Protection

  6. 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.

  7. Optimising Boltzmann codes for the PLANCK era

    International Nuclear Information System (INIS)

    Hamann, Jan; Lesgourgues, Julien; Balbi, Amedeo; Quercellini, Claudia

    2009-01-01

    High precision measurements of the Cosmic Microwave Background (CMB) anisotropies, as can be expected from the PLANCK satellite, will require high-accuracy theoretical predictions as well. One possible source of theoretical uncertainty is the numerical error in the output of the Boltzmann codes used to calculate angular power spectra. In this work, we carry out an extensive study of the numerical accuracy of the public Boltzmann code CAMB, and identify a set of parameters which determine the error of its output. We show that at the current default settings, the cosmological parameters extracted from data of future experiments like Planck can be biased by several tenths of a standard deviation for the six parameters of the standard ΛCDM model, and potentially more seriously for extended models. We perform an optimisation procedure that leads the code to achieve sufficient precision while at the same time keeping the computation time within reasonable limits. Our conclusion is that the contribution of numerical errors to the theoretical uncertainty of model predictions is well under control—the main challenges for more accurate calculations of CMB spectra will be of an astrophysical nature instead

  8. Geometrical exploration of a flux-optimised sodium receiver through multi-objective optimisation

    Science.gov (United States)

    Asselineau, Charles-Alexis; Corsi, Clothilde; Coventry, Joe; Pye, John

    2017-06-01

    A stochastic multi-objective optimisation method is used to determine receiver geometries with maximum second law efficiency, minimal average temperature and minimal surface area. The method is able to identify a set of Pareto optimal candidates that show advantageous geometrical features, mainly in being able to maximise the intercepted flux within the geometrical boundaries set. Receivers with first law thermal efficiencies ranging from 87% to 91% are also evaluated using the second law of thermodynamics and found to have similar efficiencies of over 60%, highlighting the influence that the geometry can play in the maximisation of the work output of receivers by influencing the distribution of the flux from the concentrator.

  9. Intelligent Support for a Computer Aided Design Optimisation Cycle

    OpenAIRE

    B. Dolšak; M. Novak; J. Kaljun

    2006-01-01

    It is becoming more and more evident that  adding intelligence  to existing computer aids, such as computer aided design systems, can lead to significant improvements in the effective and reliable performance of various engineering tasks, including design optimisation. This paper presents three different intelligent modules to be applied within a computer aided design optimisation cycle to enable more intelligent and less experience-dependent design performance. 

  10. 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

  11. OPTIMISATION OF A DRIVE SYSTEM AND ITS EPICYCLIC GEAR SET

    OpenAIRE

    Bellegarde , Nicolas; Dessante , Philippe; Vidal , Pierre; Vannier , Jean-Claude

    2007-01-01

    International audience; This paper describes the design of a drive consisting of a DC motor, a speed reducer, a lead screw transformation system, a power converter and its associated DC source. The objective is to reduce the mass of the system. Indeed, the volume and weight optimisation of an electrical drive is an important issue for embedded applications. Here, we present an analytical model of the system in a specific application and afterwards an optimisation of the motor and speed reduce...

  12. 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.

  13. Design of optimised backstepping controller for the synchronisation of chaotic Colpitts oscillator using shark smell algorithm

    Science.gov (United States)

    Fouladi, Ehsan; Mojallali, Hamed

    2018-01-01

    In this paper, an adaptive backstepping controller has been tuned to synchronise two chaotic Colpitts oscillators in a master-slave configuration. The parameters of the controller are determined using shark smell optimisation (SSO) algorithm. Numerical results are presented and compared with those of particle swarm optimisation (PSO) algorithm. Simulation results show better performance in terms of accuracy and convergence for the proposed optimised method compared to PSO optimised controller or any non-optimised backstepping controller.

  14. Model-Free Trajectory Optimisation for Unmanned Aircraft Serving as Data Ferries for Widespread Sensors

    Directory of Open Access Journals (Sweden)

    Ben Pearre

    2012-10-01

    Full Text Available Given multiple widespread stationary data sources such as ground-based sensors, an unmanned aircraft can fly over the sensors and gather the data via a wireless link. Performance criteria for such a network may incorporate costs such as trajectory length for the aircraft or the energy required by the sensors for radio transmission. Planning is hampered by the complex vehicle and communication dynamics and by uncertainty in the locations of sensors, so we develop a technique based on model-free learning. We present a stochastic optimisation method that allows the data-ferrying aircraft to optimise data collection trajectories through an unknown environment in situ, obviating the need for system identification. We compare two trajectory representations, one that learns near-optimal trajectories at low data requirements but that fails at high requirements, and one that gives up some performance in exchange for a data collection guarantee. With either encoding the ferry is able to learn significantly improved trajectories compared with alternative heuristics. To demonstrate the versatility of the model-free learning approach, we also learn a policy to minimise the radio transmission energy required by the sensor nodes, allowing prolonged network lifetime.

  15. 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.

  16. Optimisation of integrated energy and materials systems

    International Nuclear Information System (INIS)

    Gielen, D.J.; Okken, P.A.

    1994-06-01

    To define cost-effective long term CO2 reduction strategies an integrated energy and materials system model for the Netherlands for the period 2000-2040 is developed. The model is based upon the energy system model MARKAL, which configures an optimal mix of technologies to satisfy the specified energy and product/materials service demands. This study concentrates on CO 2 emission reduction in the materials system. For this purpose, the energy system model is enlarged with a materials system model including all steps 'from cradle to grave'. The materials system model includes 29 materials, 20 product groups and 30 waste materials. The system is divided into seven types of technologies; 250 technologies are modeled. The results show that the integrated optimisation of the energy system and the materials system can significantly reduce the emission reduction costs, especially at higher reduction percentages. The reduction is achieved through shifts in materials production and waste handling and through materials substitution in products. Shifts in materials production and waste management seem cost-effective, while the cost-effectiveness of shifts in product composition is sensitive due to the cost structure of products. For the building sector, transportation applications and packaging, CO 2 policies show a significant impact on prices, and shifts in product composition could occur. For other products, the reduction through materials substitution seems less promising. The impact on materials consumption seems most significant for cement (reduced), timber and aluminium (both increased). For steel and plastics, the net effect is balanced, but shifts between applications do occur. The MARKAL-approach is feasible to study integrated energy and materials systems. The progress compared to other environmental system analysis instruments is much more insight in the interaction of technologies on a national scale and in time

  17. An approach to next step device optimisation

    International Nuclear Information System (INIS)

    Salpietro, E.

    2000-01-01

    The requirements for ITER EDA were to achieve ignition with a good safety margin, and controlled long inductive burn. These requirements lead to a big device, which requested a too ambitious step to be undertaken by the world fusion community. More realistic objectives for a next step device shall be to demonstrate the net production of energy with a high energy gain factor (Q) and a high boot strap current fraction (>60%) which is required for a Fusion Power Plant (FPP). The Next Step Device (NSD) shall also allow operation flexibility in order to explore a large range of plasma parameters to find out the optimum concept for the fusion power plant prototype. These requirements could be too demanding for one single device and could probably be better explored in a strongly integrated world programme. The cost of one or more devices is the decisive factor for the choice of the fusion power development programme strategy. The plasma elongation and triangularity have a strong impact in the cost of the device and are limited by the plasma vertical position control issue. The distance between plasma separatrix and the toroidal field conductor does not vary a lot between devices. It is determined by the sum of the distance between first wall-plasma sepratrix and the thickness of the nuclear shield required to protect the toroidal field coil insultation. The thickness of the TF coil is determined by the allowable stresses and superconducting characteristics. The outer radius of the central solenoid is the result of an optimisation to provide the magnetic flux to inductively drive the plasma. Therefore, in order to achieve the objectives for Q and boot-strap current fractions at the minimum cost, the plasma aspect ratio and magnetic field value shall be determined. The paper will present the critical issues for the next device and will make considerations on the optimal way to proceed towards the realisation of the fusion power plant

  18. Optimisation of material discrimination using spectral CT

    International Nuclear Information System (INIS)

    Nik, S.J.; Meyer, J.; Watts, R.

    2010-01-01

    Full text: Spectral computed tomography (CT) using novel X-ray photon counting detectors (PCDs) with energy resolving capabilities is capable of providing energy-selective images. This extra energy information may allow materials such as iodine and calcium, or water and fat to be distinguished. PCDs have energy thresholds, enabling the classification of photons into multiple energy bins. The inform tion content of spectral CT images depends on how the photons are grouped together. [n this work, a method is presented to optimise energy windows for maximum material discrimination. Given a combination of thicknesses, the reference number of expected photons in each energy bin is computed using the Bee Lambert equation. A similar calculation is performed for an exhaustive range of thicknesses and the number of photons in each case is com pared to the reference, allowing a statistical map of the uncertainty in thickness parameters to be constructed. The 63%-confidence region in the two-dimensional thickness space is a representation of how optimal the bins are for material separation. The model is demonstrated with 0.1 mm of iodine and 2.2 mm of calcium using two adjacent bins encompassing the entire energy range. Bins bordering at the iodine k-edge of 33.2 keY are found to be optimal. When compared to two abutted energy bins with equal incident counts as used in the literature (bordering at 54 keY), the thickness uncertainties are reduced from approximately 4% to less than I % (see Figure). This approach has been developed for two materials and is expandable to an arbitrary number of materials and bins.

  19. Algorithme intelligent d'optimisation d'un design structurel de grande envergure

    Science.gov (United States)

    Dominique, Stephane

    The implementation of an automated decision support system in the field of design and structural optimisation can give a significant advantage to any industry working on mechanical designs. Indeed, by providing solution ideas to a designer or by upgrading existing design solutions while the designer is not at work, the system may reduce the project cycle time, or allow more time to produce a better design. This thesis presents a new approach to automate a design process based on Case-Based Reasoning (CBR), in combination with a new genetic algorithm named Genetic Algorithm with Territorial core Evolution (GATE). This approach was developed in order to reduce the operating cost of the process. However, as the system implementation cost is quite expensive, the approach is better suited for large scale design problem, and particularly for design problems that the designer plans to solve for many different specification sets. First, the CBR process uses a databank filled with every known solution to similar design problems. Then, the closest solutions to the current problem in term of specifications are selected. After this, during the adaptation phase, an artificial neural network (ANN) interpolates amongst known solutions to produce an additional solution to the current problem using the current specifications as inputs. Each solution produced and selected by the CBR is then used to initialize the population of an island of the genetic algorithm. The algorithm will optimise the solution further during the refinement phase. Using progressive refinement, the algorithm starts using only the most important variables for the problem. Then, as the optimisation progress, the remaining variables are gradually introduced, layer by layer. The genetic algorithm that is used is a new algorithm specifically created during this thesis to solve optimisation problems from the field of mechanical device structural design. The algorithm is named GATE, and is essentially a real number

  20. 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....... Accordingly, two novel optimisation configurations are developed, where the optimisation either acts on the actuators or acts on the regulatory control layer. These two optimisation designs are evaluated on a sub-catchment of the sewer system in Copenhagen, and found to perform better than the existing...

  1. Robustness analysis of bogie suspension components Pareto optimised values

    Science.gov (United States)

    Mousavi Bideleh, Seyed Milad

    2017-08-01

    Bogie suspension system of high speed trains can significantly affect vehicle performance. Multiobjective optimisation problems are often formulated and solved to find the Pareto optimised values of the suspension components and improve cost efficiency in railway operations from different perspectives. Uncertainties in the design parameters of suspension system can negatively influence the dynamics behaviour of railway vehicles. In this regard, robustness analysis of a bogie dynamics response with respect to uncertainties in the suspension design parameters is considered. A one-car railway vehicle model with 50 degrees of freedom and wear/comfort Pareto optimised values of bogie suspension components is chosen for the analysis. Longitudinal and lateral primary stiffnesses, longitudinal and vertical secondary stiffnesses, as well as yaw damping are considered as five design parameters. The effects of parameter uncertainties on wear, ride comfort, track shift force, stability, and risk of derailment are studied by varying the design parameters around their respective Pareto optimised values according to a lognormal distribution with different coefficient of variations (COVs). The robustness analysis is carried out based on the maximum entropy concept. The multiplicative dimensional reduction method is utilised to simplify the calculation of fractional moments and improve the computational efficiency. The results showed that the dynamics response of the vehicle with wear/comfort Pareto optimised values of bogie suspension is robust against uncertainties in the design parameters and the probability of failure is small for parameter uncertainties with COV up to 0.1.

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

    International Nuclear Information System (INIS)

    Baath, M.; Haakansson, M.; Hansson, J.; Maansson, L. G.

    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. (authors)

  3. Establishing Local Reference Dose Values and Optimisation Strategies

    International Nuclear Information System (INIS)

    Connolly, P.; Moores, B.M.

    2000-01-01

    The revised EC Patient Directive 97/43 EURATOM introduces the concepts of clinical audit, diagnostic reference levels and optimisation of radiation protection in diagnostic radiology. The application of reference dose levels in practice involves the establishment of reference dose values as actual measurable operational quantities. These values should then form part of an ongoing optimisation and audit programme against which routine performance can be compared. The CEC Quality Criteria for Radiographic Images provides guidance reference dose values against which local performance can be compared. In many cases these values can be improved upon quite considerably. This paper presents the results of a local initiative in the North West of the UK aimed at establishing local reference dose values for a number of major hospital sites. The purpose of this initiative is to establish a foundation for both optimisation strategies and clinical audit as an ongoing and routine practice. The paper presents results from an ongoing trial involving patient dose measurements for several radiological examinations upon the sites. The results of an attempt to establish local reference dose values from measured dose values and to employ them in optimisation strategies are presented. In particular emphasis is placed on the routine quality control programmes necessary to underpin this strategy including the effective data management of results from such programmes and how they can be employed to optimisation practices. (author)

  4. Data for TROTS – The Radiotherapy Optimisation Test Set

    Directory of Open Access Journals (Sweden)

    Sebastiaan Breedveld

    2017-06-01

    Full Text Available The Radiotherapy Optimisation Test Set (TROTS is an extensive set of problems originating from radiotherapy (radiation therapy treatment planning. This dataset is created for 2 purposes: (1 to supply a large-scale dense dataset to measure performance and quality of mathematical solvers, and (2 to supply a dataset to investigate the multi-criteria optimisation and decision-making nature of the radiotherapy problem. The dataset contains 120 problems (patients, divided over 6 different treatment protocols/tumour types. Each problem contains numerical data, a configuration for the optimisation problem, and data required to visualise and interpret the results. The data is stored as HDF5 compatible Matlab files, and includes scripts to work with the dataset.

  5. CLIC crab cavity design optimisation for maximum luminosity

    Energy Technology Data Exchange (ETDEWEB)

    Dexter, A.C., E-mail: a.dexter@lancaster.ac.uk [Lancaster University, Lancaster, LA1 4YR (United Kingdom); Cockcroft Institute, Daresbury, Warrington, WA4 4AD (United Kingdom); Burt, G.; Ambattu, P.K. [Lancaster University, Lancaster, LA1 4YR (United Kingdom); Cockcroft Institute, Daresbury, Warrington, WA4 4AD (United Kingdom); Dolgashev, V. [SLAC, Menlo Park, CA 94025 (United States); Jones, R. [University of Manchester, Manchester, M13 9PL (United Kingdom)

    2011-11-21

    The bunch size and crossing angle planned for CERN's compact linear collider CLIC dictate that crab cavities on opposing linacs will be needed to rotate bunches of particles into alignment at the interaction point if the desired luminosity is to be achieved. Wakefield effects, RF phase errors between crab cavities on opposing linacs and unpredictable beam loading can each act to reduce luminosity below that anticipated for bunches colliding in perfect alignment. Unlike acceleration cavities, which are normally optimised for gradient, crab cavities must be optimised primarily for luminosity. Accepting the crab cavity technology choice of a 12 GHz, normal conducting, travelling wave structure as explained in the text, this paper develops an analytical approach to optimise cell number and iris diameter.

  6. Cultural-based particle swarm for dynamic optimisation problems

    Science.gov (United States)

    Daneshyari, Moayed; Yen, Gary G.

    2012-07-01

    Many practical optimisation problems are with the existence of uncertainties, among which a significant number belong to the dynamic optimisation problem (DOP) category in which the fitness function changes through time. In this study, we propose the cultural-based particle swarm optimisation (PSO) to solve DOP problems. A cultural framework is adopted incorporating the required information from the PSO into five sections of the belief space, namely situational, temporal, domain, normative and spatial knowledge. The stored information will be adopted to detect the changes in the environment and assists response to the change through a diversity-based repulsion among particles and migration among swarms in the population space, and also helps in selecting the leading particles in three different levels, personal, swarm and global levels. Comparison of the proposed heuristics over several difficult dynamic benchmark problems demonstrates the better or equal performance with respect to most of other selected state-of-the-art dynamic PSO heuristics.

  7. The principle of optimisation: reasons for success and legal criticism

    International Nuclear Information System (INIS)

    Fernandez Regalado, Luis

    2008-01-01

    The International Commission on Radiological Protection (ICRP) has adopted new recommendations in 2007. In broad outlines they fundamentally continue the recommendations already approved in 1990 and later on. The principle of optimisation of protection, together with the principles of justification and dose limits, remains playing a key role of the ICRP recommendations, and it has so been for the last few years. This principle, somehow reinforced in the 2007 ICRP recommendations, has been incorporated into norms and legislation which have peacefully been in force in many countries all over the world. There are three main reasons to explain the success in the application of the principle of optimisation in radiological protection: First, the subjectivity of the sentence that embraces the principle of optimisation, 'As low as reasonably achievable' (ALARA), that allows different valid interpretations under different circumstances. Second, the pragmatism and adaptability of ALARA to all exposure situations. And third, the scientific humbleness which is behind the principle of optimisation, which makes a clear contrast with the old fashioned scientific positivism that enshrined scientist opinions. Nevertheless, from a legal point of view, there is some criticism cast over the principle of optimisation in radiological protection, where it has been transformed in compulsory norm. This criticism is based on two arguments: The lack of democratic participation in the process of elaboration of the norm, and the legal uncertainty associated to its application. Both arguments are somehow known by the ICRP which, on the one hand, has broadened the participation of experts, associations and the professional radiological protection community, increasing the transparency on how decisions on recommendations have been taken, and on the other hand, the ICRP has warned about the need for authorities to specify general criteria to develop the principle of optimisation in national

  8. Optimisation in X-ray and Molecular Imaging 2015

    International Nuclear Information System (INIS)

    Baath, Magnus; Hoeschen, Christoph; Mattsson, Soeren; Mansson, Lars Gunnar

    2016-01-01

    This issue of Radiation Protection Dosimetry is based on contributions to Optimisation in X-ray and Molecular Imaging 2015 - the 4. Malmoe Conference on Medical Imaging (OXMI 2015). The conference was jointly organised by members of former and current research projects supported by the European Commission EURATOM Radiation Protection Research Programme, in cooperation with the Swedish Society for Radiation Physics. The conference brought together over 150 researchers and other professionals from hospitals, universities and industries with interests in different aspects of the optimisation of medical imaging. More than 100 presentations were given at this international gathering of medical physicists, radiologists, engineers, technicians, nurses and educational researchers. Additionally, invited talks were offered by world-renowned experts on radiation protection, spectral imaging and medical image perception, thus covering several important aspects of the generation and interpretation of medical images. The conference consisted of 13 oral sessions and a poster session, as reflected by the conference title connected by their focus on the optimisation of the use ionising radiation in medical imaging. The conference included technology-specific topics such as computed tomography and tomosynthesis, but also generic issues of interest for the optimisation of all medical imaging, such as image perception and quality assurance. Radiation protection was covered by e.g. sessions on patient dose benchmarking and occupational exposure. Technically-advanced topics such as modelling, Monte Carlo simulation, reconstruction, classification, and segmentation were seen taking advantage of recent developments of hardware and software, showing that the optimisation community is at the forefront of technology and adapts well to new requirements. These peer-reviewed proceedings, representing a continuation of a series of selected reports from meetings in the field of medical imaging

  9. 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...

  10. 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.

  11. 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.

  12. MANAGEMENT OPTIMISATION OF MASS CUSTOMISATION MANUFACTURING USING COMPUTATIONAL INTELLIGENCE

    Directory of Open Access Journals (Sweden)

    Louwrens Butler

    2018-05-01

    Full Text Available Computational intelligence paradigms can be used for advanced manufacturing system optimisation. A static simulation model of an advanced manufacturing system was developed in order to simulate a manufacturing system. The purpose of this advanced manufacturing system was to mass-produce a customisable product range at a competitive cost. The aim of this study was to determine whether this new algorithm could produce a better performance than traditional optimisation methods. The algorithm produced a lower cost plan than that for a simulated annealing algorithm, and had a lower impact on the workforce.

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

    Directory of Open Access Journals (Sweden)

    María Alejandra Guzmán

    2005-05-01

    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.

  14. The optimisation study of tbp synthesis process by phosphoric acid

    International Nuclear Information System (INIS)

    Amedjkouh, A.; Attou, M.; Azzouz, A.; Zaoui, B.

    1995-07-01

    The present work deals with the optimisation study of TBP synthesis process by phosphoric acid. This way of synthesis is more advantageous than POCL3 or P2O5 as phosphatant agents. these latters are toxic and dangerous for the environnement. The optimisation study is based on a series of 16 experiences taking into account the range of variation of the following parameters : temperature, pressure, reagents mole ratio, promoter content. the yield calculation is based on the randomisation of an equation including all parameters. the resolution of this equation gave a 30% TBP molar ratio. this value is in agreement with that of experimental data

  15. 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...... for synthesized BPMN components, based on probabilistic computation tree logic and real-valued reward structures of the BPMN model, allowing for the specification of complex quantitative goals. We here present a simple algorithm, inspired by concepts from evolutionary algorithms, which iteratively generates...

  16. The optimisation of wedge filters in radiotherapy of the prostate

    International Nuclear Information System (INIS)

    Oldham, Mark; Neal, Anthony J.; Webb, Steve

    1995-01-01

    A treatment plan optimisation algorithm has been applied to 12 patients with early prostate cancer in order to determine the optimum beam-weights and wedge angles for a standard conformal three-field treatment technique. The optimisation algorithm was based on fast-simulated-annealing using a cost function designed to achieve a uniform dose in the planning-target-volume (PTV) and to minimise the integral doses to the organs-at-risk. The algorithm has been applied to standard conformal three-field plans created by an experienced human planner, and run in three PLAN MODES: (1) where the wedge angles were fixed by the human planner and only the beam-weights were optimised; (2) where both the wedge angles and beam-weights were optimised; and (3) where both the wedge angles and beam-weights were optimised and a non-uniform dose was prescribed to the PTV. In the latter PLAN MODE, a uniform 100% dose was prescribed to all of the PTV except for that region that overlaps with the rectum where a lower (e.g., 90%) dose was prescribed. The resulting optimised plans have been compared with those of the human planner who found beam-weights by conventional forward planning techniques. Plans were compared on the basis of dose statistics, normal-tissue-complication-probability (NTCP) and tumour-control-probability (TCP). The results of the comparison showed that all three PLAN MODES produced plans with slightly higher TCP for the same rectal NTCP, than the human planner. The best results were observed for PLAN MODE 3, where an average increase in TCP of 0.73% (± 0.20, 95% confidence interval) was predicted by the biological models. This increase arises from a beneficial dose gradient which is produced across the tumour. Although the TCP gain is small it comes with no increase in treatment complexity, and could translate into increased cures given the large numbers of patients being referred. A study of the beam-weights and wedge angles chosen by the optimisation algorithm revealed

  17. 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.

  18. Time varying acceleration coefficients particle swarm optimisation (TVACPSO): A new optimisation algorithm for estimating parameters of PV cells and modules

    International Nuclear Information System (INIS)

    Jordehi, Ahmad Rezaee

    2016-01-01

    Highlights: • A modified PSO has been proposed for parameter estimation of PV cells and modules. • In the proposed modified PSO, acceleration coefficients are changed during run. • The proposed modified PSO mitigates premature convergence problem. • Parameter estimation problem has been solved for both PV cells and PV modules. • The results show that proposed PSO outperforms other state of the art algorithms. - Abstract: Estimating circuit model parameters of PV cells/modules represents a challenging problem. PV cell/module parameter estimation problem is typically translated into an optimisation problem and is solved by metaheuristic optimisation problems. Particle swarm optimisation (PSO) is considered as a popular and well-established optimisation algorithm. Despite all its advantages, PSO suffers from premature convergence problem meaning that it may get trapped in local optima. Personal and social acceleration coefficients are two control parameters that, due to their effect on explorative and exploitative capabilities, play important roles in computational behavior of PSO. In this paper, in an attempt toward premature convergence mitigation in PSO, its personal acceleration coefficient is decreased during the course of run, while its social acceleration coefficient is increased. In this way, an appropriate tradeoff between explorative and exploitative capabilities of PSO is established during the course of run and premature convergence problem is significantly mitigated. The results vividly show that in parameter estimation of PV cells and modules, the proposed time varying acceleration coefficients PSO (TVACPSO) offers more accurate parameters than conventional PSO, teaching learning-based optimisation (TLBO) algorithm, imperialistic competitive algorithm (ICA), grey wolf optimisation (GWO), water cycle algorithm (WCA), pattern search (PS) and Newton algorithm. For validation of the proposed methodology, parameter estimation has been done both for

  19. DevOps for network function virtualisation: an architectural approach

    OpenAIRE

    Karl, H.; Draexler, S.; Peuster, M.; Galis, A.; Bredel, M.; Ramos, A.; Martrat, J.; Siddiqui, M. S.; Van Rossem, S.; Tavernier, W.; Xilouris, G.

    2016-01-01

    The Service Programming and Orchestration for Virtualised Software Networks (SONATA) project targets both the flexible programmability of software networks and the optimisation of their deployments by means of integrating Development and Operations in order to accelerate industry adoption of software networks and reduce time-to-market for networked services. SONATA supports network function chaining and orchestration, making service platforms modular and easier to customise to the needs of di...

  20. 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

    , 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...... 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...... 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...

  1. Multigrid Implementation of Cellular Automata for Topology Optimisation of Continuum Structures with Design Dependent loads

    NARCIS (Netherlands)

    Zakhama, R.

    2009-01-01

    Topology optimisation of continuum structures has become mature enough to be often applied in industry and continues to attract the attention of researchers and software companies in various engineering fields. Traditionally, most available algorithms for solving topology optimisation problems are

  2. 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...

  3. Epidemics and rumours in complex networks

    CERN Document Server

    Draief, Moez

    2009-01-01

    Information propagation through peer-to-peer systems, online social systems, wireless mobile ad hoc networks and other modern structures can be modelled as an epidemic on a network of contacts. Understanding how epidemic processes interact with network topology allows us to predict ultimate course, understand phase transitions and develop strategies to control and optimise dissemination. This book is a concise introduction for applied mathematicians and computer scientists to basic models, analytical tools and mathematical and algorithmic results. Mathematical tools introduced include coupling

  4. 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.

  5. Formulation des betons autopla~ants : Optimisation du squelette ...

    African Journals Online (AJOL)

    Formulation des betons autopla~ants : Optimisation du squelette granulaire par la methode graphique de Dreux - Gorisse. Fatiha Boumaza - Zeraoulia* & Mourad Behim. Laboratoire Materiaux, Geo - Materiaux et Environnement - Departement de Genie Civil. Universite Badji Mokhtar Annaba - BP 12, 23000 Annaba - ...

  6. 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 tha...

  7. Development of an Optimised Losartan Potassium Press-Coated ...

    African Journals Online (AJOL)

    The optimised formulation was further characterized with Fourier-transform infrared spectroscopy (FTIR) and powder X-ray diffractometry (PXRD) to investigate any drug/excipient modifications/interactions. Results: The tensile strength values of all the PCT were between 1.12 and 1.23MNm-2 and friability was < 0.36 %.

  8. Statistical Optimisation of Fermentation Conditions for Citric Acid ...

    African Journals Online (AJOL)

    This study investigated the optimisation of fermentation conditions during citric acid production via solid state fermentation (SSF) of pineapple peels using Aspergillus niger. A three-variable, three-level Box-Behnken design (BBD) comprising 17 experimental runs was used to develop a statistical model for the fermentation ...

  9. Optimising the Blended Learning Environment: The Arab Open University Experience

    Science.gov (United States)

    Hamdi, Tahrir; Abu Qudais, Mohammed

    2018-01-01

    This paper will offer some insights into possible ways to optimise the blended learning environment based on experience with this modality of teaching at Arab Open University/Jordan branch and also by reflecting upon the results of several meta-analytical studies, which have shown blended learning environments to be more effective than their face…

  10. Comparing and Optimising Parallel Haskell Implementations for Multicore Machines

    DEFF Research Database (Denmark)

    Berthold, Jost; Marlow, Simon; Hammond, Kevin

    2009-01-01

    In this paper, we investigate the differences and tradeoffs imposed by two parallel Haskell dialects running on multicore machines. GpH and Eden are both constructed using the highly-optimising sequential GHC compiler, and share thread scheduling, and other elements, from a common code base. The ...

  11. Larval feeding inhibition assay – need for optimisation

    DEFF Research Database (Denmark)

    Azuhnwi, Blasius; Desrues, O.; Hoste, H.

    2013-01-01

    for this observed variation in results include: parasite (species/strain); material tested; or season. There is thus need to optimise LFIA to permit intra and inter-laboratory comparison of results. We investigate here, if changes in EC50 values occur over the patency phase of a nematode species using two test...

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

    African Journals Online (AJOL)

    2012-02-15

    Feb 15, 2012 ... In a typical mating, the queen mates with 7 to 20 drones. Each time the .... Honey bee mating optimisation model's pseudo-code ... for this analysis, which consists of 47 years of monthly time ... tive of Karkheh Reservoir is to control and regulate the flow of ..... Masters thesis, Maastricht University, Maastricht.

  13. Analysing the performance of dynamic multi-objective optimisation algorithms

    CSIR Research Space (South Africa)

    Helbig, M

    2013-06-01

    Full Text Available and the goal of the algorithm is to track a set of tradeoff solutions over time. Analysing the performance of a dynamic multi-objective optimisation algorithm (DMOA) is not a trivial task. For each environment (before a change occurs) the DMOA has to find a set...

  14. Optimisation of dialysate flow in on-line hemodiafiltration

    Directory of Open Access Journals (Sweden)

    Francisco Maduell

    2015-09-01

    Conclusion: Qd variations in OL-HDF do not change convective volume. A higher Qd was associated to a slightly increased urea clearance with no change being observed for medium and large molecules. Qd optimisation to the minimal level assuring an adequate dialysis dose and allowing water and dialysate use to be rationalised should be recommended.

  15. Day-ahead economic optimisation of energy storage

    NARCIS (Netherlands)

    Lampropoulos, I.; Garoufalis, P.; Bosch, van den P.P.J.; Groot, de R.J.W.; Kling, W.L.

    2014-01-01

    This article addresses the day-ahead economic optimisation of energy storage systems within the setting of electricity spot markets. The case study is about a lithium-ion battery system integrated in a low voltage distribution grid with residential customers and photovoltaic generation in the

  16. Optimisation of the image resolution of a positron emission tomograph

    International Nuclear Information System (INIS)

    Ziemons, K.

    1993-10-01

    The resolution and the respective signal-to-noise ratios of reconstructed pictures were a point of main interest of the work for optimisation of PET systems. Monte-Carlo modelling calculations were applied to derive possible improvements of the technical design or performance of the PET system. (DG) [de

  17. FISHRENT; Bio-economic simulation and optimisation model

    NARCIS (Netherlands)

    Salz, P.; Buisman, F.C.; Soma, K.; Frost, H.; Accadia, P.; Prellezo, R.

    2011-01-01

    Key findings: The FISHRENT model is a major step forward in bio-economic model-ling, combining features that have not been fully integrated in earlier models: 1- Incorporation of any number of species (or stock) and/or fleets 2- Integration of simulation and optimisation over a period of 25 years 3-

  18. Design of optimised backstepping controller for the synchronisation

    Indian Academy of Sciences (India)

    In this paper, an adaptive backstepping controller has been tuned to synchronise two chaotic Colpitts oscillators in a master–slave configuration. The parameters of the controller are determined using shark smell optimisation (SSO) algorithm. Numerical results are presented and compared with those of particle swarm ...

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

    DEFF Research Database (Denmark)

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

    2012-01-01

    applicationsin the process industry. The paper addresses the fact that dynamic performance of the system is important, to ensure optimal changes between different operation conditions. To enable optimisation of the dynamic controller behaviour a method for designing the required excitation signal is presented...

  20. Preconditioned stochastic gradient descent optimisation for monomodal image registration

    NARCIS (Netherlands)

    Klein, S.; Staring, M.; Andersson, J.P.; Pluim, J.P.W.; Fichtinger, G.; Martel, A.; Peters, T.

    2011-01-01

    We present a stochastic optimisation method for intensity-based monomodal image registration. The method is based on a Robbins-Monro stochastic gradient descent method with adaptive step size estimation, and adds a preconditioning matrix. The derivation of the pre-conditioner is based on the

  1. Optimisation of Hidden Markov Model using Baum–Welch algorithm

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science; Volume 126; Issue 1. Optimisation of Hidden Markov Model using Baum–Welch algorithm for prediction of maximum and minimum temperature over Indian Himalaya. J C Joshi Tankeshwar Kumar Sunita Srivastava Divya Sachdeva. Volume 126 Issue 1 February 2017 ...

  2. optimisation of compressive strength of periwinkle shell aggregate

    African Journals Online (AJOL)

    user

    2017-01-01

    Jan 1, 2017 ... In this paper, a regression model is developed to predict and optimise the compressive strength of periwinkle shell aggregate concrete using Scheffe's regression theory. The results obtained from the derived regression model agreed favourably with the experimental data. The model was tested for ...

  3. Smart optimisation and sensitivity analysis in water distribution systems

    CSIR Research Space (South Africa)

    Page, Philip R

    2015-12-01

    Full Text Available optimisation of a water distribution system by keeping the average pressure unchanged as water demands change, by changing the speed of the pumps. Another application area considered, using the same mathematical notions, is the study of the sensitivity...

  4. Estimators for initial conditions for optimisation in learning hydraulic systems

    NARCIS (Netherlands)

    Post, W.J.A.E.M.; Burrows, C.R.; Edge, K.A.

    1998-01-01

    In Learning Hydraulic Systems (LHS1. developed at the Eindhoven University of Technology, a specialised optimisation routine is employed In order to reduce energy losses in hydraulic systems. Typical load situations which can be managed by LHS are variable cyclic loads, as can be observed In many

  5. An optimised portfolio management model, incorporating best practices

    OpenAIRE

    2015-01-01

    M.Ing. (Engineering Management) Driving sustainability, optimising return on investments and cultivating a competitive market advantage, are imperative for organisational success and growth. In order to achieve the business objectives and value proposition, effective management strategies must be efficiently implemented, monitored and controlled. Failure to do so ultimately result in; financial loss due to increased capital and operational expenditure, schedule slippages, substandard deliv...

  6. 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.)

  7. Optimisation Study on the Production of Anaerobic Digestate ...

    African Journals Online (AJOL)

    Organic fraction of municipal solid waste (OFMSW) is a rich substrate for biogas and compost production. Anaerobic Digestate compost (ADC) is an organic fertilizer produced from stabilized residuals of anaerobic digestion of OFMSW. This paper reports the result of studies carried out to optimise the production of ADC from ...

  8. Optimising performance in steady state for a supermarket refrigeration system

    DEFF Research Database (Denmark)

    Green, Torben; Kinnaert, Michel; Razavi-Far, Roozbeh

    2012-01-01

    Using a supermarket refrigeration system as an illustrative example, the paper postulates that by appropriately utilising knowledge of plant operation, the plant wide performance can be optimised based on a small set of variables. Focusing on steady state operations, the total system performance...

  9. 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.

  10. 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 and

  11. 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...

  12. Optimisation of wort production from rice malt using enzymes and ...

    African Journals Online (AJOL)

    Commercially, rice malt has never been successfully used in brewing because of its low free α-amino nitrogen (FAN) content. This study was designed to optimise rice malt replacement for barley malt in wort production and to improve FAN by adding α-amylase and protease. The response surface methodology (RSM) ...

  13. Optimising the operation of hybrid coolers by means of efficient control equipment; Optimierung der Betriebsweise von Hybridkuehlern durch effiziente Steuerungstechnik

    Energy Technology Data Exchange (ETDEWEB)

    Odrich, T.; Koenig, H. [Jaeggi/Guentner (Schweiz) AG, Trimbach (Switzerland)

    2007-07-01

    Due to its functional principle and design, the hybrid dry cooler holds a high potential for saving water and energy. Purely convective heat discharge during dry operation in the case of a high annual rate of utilisation, evaporative cooling during the wetting cycle at peak load times or high ambient temperatures and infinitely adjustable fan speed in both operating modes permit a very substantial recooling performance at low operating costs and with little space requirement. However, the efficiency of hybrid dry coolers depends to a large degree on how intelligently the cooling functions are controlled and on the control strategy. The present article demonstrates that the control strategy contributes decisively to minimising water and energy consumption and costs. Besides describing the actual functions of a hybrid cooler control system it presents a control strategy for automatic lowering of the setpoint and hence optimisation of the refrigeration process. It discusses the option of operating multiple hybrid coolers by means of a hydraulic network and presents an optimised control concept for this purpose which is based on a master control unit. In conclusion the study shows that hybrid coolers need their own optimised control unit if maximum savings in energy and water are to be achieved.

  14. 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...

  15. Optimised resource construction for verifiable quantum computation

    International Nuclear Information System (INIS)

    Kashefi, Elham; Wallden, Petros

    2017-01-01

    Recent developments have brought the possibility of achieving scalable quantum networks and quantum devices closer. From the computational point of view these emerging technologies become relevant when they are no longer classically simulatable. Hence a pressing challenge is the construction of practical methods to verify the correctness of the outcome produced by universal or non-universal quantum devices. A promising approach that has been extensively explored is the scheme of verification via encryption through blind quantum computation. We present here a new construction that simplifies the required resources for any such verifiable protocol. We obtain an overhead that is linear in the size of the input (computation), while the security parameter remains independent of the size of the computation and can be made exponentially small (with a small extra cost). Furthermore our construction is generic and could be applied to any universal or non-universal scheme with a given underlying graph. (paper)

  16. 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...

  17. Extension of market concept with market-driven optimisation of distribution system operation

    DEFF Research Database (Denmark)

    Wu, Qiuwei; Østergaard, Jacob

    2013-01-01

    not explicitly submitted, but derived from historic demand response behaviour. The locational prices resulting from this local optimisation were used to alleviate the congestion that would result from response to a global price, as issued within the EcoGrid EU real time market for system balancing services from......This report describes the development of a pricing mechanism for the alleviation of congestion at the 10kV distribution network level using demand flexibility in a 5-minute real-time market environment. Demand was incorporated into an OPF based market clearing procedure in which demand bids were...... distributed resources. A complementary direct control framework was developed to operate in tandem with the pricing mechanism to ensure the reliable alleviation of congestion...

  18. Optimisation of Lagrangian Flash Flood Microsensors Dropped by Unmanned Aerial Vehicle

    KAUST Repository

    Abdulaal, Mohammed

    2014-05-01

    Abstract Physical Sciences and Engineering Division Mechanical Engineering Department Master of Science Optimisation of Lagrangian Flash Flood Microsensors Dropped by Unmanned Aerial Vehicle by Mohammed Abdulaal Floods are the most common natural disasters, causing thousands of casualties every year in the world. In particular, ash ood events are particularly deadly because of the short timescales on which they occur. Classical sensing solutions such as xed wireless sensor networks or satellite imagery are either too expensive or too inaccurate. Nevertheless, Unmanned Aerial Vehicles equipped with mobile microsensors could be capable of sensing ash oods in real time for a low overall cost, saving lives and greatly improving the e ciency of the emergency response. Using ood simulation data, we show that this system could be used to detect ash oods. We also present an ongoing implementation of this system using 3D printed sensors and sensor delivery systems on a UAV testbed as well as some preliminary results.

  19. Techno-economic optimisation of three gas liquefaction processes for small-scale applications

    DEFF Research Database (Denmark)

    Nguyen, Tuong-Van; Rothuizen, Erasmus Damgaard; Elmegaard, Brian

    2016-01-01

    inventory. The present work investigates three configurations (single-mixed refrigerant, single and dual reverse Brayton cycles) for small-scale applications, which are optimised and evaluated individually. The influences of the refrigerant properties and process technologies are analysed, and the most...... promising cycle setups are identified. The findings illustrate the resulting trade-offs between the system performance and investment costs, which differ significantly with the type of refrigeration cycle. Although these configurations are suitable for small-scale applications, mixed-refrigerant processes...... thermodynamic models leads to relative deviations of up to 1% for the power consumption and 20% for the network conductance. Particular caution should thus be exercised when extrapolating the results of process models to the design of actual gas liquefaction systems....

  20. High-temperature superconducting fault-current limiter - optimisation of superconducting elements

    International Nuclear Information System (INIS)

    2004-01-01

    This report summarises the findings of a study initiated to continue the work of a DTI-LINK Collaborative Research Programme 'Enhancing the Properties of Bulk High Temperature Superconductors and their Potential Application as Fault Current Limiters (FCL). Details are given of computer modelling of the quenching process involving the transition from superconducting to normal conducting states undergone by the material when large currents are present. The design of compound elements, and a multi-element model are described along with FCL design covering distribution bus-coupler, embedded generator connection, larger generator connection, hazardous area safety, and interconnection to fault-prone network. The evaluation of thermal loss, test equipment and schedule, the optimised element, installed cost data, and the UK market are considered

  1. Improving linear transport infrastructure efficiency by automated learning and optimised predictive maintenance techniques (INFRALERT)

    Science.gov (United States)

    Jiménez-Redondo, Noemi; Calle-Cordón, Alvaro; Kandler, Ute; Simroth, Axel; Morales, Francisco J.; Reyes, Antonio; Odelius, Johan; Thaduri, Aditya; Morgado, Joao; Duarte, Emmanuele

    2017-09-01

    The on-going H2020 project INFRALERT aims to increase rail and road infrastructure capacity in the current framework of increased transportation demand by developing and deploying solutions to optimise maintenance interventions planning. It includes two real pilots for road and railways infrastructure. INFRALERT develops an ICT platform (the expert-based Infrastructure Management System, eIMS) which follows a modular approach including several expert-based toolkits. This paper presents the methodologies and preliminary results of the toolkits for i) nowcasting and forecasting of asset condition, ii) alert generation, iii) RAMS & LCC analysis and iv) decision support. The results of these toolkits in a meshed road network in Portugal under the jurisdiction of Infraestruturas de Portugal (IP) are presented showing the capabilities of the approaches.

  2. Casemix Funding Optimisation: Working Together to Make the Most of Every Episode.

    Science.gov (United States)

    Uzkuraitis, Carly; Hastings, Karen; Torney, Belinda

    2010-10-01

    Eastern Health, a large public Victorian Healthcare network, conducted a WIES optimisation audit across the casemix-funded sites for separations in the 2009/2010 financial year. The audit was conducted using existing staff resources and resulted in a significant increase in casemix funding at a minimal cost. The audit showcased the skill set of existing staff and resulted in enormous benefits to the coding and casemix team by demonstrating the value of the combination of skills that makes clinical coders unique. The development of an internal web-based application allowed accurate and timely reporting of the audit results, providing the basis for a restructure of the coding and casemix service, along with approval for additional staffing resources and inclusion of a regular auditing program to focus on the creation of high quality data for research, health services management and financial reimbursement.

  3. Coil optimisation for transcranial magnetic stimulation in realistic head geometry.

    Science.gov (United States)

    Koponen, Lari M; Nieminen, Jaakko O; Mutanen, Tuomas P; Stenroos, Matti; Ilmoniemi, Risto J

    Transcranial magnetic stimulation (TMS) allows focal, non-invasive stimulation of the cortex. A TMS pulse is inherently weakly coupled to the cortex; thus, magnetic stimulation requires both high current and high voltage to reach sufficient intensity. These requirements limit, for example, the maximum repetition rate and the maximum number of consecutive pulses with the same coil due to the rise of its temperature. To develop methods to optimise, design, and manufacture energy-efficient TMS coils in realistic head geometry with an arbitrary overall coil shape. We derive a semi-analytical integration scheme for computing the magnetic field energy of an arbitrary surface current distribution, compute the electric field induced by this distribution with a boundary element method, and optimise a TMS coil for focal stimulation. Additionally, we introduce a method for manufacturing such a coil by using Litz wire and a coil former machined from polyvinyl chloride. We designed, manufactured, and validated an optimised TMS coil and applied it to brain stimulation. Our simulations indicate that this coil requires less than half the power of a commercial figure-of-eight coil, with a 41% reduction due to the optimised winding geometry and a partial contribution due to our thinner coil former and reduced conductor height. With the optimised coil, the resting motor threshold of abductor pollicis brevis was reached with the capacitor voltage below 600 V and peak current below 3000 A. The described method allows designing practical TMS coils that have considerably higher efficiency than conventional figure-of-eight coils. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Performance optimisations for distributed analysis in ALICE

    International Nuclear Information System (INIS)

    Betev, L; Gheata, A; Grigoras, C; Hristov, P; Gheata, M

    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 frameworks 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 resources 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 an important factor to satisfy the analysis needs. We have instrumented all analysis jobs with ''sensors'' collecting comprehensive monitoring information on the job running conditions and performance in order to identify bottlenecks in the data processing flow. This data are collected by the MonALISa-based ALICE Grid monitoring system and are used to steer and improve the job submission and management policy, to identify operational problems in real time and to perform automatic corrective actions. In parallel with an upgrade of our production system we are aiming for low level improvements related to data format, data management and merging of results to allow for a better performing ALICE analysis

  5. Optimisation of X-ray examinations: General principles and an Irish perspective

    International Nuclear Information System (INIS)

    Matthews, Kate; Brennan, Patrick C.

    2009-01-01

    In Ireland, the European Medical Exposures Directive [Council Directive 97/43] was enacted into national law in Statutory Instrument 478 of 2002. This series of three review articles discusses the status of justification and optimisation of X-ray examinations nationally, and progress with the establishment of Irish diagnostic reference levels. In this second article, literature relating to optimisation issues arising in SI 478 of 2002 is reviewed. Optimisation associated with X-ray equipment and optimisation during day-to-day practice are considered. Optimisation proposals found in published research are summarised, and indicate the complex nature of optimisation. A paucity of current, research-based guidance documentation is identified. This is needed in order to support a range of professional staff in their practical implementation of optimisation.

  6. 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...

  7. 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

  8. Current NRPB recommendations on optimisation of protection of workers

    International Nuclear Information System (INIS)

    Wrixon, A.D.

    1994-01-01

    The National Radiological Protection Board is required by Ministerial Direction to provide advice on the relevance of the recommendations of the International Commission on Radiological Protection to the UK. Its advice was published in the Spring of 1993 after a period of consultation. In this article, which formed the basis of a presentation at an SRP Meeting on 29 April 1994, the Board's advice on the optimisation of protection of workers is explored and presented in the context of the developments in the understanding of the principle that have taken place in recent years. The most significant developments are the realisation that implementation of the principle is an essential function of good management and the recognition that the interests of the individual are not sufficiently taken into account by the dose limits alone but doses to individuals should be both constrained and optimised. (author)

  9. Optimised mounting conditions for poly (ether sulfone) in radiation detection.

    Science.gov (United States)

    Nakamura, Hidehito; Shirakawa, Yoshiyuki; Sato, Nobuhiro; Yamada, Tatsuya; Kitamura, Hisashi; Takahashi, Sentaro

    2014-09-01

    Poly (ether sulfone) (PES) is a candidate for use as a scintillation material in radiation detection. Its characteristics, such as its emission spectrum and its effective refractive index (based on the emission spectrum), directly affect the propagation of light generated to external photodetectors. It is also important to examine the presence of background radiation sources in manufactured PES. Here, we optimise the optical coupling and surface treatment of the PES, and characterise its background. Optical grease was used to enhance the optical coupling between the PES and the photodetector; absorption by the grease of short-wavelength light emitted from PES was negligible. Diffuse reflection induced by surface roughening increased the light yield for PES, despite the high effective refractive index. Background radiation derived from the PES sample and its impurities was negligible above the ambient, natural level. Overall, these results serve to optimise the mounting conditions for PES in radiation detection. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Optimisation of patient and staff exposure in interventional cardiology

    International Nuclear Information System (INIS)

    Padovani, R.; Malisan, M.R.; Bernardi, G.; Vano, E.; Neofotistou, V.

    2001-01-01

    The Council Directive of the European Community 97/43/Euratom (MED) deals with the health protection of individuals against dangers of ionising radiation in relation to medical exposure, and also focuses attention on some special practices (Art. 9), including interventional radiology, a technique involving high doses to the patient. The paper presents the European approach to optimisation of exposure in interventional cardiology. The DIMOND research consortium (DIMOND: Digital Imaging: Measures for Optimising Radiological Information Content and Dose) is working to develop quality criteria for cineangiographic images, to develop procedures for the classification of complexity of therapeutic and diagnostic procedures and to derive reference levels, related also to procedure complexity. DIMOND project also includes aspects of equipment characteristics and performance and content of training in radiation protection of personnel working in interventional radiology field. (author)

  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. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. 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 robust control technique is applied is compared with the classical proportional-integral (PI) performance, by means of time domain simulation in a point-to-point HVDC connection. The three main parameters in the discussion are the wind power delivered from the offshore wind power plant, the variation...

  13. 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.

  14. Energy balance of the optimised CVT-hybrid-driveline

    Energy Technology Data Exchange (ETDEWEB)

    Hoehn, Bernd-Robert; Pflaum, Hermann; Lechner, Claus [Forschungsstelle fuer Zahnraeder und Getriebebau, Technische Univ. Muenchen, Garching (Germany)

    2009-07-01

    Funded by the DFG (German Research Foundation) and some industry partners like GM Powertrain Europe, ZF, EPCOS the Optimised CVT-Hybrid was developed at Technische Universitaet Muenchen in close collaboration with the industry and is currently under scientific investigation. Designed as a parallel hybrid vehicle the Optimised CVT-Hybrid combines a series-production diesel engine with a small electric motor. The core element of the driveline is a two range continuously variable transmission (i{radical}i-transmission), which is based on a chain variator. By a special shifting process without interruption of traction force the ratio range of the chain variator is used twice; thereby a wide transmission-ratio spread is achieved by low complexity. Thus the transmission provides a large pull-away ratio for the small electric motor and a fuel-efficient overdrive ratio for the ic-engine. Instead of heavy and space-consuming accumulators a small efficient package of double layer capacitors (UltraCaps) is used for electric energy and power storage. The driveline management is done by an optimised vehicle controller. Within the scope of the research project two prototype drivelines were manufactured. One driveline is integrated into an Opel Vectra Caravan and is available for investigations at the roller dynamometer and in the actual road traffic. The second hybrid driveline is assembled at the powertrain test rig of the FZG for detailed analysis of system behaviour and fuel consumption. Based on measurements of standardised driving cycles system behaviour, fuel consumption and a detailed energy balance of the Optimised CVT-Hybrid are presented. In comparison to the series-production vehicle the fuel savings are shown. (orig.)

  15. Optimising metadata workflows in a distributed information environment

    OpenAIRE

    Robertson, R. John; Barton, Jane

    2005-01-01

    The different purposes present within a distributed information environment create the potential for repositories to enhance their metadata by capitalising on the diversity of metadata available for any given object. This paper presents three conceptual reference models required to achieve this optimisation of metadata workflow: the ecology of repositories, the object lifecycle model, and the metadata lifecycle model. It suggests a methodology for developing the metadata lifecycle model, and ...

  16. A study of certain Monte Carlo search and optimisation methods

    International Nuclear Information System (INIS)

    Budd, C.

    1984-11-01

    Studies are described which might lead to the development of a search and optimisation facility for the Monte Carlo criticality code MONK. The facility envisaged could be used to maximise a function of k-effective with respect to certain parameters of the system or, alternatively, to find the system (in a given range of systems) for which that function takes a given value. (UK)

  17. Optimisation multi-objectif des systemes energetiques

    Science.gov (United States)

    Dipama, Jean

    optimization method which is very robust and widely used to solve problems usually difficult to handle by traditional methods. Genetic algorithms (GAs) have been used in previous research and proved to be efficient in optimizing heat exchangers networks (HEN) (Dipama et al., 2008). So, HEN have been synthesized to recover the maximum heat in an industrial process. The optimization problem formulated in the context of this work consists of a single objective, namely the maximization of energy recovery. The optimization algorithm developed in this thesis extends the ability of GAs by taking into account several objectives simultaneously. This algorithm provides an innovation in the method of finding optimal solutions, by using a technique which consist of partitioning the solutions space in the form of parallel grids called "watching corridors". These corridors permit to specify areas (the observation corridors) in which the most promising feasible solutions are found and used to guide the search towards optimal solutions. A measure of the progress of the search is incorporated into the optimization algorithm to make it self-adaptive through the use of appropriate genetic operators at each stage of optimization process. The proposed method allows a fast convergence and ensure a diversity of solutions. Moreover, this method gives the algorithm the ability to overcome difficulties associated with optimizing problems with complex Pareto front landscapes (e.g., discontinuity, disjunction, etc.). The multi-objective optimization algorithm has been first validated using numerical test problems found in the literature as well as energy systems optimization problems. Finally, the proposed optimization algorithm has been applied for the optimization of the secondary loop of Gentilly-2 nuclear power plant, and a set of solutions have been found which permit to make the power plant operate in optimal conditions. (Abstract shortened by UMI.)

  18. Statistical optimisation techniques in fatigue signal editing problem

    International Nuclear Information System (INIS)

    Nopiah, Z. M.; Osman, M. H.; Baharin, N.; Abdullah, S.

    2015-01-01

    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

  19. 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.

  20. 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.)

  1. 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 ...

  2. 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

    2015-11-01

    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.

  3. Crystal structure optimisation using an auxiliary equation of state

    International Nuclear Information System (INIS)

    Jackson, Adam J.; Skelton, Jonathan M.; Hendon, Christopher H.; Butler, Keith T.; 3 Institute and Department of Materials Science and Engineering, Yonsei University, Seoul 120-749 (Korea, Republic of))" data-affiliation=" (Centre for Sustainable Chemical Technologies and Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY (United Kingdom); Global E3 Institute and Department of Materials Science and Engineering, Yonsei University, Seoul 120-749 (Korea, Republic of))" >Walsh, Aron

    2015-01-01

    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 2 ZnSnS 4 and the magnetic metal-organic framework HKUST-1

  4. 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.

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

    DEFF Research Database (Denmark)

    Lerch, Dariusz Michal; Völcker, Carsten; Capolei, Andrea

    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...... is injected at the injection wells of the down-hole pipes. This sustains the pressure in the reservoir and drives oil towards production wells. There are however, many factors contributing to the poor conventional secondary recovery methods e.g. strong surface tension, heterogeneity of the porous rock...... 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...

  6. 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)

  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. Warpage optimisation on the moulded part with straight-drilled and conformal cooling channels using response surface methodology (RSM) and glowworm swarm optimisation (GSO)

    Science.gov (United States)

    Hazwan, M. H. M.; Shayfull, Z.; Sharif, S.; Nasir, S. M.; Zainal, N.

    2017-09-01

    In injection moulding process, quality and productivity are notably important and must be controlled for each product type produced. Quality is measured as the extent of warpage of moulded parts while productivity is measured as a duration of moulding cycle time. To control the quality, many researchers have introduced various of optimisation approaches which have been proven enhanced the quality of the moulded part produced. In order to improve the productivity of injection moulding process, some of researches have proposed the application of conformal cooling channels which have been proven reduced the duration of moulding cycle time. Therefore, this paper presents an application of alternative optimisation approach which is Response Surface Methodology (RSM) with Glowworm Swarm Optimisation (GSO) on the moulded part with straight-drilled and conformal cooling channels mould. This study examined the warpage condition of the moulded parts before and after optimisation work applied for both cooling channels. A front panel housing have been selected as a specimen and the performance of proposed optimisation approach have been analysed on the conventional straight-drilled cooling channels compared to the Milled Groove Square Shape (MGSS) conformal cooling channels by simulation analysis using Autodesk Moldflow Insight (AMI) 2013. Based on the results, melt temperature is the most significant factor contribute to the warpage condition and warpage have optimised by 39.1% after optimisation for straight-drilled cooling channels and cooling time is the most significant factor contribute to the warpage condition and warpage have optimised by 38.7% after optimisation for MGSS conformal cooling channels. In addition, the finding shows that the application of optimisation work on the conformal cooling channels offers the better quality and productivity of the moulded part produced.

  9. Nuclear Power Plant Life Management - Challenges and Proposal for a Unified Model Integrating Safety and Economics

    International Nuclear Information System (INIS)

    Contri, Paolo; Elsing, Bernhard

    2011-01-01

    In recent years many electric utilities and nuclear power plants adopted policies for improved coordination of both safety and non-safety programs, called plant life management (PLIM), also in view on plant life extension programs, but mainly for an optimisation of operating costs. The implementation of PLIM programs has followed many different approaches, being intrinsically dependent on the national regulatory framework and technical traditions. In Countries with some experience, the PLIM program proved very convenient, especially when coupled with Maintenance, Surveillance an Inspection (MS and I) optimization: average savings are reported in the range of 20-30% of total (maintenance) costs. A unified European model for PLIM was developed at the JRC-Institute for Energy with the support of a network of stakeholders (SENUF), and validated at some EU nuclear plants. This paper provides a summary of the model features, the result of its validation at some plants and summarises the perceived scientific/technological challenges on which JRC proposes to focus, based upon its competencies and skills, having in mind both the European and world-wide context and its potential evolution. (author)

  10. 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

  11. Optimised performance of industrial high resolution computerised tomography

    International Nuclear Information System (INIS)

    Maangaard, M.

    2000-01-01

    The purpose of non-destructive evaluation (NDE) is to acquire knowledge of the investigated sample. Digital x-ray imaging techniques such as radiography or computerised tomography (CT) produce images of the interior of a sample. The obtained image quality determines the possibility of detecting sample related features, e.g. details and flaws. This thesis presents a method of optimising the performance of industrial X-ray equipment for the imaging task at issue in order to obtain images with high quality. CT produces maps of the X-ray linear attenuation of the sample's interior. CT can produce two dimensional cross-section images or three-dimensional images with volumetric information on the investigated sample. The image contrast and noise depend on both the investigated sample and the equipment and settings used (X-ray tube potential, X-ray filtration, exposure time, etc.). Hence, it is vital to find the optimal equipment settings in order to obtain images of high quality. To be able to mathematically optimise the image quality, it is necessary to have a model of the X-ray imaging system together with an appropriate measure of image quality. The optimisation is performed with a developed model for an X-ray image-intensifier-based radiography system. The model predicts the mean value and variance of the measured signal level in the collected radiographic images. The traditionally used measure of physical image quality is the signal-to-noise ratio (SNR). To calculate the signal-to-noise ratio, a well-defined detail (flaw) is required. It was found that maximising the SNR leads to ambiguities, the optimised settings found by maximising the SNR were dependent on the material in the detail. When CT is performed on irregular shaped samples containing density and compositional variations, it is difficult to define which SNR to use for optimisation. This difficulty is solved by the measures of physical image quality proposed here, the ratios geometry

  12. Satellite Vibration Testing: Angle optimisation method to Reduce Overtesting

    Science.gov (United States)

    Knight, Charly; Remedia, Marcello; Aglietti, Guglielmo S.; Richardson, Guy

    2018-06-01

    Spacecraft overtesting is a long running problem, and the main focus of most attempts to reduce it has been to adjust the base vibration input (i.e. notching). Instead this paper examines testing alternatives for secondary structures (equipment) coupled to the main structure (satellite) when they are tested separately. Even if the vibration source is applied along one of the orthogonal axes at the base of the coupled system (satellite plus equipment), the dynamics of the system and potentially the interface configuration mean the vibration at the interface may not occur all along one axis much less the corresponding orthogonal axis of the base excitation. This paper proposes an alternative testing methodology in which the testing of a piece of equipment occurs at an offset angle. This Angle Optimisation method may have multiple tests but each with an altered input direction allowing for the best match between all specified equipment system responses with coupled system tests. An optimisation process that compares the calculated equipment RMS values for a range of inputs with the maximum coupled system RMS values, and is used to find the optimal testing configuration for the given parameters. A case study was performed to find the best testing angles to match the acceleration responses of the centre of mass and sum of interface forces for all three axes, as well as the von Mises stress for an element by a fastening point. The angle optimisation method resulted in RMS values and PSD responses that were much closer to the coupled system when compared with traditional testing. The optimum testing configuration resulted in an overall average error significantly smaller than the traditional method. Crucially, this case study shows that the optimum test campaign could be a single equipment level test opposed to the traditional three orthogonal direction tests.

  13. Reflections on the juridicial roots of the principle of optimisation

    International Nuclear Information System (INIS)

    Lochard, J.; Boehler, M.C.

    1992-01-01

    The disciplines of jurisprudence tend in general towards a rationalisation and stabilisation of social or economic practice and are oriented towards concepts or practices which belong to the field of the determinate. When it comes to the principle of optimising radiological protection, however, the classical juridical technique of administrative law does not exactly answer the problems of implementing this. From the obligations of performance traditionally imposed by the government, a transition to obligation of behaviour by those involved seems to be called for, and this is what makes the optimisation principle difficult to qualify juridically. Instead of a law of command, exemption and control the government must essentially put its trust in the operators of nuclear installations by issuing a standard which sets an objective rather than a standard with the force of a regulation as in the past. Does the future of the juridical sciences in fact lie in the development of an administrative law of the indeterminate which would oblige the government to recognise that, even in the field of the determinate, it is not always government which knows best? While our classical administrative law is a law of command and control, the administrative law of the indeterminate will be that of the law of common effort, framed in collective acts and based on trust, consultation, and obligations of behaviour, all under the control of a judge who intervenes when there is a manifest contradiction between the acts and the promised behaviour. In French law optimisation has remained a general principle unaccompanied by specific provisions for its implementation. The object of our paper is to examine on what juridical foundations it would be possible to apply this principle at practical level without betraying its spirit. (author)

  14. Analysis and optimisation of a mixed fluid cascade (MFC) process

    Science.gov (United States)

    Ding, He; Sun, Heng; Sun, Shoujun; Chen, Cheng

    2017-04-01

    A mixed fluid cascade (MFC) process that comprises three refrigeration cycles has great capacity for large-scale LNG production, which consumes a great amount of energy. Therefore, any performance enhancement of the liquefaction process will significantly reduce the energy consumption. The MFC process is simulated and analysed by use of proprietary software, Aspen HYSYS. The effect of feed gas pressure, LNG storage pressure, water-cooler outlet temperature, different pre-cooling regimes, liquefaction, and sub-cooling refrigerant composition on MFC performance are investigated and presented. The characteristics of its excellent numerical calculation ability and the user-friendly interface of MATLAB™ and powerful thermo-physical property package of Aspen HYSYS are combined. A genetic algorithm is then invoked to optimise the MFC process globally. After optimisation, the unit power consumption can be reduced to 4.655 kW h/kmol, or 4.366 kW h/kmol on condition that the compressor adiabatic efficiency is 80%, or 85%, respectively. Additionally, to improve the process further, with regards its thermodynamic efficiency, configuration optimisation is conducted for the MFC process and several configurations are established. By analysing heat transfer and thermodynamic performances, the configuration entailing a pre-cooling cycle with three pressure levels, liquefaction, and a sub-cooling cycle with one pressure level is identified as the most efficient and thus optimal: its unit power consumption is 4.205 kW h/kmol. Additionally, the mechanism responsible for the weak performance of the suggested liquefaction cycle configuration lies in the unbalanced distribution of cold energy in the liquefaction temperature range.

  15. Study on the evolutionary optimization of the topology of network control systems

    DEFF Research Database (Denmark)

    Zhou, Z.; Chen, B.; Wang, H.

    2010-01-01

    Computer networks have been very popular in enterprise applications. However, optimisation of network designs that allows networks to be used more efficiently in industrial environment and enterprise applications remains an interesting research topic. This article mainly discusses the topology...... control network are considered in the optimisation process. In respect to the evolutionary algorithm design, an improved arena algorithm is proposed for the construction of the non-dominated set of the population. In addition, for the evaluation of individuals, the integrated use of the dominative...

  16. Optimising medication for Parkinson's disease patients with dysphagia.

    Science.gov (United States)

    Patel, Krupa

    2015-07-01

    In addition to movement disorders, Parkinson's disease (PD) is associated with several nonmotor symptoms, including dysphagia (swallowing difficulties). Dysphagia can make the consumption of solid medicines difficult, which potentially contributes to the poor adherence that is common among people with PD. However, patients may be reluctant to admit that they experience dysphagia. Community nurses should actively enquire into swallowing difficulties among all patients, not only those with PD, and should work with pharmacists and other members of the multidisciplinary team to help optimise medication management to help improve adherence.

  17. Optimisation of strain selection in evolutionary continuous culture

    Science.gov (United States)

    Bayen, T.; Mairet, F.

    2017-12-01

    In this work, we study a minimal time control problem for a perfectly mixed continuous culture with n ≥ 2 species and one limiting resource. The model that we consider includes a mutation factor for the microorganisms. Our aim is to provide optimal feedback control laws to optimise the selection of the species of interest. Thanks to Pontryagin's Principle, we derive optimality conditions on optimal controls and introduce a sub-optimal control law based on a most rapid approach to a singular arc that depends on the initial condition. Using adaptive dynamics theory, we also study a simplified version of this model which allows to introduce a near optimal strategy.

  18. Optimisation of a parallel ocean general circulation model

    Science.gov (United States)

    Beare, M. I.; Stevens, D. P.

    1997-10-01

    This paper presents the development of a general-purpose parallel ocean circulation model, for use on a wide range of computer platforms, from traditional scalar machines to workstation clusters and massively parallel processors. Parallelism is provided, as a modular option, via high-level message-passing routines, thus hiding the technical intricacies from the user. An initial implementation highlights that the parallel efficiency of the model is adversely affected by a number of factors, for which optimisations are discussed and implemented. The resulting ocean code is portable and, in particular, allows science to be achieved on local workstations that could otherwise only be undertaken on state-of-the-art supercomputers.

  19. Optimisation of test and maintenance based on probabilistic methods

    International Nuclear Information System (INIS)

    Cepin, M.

    2001-01-01

    This paper presents a method, which based on models and results of probabilistic safety assessment, minimises the nuclear power plant risk by optimisation of arrangement of safety equipment outages. The test and maintenance activities of the safety equipment are timely arranged, so the classical static fault tree models are extended with the time requirements to be capable to model real plant states. A house event matrix is used, which enables modelling of the equipment arrangements through the discrete points of time. The result of the method is determination of such configuration of equipment outages, which result in the minimal risk. Minimal risk is represented by system unavailability. (authors)

  20. Generation of safe optimised execution strategies for uml models

    DEFF Research Database (Denmark)

    Herbert, Luke Thomas; Herbert-Hansen, Zaza Nadja Lee

    When designing safety critical systems there is a need for verification of safety properties while ensuring system operations have a specific performance profile. We present a novel application of model checking to derive execution strategies, sequences of decisions at workflow branch points...... which optimise a set of reward variables, while simultaneously observing constraints which encode any required safety properties and accounting for the underlying stochastic nature of the system. By evaluating quantitative properties of the generated adversaries we are able to construct an execution...

  1. Parametric studies and optimisation of pumped thermal electricity storage

    International Nuclear Information System (INIS)

    McTigue, Joshua D.; White, Alexander J.; Markides, Christos N.

    2015-01-01

    Highlights: • PTES is modelled by cycle analysis and a Schumann-style model of the thermal stores. • Optimised trade-off surfaces show a flat efficiency vs. energy density profile. • Overall roundtrip efficiencies of around 70% are not inconceivable. - Abstract: Several of the emerging technologies for electricity storage are based on some form of thermal energy storage (TES). Examples include liquid air energy storage, pumped heat energy storage and, at least in part, advanced adiabatic compressed air energy storage. Compared to other large-scale storage methods, TES benefits from relatively high energy densities, which should translate into a low cost per MW h of storage capacity and a small installation footprint. TES is also free from the geographic constraints that apply to hydro storage schemes. TES concepts for electricity storage rely on either a heat pump or refrigeration cycle during the charging phase to create a hot or a cold storage space (the thermal stores), or in some cases both. During discharge, the thermal stores are depleted by reversing the cycle such that it acts as a heat engine. The present paper is concerned with a form of TES that has both hot and cold packed-bed thermal stores, and for which the heat pump and heat engine are based on a reciprocating Joule cycle, with argon as the working fluid. A thermodynamic analysis is presented based on traditional cycle calculations coupled with a Schumann-style model of the packed beds. Particular attention is paid to the various loss-generating mechanisms and their effect on roundtrip efficiency and storage density. A parametric study is first presented that examines the sensitivity of results to assumed values of the various loss factors and demonstrates the rather complex influence of the numerous design variables. Results of an optimisation study are then given in the form of trade-off surfaces for roundtrip efficiency, energy density and power density. The optimised designs show a

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

    OpenAIRE

    Alexander May; Adrian Anslow; Udechukwu Ojiako; Yue Wu; Alasdair Marshall; Maxwell Chipulu

    2014-01-01

    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 ...

  3. Optimising and Predicting Performance of Industrial Filtrations using Process Data

    DEFF Research Database (Denmark)

    David Bähner, Franz; Santacoloma, Paloma A.; Abildskov, Jens

    2017-01-01

    Industrial cake filtration is non-trivial from an operational point of view. Discrete events such as the removal of filter cake occur on a frequent but irregular basis. These events tend to upset the steady state of the incorporating line, which may constrain plantwide optimisation. A case study...... has been carried out with an industrial partner where changes in the biological feedstock act as strong disturbances on a series of manually reinitialised dead-end pressure leaf filters. This renders production planning a challenging task which,so far, is carried out by experienced operators. We look...

  4. Stochastic Automata for Outdoor Semantic Mapping using Optimised Signal Quantisation

    DEFF Research Database (Denmark)

    Caponetti, Fabio; Blas, Morten Rufus; Blanke, Mogens

    2011-01-01

    Autonomous robots require many types of information to obtain intelligent and safe behaviours. For outdoor operations, semantic mapping is essential and this paper proposes a stochastic automaton to localise the robot within the semantic map. For correct modelling and classi¯cation under...... uncertainty, this paper suggests quantising robotic perceptual features, according to a probabilistic description, and then optimising the quantisation. The proposed method is compared with other state-of-the-art techniques that can assess the con¯dence of their classi¯cation. Data recorded on an autonomous...

  5. Operation, optimisation, and performance of the DELPHI RICH detectors

    CERN Document Server

    Albrecht, E; Augustinus, A; Baillon, Paul; Battaglia, Marco; Bloch, D; Boudinov, E; Brunet, J M; Carrié, P; Cavalli, P; Christophel, E; Davenport, M; Dracos, M; Eklund, L; Erzen, B; Fischer, P A; Fokitis, E; Fontanelli, F; Gracco, Valerio; Hallgren, A; Joram, C; Juillot, P; Kjaer, N J; Kluit, P M; Lenzen, G; Liko, D; Mahon, J R; Maltezos, S; Markou, A; Neufeld, N; Nielsen, B S; Petrolini, A; Podobnik, T; Polok, G; Sajot, G; Sannino, M; Schyns, E; Strub, R; Tegenfeldt, F; Thadome, J; Tristram, G; Ullaland, O; Vulpen, I V

    1999-01-01

    The Ring Imaging Cherenkov detectors of DELPHI represent a large-scale particle identification system which covers almost the full angular acceptance of DELPHI. The combination of liquid and gas radiators (C sub 4 F sub 1 sub 0 , C sub 5 F sub 1 sub 2 , and C sub 6 F sub 1 sub 4) provides particle identification over the whole secondary particle momentum spectrum at LEP I and LEP II. Continuing optimisation on the hardware as well as on the online and offline software level have resulted in a stable operation of the complete detector system for more than five years at full physics performance.

  6. Optimisation of trawl energy efficiency under fishing effort constraint

    OpenAIRE

    Priour, Daniel; Khaled, Ramez

    2009-01-01

    Trawls energy efficiency is greatly affected by the drag, as well as by the swept area. The drag results in an increase of the energy consumption and the sweeping influences the catch. Methods of optimisation of the trawl design have been developed in order to reduce the volume of carburant per kg of caught fish and consequently the drag per swept area of the trawl. Based on a finite element method model for flexible netting structures, the tool modifies step by step a reference design. For e...

  7. Optimality principles in the regulation of metabolic networks.

    Science.gov (United States)

    Berkhout, Jan; Bruggeman, Frank J; Teusink, Bas

    2012-08-29

    One of the challenging tasks in systems biology is to understand how molecular networks give rise to emergent functionality and whether universal design principles apply to molecular networks. To achieve this, the biophysical, evolutionary and physiological constraints that act on those networks need to be identified in addition to the characterisation of the molecular components and interactions. Then, the cellular "task" of the network-its function-should be identified. A network contributes to organismal fitness through its function. The premise is that the same functions are often implemented in different organisms by the same type of network; hence, the concept of design principles. In biology, due to the strong forces of selective pressure and natural selection, network functions can often be understood as the outcome of fitness optimisation. The hypothesis of fitness optimisation to understand the design of a network has proven to be a powerful strategy. Here, we outline the use of several optimisation principles applied to biological networks, with an emphasis on metabolic regulatory networks. We discuss the different objective functions and constraints that are considered and the kind of understanding that they provide.

  8. Design and manufacture of Portland cement - application of sensitivity analysis in exploration and optimisation Part II. Optimisation

    DEFF Research Database (Denmark)

    Svinning, K.; Høskuldsson, Agnar

    2006-01-01

    A program for a model-based optimisation has been developed. The program contains two subprograms. The first one does minimising or maximising constrained by one original PLS-component or one equal to a combination of several. The second one does searching for the optimal combination of PLS-compo......-components, which gives max or min y. The program has proved to be applicable for achieving realistic results for implementation in the design of Portland cement with respect to performance and in the quality control during production....

  9. Radiation protection optimisation techniques and their application in industry

    Energy Technology Data Exchange (ETDEWEB)

    Lefaure, C

    1997-12-31

    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.

  10. Concepts of optimisation and justification consequences for radiological mass screening

    International Nuclear Information System (INIS)

    Carmichael, J.H.E.

    1987-01-01

    Mass radiological screening campaigns have been mounted in many countries for different conditions and the needs of one country are not necessarily those of another. However, in the European community there is a reasonable uniformity about disease patterns and therefore, a mass screening situation applicable to one country is probably equally applicable throughout the Community. In radiation protection terms, all these potential surveys must be looked at under the same factors. In radiation protection, one thinks first of all justification of the practice. Then one follows it by optimisation of the technique used, so as to obtain the best balance between benefit and detriment, and at this point one must remember that the radiation protection concept of optimisation includes a financial element as well as a purely clinical element and this must lead us on eventually to touch on cost effectiveness. The last portion of the ICRP system is the actual setting of dose limits. Now these are really only applicable to workers not to patients. One cannot set an upper limit on the dose one is prepared to use in a diagnostic radiological examination, but one can say that the dose per examination, should be examined and that the dose range of that examination between various institutions should be ascertained. This should enable any one institution to see where their dose range lies in the larger dose range, and to see that their radiological practice is giving as low a dose as is reasonably achievable

  11. Optimisation Of Volvariella volvacea Spawn Production For High Mycelia Growth

    International Nuclear Information System (INIS)

    Nie, H.J.; Azhar Mohamad; Joyce, Y.S.M.; Muhamad Najmi Moin

    2016-01-01

    Volvariella volvacea is a tropical mushroom cultivated throughout the world mostly in Asia and Europe for its taste, nutrition, fast growing nature and simple method of cultivation. It is also widely cultivated in Malaysia and known locally as Paddy Straw Mushroom. Growers strive to obtain high quality mushroom spawn to achieve high production. High quality spawn with fast mycelia growth are achieved through strain selection and optimisation of seedling production conditions. This study aims to optimise spawn production through 3 studies along the production main stages. Firstly, comparisons were made between agar media. Mycelia grown on Malt Extract Agar (MEA) covered the agar plates 2 days faster than Potato Dextrose Agar (PDA) grown mycelia. The next stage is of mother grain spawn production by inoculating a bag of grains from mycelia agar plugs. Bags are then sealed with caps. The amount of aeration for grain spawn were studied by using two types of caps. Caps with hole allowed more aeration compared to caps without holes. Study determined bags with more aeration colonised grains 2 days faster than bags with lesser aeration. For the final stage of producing planting spawn, the growth on paddy straw substrate with and without kapok (10 %) were evaluated. Results revealed mycelia fully colonised the substrate bags without kapok 1-2 days faster than substrate bags with kapok. These findings contribute in achieving production of high quality Volvariella volvacea spawn. (author)

  12. Performance characterisation and optimisation of the HIPOS positron generator setup

    Energy Technology Data Exchange (ETDEWEB)

    Tucek, K., E-mail: kamil.tucek@ec.europa.eu [European Commission, Joint Research Centre, Institute for Energy and Transport, P.O. Box 2, NL-1755 ZG Petten (Netherlands); Zeman, A.; Daquino, G.; Debarberis, L. [European Commission, Joint Research Centre, Institute for Energy and Transport, P.O. Box 2, NL-1755 ZG Petten (Netherlands); Hogenbirk, A. [Nuclear Research and Consultancy Group (NRG), P.O. Box 25, NL-1755 ZG Petten (Netherlands)

    2012-01-01

    As part of an Exploratory Research Project at the Institute for Energy and Transport (Joint Research Centre of the European Commission), a feasibility assessment was performed for the construction and placement of a high-intensity positron facility (HIPOS) in a beam tube, HB9, at the High flux reactor (HFR) in Petten. This paper reports on the results of Monte Carlo simulations to optimise the concept of the HIPOS positron generator and to determine the performance characteristics of the chosen generator design. In the first step, a detailed model of the HFR reactor core, reflector, instrumentation and HB9 beam tube was prepared, and coupled neutron and photon transport calculations were carried out with the MCNP4C3 code to establish neutron and photon source terms on boundary surfaces of the HB9 beam tube. These sources were subsequently used with the MCNPX code to optimise the positron generator concept and geometry. The results showed that the positron beam can reach an integral intensity of 10{sup 13} e{sup +}/s before the moderation stage, easily meeting the specified target and confirming the hypothesis that very high positron yields can be obtained by using combined neutron and gamma radiation sources from a high flux reactor. Full details of the research work are reported in this study.

  13. Water distribution systems design optimisation using metaheuristics and hyperheuristics

    Directory of Open Access Journals (Sweden)

    DN Raad

    2011-06-01

    Full Text Available The topic of multi-objective water distribution systems (WDS design optimisation using metaheuristics is investigated, comparing numerous modern metaheuristics, including sev- eral multi-objective evolutionary algorithms, an estimation of distribution algorithm and a recent hyperheuristic named AMALGAM (an evolutionary framework for the simultaneous incorporation of multiple metaheuristics, in order to determine which approach is most capa- ble with respect to WDS design optimisation. Novel metaheuristics and variants of existing algorithms are developed, for a total of twenty-three algorithms examined. Testing with re- spect to eight small-to-large-sized WDS benchmarks from the literature reveal that the four top-performing algorithms are mutually non-dominated with respect to the various perfor- mance metrics used. These algorithms are NSGA-II, TAMALGAMJndu , TAMALGAMndu and AMALGAMSndp (the last three being novel variants of AMALGAM. However, when these four algorithms are applied to the design of a very large real-world benchmark, the AMALGAM paradigm outperforms NSGA-II convincingly, with AMALGAMSndp exhibiting the best performance overall.

  14. ICT for whole life optimisation of residential buildings

    Energy Technology Data Exchange (ETDEWEB)

    Haekkinen, T.; Vares, S.; Huovila, P.; Vesikari, E.; Porkka, J. (VTT Technical Research Centre of Finland, Espoo (FI)); Nilsson, L.-O.; Togeroe, AA. (Lund University (SE)); Jonsson, C.; Suber, K. (Skanska Sverige AB (SE)); Andersson, R.; Larsson, R. (Cementa, Malmoe (SE)); Nuorkivi, I. (Skanska Oyj, Helsinki (FI))

    2007-08-15

    The research project 'ICT for whole life optimisation of residential buildings' (ICTWLORB) developed and tested the whole life design and optimisation methods for residential buildings. The objective of the ICTWLORB project was to develop and implement an ICT based tool box for integrated life cycle design of residential building. ICTWLORB was performed in cooperation with Swedish and Finnish partners. The ICTWLORB project defined as a premise that an industrialised building process is characterised by two main elements: a building concept based approach and efficient information management. Building concept based approach enables (1) the product development of the end product, (2) repetition of the basic elements of the building from one project to others and (3) customisation of the end-product considering the specific needs of the case and the client. Information management enables (1) the consideration of wide spectrum of aspects including building performance, environmental aspects, life cycle costs and service life, and (2) rapid adapting of the design to the specific requirements of the case. (orig.)

  15. Fractures in sport: Optimising their management and outcome

    Science.gov (United States)

    Robertson, Greg AJ; Wood, Alexander M

    2015-01-01

    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. PMID:26716081

  16. Optimisation of Transmission Systems by use of Phase Shifting Transformers

    Energy Technology Data Exchange (ETDEWEB)

    Verboomen, J

    2008-10-13

    In this thesis, transmission grids with PSTs (Phase Shifting Transformers) are investigated. In particular, the following goals are put forward: (a) The analysis and quantification of the impact of a PST on a meshed grid. This includes the development of models for the device; (b) The development of methods to obtain optimal coordination of several PSTs in a meshed grid. An objective function should be formulated, and an optimisation method must be adopted to solve the problem; and (c) The investigation of different strategies to use a PST. Chapter 2 gives a short overview of active power flow controlling devices. In chapter 3, a first step towards optimal PST coordination is taken. In chapter 4, metaheuristic optimisation methods are discussed. Chapter 5 introduces DC load flow approximations, leading to analytically closed equations that describe the relation between PST settings and active power flows. In chapter 6, some applications of the methods that are developed in earlier chapters are presented. Chapter 7 contains the conclusions of this thesis, as well as recommendations for future work.

  17. Radiological procedures: Quality criteria and dose optimisation: French status

    International Nuclear Information System (INIS)

    Grenier, Ph.; Marshall-Depommier, E.; Bourguignon, M.; Beauvais-March, H.; Valero, M.; Lacronique, J.F.; Frijal, G.

    2001-01-01

    The Council Directive 97/43/Euratom of June 30 1997 on health protection of individuals against the dangers of ionising radiation in relation to medical exposure has come into force on May, 13 th 2000. French health directorate has entrusted the 'Office de Protection contre les Rayonnements Ionisants (OPRI)' together with the 'Societe Francaise de Radiologie' (SFR) to implement article 6 related to radiological procedures, in order to bring into operation the principle of optimisation. The most frequent diagnostic radiology and interventional procedures (120 protocols) have been standardised in writing. Corresponding patient dosimetry has been determined from measurements on site, calculations and literature review. The criteria for optimisation have been highlighted for each protocols. With the help of the French Society of Medical Physicists (SFPM), measurements are being collected on a large scale in France. Then, knowing more precisely the patient dosimetry of each protocol, referral criteria will be reviewed and prioritised to implement the principle of justification. The authors will present and explain the chosen methodology (methodology of the Accreditation and Evaluation in Health Agency: ANAES) for completing this two years workload program, and will demonstrate clinical examples as well. (author)

  18. Some Current Problems in Optimisation of Radiation Protection System

    International Nuclear Information System (INIS)

    Franic, Z.; Prlic, I.

    2001-01-01

    Full text: The current system of radiation protection is generally based on recommendations promulgated in the International Commission on Radiological Protection (ICRP) publication 60. These principles and recommendations were subsequently adopted by the International Atomic Energy Agency (IAEA) in International Basic Safety Standards for Protection against Ionising Radiation and for the Safety of Radiation Sources (BSS). However, in recent years certain problems have arisen such as application of risk factors at low doses, use and interpretation of a collective dose, concept of dose commitment, optimisation of all types of occupational exposure and practices, implementation of ALARA approach in the common occupational as well as in quite complex situations etc. In this paper are presented some of the issues that have to be addressed in the development of the new ICRP Recommendations that are planned to be developed in next four or five years. As the new radiation protection philosophy shifts from society-based control of stochastic risks to an individual-based policy, consequently it will require introduction of modified approach to optimisation process and probably introduction of some new dosimetric quantities. (author)

  19. Infrastructure optimisation via MBR retrofit: a design guide.

    Science.gov (United States)

    Bagg, W K

    2009-01-01

    Wastewater management is continually evolving with the development and implementation of new, more efficient technologies. One of these is the Membrane Bioreactor (MBR). Although a relatively new technology in Australia, MBR wastewater treatment has been widely used elsewhere for over 20 years, with thousands of MBRs now in operation worldwide. Over the past 5 years, MBR technology has been enthusiastically embraced in Australia as a potential treatment upgrade option, and via retrofit typically offers two major benefits: (1) more capacity using mostly existing facilities, and (2) very high quality treated effluent. However, infrastructure optimisation via MBR retrofit is not a simple or low-cost solution and there are many factors which should be carefully evaluated before deciding on this method of plant upgrade. The paper reviews a range of design parameters which should be carefully evaluated when considering an MBR retrofit solution. Several actual and conceptual case studies are considered to demonstrate both advantages and disadvantages. Whilst optimising existing facilities and production of high quality water for reuse are powerful drivers, it is suggested that MBRs are perhaps not always the most sustainable Whole-of-Life solution for a wastewater treatment plant upgrade, especially by way of a retrofit.

  20. Multifunctional optimised scope simulators in Central and Eastern Europe

    International Nuclear Information System (INIS)

    Bartak, J.; Hauesberger, P.; Dalleur, J.P.; Houard, J.

    1999-01-01

    In the field of operator training, multiple functions have to be covered such as basic principles training, training on specific systems, operations training addressing operating procedures in normal, incidental and accidental situations, plant physical phenomena analysis. Training simulators are appropriate tools to meet theses needs. Optimisation of the scope of simulation is required to meet specific training objectives and produce cost-effective solutions that allow for possible future extensions. Training needs and training programs have to be identified with the participation of final users, leading to the development of appropriate training materials: 'multifunctional' (also called analytical) optimised scope simulators are a concrete solution to meeting this challenge. For these simulators, the quality of physical models used is equivalent to that used in the full-scope replica-type simulators. Moreover, all state-of-the-art technical requirements in terms of development of training simulators, must be satisfied: realism of modelling, tolerances, simulated incidents and accidents. Examples of this concept will be illustrated in the paper through the presentation of recent developments of simulators in Central and Eastern European NPPs (VVER-1000, VVER-440, RBMK, BN600, PWR 600). A brief presentation of the software workshop used to develop these simulators concludes the paper. (author)

  1. Utility systems operation: Optimisation-based decision making

    International Nuclear Information System (INIS)

    Velasco-Garcia, Patricia; Varbanov, Petar Sabev; Arellano-Garcia, Harvey; Wozny, Guenter

    2011-01-01

    Utility systems provide heat and power to industrial sites. The importance of operating these systems in an optimal way has increased significantly due to the unstable and in the long term rising prices of fossil fuels as well as the need for reducing the greenhouse gas emissions. This paper presents an analysis of the problem for supporting operator decision making under conditions of variable steam demands from the production processes on an industrial site. An optimisation model has been developed, where besides for running the utility system, also the costs associated with starting-up the operating units have been modelled. The illustrative case study shows that accounting for the shut-downs and start-ups of utility operating units can bring significant cost savings. - Highlights: → Optimisation methodology for decision making on running utility systems. → Accounting for varying steam demands. → Optimal operating specifications when a demand change occurs. → Operating costs include start-up costs of boilers and other units. → Validated on a real-life case study. Up to 20% cost savings are possible.

  2. Radiation protection optimisation techniques and their application in industry

    International Nuclear Information System (INIS)

    Lefaure, C.

    1996-01-01

    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)

  3. 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.

  4. A Synchronous-Asynchronous Particle Swarm Optimisation Algorithm

    Science.gov (United States)

    Ab Aziz, Nor Azlina; Mubin, Marizan; Mohamad, Mohd Saberi; Ab Aziz, Kamarulzaman

    2014-01-01

    In the original particle swarm optimisation (PSO) algorithm, the particles' velocities and positions are updated after the whole swarm performance is evaluated. This algorithm is also known as synchronous PSO (S-PSO). The strength of this update method is in the exploitation of the information. Asynchronous update PSO (A-PSO) has been proposed as an alternative to S-PSO. A particle in A-PSO updates its velocity and position as soon as its own performance has been evaluated. Hence, particles are updated using partial information, leading to stronger exploration. In this paper, we attempt to improve PSO by merging both update methods to utilise the strengths of both methods. The proposed synchronous-asynchronous PSO (SA-PSO) algorithm divides the particles into smaller groups. The best member of a group and the swarm's best are chosen to lead the search. Members within a group are updated synchronously, while the groups themselves are asynchronously updated. Five well-known unimodal functions, four multimodal functions, and a real world optimisation problem are used to study the performance of SA-PSO, which is compared with the performances of S-PSO and A-PSO. The results are statistically analysed and show that the proposed SA-PSO has performed consistently well. PMID:25121109

  5. Analysis and Comparison of Typical Models within Distribution Network Design

    DEFF Research Database (Denmark)

    Jørgensen, Hans Jacob; Larsen, Allan; Madsen, Oli B.G.

    This paper investigates the characteristics of typical optimisation models within Distribution Network Design. During the paper fourteen models known from the literature will be thoroughly analysed. Through this analysis a schematic approach to categorisation of distribution network design models...... for educational purposes. Furthermore, the paper can be seen as a practical introduction to network design modelling as well as a being an art manual or recipe when constructing such a model....

  6. Undermining and Strengthening Social Networks through Network Modification

    Science.gov (United States)

    Mellon, Jonathan; Yoder, Jordan; Evans, Daniel

    2016-10-01

    Social networks have well documented effects at the individual and aggregate level. Consequently it is often useful to understand how an attempt to influence a network will change its structure and consequently achieve other goals. We develop a framework for network modification that allows for arbitrary objective functions, types of modification (e.g. edge weight addition, edge weight removal, node removal, and covariate value change), and recovery mechanisms (i.e. how a network responds to interventions). The framework outlined in this paper helps both to situate the existing work on network interventions but also opens up many new possibilities for intervening in networks. In particular use two case studies to highlight the potential impact of empirically calibrating the objective function and network recovery mechanisms as well as showing how interventions beyond node removal can be optimised. First, we simulate an optimal removal of nodes from the Noordin terrorist network in order to reduce the expected number of attacks (based on empirically predicting the terrorist collaboration network from multiple types of network ties). Second, we simulate optimally strengthening ties within entrepreneurial ecosystems in six developing countries. In both cases we estimate ERGM models to simulate how a network will endogenously evolve after intervention.

  7. Interpretation of optimisation in the context of a disposal facility for long-lived radioactive waste

    International Nuclear Information System (INIS)

    1999-01-01

    Full text: Guidance on the Requirements for Authorisation (the GRA) issued by the Environment Agency for England and Wales requires that all disposals of radioactive waste are undertaken in a manner consistent with four principles for the protection of the public. Among these is a principle of Optimisation, that: 'The radiological detriment to members of the public that may result from the disposal of radioactive waste shall be as low as reasonably achievable, economic and social factors being taken into account'. The principle of optimisation is widely accepted and has been discussed in both UK national policy and guidance and in documents from international organisations. The practical interpretation of optimisation in the context of post-closure safety of radioactive waste repositories is, however, still open to question. In particular, the strategies and procedures that a developer might employ to implement optimisation in the siting and development of a repository, and demonstrate optimisation in a safety case, are not defined. In preparation for its role of regulatory review, the Agency has undertaken a pilot study to explore the possible interpretations of optimisation stemming from the GRA, and to identify possible strategies and procedures that a developer might follow. A review has been undertaken of UK regulatory guidance and related documents, and also international guidance, referring to optimisation in relation to radioactive waste disposal facilities. In addition, diverse examples of the application of optimisation have been identified in the international and UK performance assessment literature. A one-day meeting was organised bringing together Agency staff and technical experts with different experiences and perspectives on the subject of optimisation in the context of disposal facilities for radioactive waste. This meeting identified and discussed key issues and possible approaches to optimisation, and specifically: (1) The meaning of

  8. Optimality Principles in the Regulation of Metabolic Networks

    Directory of Open Access Journals (Sweden)

    Jan Berkhout

    2012-08-01

    Full Text Available One of the challenging tasks in systems biology is to understand how molecular networks give rise to emergent functionality and whether universal design principles apply to molecular networks. To achieve this, the biophysical, evolutionary and physiological constraints that act on those networks need to be identified in addition to the characterisation of the molecular components and interactions. Then, the cellular “task” of the network—its function—should be identified. A network contributes to organismal fitness through its function. The premise is that the same functions are often implemented in different organisms by the same type of network; hence, the concept of design principles. In biology, due to the strong forces of selective pressure and natural selection, network functions can often be understood as the outcome of fitness optimisation. The hypothesis of fitness optimisation to understand the design of a network has proven to be a powerful strategy. Here, we outline the use of several optimisation principles applied to biological networks, with an emphasis on metabolic regulatory networks. We discuss the different objective functions and constraints that are considered and the kind of understanding that they provide.

  9. Aspects of approximate optimisation: overcoming the curse of dimensionality and design of experiments

    NARCIS (Netherlands)

    Trichon, Sophie; Bonte, M.H.A.; Ponthot, Jean-Philippe; van den Boogaard, Antonius H.

    2007-01-01

    Coupling optimisation algorithms to Finite Element Methods (FEM) is a very promising way to achieve optimal metal forming processes. However, many optimisation algorithms exist and it is not clear which of these algorithms to use. This paper investigates the sensitivity of a Sequential Approximate

  10. Optimisation of the PCR-invA primers for the detection of Salmonella ...

    African Journals Online (AJOL)

    A polymerase chain reaction (PCR)-based method for the detection of Salmonella species in water samples was optimised and evaluated for speed, specificity and sensitivity. Optimisation of Mg2+ and primer concentrations and cycling parameters increased the sensitivity and limit of detection of PCR to 2.6 x 104 cfu/m.

  11. Design of Circularly-Polarised, Crossed Drooping Dipole, Phased Array Antenna Using Genetic Algorithm Optimisation

    DEFF Research Database (Denmark)

    Larsen, Niels Vesterdal

    2007-01-01

    A printed drooping dipole array is designed and constructed. The design is based on a genetic algorithm optimisation procedure used in conjunction with the software programme AWAS. By optimising the array G/T for specific combinations of scan angles and frequencies an optimum design is obtained...

  12. A constriction factor based particle swarm optimisation algorithm to solve the economic dispatch problem including losses

    Energy Technology Data Exchange (ETDEWEB)

    Young, Steven; Montakhab, Mohammad; Nouri, Hassan

    2011-07-15

    Economic dispatch (ED) is one of the most important problems to be solved in power generation as fractional percentage fuel reductions represent significant cost savings. ED wishes to optimise the power generated by each generating unit in a system in order to find the minimum operating cost at a required load demand, whilst ensuring both equality and inequality constraints are met. For the process of optimisation, a model must be created for each generating unit. The particle swarm optimisation technique is an evolutionary computation technique with one of the most powerful methods for solving global optimisation problems. The aim of this paper is to add in a constriction factor to the particle swarm optimisation algorithm (CFBPSO). Results show that the algorithm is very good at solving the ED problem and that CFBPSO must be able to work in a practical environment and so a valve point effect with transmission losses should be included in future work.

  13. Simulation and optimisation modelling approach for operation of the Hoa Binh Reservoir, Vietnam

    DEFF Research Database (Denmark)

    Ngo, Long le; Madsen, Henrik; Rosbjerg, Dan

    2007-01-01

    Hoa Binh, the largest reservoir in Vietnam, plays an important role in flood control for the Red River delta and hydropower generation. Due to its multi-purpose character, conflicts and disputes in operating the reservoir have been ongoing since its construction, particularly in the flood season....... This paper proposes to optimise the control strategies for the Hoa Binh reservoir operation by applying a combination of simulation and optimisation models. The control strategies are set up in the MIKE 11 simulation model to guide the releases of the reservoir system according to the current storage level......, the hydro-meteorological conditions, and the time of the year. A heuristic global optimisation tool, the shuffled complex evolution (SCE) algorithm, is adopted for optimising the reservoir operation. The optimisation puts focus on the trade-off between flood control and hydropower generation for the Hoa...

  14. Application of Three Existing Stope Boundary Optimisation Methods in an Operating Underground Mine

    Science.gov (United States)

    Erdogan, Gamze; Yavuz, Mahmut

    2017-12-01

    The underground mine planning and design optimisation process have received little attention because of complexity and variability of problems in underground mines. Although a number of optimisation studies and software tools are available and some of them, in special, have been implemented effectively to determine the ultimate-pit limits in an open pit mine, there is still a lack of studies for optimisation of ultimate stope boundaries in underground mines. The proposed approaches for this purpose aim at maximizing the economic profit by selecting the best possible layout under operational, technical and physical constraints. In this paper, the existing three heuristic techniques including Floating Stope Algorithm, Maximum Value Algorithm and Mineable Shape Optimiser (MSO) are examined for optimisation of stope layout in a case study. Each technique is assessed in terms of applicability, algorithm capabilities and limitations considering the underground mine planning challenges. Finally, the results are evaluated and compared.

  15. Optimisation of electron beam characteristics by simulated annealing

    International Nuclear Information System (INIS)

    Ebert, M.A.; University of Adelaide, SA; Hoban, P.W.

    1996-01-01

    Full text: With the development of technology in the field of treatment beam delivery, the possibility of tailoring radiation beams (via manipulation of the beam's phase space) is foreseeable. This investigation involved evaluating a method for determining the characteristics of pure electron beams which provided dose distributions that best approximated desired distributions. The aim is to determine which degrees of freedom are advantageous and worth pursuing in a clinical setting. A simulated annealing routine was developed to determine optimum electron beam characteristics. A set of beam elements are defined at the surface of a homogeneous water equivalent phantom defining discrete positions and angles of incidence, and electron energies. The optimal weighting of these elements is determined by the (generally approximate) solution to the linear equation, Dw = d, where d represents the dose distribution calculated over the phantom, w the vector of (50 - 2x10 4 ) beam element relative weights, and D a normalised matrix of dose deposition kernels. In the iterative annealing procedure, beam elements are randomly selected and beam weighting distributions are sampled and used to perturb the selected elements. Perturbations are accepted or rejected according to standard simulated annealing criteria. The result (after the algorithm has terminated due to meeting an iteration or optimisation specification) is an approximate solution for the beam weight vector (w) specified by the above equation. This technique has been applied for several sample dose distributions and phase space restrictions. An example is given of the phase space obtained when endeavouring to conform to a rectangular 100% dose region with polyenergetic though normally incident electrons. For regular distributions, intuitive conclusions regarding the benefits of energy/angular manipulation may be made, whereas for complex distributions, variations in intensity over beam elements of varying energy and

  16. Using response surface methodology in optimisation of biodiesel production via alkali catalysed transesterification of waste cooking oil

    CSIR Research Space (South Africa)

    Naidoo, R

    2016-03-01

    Full Text Available The report focuses on optimisation of alkali catalysis as a process for producing biodiesel from waste cooking oils. Biodiesel production parameters that were optimised were methanol to oil ratio, catalyst concentration, reaction temperature...

  17. Interior point algorithm-based power flow optimisation of a combined AC and DC multi-terminal grid

    Directory of Open Access Journals (Sweden)

    Farhan Beg

    2015-01-01

    Full Text Available The high cost of power electronic equipment, lower reliability and poor power handling capacity of the semiconductor devices had stalled the deployment of systems based on DC (multi-terminal direct current system (MTDC networks. The introduction of voltage source converters (VSCs for transmission has renewed the interest in the development of large interconnected grids based on both alternate current (AC and DC transmission networks. Such a grid platform also realises the added advantage of integrating the renewable energy sources into the grid. Thus a grid based on DC MTDC network is a possible solution to improve energy security and check the increasing supply demand gap. An optimal power solution for combined AC and DC grids obtained by the solution of the interior point algorithm is proposed in this study. Multi-terminal HVDC grids lie at the heart of various suggested transmission capacity increases. A significant difference is observed when MTDC grids are solved for power flows in place of conventional AC grids. This study deals with the power flow problem of a combined MTDC and an AC grid. The AC side is modelled with the full power flow equations and the VSCs are modelled using a connecting line, two generators and an AC node. The VSC and the DC losses are also considered. The optimisation focuses on several different goals. Three different scenarios are presented in an arbitrary grid network with ten AC nodes and five converter stations.

  18. Modelling formation of disinfection by-products in water distribution: Optimisation using a multi-objective evolutionary algorithm

    KAUST Repository

    Radhakrishnan, Mohanasundar; Pathirana, Assela; Ghebremichael, Kebreab A.; Amy, Gary L.

    2012-01-01

    Concerns have been raised regarding disinfection by-products (DBPs) formed as a result of the reaction of halogen-based disinfectants with DBP precursors. In order to appreciate the chemical and biological tradeoffs, it is imperative to understand the formation trends of DBPs and their spread in the distribution network. However, the water at a point in a complex distribution system is a mixture from various sources, whose proportions are complex to estimate and requires advanced hydraulic analysis. To understand the risks of DBPs and to develop mitigation strategies, it is important to understand the distribution of DBPs in a water network, which requires modelling. The goal of this research was to integrate a steady-state water network model with a particle backtracking algorithm and chlorination as well as DBPs models in order to assess the tradeoffs between biological and chemical risks in the distribution network. A multi-objective optimisation algorithm was used to identify the optimal proportion of water from various sources, dosages of alum, and dosages of chlorine in the treatment plant and in booster locations to control the formation of chlorination DBPs and to achieve a balance between microbial and chemical risks. © IWA Publishing 2012.

  19. Modelling formation of disinfection by-products in water distribution: Optimisation using a multi-objective evolutionary algorithm

    KAUST Repository

    Radhakrishnan, Mohanasundar

    2012-05-01

    Concerns have been raised regarding disinfection by-products (DBPs) formed as a result of the reaction of halogen-based disinfectants with DBP precursors. In order to appreciate the chemical and biological tradeoffs, it is imperative to understand the formation trends of DBPs and their spread in the distribution network. However, the water at a point in a complex distribution system is a mixture from various sources, whose proportions are complex to estimate and requires advanced hydraulic analysis. To understand the risks of DBPs and to develop mitigation strategies, it is important to understand the distribution of DBPs in a water network, which requires modelling. The goal of this research was to integrate a steady-state water network model with a particle backtracking algorithm and chlorination as well as DBPs models in order to assess the tradeoffs between biological and chemical risks in the distribution network. A multi-objective optimisation algorithm was used to identify the optimal proportion of water from various sources, dosages of alum, and dosages of chlorine in the treatment plant and in booster locations to control the formation of chlorination DBPs and to achieve a balance between microbial and chemical risks. © IWA Publishing 2012.

  20. Multi-objective optimisation with stochastic discrete-event simulation in retail banking: a case study

    Directory of Open Access Journals (Sweden)

    E Scholtz

    2012-12-01

    Full Text Available The cash management of an autoteller machine (ATM is a multi-objective optimisation problem which aims to maximise the service level provided to customers at minimum cost. This paper focus on improved cash management in a section of the South African retail banking industry, for which a decision support system (DSS was developed. This DSS integrates four Operations Research (OR methods: the vehicle routing problem (VRP, the continuous review policy for inventory management, the knapsack problem and stochastic, discrete-event simulation. The DSS was applied to an ATM network in the Eastern Cape, South Africa, to investigate 90 different scenarios. Results show that the application of a formal vehicle routing method consistently yields higher service levels at lower cost when compared to two other routing approaches, in conjunction with selected ATM reorder levels and a knapsack-based notes dispensing algorithm. It is concluded that the use of vehicle routing methods is especially beneficial when the bank has substantial control over transportation cost.

  1. Optimised compact SF6 switchgear, mobile substations and modules for improved substation economics

    Energy Technology Data Exchange (ETDEWEB)

    Mikes, E.G. [Areva T and D gas insulated substations, Oberetfelder (Switzerland); Montillet, G.F. [Areva T and D, Charleroi, PA (United States)

    2007-07-01

    One of the key elements of the electrical transmission and subdistribution networks in dense industrial areas and cities are gas insulated substations (GIS). More economical and ecological aspects in new designs are increasingly forcing the selection of smaller optimised switchgear. This paper discussed new spring mechanisms, gasket design, monitoring systems, and eco-design. Utilities are looking for new substations, upgrades, refurbishments and more efficient solutions for an extension to the current expanding infrastructure. For temporary installations, mines and some specific industries mobile substations are a great opportunity. The paper discussed several types of designs, including mobile GIS and one platform solutions for small and midsize substations; prefabricated and container solutions; hybrid switchgear modules with integrated control and monitoring functions; and optimization of GIS solutions for different station layouts having combined-functions such as circuit breaker/disconnector units. It was concluded that the search for the ongoing enhancement of the solutions in terms of cost-effectiveness and increased availability by utilities demonstrate that the system's rated voltage level and single-line-diagram configuration and in some cases the geographical position are the critical elements that determine the choice between several alternatives. 13 refs, 16 figs.

  2. Automated Sperm Head Detection Using Intersecting Cortical Model Optimised by Particle Swarm Optimization.

    Science.gov (United States)

    Tan, Weng Chun; Mat Isa, Nor Ashidi

    2016-01-01

    In human sperm motility analysis, sperm segmentation plays an important role to determine the location of multiple sperms. To ensure an improved segmentation result, the Laplacian of Gaussian filter is implemented as a kernel in a pre-processing step before applying the image segmentation process to automatically segment and detect human spermatozoa. This study proposes an intersecting cortical model (ICM), which was derived from several visual cortex models, to segment the sperm head region. However, the proposed method suffered from parameter selection; thus, the ICM network is optimised using particle swarm optimization where feature mutual information is introduced as the new fitness function. The final results showed that the proposed method is more accurate and robust than four state-of-the-art segmentation methods. The proposed method resulted in rates of 98.14%, 98.82%, 86.46% and 99.81% in accuracy, sensitivity, specificity and precision, respectively, after testing with 1200 sperms. The proposed algorithm is expected to be implemented in analysing sperm motility because of the robustness and capability of this algorithm.

  3. Analysis and Optimisation of Carcass Production for Flexible Pipes

    DEFF Research Database (Denmark)

    Nielsen, Peter Søe

    Un-bonded flexible pipes are used in the offshore oil and gas industry worldwide transporting hydrocarbons from seafloor to floating production vessels topside. Flexible pipes are advantageous over rigid pipelines in dynamic applications and during installation as they are delivered in full length......-axial tension FLC points were attained. Analysis of weld fracture of duplex stainless steel EN 1.4162 is carried out determining strains with GOM ARAMIS automated strain measurement system, which shows that strain increases faster in the weld zone than the global strain of the parent material. Fracture...... is the analysis and optimisation of the carcass manufacturing process by means of a fundamental investigation in the fields of formability, failure modes / mechanisms, Finite Element Analysis (FEA), simulative testing and tribology. A study of failure mechanisms in carcass production is performed by being present...

  4. Environmental aspects of the implementation of geogrids for pavement optimisation

    Science.gov (United States)

    Kawalec, Jacek; Gołos, Michał; Mazurowski, Piotr

    2018-05-01

    Technological developments in highway construction should not only result in durable, safe and cost-effective solutions for roads and pavements but also, and perhaps above all, lead to solutions that minimise the negative impact of construction on the environment. One of the ways to ensure these requirements are met is to apply technology using geosynthetics. This paper discusses the stabilisation of aggregate with hexagonal geogrids and the benefits - from the point of view of reducing the emission of harmful gases to the atmosphere - which can be realised from this approach, compared with traditional approaches. Solutions for the improvement of weak subgrades and optimisation of the entire pavement structure are discussed, along with the presentation of sample calculations of greenhouse gas emissions, carried out with the use of specialized software related to the construction of the structures in various technologies.

  5. Modelling, analysis and optimisation of energy systems on offshore platforms

    DEFF Research Database (Denmark)

    Nguyen, Tuong-Van

    of oil and gas facilities, (ii) the means to reduce their performance losses, and (iii) the systematic design of future plants. This work builds upon a combination of modelling tools, performance evaluation methods and multi-objective optimisation routines to reproduce the behaviour of five offshore......Nowadays, the offshore production of oil and gas requires on-site processing, which includes operations such as separation, compression and purification. The offshore system undergoes variations of the petroleum production rates over the field life – it is therefore operated far from its nominal...... with the combustion, pressure-change and cooling operations, but these processes are ranked differently depending on the plant layout and on the field production stage. The most promising improvements consist of introducing a multi-level production manifold, avoiding anti-surge gas recirculation, installing a waste...

  6. Optimised Iteration in Coupled Monte Carlo - Thermal-Hydraulics Calculations

    Science.gov (United States)

    Hoogenboom, J. Eduard; Dufek, Jan

    2014-06-01

    This paper describes an optimised iteration scheme for the number of neutron histories and the relaxation factor in successive iterations of coupled Monte Carlo and thermal-hydraulic reactor calculations based on the stochastic iteration method. The scheme results in an increasing number of neutron histories for the Monte Carlo calculation in successive iteration steps and a decreasing relaxation factor for the spatial power distribution to be used as input to the thermal-hydraulics calculation. The theoretical basis is discussed in detail and practical consequences of the scheme are shown, among which a nearly linear increase per iteration of the number of cycles in the Monte Carlo calculation. The scheme is demonstrated for a full PWR type fuel assembly. Results are shown for the axial power distribution during several iteration steps. A few alternative iteration method are also tested and it is concluded that the presented iteration method is near optimal.

  7. Pre-Industry-Optimisation of the Laser Welding Process

    DEFF Research Database (Denmark)

    Gong, Hui

    This dissertation documents the investigations into on-line monitoring the CO2 laser welding process and optimising the process parameters for achieving high quality welds. The requirements for realisation of an on-line control system are, first of all, a clear understanding of the dynamic...... phenomena of the laser welding process including the behaviour of the keyhole and plume, and the correlation between the adjustable process parameters: laser power, welding speed, focal point position, gas parameters etc. and the characteristics describing the quality of the weld: seam depth and width......, porosity etc. Secondly, a reliable monitoring system for sensing the laser-induced plasma and plume emission and detecting weld defects and process parameter deviations from the optimum conditions. Finally, an efficient control system with a fast signal processor and a precise feed-back controller...

  8. Optimisation of Marine Boilers using Model-based Multivariable Control

    DEFF Research Database (Denmark)

    Solberg, Brian

    Traditionally, marine boilers have been controlled using classical single loop controllers. To optimise marine boiler performance, reduce new installation time and minimise the physical dimensions of these large steel constructions, a more comprehensive and coherent control strategy is needed....... This research deals with the application of advanced control to a specific class of marine boilers combining well-known design methods for multivariable systems. This thesis presents contributions for modelling and control of the one-pass smoke tube marine boilers as well as for hybrid systems control. Much...... of the focus has been directed towards water level control which is complicated by the nature of the disturbances acting on the system as well as by low frequency sensor noise. This focus was motivated by an estimated large potential to minimise the boiler geometry by reducing water level fluctuations...

  9. HOM Coupler Optimisation for the Superconducting RF Cavities in ESS

    CERN Document Server

    Ainsworth, R; Calaga, R

    2012-01-01

    The European Spallation Source (ESS) will be the world’s most powerful next generation neutron source. It consists of a linear accelerator, target, and instruments for neutron experiments. The linac is designed to accelerate protons to a final energy of 2.5 GeV, with an average design beam power of 5 MW, for collision with a target used to produce a high neutron flux. A section of the linac will contain Superconducting RF (SCRF) cavities designed at 704 MHz. Beam induced HOMs in these cavities may drive the beam unstable and increase the cryogenic load, therefore HOM couplers are installed to provide sufficient damping. Previous studies have shown that these couplers are susceptible to multipacting, a resonant process which can absorb RF power and lead to heating effects. This paper will show how a coupler suffering from multipacting has been redesigned to limit this effect. Optimisation of the RF damping is also discussed.

  10. Analysis and Optimisation of Hierarchically Scheduled Multiprocessor Embedded Systems

    DEFF Research Database (Denmark)

    Pop, Traian; Pop, Paul; Eles, Petru

    2008-01-01

    We present an approach to the analysis and optimisation of heterogeneous multiprocessor embedded systems. The systems are heterogeneous not only in terms of hardware components, but also in terms of communication protocols and scheduling policies. When several scheduling policies share a resource......, they are organised in a hierarchy. In this paper, we first develop a holistic scheduling and schedulability analysis that determines the timing properties of a hierarchically scheduled system. Second, we address design problems that are characteristic to such hierarchically scheduled systems: assignment...... of scheduling policies to tasks, mapping of tasks to hardware components, and the scheduling of the activities. We also present several algorithms for solving these problems. Our heuristics are able to find schedulable implementations under limited resources, achieving an efficient utilisation of the system...

  11. Optimising agile development practices for the maintenance operation: nine heuristics

    DEFF Research Database (Denmark)

    Heeager, Lise Tordrup; Rose, Jeremy

    2014-01-01

    Agile methods are widely used and successful in many development situations and beginning to attract attention amongst the software maintenance community – both researchers and practitioners. However, it should not be assumed that implementing a well-known agile method for a maintenance department...... is therefore a trivial endeavour - the maintenance operation differs in some important respects from development work. Classical accounts of software maintenance emphasise more traditional software engineering processes, whereas recent research accounts of agile maintenance efforts uncritically focus...... on benefits. In an action research project at Aveva in Denmark we assisted with the optimisation of SCRUM, tailoring the standard process to the immediate needs of the developers. We draw on both theoretical and empirical learning to formulate nine heuristics for maintenance practitioners wishing to go agile....

  12. Optimisation of a parallel ocean general circulation model

    Directory of Open Access Journals (Sweden)

    M. I. Beare

    1997-10-01

    Full Text Available This paper presents the development of a general-purpose parallel ocean circulation model, for use on a wide range of computer platforms, from traditional scalar machines to workstation clusters and massively parallel processors. Parallelism is provided, as a modular option, via high-level message-passing routines, thus hiding the technical intricacies from the user. An initial implementation highlights that the parallel efficiency of the model is adversely affected by a number of factors, for which optimisations are discussed and implemented. The resulting ocean code is portable and, in particular, allows science to be achieved on local workstations that could otherwise only be undertaken on state-of-the-art supercomputers.

  13. Optimisation of a parallel ocean general circulation model

    Directory of Open Access Journals (Sweden)

    M. I. Beare

    Full Text Available This paper presents the development of a general-purpose parallel ocean circulation model, for use on a wide range of computer platforms, from traditional scalar machines to workstation clusters and massively parallel processors. Parallelism is provided, as a modular option, via high-level message-passing routines, thus hiding the technical intricacies from the user. An initial implementation highlights that the parallel efficiency of the model is adversely affected by a number of factors, for which optimisations are discussed and implemented. The resulting ocean code is portable and, in particular, allows science to be achieved on local workstations that could otherwise only be undertaken on state-of-the-art supercomputers.

  14. Optimised to Fail: Card Readers for Online Banking

    Science.gov (United States)

    Drimer, Saar; Murdoch, Steven J.; Anderson, Ross

    The Chip Authentication Programme (CAP) has been introduced by banks in Europe to deal with the soaring losses due to online banking fraud. A handheld reader is used together with the customer’s debit card to generate one-time codes for both login and transaction authentication. The CAP protocol is not public, and was rolled out without any public scrutiny. We reverse engineered the UK variant of card readers and smart cards and here provide the first public description of the protocol. We found numerous weaknesses that are due to design errors such as reusing authentication tokens, overloading data semantics, and failing to ensure freshness of responses. The overall strategic error was excessive optimisation. There are also policy implications. The move from signature to PIN for authorising point-of-sale transactions shifted liability from banks to customers; CAP introduces the same problem for online banking. It may also expose customers to physical harm.

  15. Dose evaluation from multiple detector outputs using convex optimisation

    International Nuclear Information System (INIS)

    Hashimoto, M.; Iimoto, T.; Kosako, T.

    2011-01-01

    A dose evaluation using multiple radiation detectors can be improved by the convex optimisation method. It enables flexible dose evaluation corresponding to the actual radiation energy spectrum. An application to the neutron ambient dose equivalent evaluation is investigated using a mixed-gas proportional counter. The convex derives the certain neutron ambient dose with certain width corresponding to the true neutron energy spectrum. The range of the evaluated dose is comparable to the error of conventional neutron dose measurement equipments. An application to the neutron individual dose equivalent measurement is also investigated. Convexes of particular dosemeter combinations evaluate the individual dose equivalent better than the dose evaluation of a single dosemeter. The combinations of dosemeters with high orthogonality of their response characteristics tend to provide a good suitability for dose evaluation. (authors)

  16. Optimisation of bitumen emulsion properties for ballast stabilisation

    International Nuclear Information System (INIS)

    D’Angelo, G.; Lo Presti, D.; Thom, N.

    2017-01-01

    Ballasted track, while providing economical and practical advantages, is associated with high costs and material consumption due to frequent maintenance. More sustainable alternatives to conventional ballasted trackbeds should therefore aim at extending its durability, particularly considering ongoing increases in traffic speed and loads. In this regard, the authors have investigated a solution consisting of bitumen stabilised ballast (BSB), designed to be used for new trackbeds as well as in reinforcing existing ones. This study presents the idea behind the technology and then focuses on a specific part of its development: the optimisation of bitumen emulsion properties and dosage in relation to ballast field conditions. Results showed that overall bitumen stabilisation improved ballast resistance to permanent deformation by enhancing stiffness and damping properties. Scenarios with higher dosage of bitumen emulsion, higher viscosity, quicker setting behaviour, and harder base bitumen seem to represent the most desirable conditions to achieve enhanced in-field performance. [es

  17. Optimised deployment of hydro-power generation facilities

    International Nuclear Information System (INIS)

    Werlen, K.

    2004-01-01

    This article discusses how the opening-up of the European electricity market has led to the creation of more room for manoeuvre in the deployment of the generation capacity of dam and pumped-storage-based hydropower facilities and low-head power stations. Software tools for the optimisation of the operation of power generation facilities that can take care of complex hydraulic interdependencies are described. The use of the software for the assessment of new installations being planned or of older installations being extended is examined. The influence of climatic conditions, market prices for power, the general requirements placed on the system and other influences on financial gain are looked at. The article makes recommendations on those factors influencing the design of the software and for its optimal use in practice

  18. Optimisation of industrial wastes reuse as construction materials.

    Science.gov (United States)

    Collivignarelli, C; Sorlini, S

    2001-12-01

    This study concerns the reuse of two inorganic wastes, foundry residues and fly ashes from municipal solid waste incineration, as "recycled aggregate" in concrete production. This kind of reuse was optimised by waste treatment with the following steps: waste washing with water; waste stabilisation-solidification treatment with inorganic reagents; final grinding of the stabilised waste after curing for about 10-20 days. Both the treated wastes were reused in concrete production with different mix-designs. Concrete specimens were characterised by means of conventional physical-mechanical tests (compression, elasticity modulus, shrinkage) and different leaching tests. Experimental results showed that a good structural and environmental quality of "recycled concrete" is due both to a correct waste treatment and to a correct mix-design for concrete mixture.

  19. Use of universal functional optimisation for TL glow curve analysis

    International Nuclear Information System (INIS)

    Pernicka, F.; Linh, H.Q.

    1996-01-01

    The effective use of any TL instrument requires an efficient software package to be able to fulfil different tasks required by research and practical applications. One of the standard features of the package used at the NPI Prague is the application of the interactive modular system Universal Functional Optimisation (UFO) for glow curve deconvolution. The whole system has been tested on standard glow curves using different models of the TL process (a single peak described by the Podgorsak approximation, first order kinetics and/or general order kinetics). Calculated values of basic TL parameters (E and s) show a good agreement with the results obtained by other authors. The main advantage of the system is in its modularity that enables flexible changes in the TL model and mathematical procedures of the glow curve analysis. (author)

  20. Adaptive optimisation-offline cyber attack on remote state estimator

    Science.gov (United States)

    Huang, Xin; Dong, Jiuxiang

    2017-10-01

    Security issues of cyber-physical systems have received increasing attentions in recent years. In this paper, deception attacks on the remote state estimator equipped with the chi-squared failure detector are considered, and it is assumed that the attacker can monitor and modify all the sensor data. A novel adaptive optimisation-offline cyber attack strategy is proposed, where using the current and previous sensor data, the attack can yield the largest estimation error covariance while ensuring to be undetected by the chi-squared monitor. From the attacker's perspective, the attack is better than the existing linear deception attacks to degrade the system performance. Finally, some numerical examples are provided to demonstrate theoretical results.

  1. Optimising, generalising and integrating educational practice using neuroscience

    Science.gov (United States)

    Colvin, Robert

    2016-07-01

    Practical collaboration at the intersection of education and neuroscience research is difficult because the combined discipline encompasses both the activity of microscopic neurons and the complex social interactions of teachers and students in a classroom. Taking a pragmatic view, this paper discusses three education objectives to which neuroscience can be effectively applied: optimising, generalising and integrating instructional techniques. These objectives are characterised by: (1) being of practical importance; (2) building on existing education and cognitive research; and (3) being infeasible to address based on behavioural experiments alone. The focus of the neuroscientific aspect of collaborative research should be on the activity of the brain before, during and after learning a task, as opposed to performance of a task. The objectives are informed by literature that highlights possible pitfalls with educational neuroscience research, and are described with respect to the static and dynamic aspects of brain physiology that can be measured by current technology.

  2. Optimisation-Based Solution Methods for Set Partitioning Models

    DEFF Research Database (Denmark)

    Rasmussen, Matias Sevel

    The scheduling of crew, i.e. the construction of work schedules for crew members, is often not a trivial task, but a complex puzzle. The task is complicated by rules, restrictions, and preferences. Therefore, manual solutions as well as solutions from standard software packages are not always su......_cient with respect to solution quality and solution time. Enhancement of the overall solution quality as well as the solution time can be of vital importance to many organisations. The _elds of operations research and mathematical optimisation deal with mathematical modelling of di_cult scheduling problems (among...... other topics). The _elds also deal with the development of sophisticated solution methods for these mathematical models. This thesis describes the set partitioning model which has been widely used for modelling crew scheduling problems. Integer properties for the set partitioning model are shown...

  3. Financial optimisation and risk management in refining activities

    International Nuclear Information System (INIS)

    Fiorenzani, S.

    2006-01-01

    The real options approach has become a benchmark in real assets evaluation and optimal management problems, especially in liberalised and competitive markets such as the oil and hydrocarbon markets. This paper describes how the same approach can be a useful tool for both risk management decisions and the financial optimisation problem. Refineries are black boxes, which can be used for the transformation of crude oil into more refined hydrocarbon products. These black boxes are characterised by operational flexibilities and constraints, which should be optimally managed in order to maximise the refiner's economic goals. Stochastic dynamic programming represents the right mathematical instrument employed to solve the decision-making problem in such an economic environment. (author)

  4. Bivalent heating systems - Potential for savings through system optimisation

    International Nuclear Information System (INIS)

    Good, J.; Jenni, A.; Nussbaumer, T.

    2005-01-01

    This article tales a look at the potential for optimising bivalent heating installations for district heating systems fired with oil and wood. The influence of increases in the price of heating oil as compared to wood fuels is discussed. The authors comment that the proportion of expensive heating oil used in such installations is often too high. Price developments for both classes of fuel in 2005 are discussed. Factors influencing the proportions of oil and wood fuel used are listed and discussed, as is the mode of operation of the district heating systems, their extension and the consumers connected to them. The article provides information on the performance of 30 installations examined. Measures that can be taken to reduce the amount of heating oil used and to increase installation efficiency are presented and discussed

  5. Optimisation of amplitude distribution of magnetic Barkhausen noise

    Science.gov (United States)

    Pal'a, Jozef; Jančárik, Vladimír

    2017-09-01

    The magnetic Barkhausen noise (MBN) measurement method is a widely used non-destructive evaluation technique used for inspection of ferromagnetic materials. Besides other influences, the excitation yoke lift-off is a significant issue of this method deteriorating the measurement accuracy. In this paper, the lift-off effect is analysed mainly on grain oriented Fe-3%Si steel subjected to various heat treatment conditions. Based on investigation of relationship between the amplitude distribution of MBN and lift-off, an approach to suppress the lift-off effect is proposed. Proposed approach utilizes the digital feedback optimising the measurement based on the amplitude distribution of MBN. The results demonstrated that the approach can highly suppress the lift-off effect up to 2 mm.

  6. Optimisation of internal contamination monitoring programme by integration of uncertainties

    International Nuclear Information System (INIS)

    Davesne, E.; Casanova, P.; Chojnacki, E.; Paquet, F.; Blanchardon, E.

    2011-01-01

    Potential internal contamination of workers is monitored by periodic bioassay measurements interpreted in terms of intake and committed effective dose by the use of biokinetic and dosimetric models. After a prospective evaluation of exposure at a workplace, a suitable monitoring programme can be defined by choosing adequate measurement techniques and frequency. In this study, the sensitivity of a programme is evaluated by the minimum intake and dose, which may be detected with a given level of confidence by taking into account uncertainties on exposure conditions and measurements. This is made for programme optimisation, which is performed by comparing the sensitivities of different alternative programmes. These methods were applied at the AREVA NC reprocessing plant and support the current monitoring programme as the best compromise between the cost of the measurements and the sensitivity of the programme. (authors)

  7. Reducing surface roughness by optimising the turning parameters

    Directory of Open Access Journals (Sweden)

    Senthil Kumar, K.

    2013-08-01

    Full Text Available Modern manufacturers worldwide look for the cheapest quality-manufactured machined components to compete in the market. Good surface quality is desired for the proper functioning of the parts produced. The surface quality is influenced by the cutting speed, feed rate, depth of cut, and many other parameters. In this paper, the Taguchi method a powerful tool to design optimisation for quality is used to find the optimal machining parameters for the turning operation. An orthogonal array, the signal-to-noise (S/N ratio, and the analysis of variance (ANOVA are employed to investigate the machining characteristics of super duplex stainless steel bars using uncoated carbide cutting tools. The effect of machining parameters on surface roughness was discovered. Confirmation tests were conducted at optimal conditions to compare the experimental results with the predicted values.

  8. Optimisation of LHCb Applications for Multi- and Manycore Job Submission

    CERN Document Server

    Rauschmayr, Nathalie; Graciani Diaz, Ricardo; Charpentier, Philippe

    The Worldwide LHC Computing Grid (WLCG) is the largest Computing Grid and is used by all Large Hadron Collider experiments in order to process their recorded data. It provides approximately 400k cores and storages. Nowadays, most of the resources consist of multi- and manycore processors. Conditions at the Large Hadron Collider experiments will change and much larger workloads and jobs consuming more memory are expected in future. This has lead to a shift of paradigm which focuses on executing jobs as multiprocessor tasks in order to use multi- and manycore processors more efficiently. All experiments at CERN are currently investigating how such computing resources can be used more efficiently in terms of memory requirements and handling of concurrency. Until now, there are still many unsolved issues regarding software, scheduling, CPU accounting, task queues, which need to be solved by grid sites and experiments. This thesis develops a systematic approach to optimise the software of the LHCb experiment fo...

  9. Stress analysis studies in optimised 'D' shaped TOKAMAK magnet designs

    International Nuclear Information System (INIS)

    Diserens, N.J.

    1975-07-01

    A suite of computer programs TOK was developed which enabled simple data input to be used for computation of magnetic fields and forces in a toroidal system of coils with either D-shaped or circular cross section. An additional requirement was that input data to the Swansea stress analysis program FINESSE could be output from the TOK fields and forces program, and that graphical output from either program should be available. A further program was required to optimise the coil shape. This used the field calculating routines from the TOK program. The starting point for these studies was the proposed 40 coil Princeton design. The stresses resulting from three different shapes of D-coil were compared. (author)

  10. Selecting a climate model subset to optimise key ensemble properties

    Directory of Open Access Journals (Sweden)

    N. Herger

    2018-02-01

    Full Text Available End users studying impacts and risks caused by human-induced climate change are often presented with large multi-model ensembles of climate projections whose composition and size are arbitrarily determined. An efficient and versatile method that finds a subset which maintains certain key properties from the full ensemble is needed, but very little work has been done in this area. Therefore, users typically make their own somewhat subjective subset choices and commonly use the equally weighted model mean as a best estimate. However, different climate model simulations cannot necessarily be regarded as independent estimates due to the presence of duplicated code and shared development history. Here, we present an efficient and flexible tool that makes better use of the ensemble as a whole by finding a subset with improved mean performance compared to the multi-model mean while at the same time maintaining the spread and addressing the problem of model interdependence. Out-of-sample skill and reliability are demonstrated using model-as-truth experiments. This approach is illustrated with one set of optimisation criteria but we also highlight the flexibility of cost functions, depending on the focus of different users. The technique is useful for a range of applications that, for example, minimise present-day bias to obtain an accurate ensemble mean, reduce dependence in ensemble spread, maximise future spread, ensure good performance of individual models in an ensemble, reduce the ensemble size while maintaining important ensemble characteristics, or optimise several of these at the same time. As in any calibration exercise, the final ensemble is sensitive to the metric, observational product, and pre-processing steps used.

  11. Paramedic literature search filters: optimised for clinicians and academics.

    Science.gov (United States)

    Olaussen, Alexander; Semple, William; Oteir, Alaa; Todd, Paula; Williams, Brett

    2017-10-11

    Search filters aid clinicians and academics to accurately locate literature. Despite this, there is no search filter or Medical Subject Headings (MeSH) term pertaining to paramedics. Therefore, the aim of this study was to create two filters to meet to different needs of paramedic clinicians and academics. We created a gold standard from a reference set, which we measured against single terms and search filters. The words and phrases used stemmed from selective exclusion of terms from the previously published Prehospital Search Filter 2.0 as well as a Delphi session with an expert panel of paramedic researchers. Independent authors deemed articles paramedic-relevant or not following an agreed definition. We measured sensitivity, specificity, accuracy and number needed to read (NNR). We located 2102 articles of which 431 (20.5%) related to paramedics. The performance of single terms was on average of high specificity (97.1% (Standard Deviation 7.4%), but of poor sensitivity (12.0%, SD 18.7%). The NNR ranged from 1 to 8.6. The sensitivity-maximising search filter yielded 98.4% sensitivity, with a specificity of 74.3% and a NNR of 2. The specificity-maximising filter achieved 88.3% in specificity, which only lowered the sensitivity to 94.7%, and thus a NNR of 1.48. We have created the first two paramedic specific search filters, one optimised for sensitivity and one optimised for specificity. The sensitivity-maximising search filter yielded 98.4% sensitivity, and a NNR of 2. The specificity-maximising filter achieved 88.3% in specificity, which only lowered the sensitivity to 94.7%, and a NNR of 1.48. A paramedic MeSH term is needed.

  12. Selecting a climate model subset to optimise key ensemble properties

    Science.gov (United States)

    Herger, Nadja; Abramowitz, Gab; Knutti, Reto; Angélil, Oliver; Lehmann, Karsten; Sanderson, Benjamin M.

    2018-02-01

    End users studying impacts and risks caused by human-induced climate change are often presented with large multi-model ensembles of climate projections whose composition and size are arbitrarily determined. An efficient and versatile method that finds a subset which maintains certain key properties from the full ensemble is needed, but very little work has been done in this area. Therefore, users typically make their own somewhat subjective subset choices and commonly use the equally weighted model mean as a best estimate. However, different climate model simulations cannot necessarily be regarded as independent estimates due to the presence of duplicated code and shared development history. Here, we present an efficient and flexible tool that makes better use of the ensemble as a whole by finding a subset with improved mean performance compared to the multi-model mean while at the same time maintaining the spread and addressing the problem of model interdependence. Out-of-sample skill and reliability are demonstrated using model-as-truth experiments. This approach is illustrated with one set of optimisation criteria but we also highlight the flexibility of cost functions, depending on the focus of different users. The technique is useful for a range of applications that, for example, minimise present-day bias to obtain an accurate ensemble mean, reduce dependence in ensemble spread, maximise future spread, ensure good performance of individual models in an ensemble, reduce the ensemble size while maintaining important ensemble characteristics, or optimise several of these at the same time. As in any calibration exercise, the final ensemble is sensitive to the metric, observational product, and pre-processing steps used.

  13. Optimisation of beryllium-7 gamma analysis following BCR sequential extraction

    International Nuclear Information System (INIS)

    Taylor, A.; Blake, W.H.; Keith-Roach, M.J.

    2012-01-01

    Graphical abstract: Showing decrease in analytical uncertainty using the optimal (combined preconcentrated sample extract) method. nv (no value) where extract activities were 7 Be geochemical behaviour is required to support tracer studies. ► Sequential extraction with natural 7 Be returns high analytical uncertainties. ► Preconcentrating extracts from a large sample mass improved analytical uncertainty. ► This optimised method can be readily employed in studies using low activity samples. - Abstract: The application of cosmogenic 7 Be as a sediment tracer at the catchment-scale requires an understanding of its geochemical associations in soil to underpin the assumption of irreversible adsorption. Sequential extractions offer a readily accessible means of determining the associations of 7 Be with operationally defined soil phases. However, the subdivision of the low activity concentrations of fallout 7 Be in soils into geochemical fractions can introduce high gamma counting uncertainties. Extending analysis time significantly is not always an option for batches of samples, owing to the on-going decay of 7 Be (t 1/2 = 53.3 days). Here, three different methods of preparing and quantifying 7 Be extracted using the optimised BCR three-step scheme have been evaluated and compared with a focus on reducing analytical uncertainties. The optimal method involved carrying out the BCR extraction in triplicate, sub-sampling each set of triplicates for stable Be analysis before combining each set and coprecipitating the 7 Be with metal oxyhydroxides to produce a thin source for gamma analysis. This method was applied to BCR extractions of natural 7 Be in four agricultural soils. The approach gave good counting statistics from a 24 h analysis period (∼10% (2σ) where extract activity >40% of total activity) and generated statistically useful sequential extraction profiles. Total recoveries of 7 Be fell between 84 and 112%. The stable Be data demonstrated that the

  14. Using Network Dynamical Influence to Drive Consensus

    Science.gov (United States)

    Punzo, Giuliano; Young, George F.; MacDonald, Malcolm; Leonard, Naomi E.

    2016-05-01

    Consensus and decision-making are often analysed in the context of networks, with many studies focusing attention on ranking the nodes of a network depending on their relative importance to information routing. Dynamical influence ranks the nodes with respect to their ability to influence the evolution of the associated network dynamical system. In this study it is shown that dynamical influence not only ranks the nodes, but also provides a naturally optimised distribution of effort to steer a network from one state to another. An example is provided where the “steering” refers to the physical change in velocity of self-propelled agents interacting through a network. Distinct from other works on this subject, this study looks at directed and hence more general graphs. The findings are presented with a theoretical angle, without targeting particular applications or networked systems; however, the framework and results offer parallels with biological flocks and swarms and opportunities for design of technological networks.

  15. Optimisation of compressed-air supply for control purposes at Valorec Services AG; Optimierung der Steuerluft - Versorgung bei der Valorec Services AG

    Energy Technology Data Exchange (ETDEWEB)

    Dott, R.; Afjei, T.

    2005-07-01

    This final report for the Swiss Federal Office of Energy (SFOE) presents the results of a project that looked at the possibilities of optimising the supply of compressed air provided around the clock by four compressor systems of varying ages in a facility in Basle, Switzerland. The initial situation is analysed and the potential for making savings is estimated. Various possibilities for improvement are considered including changing the topology of the compressed-air network, the replacement of certain compressors and a new control system. Appropriate measures are proposed and compared with new installations.

  16. Visual grading characteristics and ordinal regression analysis during optimisation of CT head examinations.

    Science.gov (United States)

    Zarb, Francis; McEntee, Mark F; Rainford, Louise

    2015-06-01

    To evaluate visual grading characteristics (VGC) and ordinal regression analysis during head CT optimisation as a potential alternative to visual grading assessment (VGA), traditionally employed to score anatomical visualisation. Patient images (n = 66) were obtained using current and optimised imaging protocols from two CT suites: a 16-slice scanner at the national Maltese centre for trauma and a 64-slice scanner in a private centre. Local resident radiologists (n = 6) performed VGA followed by VGC and ordinal regression analysis. VGC alone indicated that optimised protocols had similar image quality as current protocols. Ordinal logistic regression analysis provided an in-depth evaluation, criterion by criterion allowing the selective implementation of the protocols. The local radiology review panel supported the implementation of optimised protocols for brain CT examinations (including trauma) in one centre, achieving radiation dose reductions ranging from 24 % to 36 %. In the second centre a 29 % reduction in radiation dose was achieved for follow-up cases. The combined use of VGC and ordinal logistic regression analysis led to clinical decisions being taken on the implementation of the optimised protocols. This improved method of image quality analysis provided the evidence to support imaging protocol optimisation, resulting in significant radiation dose savings. • There is need for scientifically based image quality evaluation during CT optimisation. • VGC and ordinal regression analysis in combination led to better informed clinical decisions. • VGC and ordinal regression analysis led to dose reductions without compromising diagnostic efficacy.

  17. Energy Savings from Optimised In-Field Route Planning for Agricultural Machinery

    Directory of Open Access Journals (Sweden)

    Efthymios Rodias

    2017-10-01

    Full Text Available Various types of sensors technologies, such as machine vision and global positioning system (GPS have been implemented in navigation of agricultural vehicles. Automated navigation systems have proved the potential for the execution of optimised route plans for field area coverage. This paper presents an assessment of the reduction of the energy requirements derived from the implementation of optimised field area coverage planning. The assessment regards the analysis of the energy requirements and the comparison between the non-optimised and optimised plans for field area coverage in the whole sequence of operations required in two different cropping systems: Miscanthus and Switchgrass production. An algorithmic approach for the simulation of the executed field operations by following both non-optimised and optimised field-work patterns was developed. As a result, the corresponding time requirements were estimated as the basis of the subsequent energy cost analysis. Based on the results, the optimised routes reduce the fuel energy consumption up to 8%, the embodied energy consumption up to 7%, and the total energy consumption from 3% up to 8%.

  18. Ants Colony Optimisation of a Measuring Path of Prismatic Parts on a CMM

    Directory of Open Access Journals (Sweden)

    Stojadinovic Slavenko M.

    2016-03-01

    Full Text Available This paper presents optimisation of a measuring probe path in inspecting the prismatic parts on a CMM. The optimisation model is based on: (i the mathematical model that establishes an initial collision-free path presented by a set of points, and (ii the solution of Travelling Salesman Problem (TSP obtained with Ant Colony Optimisation (ACO. In order to solve TSP, an ACO algorithm that aims to find the shortest path of ant colony movement (i.e. the optimised path is applied. Then, the optimised path is compared with the measuring path obtained with online programming on CMM ZEISS UMM500 and with the measuring path obtained in the CMM inspection module of Pro/ENGINEER® software. The results of comparing the optimised path with the other two generated paths show that the optimised path is at least 20% shorter than the path obtained by on-line programming on CMM ZEISS UMM500, and at least 10% shorter than the path obtained by using the CMM module in Pro/ENGINEER®.

  19. Kernel Function Tuning for Single-Layer Neural Networks

    Czech Academy of Sciences Publication Activity Database

    Vidnerová, Petra; Neruda, Roman

    -, accepted 28.11. 2017 (2018) ISSN 2278-0149 R&D Projects: GA ČR GA15-18108S Institutional support: RVO:67985807 Keywords : single-layer neural networks * kernel methods * kernel function * optimisation Subject RIV: IN - Informatics, Computer Science http://www.ijmerr.com/

  20. Optimum reliable operation of water distribution networks by ...

    African Journals Online (AJOL)

    In recent decades much attention has been paid to optimal operation of water distribution networks (WDNs). In this regard, the system operation costs, including energy and disinfection chemicals, as well as system reliability should be simultaneously considered in system performance optimisation, to provide the minimum ...

  1. Optimising neutron polarizers--measuring the flipping ratio and related quantities

    CERN Document Server

    Goossens, D J

    2002-01-01

    The continuing development of gaseous spin polarized sup 3 He transmission filters for use as neutron polarizers makes the choice of optimum thickness for these filters an important consideration. The 'quality factors' derived for the optimisation of transmission filters for particular measurements are general to all neutron polarizers. In this work optimisation conditions for neutron polarizers are derived and discussed for the family of studies related to measuring the flipping ratio from samples. The application of the optimisation conditions to sup 3 He transmission filters and other types of neutron polarizers is discussed. Absolute comparisons are made between the effectiveness of different types of polarizers for this sort of work.

  2. Thickness Optimisation of Textiles Subjected to Heat and Mass Transport during Ironing

    Directory of Open Access Journals (Sweden)

    Korycki Ryszard

    2016-09-01

    Full Text Available Let us next analyse the coupled problem during ironing of textiles, that is, the heat is transported with mass whereas the mass transport with heat is negligible. It is necessary to define both physical and mathematical models. Introducing two-phase system of mass sorption by fibres, the transport equations are introduced and accompanied by the set of boundary and initial conditions. Optimisation of material thickness during ironing is gradient oriented. The first-order sensitivity of an arbitrary objective functional is analysed and included in optimisation procedure. Numerical example is the thickness optimisation of different textile materials in ironing device.

  3. 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

    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...... switching the drug in nonresponders to another antipsychotic. We described important methodological choices of the OPTiMiSE trial. RESULTS: We found 10 RCTs on switching antipsychotic drugs. No trial was conclusive and none was concerned with first-episode schizophrenia. In OPTiMiSE, 500 first episode...

  4. Suppression of plasma turbulence during optimised shear configurations in JET

    International Nuclear Information System (INIS)

    Conway, G.D.; Borba, D.N.; Alper, B.

    1999-08-01

    Density turbulence suppression is observed in the internal transport barrier (ITB) region of JET discharges with optimised magnetic shear. The suppression occurs in two stages. First, low frequency turbulence is reduced across the plasma core by a toroidal velocity shear generated by intense auxiliary heating. Then when the ITB forms, high frequency turbulence is reduced locally within the steep pressure gradient region of the ITB, consistent with the effects of enhanced E x B poloidal shear. The turbulence suppression is correlated with reduced plasma transport and improved fusion performance. Much effort has been spent in recent years in developing alternative scenarios for operating tokamak fusion reactors. One particular scenario involves reversing or reducing the central magnetic shear to form an internal transport barrier (ITB). The result is reduced plasma core energy transport and enhanced fusion performance. It is believed that ITBs may be formed through a combination of E x B velocity shear and magnetic shear stabilisation of plasma turbulence and instabilities. In this Letter we present results from JET optimised shear discharges showing that turbulence suppression during ITB formation occurs in two stages. First low frequency turbulence is reduced across the plasma core, coinciding with a region of strong toroidal velocity shear; then high frequency turbulence is locally suppressed around the ITB region, consistent with enhanced pressure gradient driven E x B poloidal shear. The measurements were made using a system of X-mode reflectometers consisting of two, dual-channel toroidal correlation reflectometers at 75 GHz (covering plasma outboard edge) and 105 GHz (core and inboard edge), and a 92-96 GHz swept frequency radial correlation reflectometer (plasma core). Reflectometry is a powerful tool for measuring density fluctuations. The highly localised reflection of the microwave beam gives excellent spatial localisation. Measurements can be made

  5. Optimisation of beryllium-7 gamma analysis following BCR sequential extraction

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, A. [Plymouth University, School of Geography, Earth and Environmental Sciences, 8 Kirkby Place, Plymouth PL4 8AA (United Kingdom); Blake, W.H., E-mail: wblake@plymouth.ac.uk [Plymouth University, School of Geography, Earth and Environmental Sciences, 8 Kirkby Place, Plymouth PL4 8AA (United Kingdom); Keith-Roach, M.J. [Plymouth University, School of Geography, Earth and Environmental Sciences, 8 Kirkby Place, Plymouth PL4 8AA (United Kingdom); Kemakta Konsult, Stockholm (Sweden)

    2012-03-30

    Graphical abstract: Showing decrease in analytical uncertainty using the optimal (combined preconcentrated sample extract) method. nv (no value) where extract activities were optimised method can be readily employed in studies using low activity samples. - Abstract: The application of cosmogenic {sup 7}Be as a sediment tracer at the catchment-scale requires an understanding of its geochemical associations in soil to underpin the assumption of irreversible adsorption. Sequential extractions offer a readily accessible means of determining the associations of {sup 7}Be with operationally defined soil phases. However, the subdivision of the low activity concentrations of fallout {sup 7}Be in soils into geochemical fractions can introduce high gamma counting uncertainties. Extending analysis time significantly is not always an option for batches of samples, owing to the on-going decay of {sup 7}Be (t{sub 1/2} = 53.3 days). Here, three different methods of preparing and quantifying {sup 7}Be extracted using the optimised BCR three-step scheme have been evaluated and compared with a focus on reducing analytical uncertainties. The optimal method involved carrying out the BCR extraction in triplicate, sub-sampling each set of triplicates for stable Be analysis before combining each set and coprecipitating the {sup 7}Be with metal oxyhydroxides to produce a thin source for gamma analysis. This method was applied to BCR extractions of natural {sup 7}Be in four agricultural soils. The approach gave good counting statistics from a 24 h analysis period ({approx}10% (2

  6. Social networking and ecomobility through nomadic devices

    OpenAIRE

    PAUZIE, Annie

    2012-01-01

    Widespread among population of sophisticated nomadic devices such as smart phones is a possibility to be connected to social networks 'Anytime', 'Anywhere'. It can constitute a potential to support ecomobility with information on real time of location of danger/risky zones identified by drivers belonging to community members: potential to avoid traffic jams and to optimise the trip, ridesharing through connections between drivers and travellers belonging to the same community: potential to de...

  7. Solving optimisation problems in metal forming using Finite Element simulation and metamodelling techniques

    NARCIS (Netherlands)

    Bonte, M.H.A.; van den Boogaard, Antonius H.; Huetink, Han

    2005-01-01

    During the last decades, Finite Element (FEM) simulations of metal forming processes have become important tools for designing feasible production processes. In more recent years, several authors recognised the potential of coupling FEM simulations to mathematical optimisation algorithms to design

  8. The application of test systems for balancing and optimising the biological decomposition of harmful substances

    International Nuclear Information System (INIS)

    Hupe, K.; Heerenklage, J.; Lotter, S.; Stegmann, R.

    1993-01-01

    Various closed test systems on the laboratory scale for balancing and optimising biological soil cleaning processes are introduced: Glass vessels, respirometers and reactor systems. The systems are compared by many examples. (orig.) [de

  9. Optimising Anaerobic Digestion of Manure Resources at a Regional Level

    Directory of Open Access Journals (Sweden)

    Kari-Anne Lyng

    2018-01-01

    Full Text Available An optimisation model was developed to give decision support on methods of managing manure resources within a region to reduce greenhouse gases and at the same time obtain economic profitability for the farmer. The model was tested by performing a case study on 50 farms in one region in Norway. Based on input data on the number of cattle and pigs on each farm, and the transport distance between each farm and the nearest centralised biogas plant, the model calculates the economic profit of the farmer and the greenhouse gas emissions for three manure management alternatives: (1 no biogas production; (2 farm scale biogas production; and (3 centralised biogas production. The model could minimise the greenhouse gas emissions, maximise the profit for the farmers or a combination of the two. Results from the case study showed that both options for anaerobic digestion (farm scale and centralised biogas production are beneficial in terms of the reduction of greenhouse gases and can be profitable for the farmers. The case study has validated the functionality and usefulness of the model. Some improvements are suggested for further development and use.

  10. Economic optimisation of a wind power plant for isolated locations

    International Nuclear Information System (INIS)

    Fortunato, B.; Mummolo, G.; Cavallera, G.

    1997-01-01

    This paper presents a model of a wind power plant for isolated locations composed of a vertical axis wind turbine connected to a self-excited induction generator operating at constant voltage and frequency; a back-up diesel generator and a battery system are moreover included in the system. Constant voltage and frequency are obtained only by controlling the generator appropriately. The control system is supposed to be optimised so that the system operates at the highest efficiency. In order to improve the total efficiency even further, a gear-box to vary the gear transmission ratio between the turbine and the generator has been considered. A ''Monte Carlo'' type simulation has been used to analyse the operation of that system over a one year period. The model is based on a probability density function of the wind speed derived by statistical data concerning a given location and on the probabilistic curve of the load required by an isolated location. The cost per kW h for different dimensions of the main components has been evaluated and the optimum configuration has been identified. (author)

  11. Numerical Forming Simulations and Optimisation in Advanced Materials

    International Nuclear Information System (INIS)

    Huetink, J.; Boogaard, A. H. van den; Geijselears, H. J. M.; Meinders, T.

    2007-01-01

    With the introduction of new materials as high strength steels, metastable steels and fibre reinforced composites, the need for advanced physically valid constitutive models arises. In finite deformation problems constitutive relations are commonly formulated in terms the Cauchy stress as a function of the elastic Finger tensor and an objective rate of the Cauchy stress as a function of the rate of deformation tensor. For isotropic materials models this is rather straightforward, but for anisotropic material models, including elastic anisotropy as well as plastic anisotropy, this may lead to confusing formulations. It will be shown that it is more convenient to define the constitutive relations in terms of invariant tensors referred to the deformed metric. Experimental results are presented that show new combinations of strain rate and strain path sensitivity. An adaptive through- thickness integration scheme for plate elements is developed, which improves the accuracy of spring back prediction at minimal costs. A procedure is described to automatically compensate the CAD tool shape numerically to obtain the desired product shape. Forming processes need to be optimized for cost saving and product improvement. Until recently, a trial-and-error process in the factory primarily did this optimization. An optimisation strategy is proposed that assists an engineer to model an optimization problem that suits his needs, including an efficient algorithm for solving the problem

  12. Impact of Battery Ageing on an Electric Vehicle Powertrain Optimisation

    Directory of Open Access Journals (Sweden)

    Daniel J. Auger

    2014-12-01

    Full Text Available An electric vehicle’s battery is its most expensive component, and it cannot be charged and discharged indefinitely. This affects a consumer vehicle’s end-user value. Ageing is tolerated as an unwanted operational side-effect; manufacturers have little control over it. Recent publications have considered trade-offs between efficiency and ageing in plug-in hybrids (PHEVs but there is no equivalent literature for pure EVs. For PHEVs, battery ageing has been modelled by translating current demands into chemical degradation. Given such models it is possible to produce similar trade-offs for EVs. We consider the effects of varying battery size and introducing a parallel supercapacitor pack. (Supercapacitors can smooth current demands, but their weight and electronics reduce economy. We extend existing EV optimisation techniques to include battery ageing, illustrated with vehicle case studies. We comment on the applicability to similar EV problems and identify where additional research is needed to improve on our assumptions.

  13. Enhanced selective metal adsorption on optimised agroforestry waste mixtures.

    Science.gov (United States)

    Rosales, Emilio; Ferreira, Laura; Sanromán, M Ángeles; Tavares, Teresa; Pazos, Marta

    2015-04-01

    The aim of this work is to ascertain the potentials of different agroforestry wastes to be used as biosorbents in the removal of a mixture of heavy metals. Fern (FE), rice husk (RI) and oak leaves (OA) presented the best removal percentages for Cu(II) and Ni(II), Mn(II) and Zn(II) and Cr(VI), respectively. The performance of a mixture of these three biosorbents was evaluated, and an improvement of 10% in the overall removal was obtained (19.25mg/g). The optimum mixture proportions were determined using simplex-centroid mixture design method (FE:OA:RI=50:13.7:36.3). The adsorption kinetics and isotherms of the optimised mixture were fit by the pseudo-first order kinetic model and Langmuir isotherm. The adsorption mechanism was studied, and the effects of the carboxylic, hydroxyl and phenolic groups on metal-biomass binding were demonstrated. Finally, the recoveries of the metals using biomass were investigated, and cationic metal recoveries of 100% were achieved when acidic solutions were used. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Optimisation of occupational exposures during site remediation at WISMUT

    International Nuclear Information System (INIS)

    Schmidt, P.; Wolf, F.

    2004-01-01

    Since 1991 the national corporation WISMUT GmbH has been charged with the rehabilitation of the sites of former Uranium mining and milling in East Germany. Since decommissioning and site remediation are carried out at places with enhanced dose rates and high concentrations of airborne radioactivity (Rn-222, long-lived alpha emitters), a large part of the employees is classified as occupationally exposed radiation workers. Thus, in 2002, 1,073 workers were engaged with relevant works in radiation protection areas aboveground (radiation exposed workers of category B; mean effective dose: 0.3 mSv; maximum dose: 2.2 mSv), and 514 workers still prepared by underground activities the flooding of the Uranium mines (category A; mean effective dose: 0.9 mSv; maximum effective dose: 4.9 mSv). The paper presents the measures taken by WISMUT to optimise the occupational exposure. The need for implementing appropriate ALARA methods in the field of occupational exposure is last but not least caused by the fact that for a number of employees the integral exposure over the total working life time has exceeded already the 400 mSv figure. (orig.)

  15. Optimised Dirac operators on the lattice. Construction, properties and applications

    Energy Technology Data Exchange (ETDEWEB)

    Bietenholz, W. [Humboldt-Universitaet, Berlin (Germany). Inst. fuer Physik]|[Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC

    2006-11-15

    We review a number of topics related to block variable renormalisation group transformations of quantum fields on the lattice, and to the emerging perfect lattice actions. We first illustrate this procedure by considering scalar fields. Then we proceed to lattice fermions, where we discuss perfect actions for free fields, for the Gross-Neveu model and for a supersymmetric spin model. We also consider the extension to perfect lattice perturbation theory, in particular regarding the axial anomaly and the quark gluon vertex function. Next we deal with properties and applications of truncated perfect fermions, and their chiral correction by means of the overlap formula. This yields a formulation of lattice fermions, which combines exact chiral symmetry with an optimisation of further essential properties. We summarise simulation results for these so-called overlap-hypercube fermions in the two-flavour Schwinger model and in quenched QCD. In the latter framework we establish a link to Chiral Perturbation Theory, both, in the p-regime and in the epsilon-regime. In particular we present an evaluation of the leading Low Energy Constants of the chiral Lagrangian - the chiral condensate and the pion decay constant - from QCD simulations with extremely light quarks. (orig.)

  16. Design and Optimisation of Home Scale Greywater Recycling Package

    Directory of Open Access Journals (Sweden)

    a/l Arugam Kalaichelvan

    2018-01-01

    Full Text Available Water crisis is becoming one of the biggest challenges in some countries due to over population and drought. Therefore, government and non-government organisations in well-developed countries are encouraging industries to install water recycling package to reduce water usage and consume greywater instead. However the home scale is not yet available in the market. This research focuses on design a home scale greywater treatment system for toilet flushing within 3,000 to 5,000 USD as a collaboration with DD Techniche Sdn Bhd. Greywater is the waste water produced from laundry, kitchen and bathroom except the toilet waste and contains suspended solids, microorganisms, oil, nitrates and phosphorus which needs to be treated using suitable types of treatment for safe reuse. The treatments include physical, chemical and biological water treatment in which in this study the proposed system is a combination of all three. The design is evaluated using experimental methods to meet the standard of toilet flushing quality. The greywater system consists of the mechanical parts to control the flow of greywater and store the treated water including pumps, sand filtration tank, wire mesh chassis and collection tank. The final design has dimension of 6 m3 and optimised price within the budget.

  17. Optimised Dirac operators on the lattice: construction, properties and applications

    International Nuclear Information System (INIS)

    Bietenholz, Wolfgang

    2006-12-01

    We review a number of topics related to block variable renormalisation group transformations of quantum fields on the lattice, and to the emerging perfect lattice actions. We first illustrate this procedure by considering scalar fields. Then we proceed to lattice fermions, where we discuss perfect actions for free fields, for the Gross-Neveu model and for a supersymmetric spin model. We also consider the extension to perfect lattice perturbation theory, in particular regarding the axial anomaly and the quark gluon vertex function. Next we deal with properties and applications of truncated perfect fermions, and their chiral correction by means of the overlap formula. This yields a formulation of lattice fermions, which combines exact chiral symmetry with an optimisation of further essential properties. We summarise simulation results for these so-called overlap-hypercube fermions in the two-flavour Schwinger model and in quenched QCD. In the latter framework we establish a link to Chiral Perturbation Theory, both, in the p-regime and in the e-regime. In particular we present an evaluation of the leading Low Energy Constants of the chiral Lagrangian - the chiral condensate and the pion decay constant - from QCD simulations with extremely light quarks. (author)

  18. Optimised Dirac operators on the lattice. Construction, properties and applications

    International Nuclear Information System (INIS)

    Bietenholz, W.; Deutsches Elektronen-Synchrotron

    2006-11-01

    We review a number of topics related to block variable renormalisation group transformations of quantum fields on the lattice, and to the emerging perfect lattice actions. We first illustrate this procedure by considering scalar fields. Then we proceed to lattice fermions, where we discuss perfect actions for free fields, for the Gross-Neveu model and for a supersymmetric spin model. We also consider the extension to perfect lattice perturbation theory, in particular regarding the axial anomaly and the quark gluon vertex function. Next we deal with properties and applications of truncated perfect fermions, and their chiral correction by means of the overlap formula. This yields a formulation of lattice fermions, which combines exact chiral symmetry with an optimisation of further essential properties. We summarise simulation results for these so-called overlap-hypercube fermions in the two-flavour Schwinger model and in quenched QCD. In the latter framework we establish a link to Chiral Perturbation Theory, both, in the p-regime and in the epsilon-regime. In particular we present an evaluation of the leading Low Energy Constants of the chiral Lagrangian - the chiral condensate and the pion decay constant - from QCD simulations with extremely light quarks. (orig.)

  19. Optimisation of imaging technique used in direct digital radiography

    International Nuclear Information System (INIS)

    Roberts, J A; Evans, S C; Rees, M

    2006-01-01

    The purpose of the study was to optimise the technique employed for AP shoulder and lateral cervical spine examinations following an investigation into image quality, based on clinical assessment, and effective dose, calculated from patient entrance surface dose measurements. A study was therefore conducted in an attempt to determine whether the increased radiation dose to the patient following the introduction of an anti-scatter grid was justified by the level of improvement in image quality. The study, involving 100 patients, was able to demonstrate that the increase in radiation dose to the patient when using an anti-scatter grid for AP shoulder examinations is not justified by the improved image quality. A poor level of inter-rater reliability between the consultants scoring the lateral cervical spine images prevented a firm conclusion from being reached. The fact that all images were of diagnostic quality, however, suggested that the use of the anti-scatter grid was unnecessary. Following completion of the project the hospital involved was informed of all findings

  20. Normal tissue dose-effect models in biological dose optimisation

    International Nuclear Information System (INIS)

    Alber, M.

    2008-01-01

    Sophisticated radiotherapy techniques like intensity modulated radiotherapy with photons and protons rely on numerical dose optimisation. The evaluation of normal tissue dose distributions that deviate significantly from the common clinical routine and also the mathematical expression of desirable properties of a dose distribution is difficult. In essence, a dose evaluation model for normal tissues has to express the tissue specific volume effect. A formalism of local dose effect measures is presented, which can be applied to serial and parallel responding tissues as well as target volumes and physical dose penalties. These models allow a transparent description of the volume effect and an efficient control over the optimum dose distribution. They can be linked to normal tissue complication probability models and the equivalent uniform dose concept. In clinical applications, they provide a means to standardize normal tissue doses in the face of inevitable anatomical differences between patients and a vastly increased freedom to shape the dose, without being overly limiting like sets of dose-volume constraints. (orig.)

  1. Optimised management of orphan wastes in the UK

    International Nuclear Information System (INIS)

    Doudou, Slimane; McTeer, Jennifer; Wickham, Stephen; Thied, Rob; Woodcock, Richard; Turner, Tom; Hamblin, Clive; Buckley, Matthew; Walsh, Ciara

    2013-01-01

    Orphan wastes have properties preventing them from being managed according to existing or currently planned management routes, or lack characterisation so that their management is uncertain. The identification of new management opportunities for orphan wastes could realise significant benefits by reducing the number of processing facilities required, reducing waste volumes, reducing hazard or leading to the development of centres of excellence for the processing of certain types of orphan wastes. Information on the characteristics of orphan waste existing at nuclear licensed sites across the UK has been collated and a database developed to act as a repository for the information gathered. The database provides a capability to analyse the data and to explore possible treatment technologies for each orphan waste type. Thirty five distinct orphan waste types have been defined and possible treatment options considered. Treatment technologies (including chemical, high temperature, immobilisation and physical technologies) that could be applied to one or more of the generic orphan waste streams have been identified. Wiring diagrams have been used to highlight the waste treatment / lifecycle management options that are available for each of the generic orphan groups as well as identifying areas for further research and development. This work has identified the potential for optimising the management of orphan wastes in a number of areas, and many potential opportunities were identified. Such opportunities could be investigated by waste managers at waste producing nuclear sites, to facilitate the development of new management routes for orphan wastes. (authors)

  2. 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.

  3. Optimisation of multiplet identifier processing on a PLAYSTATION® 3

    Science.gov (United States)

    Hattori, Masami; Mizuno, Takashi

    2010-02-01

    To enable high-performance computing (HPC) for applications with large datasets using a Sony® PLAYSTATION® 3 (PS3™) video game console, we configured a hybrid system consisting of a Windows® PC and a PS3™. To validate this system, we implemented the real-time multiplet identifier (RTMI) application, which identifies multiplets of microearthquakes in terms of the similarity of their waveforms. The cross-correlation computation, which is a core algorithm of the RTMI application, was optimised for the PS3™ platform, while the rest of the computation, including data input and output remained on the PC. With this configuration, the core part of the algorithm ran 69 times faster than the original program, accelerating total computation speed more than five times. As a result, the system processed up to 2100 total microseismic events, whereas the original implementation had a limit of 400 events. These results indicate that this system enables high-performance computing for large datasets using the PS3™, as long as data transfer time is negligible compared with computation time.

  4. Optimisation of antimicrobial dosing based on pharmacokinetic and pharmacodynamic principles

    Directory of Open Access Journals (Sweden)

    Grace Si Ru Hoo

    2017-01-01

    Full Text Available While suboptimal dosing of antimicrobials has been attributed to poorer clinical outcomes, clinical cure and mortality advantages have been demonstrated when target pharmacokinetic (PK and pharmacodynamic (PD indices for various classes of antimicrobials were achieved to maximise antibiotic activity. Dosing optimisation requires a good knowledge of PK/PD principles. This review serves to provide a foundation in PK/PD principles for the commonly prescribed antibiotics (β-lactams, vancomycin, fluoroquinolones and aminoglycosides, as well as dosing considerations in special populations (critically ill and obese patients. PK principles determine whether an appropriate dose of antimicrobial reaches the intended pathogen(s. It involves the fundamental processes of absorption, distribution, metabolism and elimination, and is affected by the antimicrobial's physicochemical properties. Antimicrobial pharmacodynamics define the relationship between the drug concentration and its observed effect on the pathogen. The major indicator of the effect of the antibiotics is the minimum inhibitory concentration. The quantitative relationship between a PK and microbiological parameter is known as a PK/PD index, which describes the relationship between dose administered and the rate and extent of bacterial killing. Improvements in clinical outcomes have been observed when antimicrobial agents are dosed optimally to achieve their respective PK/PD targets. With the rising rates of antimicrobial resistance and a limited drug development pipeline, PK/PD concepts can foster more rational and individualised dosing regimens, improving outcomes while simultaneously limiting the toxicity of antimicrobials.

  5. Production optimisation in the petrochemical industry by hierarchical multivariate modelling

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Magnus; Furusjoe, Erik; Jansson, Aasa

    2004-06-01

    This project demonstrates the advantages of applying hierarchical multivariate modelling in the petrochemical industry in order to increase knowledge of the total process. The models indicate possible ways to optimise the process regarding the use of energy and raw material, which is directly linked to the environmental impact of the process. The refinery of Nynaes Refining AB (Goeteborg, Sweden) has acted as a demonstration site in this project. The models developed for the demonstration site resulted in: Detection of an unknown process disturbance and suggestions of possible causes; Indications on how to increase the yield in combination with energy savings; The possibility to predict product quality from on-line process measurements, making the results available at a higher frequency than customary laboratory analysis; Quantification of the gradually lowered efficiency of heat transfer in the furnace and increased fuel consumption as an effect of soot build-up on the furnace coils; Increased knowledge of the relation between production rate and the efficiency of the heat exchangers. This report is one of two reports from the project. It contains a technical discussion of the result with some degree of detail. A shorter and more easily accessible report is also available, see IVL report B1586-A.

  6. Structural and operational optimisation of distributed energy systems

    International Nuclear Information System (INIS)

    Soederman, Jarmo; Pettersson, Frank

    2006-01-01

    A distributed energy system (DES) is a system comprising a set of energy suppliers and consumers, district heating pipelines, heat storage facilities and power transmission lines in a region. Distributed energy production has got an increasingly important role in the energy market. In this paper, a model for structural and operational optimisation of DES is presented. In the model, production and consumption of electrical power and heat, power transmissions, transport of fuels to the production plants, transport of water in the district heating pipelines and storage of heat are taken into account. The problem is formulated as a mixed integer linear programming (MILP) problem where the objective is to minimise the overall cost of DES, i.e., the sum of the running costs for the included operations and the annualised investment costs of the included equipment. An illustrative example is presented for a complex DES situation. The solution gives the DES structure, i.e., which production units, heat transport lines and storages should be built as well as their locations be, together with design parameters for plants and pipelines. The model enables the involved parties-suppliers, consumers, designers and authorities-to form a joint view of different situations as a basis for the decision making. A tool based on the model is built, which can be used in design, in creating guidelines for regional energy policies and for versatile what-if analyses

  7. Random matrix theory filters and currency portfolio optimisation

    Science.gov (United States)

    Daly, J.; Crane, M.; Ruskin, H. J.

    2010-04-01

    Random matrix theory (RMT) filters have recently been shown to improve the optimisation of financial portfolios. This paper studies the effect of three RMT filters on realised portfolio risk, using bootstrap analysis and out-of-sample testing. We considered the case of a foreign exchange and commodity portfolio, weighted towards foreign exchange, and consisting of 39 assets. This was intended to test the limits of RMT filtering, which is more obviously applicable to portfolios with larger numbers of assets. We considered both equally and exponentially weighted covariance matrices, and observed that, despite the small number of assets involved, RMT filters reduced risk in a way that was consistent with a much larger S&P 500 portfolio. The exponential weightings indicated showed good consistency with the value suggested by Riskmetrics, in contrast to previous results involving stocks. This decay factor, along with the low number of past moves preferred in the filtered, equally weighted case, displayed a trend towards models which were reactive to recent market changes. On testing portfolios with fewer assets, RMT filtering provided less or no overall risk reduction. In particular, no long term out-of-sample risk reduction was observed for a portfolio consisting of 15 major currencies and commodities.

  8. Optimised Dirac operators on the lattice: construction, properties and applications

    Energy Technology Data Exchange (ETDEWEB)

    Bietenholz, Wolfgang [Humbolt-Universitaet zu Berlin (Germany). Inst. fuer Physik; Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing (NIC)

    2006-12-15

    We review a number of topics related to block variable renormalisation group transformations of quantum fields on the lattice, and to the emerging perfect lattice actions. We first illustrate this procedure by considering scalar fields. Then we proceed to lattice fermions, where we discuss perfect actions for free fields, for the Gross-Neveu model and for a supersymmetric spin model. We also consider the extension to perfect lattice perturbation theory, in particular regarding the axial anomaly and the quark gluon vertex function. Next we deal with properties and applications of truncated perfect fermions, and their chiral correction by means of the overlap formula. This yields a formulation of lattice fermions, which combines exact chiral symmetry with an optimisation of further essential properties. We summarise simulation results for these so-called overlap-hypercube fermions in the two-flavour Schwinger model and in quenched QCD. In the latter framework we establish a link to Chiral Perturbation Theory, both, in the p-regime and in the e-regime. In particular we present an evaluation of the leading Low Energy Constants of the chiral Lagrangian - the chiral condensate and the pion decay constant - from QCD simulations with extremely light quarks. (author)

  9. Topology optimisation of passive coolers for light-emitting diode lamps

    DEFF Research Database (Denmark)

    Alexandersen, Joe

    2015-01-01

    This work applies topology optimisation to the design of passive coolers for light-emitting diode (LED) lamps. The heat sinks are cooled by the natural convection currents arising from the temperature difference between the LED lamp and the surrounding air. A large scale parallel computational....... The optimisation results show interesting features that are currently being incorporated into industrial designs for enhanced passive cooling abilities....

  10. On the impact of optimisation models in maintenance decision making: the state of the art

    International Nuclear Information System (INIS)

    Dekker, Rommert; Scarf, Philip A.

    1998-01-01

    In this paper we discuss the state of the art in applications of maintenance optimisation models. After giving a short introduction to the area, we consider several ways in which models may be used to optimise maintenance, such as case studies, operational and strategic decision support systems, and give examples of each of them. Next we discuss several areas where the models have been applied successfully. These include civil structure and aeroplane maintenance. From a comparative point of view, we discuss future prospects

  11. Optimisation de modèles de propagation à partir des données de ...

    African Journals Online (AJOL)

    optimisation radio dans les réseaux mobiles. Le présent article présente une étude comparative de cinq méthodes d'optimisation de modèles de propagation à savoir : La régression linéaire, la méthode de Newton de second ordre, le recuit ...

  12. The optimisation principle and the new ICRP recommendations: practical implications on operational radiation protection

    International Nuclear Information System (INIS)

    Lochard, J.

    1992-01-01

    The formulation of the optimisation principle proposed by the International Commission of Radiological Protection in its new recommendations is largely oriented towards better control of individual doses. In this perspective, the concept of doe constraint and the reference to equity in dose distributions are becoming key elements within the optimisation process. This paper discusses some first reflexions regarding this new orientation and outlines the main impacts that must be forwarded to the practical level. (author)

  13. Pre-segmented 2-Step IMRT with subsequent direct machine parameter optimisation – a planning study

    International Nuclear Information System (INIS)

    Bratengeier, Klaus; Meyer, Jürgen; Flentje, Michael

    2008-01-01

    Modern intensity modulated radiotherapy (IMRT) mostly uses iterative optimisation methods. The integration of machine parameters into the optimisation process of step and shoot leaf positions has been shown to be successful. For IMRT segmentation algorithms based on the analysis of the geometrical structure of the planning target volumes (PTV) and the organs at risk (OAR), the potential of such procedures has not yet been fully explored. In this work, 2-Step IMRT was combined with subsequent direct machine parameter optimisation (DMPO-Raysearch Laboratories, Sweden) to investigate this potential. In a planning study DMPO on a commercial planning system was compared with manual primary 2-Step IMRT segment generation followed by DMPO optimisation. 15 clinical cases and the ESTRO Quasimodo phantom were employed. Both the same number of optimisation steps and the same set of objective values were used. The plans were compared with a clinical DMPO reference plan and a traditional IMRT plan based on fluence optimisation and consequent segmentation. The composite objective value (the weighted sum of quadratic deviations of the objective values and the related points in the dose volume histogram) was used as a measure for the plan quality. Additionally, a more extended set of parameters was used for the breast cases to compare the plans. The plans with segments pre-defined with 2-Step IMRT were slightly superior to DMPO alone in the majority of cases. The composite objective value tended to be even lower for a smaller number of segments. The total number of monitor units was slightly higher than for the DMPO-plans. Traditional IMRT fluence optimisation with subsequent segmentation could not compete. 2-Step IMRT segmentation is suitable as starting point for further DMPO optimisation and, in general, results in less complex plans which are equal or superior to plans generated by DMPO alone

  14. Metal Removal Process Optimisation using Taguchi Method - Simplex Algorithm (TM-SA) with Case Study Applications

    OpenAIRE

    Ajibade, Oluwaseyi A.; Agunsoye, Johnson O.; Oke, Sunday A.

    2018-01-01

    In the metal removal process industry, the current practice to optimise cutting parameters adoptsa conventional method. It is based on trial and error, in which the machine operator uses experience,coupled with handbook guidelines to determine optimal parametric values of choice. This method is notaccurate, is time-consuming and costly. Therefore, there is a need for a method that is scientific, costeffectiveand precise. Keeping this in mind, a different direction for process optimisation is ...

  15. Contribution à l'optimisation de la conduite des procédés alimentaires

    OpenAIRE

    Olmos-Perez , Alejandra

    2003-01-01

    The main objective of this work is the development of a methodology to calculate the optimal operating conditions applicable in food processes control. In the first part of this work, we developed an optimization strategy in two stages. Firstly, the optimisation problem is constructed. Afterwards, a feasible optimisation method is chosen to solve the problem. This choice is made through a decisional diagram, which proposes a deterministic (sequential quadratic programming, SQP), a stochastic ...

  16. Stochastic Optimisation of Battery System Operation Strategy under different Utility Tariff Structures

    OpenAIRE

    Erdal, Jørgen Sørgård

    2017-01-01

    This master thesis develops a stochastic optimisation software for household grid-connected batteries combined with PV-systems. The objective of the optimisation is to operate the battery system in order to minimise the costs of the consumer, and it was implemented in MATLAB using a self-written stochastic dynamic programming algorithm. Load was considered as a stochastic variable and modelled as a Markov Chain. Transition probabilities between time steps were calculated using historic load p...

  17. Economic and Mathematical Modelling of Optimisation of Transaction Expenses of Engineering Enterprises

    OpenAIRE

    Makaliuk Iryna V.

    2014-01-01

    The article identifies stages of the process of optimisation of transaction expenses. It develops an economic and mathematical model of optimisation of transaction expenses of engineering enterprises by the criterion of maximisation of income from realisation of products and system of restrictions, which envisages exceeding income growth rate over the expenses growth rate. The article offers to use types of expenses by accounting accounts as indicators of transaction expenses. In the result o...

  18. Design of passive coolers for light-emitting diode lamps using topology optimisation

    DEFF Research Database (Denmark)

    Alexandersen, Joe; Sigmund, Ole; Meyer, Knud Erik

    2018-01-01

    Topology optimised designs for passive cooling of light-emitting diode (LED) lamps are investigated through extensive numerical parameter studies. The designs are optimised for either horizontal or vertical orientations and are compared to a lattice-fin design as well as a simple parameter......, while maintaining low sensitivity to orientation. Furthermore, they exhibit several defining features and provide insight and general guidelines for the design of passive coolers for LED lamps....

  19. PHYSICAL-MATEMATICALSCIENCE MECHANICS SIMULATION CHALLENGES IN OPTIMISING THEORETICAL METAL CUTTING TASKS

    Directory of Open Access Journals (Sweden)

    Rasul V. Guseynov

    2017-01-01

    Full Text Available Abstract. Objectives In the article, problems in the optimising of machining operations, which provide end-unit production of the required quality with a minimum processing cost, are addressed. Methods Increasing the effectiveness of experimental research was achieved through the use of mathematical methods for planning experiments for optimising metal cutting tasks. The minimal processing cost model, in which the objective function is polynomial, is adopted as a criterion for the selection of optimal parameters. Results Polynomial models of the influence of angles φ, α, γ on the torque applied when cutting threads in various steels are constructed. Optimum values of the geometrical tool parameters were obtained using the criterion of minimum cutting forces during processing. The high stability of tools having optimal geometric parameters is determined. It is shown that the use of experimental planning methods allows the optimisation of cutting parameters. In optimising solutions to metal cutting problems, it is found to be expedient to use multifactor experimental planning methods and to select the cutting force as the optimisation parameter when determining tool geometry. Conclusion The joint use of geometric programming and experiment planning methods in order to optimise the parameters of cutting significantly increases the efficiency of technological metal processing approaches. 

  20. Optimising Realism of Synthetic Agricultural Images using Cycle Generative Adversarial Networks

    NARCIS (Netherlands)

    Barth, R.; IJsselmuiden, J.M.M.; Hemming, J.; Henten, van E.J.

    2017-01-01

    A bottleneck of state-of-the-art machine learning methods, e.g. deep learning, for plant part image segmentation in agricultural robotics is the requirement of large manually annotated datasets. As a solution, large synthetic datasets including ground truth can be rendered that realistically reflect

  1. The tensor network theory library

    Science.gov (United States)

    Al-Assam, S.; Clark, S. R.; Jaksch, D.

    2017-09-01

    In this technical paper we introduce the tensor network theory (TNT) library—an open-source software project aimed at providing a platform for rapidly developing robust, easy to use and highly optimised code for TNT calculations. The objectives of this paper are (i) to give an overview of the structure of TNT library, and (ii) to help scientists decide whether to use the TNT library in their research. We show how to employ the TNT routines by giving examples of ground-state and dynamical calculations of one-dimensional bosonic lattice system. We also discuss different options for gaining access to the software available at www.tensornetworktheory.org.

  2. Effective augmentation of networked systems and enhancing pinning controllability

    Science.gov (United States)

    Jalili, Mahdi

    2018-06-01

    Controlling dynamics of networked systems to a reference state, known as pinning control, has many applications in science and engineering. In this paper, we introduce a method for effective augmentation of networked systems, while also providing high levels of pinning controllability for the final augmented network. The problem is how to connect a sub-network to an already existing network such that the pinning controllability is maximised. We consider the eigenratio of the augmented Laplacian matrix as a pinning controllability metric, and use graph perturbation theory to approximate the influence of edge addition on the eigenratio. The proposed metric can be effectively used to find the inter-network links connecting the disjoint networks. Also, an efficient link rewiring approach is proposed to further optimise the pinning controllability of the augmented network. We provide numerical simulations on synthetic networks and show that the proposed method is more effective than heuristic ones.

  3. Optimisation of a Swedish district heating system with reduced heat demand due to energy efficiency measures in residential buildings

    International Nuclear Information System (INIS)

    Åberg, M.; Henning, D.

    2011-01-01

    The development towards more energy efficient buildings, as well as the expansion of district heating (DH) networks, is generally considered to reduce environmental impact. But the combined effect of these two progressions is more controversial. A reduced heat demand (HD) due to higher energy efficiency in buildings might hamper co-production of electricity and DH. In Sweden, co-produced electricity is normally considered to displace electricity from less efficient European condensing power plants. In this study, a potential HD reduction due to energy efficiency measures in the existing building stock in the Swedish city Linköping is calculated. The impact of HD reduction on heat and electricity production in the Linköping DH system is investigated by using the energy system optimisation model MODEST. Energy efficiency measures in buildings reduce seasonal HD variations. Model results show that HD reductions primarily decrease heat-only production. The electricity-to-heat output ratio for the system is increased for HD reductions up to 30%. Local and global CO 2 emissions are reduced. If co-produced electricity replaces electricity from coal-fired condensing power plants, a 20% HD reduction is optimal for decreasing global CO 2 emissions in the analysed DH system. - Highlights: ► A MODEST optimisation model of the Linköping district heating system is used. ► The impact of heat demand reduction on heat and electricity production is examined. ► Model results show that heat demand reductions decrease heat-only production. ► Local and global CO 2 emissions are reduced. ► The system electricity-to-heat output increases for reduced heat demand up to 30%.

  4. Patient and staff dose optimisation in nuclear medicine diagnosis methods

    International Nuclear Information System (INIS)

    Marta Wasilewska-Radwanska; Katarzyna Natkaniec

    2007-01-01

    , control of detector uniformity. The test for rotating gamma camera additionally demands controlling precision of rotation and image system resolution. The radioisotope and chemical purity of the radiopharmaceuticals are controlled, too. The process of 99m Tc elution efficacity from 99 Mo-generator is tested and the contents of 99 Mo radioisotope in eluate is measured. The radioisotope diagnosis of brain, heart, thyroid, stomach, liver, kidney and bones as well as lymphoscintigraphy are performed. The procedure used for patient and staff's dose optimisation consists of: 1) control dose measurement performed with dosemeter on the tissue-like phantom including selected radiopharmaceutical of the same radioactivity as the one which will be applied to patient, 2) calculation of the patient dose rate, 3) calculation of the staff dose based on the results of personnel dosemeters (films or TLD), 4) preparation of the Quality Assurance instruction for the staff responsible for patient's safety. Independently of the patient and staff dose optimisation, the Quality Control of gamma camera equipments e.g. SPECT X-Ring Nucline (MEDISO) is checked for uniformity of the image from a radiopharmaceutical sample and center of rotation according to the producer's manual instruction. In addition, special lectures and courses for staff are organized several times per year to ensure a Continuous Professional Development (CPD) in the field of Quality Assurance and Quality Control.

  5. The Integration of Environmental Constraints into Tidal Array Optimisation

    Science.gov (United States)

    du Feu, Roan; de Trafford, Sebastian; Culley, Dave; Hill, Jon; Funke, Simon W.; Kramer, Stephan C.; Piggott, Matthew D.

    2015-04-01

    It has been estimated by The Carbon Trust that the marine renewable energy sector, of which tidal stream turbines are projected to play a large part, could produce 20% of the UK's present electricity requirements. This has lead to the important question of how this technology can be deployed in an economically and environmentally friendly manner. Work is currently under way to understand how the tidal turbines that constitute an array can be arranged to maximise the total power generated by that array. The work presented here continues this through the inclusion of environmental constraints. The benefits of the renewable energy sector to our environment at large are not in question. However, the question remains as to the effects this burgeoning sector will have on local environments, and how to mitigate these effects if they are detrimental. For example, the presence of tidal arrays can, through altering current velocity, drastically change the sediment transport into and out of an area along with re-suspending existing sediment. This can have the effects of scouring or submerging habitat, mobilising contaminants within the existing sediment, reducing food supply and altering the turbidity of the water. All of which greatly impact upon any fauna in the affected region. This work pays particular attention to the destruction of habitat of benthic fauna, as this is quantifiable as a direct result of change in the current speed; a primary factor in determining sediment accumulation on the sea floor. OpenTidalFarm is an open source tool that maximises the power generated by an array through repositioning the turbines within it. It currently uses a 2D shallow water model with turbines represented as bump functions of increased friction. The functional of interest, power extracted by the array, is evaluated from the flow field which is calculated at each iteration using a finite element method. A gradient-based local optimisation is then used through solving the

  6. Optimising parallel R correlation matrix calculations on gene expression data using MapReduce.

    Science.gov (United States)

    Wang, Shicai; Pandis, Ioannis; Johnson, David; Emam, Ibrahim; Guitton, Florian; Oehmichen, Axel; Guo, Yike

    2014-11-05

    High-throughput molecular profiling data has been used to improve clinical decision making by stratifying subjects based on their molecular profiles. Unsupervised clustering algorithms can be used for stratification purposes. However, the current speed of the clustering algorithms cannot meet the requirement of large-scale molecular data due to poor performance of the correlation matrix calculation. With high-throughput sequencing technologies promising to produce even larger datasets per subject, we expect the performance of the state-of-the-art statistical algorithms to be further impacted unless efforts towards optimisation are carried out. MapReduce is a widely used high performance parallel framework that can solve the problem. In this paper, we evaluate the current parallel modes for correlation calculation methods and introduce an efficient data distribution and parallel calculation algorithm based on MapReduce to optimise the correlation calculation. We studied the performance of our algorithm using two gene expression benchmarks. In the micro-benchmark, our implementation using MapReduce, based on the R package RHIPE, demonstrates a 3.26-5.83 fold increase compared to the default Snowfall and 1.56-1.64 fold increase compared to the basic RHIPE in the Euclidean, Pearson and Spearman correlations. Though vanilla R and the optimised Snowfall outperforms our optimised RHIPE in the micro-benchmark, they do not scale well with the macro-benchmark. In the macro-benchmark the optimised RHIPE performs 2.03-16.56 times faster than vanilla R. Benefiting from the 3.30-5.13 times faster data preparation, the optimised RHIPE performs 1.22-1.71 times faster than the optimised Snowfall. Both the optimised RHIPE and the optimised Snowfall successfully performs the Kendall correlation with TCGA dataset within 7 hours. Both of them conduct more than 30 times faster than the estimated vanilla R. The performance evaluation found that the new MapReduce algorithm and its

  7. Optimising cluster survey design for planning schistosomiasis preventive chemotherapy.

    Directory of Open Access Journals (Sweden)

    Sarah C L Knowles

    2017-05-01

    Full Text Available The cornerstone of current schistosomiasis control programmes is delivery of praziquantel to at-risk populations. Such preventive chemotherapy requires accurate information on the geographic distribution of infection, yet the performance of alternative survey designs for estimating prevalence and converting this into treatment decisions has not been thoroughly evaluated.We used baseline schistosomiasis mapping surveys from three countries (Malawi, Côte d'Ivoire and Liberia to generate spatially realistic gold standard datasets, against which we tested alternative two-stage cluster survey designs. We assessed how sampling different numbers of schools per district (2-20 and children per school (10-50 influences the accuracy of prevalence estimates and treatment class assignment, and we compared survey cost-efficiency using data from Malawi. Due to the focal nature of schistosomiasis, up to 53% simulated surveys involving 2-5 schools per district failed to detect schistosomiasis in low endemicity areas (1-10% prevalence. Increasing the number of schools surveyed per district improved treatment class assignment far more than increasing the number of children sampled per school. For Malawi, surveys of 15 schools per district and 20-30 children per school reliably detected endemic schistosomiasis and maximised cost-efficiency. In sensitivity analyses where treatment costs and the country considered were varied, optimal survey size was remarkably consistent, with cost-efficiency maximised at 15-20 schools per district.Among two-stage cluster surveys for schistosomiasis, our simulations indicated that surveying 15-20 schools per district and 20-30 children per school optimised cost-efficiency and minimised the risk of under-treatment, with surveys involving more schools of greater cost-efficiency as treatment costs rose.

  8. Renewables portfolio standard and regional energy structure optimisation in China

    International Nuclear Information System (INIS)

    Fan, J.; Sun, W.; Ren, D.-M.

    2005-01-01

    Eastern Coastal areas of China have been developing rapidly since the implementation of reforms and the opening of China's economic markets in 1978. As in most areas of the world, this rapid economic growth has been accompanied by large increases in energy consumption. China's coal-dominated energy structure has resulted in serious ecological and environmental problems. Exploiting renewable energy resources and introducing Renewables Portfolio Standard (RPS) are some of the most important approaches towards optimising and sustaining the energy structure of China. This paper discusses international experiences in the implementation of RPS policies and prospects for using these policies to encourage renewable energy development in China, establishes a concise definition of renewable resources, differentiating between the broad definition (which includes hydro over 25 MW in size) from the narrow definition (which limits the eligibility of hydro to below 25 MW in size), and quantitatively analyses the potential renewable energy target. The research shows that: (1) Under the narrow hydro definition the renewable energy target would be 5.1% and under the broad hydro definition it would be 18.4%. (2) Western China has contributed 90.2% of the total renewable electricity generation in the country (if big and medium hydropowers are not included). Including big and medium hydropower, the figure is 63.8%. (3) Eastern electricity companies can achieve their quota by buying Tradable Renewable Energy Certificates (TRCs or Green Certificates) and by exploiting renewable energy resources in Western China. The successful implementation of the RPS policy will achieve the goal of sharing the benefits and responsibilities of energy production between the different regions of China

  9. An optimised protocol for molecular identification of Eimeria from chickens☆

    Science.gov (United States)

    Kumar, Saroj; Garg, Rajat; Moftah, Abdalgader; Clark, Emily L.; Macdonald, Sarah E.; Chaudhry, Abdul S.; Sparagano, Olivier; Banerjee, Partha S.; Kundu, Krishnendu; Tomley, Fiona M.; Blake, Damer P.

    2014-01-01

    Molecular approaches supporting identification of Eimeria parasites infecting chickens have been available for more than 20 years, although they have largely failed to replace traditional measures such as microscopy and pathology. Limitations of microscopy-led diagnostics, including a requirement for specialist parasitological expertise and low sample throughput, are yet to be outweighed by the difficulties associated with accessing genomic DNA from environmental Eimeria samples. A key step towards the use of Eimeria species-specific PCR as a sensitive and reproducible discriminatory tool for use in the field is the production of a standardised protocol that includes sample collection and DNA template preparation, as well as primer selection from the numerous PCR assays now published. Such a protocol will facilitate development of valuable epidemiological datasets which may be easily compared between studies and laboratories. The outcome of an optimisation process undertaken in laboratories in India and the UK is described here, identifying four steps. First, samples were collected into a 2% (w/v) potassium dichromate solution. Second, oocysts were enriched by flotation in saturated saline. Third, genomic DNA was extracted using a QIAamp DNA Stool mini kit protocol including a mechanical homogenisation step. Finally, nested PCR was carried out using previously published primers targeting the internal transcribed spacer region 1 (ITS-1). Alternative methods tested included sample processing in the presence of faecal material, DNA extraction using a traditional phenol/chloroform protocol, the use of SCAR multiplex PCR (one tube and two tube versions) and speciation using the morphometric tool COCCIMORPH for the first time with field samples. PMID:24138724

  10. Toward an optimisation technique for dynamically monitored environment

    Science.gov (United States)

    Shurrab, Orabi M.

    2016-10-01

    The data fusion community has introduced multiple procedures of situational assessments; this is to facilitate timely responses to emerging situations. More directly, the process refinement of the Joint Directors of Laboratories (JDL) is a meta-process to assess and improve the data fusion task during real-time operation. In other wording, it is an optimisation technique to verify the overall data fusion performance, and enhance it toward the top goals of the decision-making resources. This paper discusses the theoretical concept of prioritisation. Where the analysts team is required to keep an up to date with the dynamically changing environment, concerning different domains such as air, sea, land, space and cyberspace. Furthermore, it demonstrates an illustration example of how various tracking activities are ranked, simultaneously into a predetermined order. Specifically, it presents a modelling scheme for a case study based scenario, where the real-time system is reporting different classes of prioritised events. Followed by a performance metrics for evaluating the prioritisation process of situational awareness (SWA) domain. The proposed performance metrics has been designed and evaluated using an analytical approach. The modelling scheme represents the situational awareness system outputs mathematically, in the form of a list of activities. Such methods allowed the evaluation process to conduct a rigorous analysis of the prioritisation process, despite any constrained related to a domain-specific configuration. After conducted three levels of assessments over three separates scenario, The Prioritisation Capability Score (PCS) has provided an appropriate scoring scheme for different ranking instances, Indeed, from the data fusion perspectives, the proposed metric has assessed real-time system performance adequately, and it is capable of conducting a verification process, to direct the operator's attention to any issue, concerning the prioritisation capability

  11. Dose optimisation of double-contrast barium enema examinations.

    Science.gov (United States)

    Berner, K; Båth, M; Jonasson, P; Cappelen-Smith, J; Fogelstam, P; Söderberg, J

    2010-01-01

    The purpose of the present work was to optimise the filtration and dose setting for double-contrast barium enema examinations using a Philips MultiDiagnost Eleva FD system. A phantom study was performed prior to a patient study. A CDRAD phantom was used in a study where copper and aluminium filtration, different detector doses and tube potentials were examined. The image quality was evaluated using the software CDRAD Analyser and the phantom dose was determined using the Monte Carlo-based software PCXMC. The original setting [100 % detector dose (660 nGy air kerma) and a total filtration of 3.5 mm Al, at 81 kVp] and two other settings identified by the phantom study (100 % detector dose and additional filtration of 1 mm Al and 0.2 mm Cu as well as 80 % detector dose and added filtration of 1 mm Al and 0.2 mm Cu) were included in the patient study. The patient study included 60 patients and up to 8 images from each patient. Six radiologists performed a visual grading characteristics study to evaluate the image quality. A four-step scale was used to judge the fulfillment of three image quality criteria. No overall statistical significant difference in image quality was found between the three settings (P > 0.05). The decrease in the effective dose for the settings in the patient study was 15 % when filtration was added and 34 % when both filtrations was added and detector dose was reduced. The study indicates that additional filtration of 1 mm Al and 0.2 mm Cu and a decrease in detector dose by 20 % from the original setting can be used in colon examinations with Philips MultiDiagnost Eleva FD to reduce the patient dose by 30 % without significantly affecting the image quality. For 20 exposures, this corresponds to a decrease in the effective dose from 1.6 to 1.1 mSv.

  12. Optimisation of multi-layer rotationally moulded foamed structures

    Science.gov (United States)

    Pritchard, A. J.; McCourt, M. P.; Kearns, M. P.; Martin, P. J.; Cunningham, E.

    2018-05-01

    Multi-layer skin-foam and skin-foam-skin sandwich constructions are of increasing interest in the rotational moulding process for two reasons. Firstly, multi-layer constructions can improve the thermal insulation properties of a part. Secondly, foamed polyethylene sandwiched between solid polyethylene skins can increase the mechanical properties of rotationally moulded structural components, in particular increasing flexural properties and impact strength (IS). The processing of multiple layers of polyethylene and polyethylene foam presents unique challenges such as the control of chemical blowing agent decomposition temperature, and the optimisation of cooling rates to prevent destruction of the foam core; therefore, precise temperature control is paramount to success. Long cooling cycle times are associated with the creation of multi-layer foam parts due to their insulative nature; consequently, often making the costs of production prohibitive. Devices such as Rotocooler®, a rapid internal mould water spray cooling system, have been shown to have the potential to significantly decrease cooling times in rotational moulding. It is essential to monitor and control such devices to minimise the warpage associated with the rapid cooling of a moulding from only one side. The work presented here demonstrates the use of threaded thermocouples to monitor the polymer melt in multi-layer sandwich constructions, in order to analyse the cooling cycle of multi-layer foamed structures. A series of polyethylene skin-foam test mouldings were produced, and the effect of cooling medium on foam characteristics, mechanical properties, and process cycle time were investigated. Cooling cycle time reductions of 45%, 26%, and 29% were found for increasing (1%, 2%, and 3%) chemical blowing agent (CBA) amount when using internal water cooling technology from ˜123°C compared with forced air cooling (FAC). Subsequently, a reduction of IS for the same skin-foam parts was found to be 1%, 4

  13. Towards the optimisation and adaptation of dry powder inhalers.

    Science.gov (United States)

    Cui, Y; Schmalfuß, S; Zellnitz, S; Sommerfeld, M; Urbanetz, N

    2014-08-15

    Pulmonary drug delivery by dry powder inhalers is becoming more and more popular. Such an inhalation device must insure that during the inhalation process the drug powder is detached from the carrier due to fluid flow stresses. The goal of the project is the development of a drug powder detachment model to be used in numerical computations (CFD, computational fluid dynamics) of fluid flow and carrier particle motion through the inhaler and the resulting efficiency of drug delivery. This programme will be the basis for the optimisation of inhaler geometry and dry powder inhaler formulation. For this purpose a multi-scale approach is adopted. First the flow field through the inhaler is numerically calculated with OpenFOAM(®) and the flow stresses experienced by the carrier particles are recorded. This information is used for micro-scale simulations using the Lattice-Boltzmann method where only one carrier particle covered with drug powder is placed in cubic flow domain and exposed to the relevant flow situations, e.g. plug and shear flow with different Reynolds numbers. Therefrom the fluid forces on the drug particles are obtained. In order to allow the determination of the drug particle detachment possibility by lift-off, sliding or rolling, also measurements by AFM (atomic force microscope) were conducted for different carrier particle surface structures. The contact properties, such as van der Waals force, friction coefficient and adhesion surface energy were used to determine, from a force or moment balance (fluid forces versus contact forces), the detachment probability by the three mechanisms as a function of carrier particle Reynolds number. These results will be used for deriving the drug powder detachment model. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Numerical analysis and optimisation of heavy water upgrading column

    International Nuclear Information System (INIS)

    Sankar, Rama; Ghosh, Brindaban; Bhanja, K.

    2013-01-01

    In the 'Pressurised Heavy Water' type of reactors, heavy water is used both as moderator and coolant. During operation of reactor downgraded heavy water is generated that needs to be upgraded for reuse in the reactor. When the isotopic purity of heavy water becomes less than 99.75%, it is termed as downgraded heavy water. Downgraded heavy water also contains impurity such as corrosion products, dirt, oil etc. Upgradation of downgraded heavy water is normally done in two steps: (i) Purification: In this step downgraded heavy water is first purified to remove corrosion products, dirt, oil, etc. and (ii) Upgradation of heavy water to increase its isotopic purity, this step is carried out by vacuum distillation of downgraded heavy water after purification. This project is aimed at mathematical modelling and numerical simulation of heavy water upgrading column. Modelling and simulation studies of the upgradation column are based on equilibrium stage model to evaluate the effect of feed location, pressure, feed composition, reflux ratio in the packed column for given reboiler and condenser duty of distillation column. State to stage modelling of two-phase two-component flow has constitutes the overall modelling of the column. The governing equations consist of stage-wise species and overall mass continuity and stage-wise energy balance. This results in tridigonal matrix equation for stage liquid fractions for heavy and light water. The stage-wise liquid flow rates and temperatures are governed by stage-wise mass and energy balance. The combined form of the corresponding governing equations, with the incorporation of thermodynamic equation of states, form a system of nonlinear equations. This system have been resolved numerically using modified Newton-Raphson method. A code in the MATLAB platform has been developed by on above numerical procedure. The optimisation of the column operating conditions is to be carried out based on parametric studies and analysis of different

  15. Wavefront-Guided and Wavefront-Optimised Laser Treatments

    Directory of Open Access Journals (Sweden)

    Canan Aslı Utine

    2012-12-01

    Full Text Available Optical aberrations of the eye are the errors of the optical system that limit the resolution, contrast and amount of detail in the image formed on the retina. Wavefront technology allows us to measure these optical aberrations, calculate mathematically, and transfer this information into excimer laser system to perform customized treatment on the cornea. Two treatment algorithms developed to create low aberration-corneal profile are wavefront-optimised (WF-O and wavefront-guided (WF-G treatments. WF-O treatment, aims not to increase the existing spherical aberration while treatment is based on manifest refractive error as in conventional laser treatments. By increasing the number of laser spots applied peripherally in order to optimize the corneal asphericity, the preoperative central:peripheral keratometry ratio is preserved and optic zone shrinkage is prevented. On the other hand, WF-G treatment is based on aberrometry measurements and aims to correct the existing high-order aberrations in the eye. Thus, retinal image with high spatial details can be achieved. However, presence of postoperative defocus can abolish the successful results obtained with WF-G treatment. Clinical randomized controlled trials showed that in patients with preoperative RMS value of <0.3 μm, higher order aberration outcomes are similar after WF-G and WF-O treatments, but WF-G treatment yields better results when it is ≥0.4 μm. In normal eyes, very limited visual advantage can be achieved with WF-G treatment and preservation of asphericity value with WF-O treatment carries greater importance. On the other hand, in case of high astigmatism or higher order aberrations other than spherical aberration, decreasing aberrations with WF-G treatment becomes more important. In this study, we aimed to make a comparative analysis of characteristics and outcomes of the two treatment algorithms. (Turk J Ophthalmol 2012; 42: 474-8

  16. The thermal performance monitoring and optimisation system (TEMPO): lessons learnt

    International Nuclear Information System (INIS)

    Beere, W.H.Aa.

    2005-09-01

    The goal of condition monitoring, fault detection and diagnosis is to ensure the success of planned operations by recognizing anomalies in a plant. This is achieved by monitoring the condition of equipment and instrumentation, and by detection, identification, diagnosis and removal of faults. The method of using physical modelling for condition monitoring has been investigated at the Institutt for energiteknikk since 1998. The result of this work was the development of the TEMPO (ThErMal Performance monitoring and Optimisation) toolbox. In this toolbox plant wide models are built up of unit sub-models. These are then linked to measurements by using data reconciliation. This enables the comparison of calculated to measured values as well as an indication of the significance of any deviation. It also allows the calculation of unmeasured variables as well as an overall 'goodness of fit' indicator. Since its first release in 2000 the TEMPO toolbox has been used to model the turbine cycles of several NPPs. Installations include Forsmark 3 and Loviisa 2 with feasibility studies for Dukovany, Olkiluoto 2, Almaraz and Paks. The experience from creating and installing TEMPO at these plants has now been collated and is presented in this report. This experience is used to indicate which direction the further development of TEMPO should take. The experience of using TEMPO has shown that the data-reconciliation method can be applied to the turbine cycles of NPPs. Problems that have arose have primarily been connected to the usability of the toolbox. This has prompted a shift in the development emphasis from the task of developing the method to that of developing its usability. A summary of improvement proposals is given in this paper. The reader is welcome to comment on these proposals or to suggest alternative improvements. (Author)

  17. Optimisation of the Future Routine Orbit for Mars Express

    Science.gov (United States)

    Carranza, Manuel; Companys, Vincente

    2007-01-01

    pericentre would cause in the following years a drift of the pericentre towards night-side observation conditions, hence uninteresting for the optical instruments. In order to prevent this an optimisation process for the future routine orbit has taken place. The share between day-side and night-side observations can be controlled by adjusting the drift of argument of pericentre and ascending node. This can in particular be achieved by changing the semimajor axis, eccentricity and/or inclination. A change of inclination is inefficient compared to a change in semimajor axis and eccentricity, and has therefore been discarded. An in-plane maneuvre can be performed to change both semi-major axis and eccentricity, and thus the period of the orbit. Although an apocentre manoeuvre is cheaper in terms of deltaV, it would result in raising the pericentre height, which is unfavourable for close observations. Hence a pericentre manoeuvre is proposed, which will increase the apocentre height. A repeat cycle is still required to allow mapping areas with adjacent ground tracks, so the change of semimajor axis must result in a new resonance. Resonances 18:5, 25:7 and 7:2 have been considered as potential candidates. The resulting long term evolution of the observation conditions has been analysed. Finally it has been decided to perform a change of orbit to reach the 18:5. Another aspect of the optimisation process is the control of the ground track. The previous MEX reference trajectory included regular maneuvres at every apocentre in order to adjust the orbital period, such that the separation of the ground tracks would be optimal, regardless of the latitude of pericentre. The implementation of the actual delatVs on-board was done partly by optimizing the attitude of reaction-wheel desaturation activities. Despite of it, this strategy has a significant propellant cost, because it prevents to optimize reaction wheel de-saturation activities to minimize propellant consumption. Therore, with

  18. Optimisation of NMR dynamic models II. A new methodology for the dual optimisation of the model-free parameters and the Brownian rotational diffusion tensor

    International Nuclear Information System (INIS)

    D'Auvergne, Edward J.; Gooley, Paul R.

    2008-01-01

    Finding the dynamics of an entire macromolecule is a complex problem as the model-free parameter values are intricately linked to the Brownian rotational diffusion of the molecule, mathematically through the autocorrelation function of the motion and statistically through model selection. The solution to this problem was formulated using set theory as an element of the universal set U-the union of all model-free spaces (d'Auvergne EJ and Gooley PR (2007) Mol BioSyst 3(7), 483-494). The current procedure commonly used to find the universal solution is to initially estimate the diffusion tensor parameters, to optimise the model-free parameters of numerous models, and then to choose the best model via model selection. The global model is then optimised and the procedure repeated until convergence. In this paper a new methodology is presented which takes a different approach to this diffusion seeded model-free paradigm. Rather than starting with the diffusion tensor this iterative protocol begins by optimising the model-free parameters in the absence of any global model parameters, selecting between all the model-free models, and finally optimising the diffusion tensor. The new model-free optimisation protocol will be validated using synthetic data from Schurr JM et al. (1994) J Magn Reson B 105(3), 211-224 and the relaxation data of the bacteriorhodopsin (1-36)BR fragment from Orekhov VY (1999) J Biomol NMR 14(4), 345-356. To demonstrate the importance of this new procedure the NMR relaxation data of the Olfactory Marker Protein (OMP) of Gitti R et al. (2005) Biochem 44(28), 9673-9679 is reanalysed. The result is that the dynamics for certain secondary structural elements is very different from those originally reported

  19. Optimisation of rocker sole footwear for prevention of first plantar ulcer: comparison of group-optimised and individually-selected footwear designs.

    Science.gov (United States)

    Preece, Stephen J; Chapman, Jonathan D; Braunstein, Bjoern; Brüggemann, Gert-Peter; Nester, Christopher J

    2017-01-01

    Appropriate footwear for individuals with diabetes but no ulceration history could reduce the risk of first ulceration. However, individuals who deem themselves at low risk are unlikely to seek out bespoke footwear which is personalised. Therefore, our primary aim was to investigate whether group-optimised footwear designs, which could be prefabricated and delivered in a retail setting, could achieve appropriate pressure reduction, or whether footwear selection must be on a patient-by-patient basis. A second aim was to compare responses to footwear design between healthy participants and people with diabetes in order to understand the transferability of previous footwear research, performed in healthy populations. Plantar pressures were recorded from 102 individuals with diabetes, considered at low risk of ulceration. This cohort included 17 individuals with peripheral neuropathy. We also collected data from 66 healthy controls. Each participant walked in 8 rocker shoe designs (4 apex positions × 2 rocker angles). ANOVA analysis was then used to understand the effect of two design features and descriptive statistics used to identify the group-optimised design. Using 200 kPa as a target, this group-optimised design was then compared to the design identified as the best for each participant (using plantar pressure data). Peak plantar pressure increased significantly as apex position was moved distally and rocker angle reduced ( p  footwear which was individually selected. In terms of optimised footwear designs, healthy participants demonstrated the same response as participants with diabetes, despite having lower plantar pressures. This is the first study demonstrating that a group-optimised, generic rocker shoe might perform almost as well as footwear selected on a patient by patient basis in a low risk patient group. This work provides a starting point for clinical evaluation of generic versus personalised pressure reducing footwear.

  20. Multiobjective optimisation of energy systems and building envelope retrofit in a residential community

    International Nuclear Information System (INIS)

    Wu, Raphael; Mavromatidis, Georgios; Orehounig, Kristina; Carmeliet, Jan

    2017-01-01

    Highlights: • Simultaneous optimisation of building envelope retrofit and energy systems. • Retrofit and energy systems change interact and should be considered simultaneously. • Case study quantifies cost-GHG emission tradeoffs for different retrofit options. - Abstract: In this paper, a method for a multi-objective and simultaneous optimisation of building energy systems and retrofit is presented. Tailored to be suitable for the diverse range of existing buildings in terms of age, size, and use, it combines dynamic energy demand simulation to explore individual retrofit scenarios with an energy hub optimisation. Implemented as an epsilon-constrained mixed integer linear program (MILP), the optimisation matches envelope retrofit with renewable and high efficiency energy supply technologies such as biomass boilers, heat pumps, photovoltaic and solar thermal panels to minimise life cycle cost and greenhouse gas (GHG) emissions. Due to its multi-objective, integrated assessment of building transformation options and its ability to capture both individual building characteristics and trends within a neighbourhood, this method is aimed to provide developers, neighbourhood and town policy makers with the necessary information to make adequate decisions. Our method is deployed in a case study of typical residential buildings in the Swiss village of Zernez, simulating energy demands in EnergyPlus and solving the optimisation problem with CPLEX. Although common trade-offs in energy system and retrofit choice can be observed, optimisation results suggest that the diversity in building age and size leads to optimal strategies for retrofitting and building system solutions, which are specific to different categories. With this method, GHG emissions of the entire community can be reduced by up to 76% at a cost increase of 3% compared to the current emission levels, if an optimised solution is selected for each building category.